Reverse evolution. Also check out his eyes
Monday, February 19, 2007
Idiopathic juxtafoveal telangiectasia and diabetes
Gass and Bodi reviewed retrospectively 140 patients with juxta foveal telangiectasis based on bio microscopic and fluorescein angiographic findings. They proposed a classification into three groups for all these patients.
Group-I
39 male patients, Non familial, visible telangiectasis and intra retinal exudation. Unilateral, developmental
Group-II
94 patients, juxta foveal telangiectasis, minimal exudation, superficial retinal crystalline deposits and right angle venules. Late in the course of the disease foveolar atrophy, intra retinal pigment plaques and SRNVM develop. Acquired during middle age and bilateral in 98%
Group-III
Bilaterally visible telangiectasis, minimal exudation and capillary occlusion, systemic disease.
Para foveal telangiectasis is often overlooked as the cause of retinal oedema, para foveal haemorrhages and exudates. In diabetes or hypertensive patients these signs are wrongly attributed to these diseases. Telangiectasis should be suspected especially if there are no peripheral haemorrhages or micro aneurysms in diabetic subjects. Laser photocoagulation has been useful in the treatment of macular edema in some cases of juxta foveal telangiectasis .
Saturday, January 13, 2007
Why you should have an eye screening?
If you are 55 years and older you should definitely have an eye screening.
Why??
Most of the eye conditions are preventable. Many of them are asymptomatic until late stage.
These are
Cataract, which is clouding of the normal human lens.
Primary open angle glaucoma, which causes blindness by raised eye pressure.
Age-related macular degeneration, which causes loss of central vision and smoking is an important risk factor.
Diabetic retinopathy, changes in the posterior part of the eye due to diabetes.
I will describe these conditions in my subsequent blogs.
So see your ophthalmologist if you have not until now..
Why??
Most of the eye conditions are preventable. Many of them are asymptomatic until late stage.
These are
Cataract, which is clouding of the normal human lens.
Primary open angle glaucoma, which causes blindness by raised eye pressure.
Age-related macular degeneration, which causes loss of central vision and smoking is an important risk factor.
Diabetic retinopathy, changes in the posterior part of the eye due to diabetes.
I will describe these conditions in my subsequent blogs.
So see your ophthalmologist if you have not until now..
Sanjay' S MCQs for part-II
1.Trochlear nerve
A.Only cranial nerve to emerge from the dorsal aspect of brain.
B.Crossed cranial nerve innervating opposite superior oblique muscle
C.Long and slender nerve
D.Nucleus located at the level of inferior colliculus ventral to aqueduct sylvius.
E.Decussates completely in anterior medullary vellum.
A - E: True
2.Fourth nerve cranial palsies
A. Identical features are seen irrespective of whether nuclear, fascicular or peripheral.
B. Diplopia is avoided by the patient by adopting contralateral head tilt and turn with chin depression.
C. Congenital lesions may not be symptomatic until adult life.
D. Trauma causes bilateral ptosis.
E. Aneurysm is one of the common causes.
A - D: True E: False, vascular is common, aneurysms and tumour are rare.
3.Third cranial nerve palsies
A.Isolated 3rd N palsies are frequently basilar. ( occurs when the N passes through sub arachnoid space)
B.Trauma and aneurysms are most important causes of isolated palsies
C.Painless, pupillary sparing isolated palsies are due to aneurysms at junction of posterior communicating and internal carotid artery.
D.Intracavernous lesions are associated with 4th, 6th and 5th nerve lesions.
E. Lesions of inferior division of 3rd nerve in its intra orbital part may occur due to vascular or traumatic cause.
A - B: True C: False, painful and papillary involvement.
D - E: True; characterized by defective adduction, depression and dilation of pupil (parasympathetic fibres pass through N to inferior oblique.
4. Isolated 3rd cranial nerve palsies
A. 25% have no causes
B. Diabetes and hypertension are most common causes of pupil sparing palsies
C. Trivial trauma not associated with loss of consciousness should possibly indicate a basal intracranial tumour stretching the nerve trunk.
D. MRA, a non invasive technique can identify aneurysms 4mm and greater located at junction of posterior communicating and internal carotid artery.
E. Surgical treatment is to be considered six months after the onset of palsy.
A - E: True
5. CT scan orbit
A. Bone excavation with round or smooth outline in presence of calcification is common in pleomorphic adenoma.
B. Contiguous bone erosion with invasion with calcification in 1/3rd cases is seen in lacrimal gland carcinoma.
C. Fusiform enlargement of optic nerve is seen in optic nerve glioma
D. Tubular thickening and calcification of optic nerve is seen in optic nerve sheath meningioma
E. Poorly defined mass of heterogeneous density is seen in rhabdomyosarcoma
A: False; calcification is rare and indicates carcinoma
B - D: True
E: False; homogeneous density.
6. Third cranial nerve
A.Lesions involving medial rectus subnucleus causes WEBINO.
B. Lesions involving the entire 3rd nerve nucleus cause ipsilateral 3rd nerve palsy
sparing ipsilateral elevation but causing contralateral weakness of elevation.
C. Levator subnucleus lesions give rise to bilateral ptosis.
D. Benedikt syndrome occurs when the fascicle passes through red nucleus.
E. Weber’s syndrome occurs when the fascicle passes through cerebral peduncle.
A - E: True
WEBINO: wall eyed bilateral inter nuclear ophthalmoplegia is characterized by exotropia, defective convergence and adduction.
7. Convergence retraction nystagmus
A. Jerk nystagmus occurs on attempted down gaze.
B. Fast phase brings two eyes into convergence
C. Associated with protrusion of globe into orbit
D. Pinealoma and vascular accidents in pretectal area can cause it.
E. May be associated with lid retraction ( Collier’s sign) and light near disscociation.
A - False; upgaze B: True; C: False; retraction of globe D - E: True
8. Ocular nystagmus
A. Is due to sensory deprivation caused by defective vision.
B. Is vertical and jerky
C. Increased by convergence
D. Abnormal head posture may be associated to dampen nystagmus.
E. Associated with loss of central vision in early life(< 2years) due to cataract, macular hypoplasia.
A: True; B: False, horizontal and pendular; C: False dampened; D- E: True
9. Regarding orbital varices
A. Most cases are unilateral and located in upper nasal quadrant.
B. Phleboliths are seen in 20% cases on X ray/ CT.
C. Presentation is early childhood to late middle age with proptosis and visible lesions
D. Natural course is progressive enlargement associated with recurrent episodes of haemorrhage and thrombosis.
E. Surgery is technically difficult and reserved for cases with recurrent episodes of thrombosis, pain, proptosis and optic nerve compression.
A - E: True
10. Direct carotid cavernous fistula (CCF)
A. Abnormal communication between artery and vein in which vein becomes arterialized.
B. May occur after head injury or spontaneous rupture
C. Anterior segment ischaemia is common and occurs in 20% cases.
D. 6th nerve is affected in 50% with variable involvement of 3rd and 4th.
E. Intravascular balloons introduced via catheter into internal carotid artery is used for closure.
A - E: True
11. Indirect CCF
A. Communications are between meningeal branches of ICA/ECA and cavernous sinus.
B. Spontaneous rupture may be precipitated by minor trauma/straining in hypertensive patients
C. Red eye and 4th nerve palsy is common.
D. Low intra ocular pressure with dilated episcleral blood vessels.
E. Exaggerated ocular pulsation is seen in tonometry.
A, B: True; C- False, 6th nerve palsy; D- False, high IOP; E- True.
12. Regarding tonometers
A. Accuracy of non contact is only in low and middle range.
B. Pulsair tonometer is a non contact tonometer and provides clinically useful measurements comparable to Goldmann.
C. Tonopen overestimates a low IOP and underestimates a high IOP.
D. Tonopen is useful in distorted and oedematous cornea and also through bandage contact lens.
E. Perkins is a hand held tonometer useful in bed bound patients.
A - E: True
13. Torsion can be measured by
A. Synaptophore
B. Maddox wing
C. Adapted Lees screen
D. Awaya cyclo test
E. Bagolini glasses
A - E: True; also used are Maddox double rods
14. Ultrasound examination of eye
A. Helps in diagnosis and determining the tumour size.
B. In choroidal melanoma, is characterized by anterior border of tumour, acoustic hollowness, choroidal excavation and orbital shadowing.
C. In retinoblastoma detects presence of calcification.
D. Useful in detection of intra ocular foreign body, globe rupture, suprachoroidal haemorrhage in cases of trauma to the globe.
E. T sign in posterior scleritis is due to thickening of posterior sclera and fluid in sub tenon’s space.
A - E: True
15. Frequency doubling perimetry
A. Portable table top instrument
B. Requires dim illumination with patching
C. Stimuli are presented in 17/19 sectors in central 20*/ 30* depending on the program used.
D. Low spatial frequency sinusoidal gratings undergoes high temporal frequency counter phase flicker.
E. Reliability indices, probabilities, mean deviation and PSD are present in the print out.
A: True; B- False, normal lighting, viewing canopy automatically covers the eye not being tested so no need for occlusion. C - E: True
16. Dark adaptation
A. Retina and pupil react to decreased illumination and is useful in patients with nyctalopia.
B. Performed using Goldmann-Weekes adaptometer.
C. Sensitive curve is tripartite.
D. Alpha point occurs 20 min after dark adaptation.
E. Flash focused on foveola, only a cone plateau is recorded.
A - B: True
C: False; Curve is bipartite. The subject is pre-adapted to a standard amount of illumination and presented with series of flashes of light 11* below fixation. The intensity of flashes are controlled by neutral density filter and threshold plotted against time. The curve is obtained wherein initial rapid segment is cone followed by slower rod segment function.
D: False; Alpha point is inflection of curve where rod limit begins, rod-cone break”. Healthy eyes have it in 7-10 minutes of dark adaptation.
E: True; May be more sensitive than electroretinogram in certain disorders.
17. Electrophysiology in retinitis pigmentosa
A. Amplitude of scotopic and later photopic b wave is reduced in early stages with minimal fundus changes.
B. Delay in implicit time.
C. Electrooculogram shows absence of light rise.
D. Patients with loss of cone mediated response have poorer visual acuity and visual field scotoma encroaching closer to fixation compared to typical rod- cone type.
E. determination of any rod mediated response in electroretinogram is critical for diagnosis in any young patient suspected of retinitis pigmentosa.
A - E: True
18. MRI scans
A. Could be axial, saggital or coronal.
B. T1 weighted image of vitreous is dark
C. T1 weighted images are preferred for studying pathological changes
D. Gadolinium is a contrast taken up for tumours and appears bright white on T1
E. Good for orbital apex lesions
A - B: True; T2 is bright. Orbital fat T1 is bright T2 is dark
C: False; T1 is for normal anatomy and T2 for pathological changes.
D: True; Paramagnetic substance.
E: True
19. Aberrant regeneration of third cranial nerve
A. Trauma or aneurysms may cause it
B. Central or peripheral response may occur
C. Lid may rise on attempted depression, adduction or occasionally abduction
D. Pupil may constrict on attempted adduction, elevation or depression
E. Convergence may occur on attempted elevation
A - E: True
B- Central response involves mass response of damaged nerve resulting in growth to the wrong muscle. Peripheral response abnormal growth of damaged axons may occur locally.
C- Pseudo Graefe’s phenomenon
D- Pseudo Argyll Robertson pupil.
Widening of palpebral fissure on adduction and narrowing on abduction- Inverse Duane
20. Injury to occipital poles may result
A. Altitudinal defects
B. Upper portion damage leads to entire inferior field of vision
C. Lower portion damage is usually managed conservatively
D. Homonymous paramacular scotoma is the normal area adjoining the scotoma
E. Riddoch phenomenon is characterized by dense homonymous hemianopia in which stationary object is not perceived but a small moving object can be perceived.
A-B: True
C: False; associated with laceration of dural sinuses and results in intracranial bleeding and is fatal.
D: False, this area is characterized by defect for colour and emphasizes the importance of examining the central fields.
E: True.
21. Occipital lobe lesions are associated with
A. Visual hallucinations
B. Colour field defects
C. Vascular injury
D. Cortical blindness
E. Macular sparing
A-E: True
A- Visual hallucinations though can occur from any part of visual system and not specific to occipital lobe. But hallucinations in occipital lobe are unformed (scintillating scotoma)
B- Cerbral dyschromatopsia
Select group of cells involved in colour stimuli are involved
Colour defect is random and does not fall into deuteran/protan types
Make errors while reading pseudo isochromatic plates of Ishihara/ colour sorting
Vascular insult is the most common cause
D- Cortical blindness
Loss of all sensations including dark and light adaptation
Loss of menace reflex
Normal pupillary reaction (pupil pathway is related to third nerve)
Normal extraocular motility
Normal fundus
Hypoxia to the striate cortex is the main cause.
No associated CNS manifestations like motor/sensory/speech disorders
22. Error with Goldmann applanation tonometer
A. Thin corneas produce falsely low readings
B. Thick cornea due to oedema produce low readings
C. For every 3D of increase in corneal power the IOP increases by 1mm Hg
D. Marked corneal astigmatism will produce an elliptical area of contact.
E. For every 4D of increase in astigmatism the IOP increases by 1mm Hg
A-E: True
When biprism is in the usual orientation, with mires horizontally, IOP will be underestimated for with-the rule astigmatism and overestimated for against the rule astigmatism. To minimize this error, the biprism may be rotated until the dividing line between the prisms is 45* to the major axis of the ellipse or an average of vertical and horizontal readings may be taken.
23. Biometry in special conditions
A. Immersion technique is the method of choice in aphakes.
B. Pseudophakic eyes needing IOL exchange have extremely high spikes at the lens followed by reduplication of echoes.
C. System gain is increased in eyes with silicone oil
D. IOL required by eyes with silicone oil is usually 2-3D weaker than indicated by standard power calculation
E. In paediatric biometry in children less than 6 months of age undercorrection has to be done by 60-75% to account for myopic shift later in life.
A-C: True; Newer biometry machines have options for aphakic/ pseudophakic modes
In an aphakic eye sound travels at the speed of 1532m/s and in a phakic eye at 1550m/s.
In a pseudophakic eye sound speed depends on sound transmission characteristic and centre thickness of IOL
Holladay formula for pseudophakic biometry
True axial length = 0.988 apparent axial length +thickness of IOL(1-1532/velocity of sound in IOL)
TAL= 0.988(AAL)+T(1-1532/V)
Velocity of sound in silicone oil is 990m/s
Shammus formula for a cataractous lens with silicone oil
TAL=1133/1550 AAL
Further adjustment for IOL power is required as silicone oil causes a hyperopic shift in aphakic eye.
D: False; stronger lens is required
E: True
For every 1mm axial length the IOL power needs to be increased by +2.5 (considering +23.0 as adult standard)
70% undercorrection of the extra power
24. Wollaston prism
A. Incorporated in the viewing telescope of the keratometer.
B. Consists of two rectangular quartz prisms cemented together.
C. Quartz prisms allow two emergent beams by a fixed angle
D. Dispersion by two prisms causes image blurring
E. Corneal curvature is measured by distance between the mires when the doubled images of the prism just touch
A-C: True; D: False; cancel dispersion of each other allowing sharp images
E- True
25.Javal Schiotz keratometer
A. Calibration is in terms of corneal radius of curvature and not dioptric refracting power of cornea
B. Each step of mire is equivalent to 1D of corneal power
C. In an astigmatic cornea two images are displaced vertically in all meridians of cornea
D. Measures axis of astigmatism as well as its magnitude
E. The mires of Haag- Streit Javal Schiotz incorporate avertical line to facilitate horizontal alignment.
A: False; Also includes dioptric refracting power of cornea.
B. True
C. False; Except in two principal meridians where there is no displacement.
D. True
E. False; Horizontal line for vertical alignment.
26. Fresnel prism/lenses
A. Sheets of polyvinyl chloride, 1mm thick with an refractive index equal to that of crown glass
B. Available in the range between +1 to +20D and -1 to -14 D
C. Patched on the convex surface of lens wetting both surfaces.
D. Temporary trial prisms to evaluate prism corrections for heterophoria
E. Temporary management of recovering muscle paresis.
A-B: True; also 30D, and 25- 18D.
C: False; D-E: True
27. Absorptive lenses
A. Clear crown glass transmits 20% of the UV overall.
B. Clear crown glass increases transmission towards visible spectrum (85% at 350nm)
C. CR-39 no UV transmission at 350 nm and 35% at 375 nm
D. UV filter coatings block all UV rays below 400 nm
E. Glass and CR-39 transmit highly in near IR
A - E: True
28. Anti reflective coatings (ARC)
A. Film of manganese fluoride in a thickness one quarter the wavelength of light
B. Improves light transmission to 100% based on wavelight interference
C. Greatest effect in red green region
D. Coating reduces glare, “ghost veiling” in plus lenses and visibility of thick edge in minus lenses.
E. Reduces shiny appearance of high index glass and plastic lenses
A: False; Magnesium chloride
B: False; 98%
C: False: Yellow green region of spectrum
D- E: True
29. Tinted lenses
A. Pink lenses transmit at high end of spectrum. Comfortable under fluorescent lighting
B. Green good absorption at both ends of spectrum, protect against UV and IR
C. Gray produces maximum colour distortion
D. Brown produces “warm” appearance
E. Yellow tints used for outdoor activities
A: True
B: True; maximum transmission is at luminosity peak of photopic spectrum
C: False; Least distortion
D: True
E: True
No Infra red (NoIR) absorptive lenses absorb between UV 400nm to IR 800 to 1500nm. Their light transmission is variable from 1-40%. Available in gray and yellow colours.
30. Intraocular lens
A. Harold Ridley performed the first successful surgical operation
B. A + 20D lens tilt of 10* induces an astigmatism of 2D
C. Contrast decreases in linear fashion as the amount of implant dislocation increases.
D. A +20D lens in air is 3 times its power in aqueous
E. Magnifying power in air is 15x
A. True
B. True
C. True
D. True;
E. True
If the IOL tilts, a refractive astigmatism results. The effect of tilting IOLs was measured in the laboratory using laser beams. Tilting of the lens caused a spherical error in addition to any astigmatic error. The spherical error was always in the plus direction and, with higher degrees of tilting, became larger than the astigmatic error. With a 20-D lens, a 10° tilt resulted in an increase of spherical power of about 1 D and an astigmatic error of 2 D; a 20° tilt increased spherical power about 4 D; and a 30° tilt increased spherical power about 12 D, increasing astigmatic error to 6.5 D.
31. A compound microscope is used in
A. Slit lamp
B. Keratometer
C. Pachymeter
D. Applanation tonometer
E. Gonioscopy lens
A-E: True
32. Regarding compound microscope
A. Consists of two concave lenses for objective and eye piece
B. Object to be studied is placed just outside the anterior focal length
C. Real, inverted, magnified image is formed behind the objective
D. Porro prisms are incorporated to obtain an erect, non inverted image and also to shorten the physical length of the instrument
E. Zoom lens allows for smooth change in magnification without change in position of object or image.
A: False; convex lens
B-E: True
33. Regarding Hruby lenses
A. used to examine the posterior vitreous and fundus with slit lamp biomicroscope
B. Powerful plano convex lens having a -58.6D
C. Forms virtual, erect, diminished image of the retina
D. Lens placed with plano surface towards the eye.
E. Best view is obtained with lens near the eye, when retinal image is found in pupillary plane.
A: True
B: False; Plano concave
C: True
D: False; Concave surface
E: True
34. Regarding Bausch and Lomb keratometer
A. Principle of constant object size and variable image size
B. Object is a circular mire with one plus and two minus signs
C. Contains 4 aperture diaphragm and two doubling prisms
D. Image doubling is unique in that it is produced side by side as well as 90* from each other.
E. Rotation is required to measure the power of cornea in other principal meridian
A: True
B: False; Two plus and two minus
C: True
D: True
E: False; -One position keratometer. In oblique astigmatism the entire instrument need to be rotated until + signs are aligned.
35. Regarding keratometers
A. The range is 36-52 D (6.5-9.38mm)
B. By interposing a lens of -1D and +1.25 D the lower limit can be extended to 30D (5.6mm) and upper limit to 61 D(10.9mm)
C. Useful in calculation of IOL power
D. Very accurate in flat or steep cornea
E. Measure refractive status in central 3mm cornea.
A-C: True
D: False
E: True
36. Regarding Goldman contact lens
A. Plano concave contact lens with higher RI compared to eye
B. Equatorial mirror(longest and oblong) enables visualization from 30* to equator
C. Smaller the mirror more peripheral the view
D. Illumination column of the slit lamp is always tilted except for viewing 12’o clock fundus (mirror at 6’0 clock)
E. For a more peripheral view of retina, tilt the lens to opposite side and ask the patient to move the eyes to the same side.
A-E: True
For a 12’oclock view , tilt lens down and patient looks up
37. Argon blue-green laser
A. Mixture of 70%(488 nm blue) and 30%(514 nm green) light
B. Argon green well absorbed by melanin and haemoglobin
C. Argon green contra indicated in macular area as it is absorbed by inner retinal layers
D. Scattering of laser light by crystalline lens in elderly necessitates higher power settings
E. Newer lasers are air cooled and limit emission to green
A,B: True
C: False; Argon blue, green is not absorbed
D,E: True
38. Diode lasers
A. 810 nm, infra red, continuous wave mode by semiconductor chip
B. Light is absorbed by melanin
C. Good for oedematous retina and also penetrates sclera
D. Photocoagulation enhanced by ICG with an absorption peak of 800- 810 nm
E. Used in endoscopic DCR
A-E: True
39. Nd:YAG laser
A.1064 infra red, usually continuous wave, but Q switched when used in the eye.
B. Laser energy emitted from neodymium molecules suspended in clear YAG crystal
C. Invisible laser, requires Helium-Neon aiming beam(632.8nm)
D. Photodisruption of capsule
E. Laser beam and aiming beam focused at same spot before starting
A-E: True
40. Blepharophimosis syndrome
A. Autosomal dominant with moderate to severe ptosis
B. Poor levator function, amblyopia is a possibility
C. Short horizontal palpebral fissure
D. Telecanthus, epicanthus inversus and lateral ectropion of lower lid
E. Poorly developed nasal bridge and hypoplasia of superior orbital rims
A-E: True
I made these MCQ's while reading and with the hope I can remember very well next time I revise..
A.Only cranial nerve to emerge from the dorsal aspect of brain.
B.Crossed cranial nerve innervating opposite superior oblique muscle
C.Long and slender nerve
D.Nucleus located at the level of inferior colliculus ventral to aqueduct sylvius.
E.Decussates completely in anterior medullary vellum.
A - E: True
2.Fourth nerve cranial palsies
A. Identical features are seen irrespective of whether nuclear, fascicular or peripheral.
B. Diplopia is avoided by the patient by adopting contralateral head tilt and turn with chin depression.
C. Congenital lesions may not be symptomatic until adult life.
D. Trauma causes bilateral ptosis.
E. Aneurysm is one of the common causes.
A - D: True E: False, vascular is common, aneurysms and tumour are rare.
3.Third cranial nerve palsies
A.Isolated 3rd N palsies are frequently basilar. ( occurs when the N passes through sub arachnoid space)
B.Trauma and aneurysms are most important causes of isolated palsies
C.Painless, pupillary sparing isolated palsies are due to aneurysms at junction of posterior communicating and internal carotid artery.
D.Intracavernous lesions are associated with 4th, 6th and 5th nerve lesions.
E. Lesions of inferior division of 3rd nerve in its intra orbital part may occur due to vascular or traumatic cause.
A - B: True C: False, painful and papillary involvement.
D - E: True; characterized by defective adduction, depression and dilation of pupil (parasympathetic fibres pass through N to inferior oblique.
4. Isolated 3rd cranial nerve palsies
A. 25% have no causes
B. Diabetes and hypertension are most common causes of pupil sparing palsies
C. Trivial trauma not associated with loss of consciousness should possibly indicate a basal intracranial tumour stretching the nerve trunk.
D. MRA, a non invasive technique can identify aneurysms 4mm and greater located at junction of posterior communicating and internal carotid artery.
E. Surgical treatment is to be considered six months after the onset of palsy.
A - E: True
5. CT scan orbit
A. Bone excavation with round or smooth outline in presence of calcification is common in pleomorphic adenoma.
B. Contiguous bone erosion with invasion with calcification in 1/3rd cases is seen in lacrimal gland carcinoma.
C. Fusiform enlargement of optic nerve is seen in optic nerve glioma
D. Tubular thickening and calcification of optic nerve is seen in optic nerve sheath meningioma
E. Poorly defined mass of heterogeneous density is seen in rhabdomyosarcoma
A: False; calcification is rare and indicates carcinoma
B - D: True
E: False; homogeneous density.
6. Third cranial nerve
A.Lesions involving medial rectus subnucleus causes WEBINO.
B. Lesions involving the entire 3rd nerve nucleus cause ipsilateral 3rd nerve palsy
sparing ipsilateral elevation but causing contralateral weakness of elevation.
C. Levator subnucleus lesions give rise to bilateral ptosis.
D. Benedikt syndrome occurs when the fascicle passes through red nucleus.
E. Weber’s syndrome occurs when the fascicle passes through cerebral peduncle.
A - E: True
WEBINO: wall eyed bilateral inter nuclear ophthalmoplegia is characterized by exotropia, defective convergence and adduction.
7. Convergence retraction nystagmus
A. Jerk nystagmus occurs on attempted down gaze.
B. Fast phase brings two eyes into convergence
C. Associated with protrusion of globe into orbit
D. Pinealoma and vascular accidents in pretectal area can cause it.
E. May be associated with lid retraction ( Collier’s sign) and light near disscociation.
A - False; upgaze B: True; C: False; retraction of globe D - E: True
8. Ocular nystagmus
A. Is due to sensory deprivation caused by defective vision.
B. Is vertical and jerky
C. Increased by convergence
D. Abnormal head posture may be associated to dampen nystagmus.
E. Associated with loss of central vision in early life(< 2years) due to cataract, macular hypoplasia.
A: True; B: False, horizontal and pendular; C: False dampened; D- E: True
9. Regarding orbital varices
A. Most cases are unilateral and located in upper nasal quadrant.
B. Phleboliths are seen in 20% cases on X ray/ CT.
C. Presentation is early childhood to late middle age with proptosis and visible lesions
D. Natural course is progressive enlargement associated with recurrent episodes of haemorrhage and thrombosis.
E. Surgery is technically difficult and reserved for cases with recurrent episodes of thrombosis, pain, proptosis and optic nerve compression.
A - E: True
10. Direct carotid cavernous fistula (CCF)
A. Abnormal communication between artery and vein in which vein becomes arterialized.
B. May occur after head injury or spontaneous rupture
C. Anterior segment ischaemia is common and occurs in 20% cases.
D. 6th nerve is affected in 50% with variable involvement of 3rd and 4th.
E. Intravascular balloons introduced via catheter into internal carotid artery is used for closure.
A - E: True
11. Indirect CCF
A. Communications are between meningeal branches of ICA/ECA and cavernous sinus.
B. Spontaneous rupture may be precipitated by minor trauma/straining in hypertensive patients
C. Red eye and 4th nerve palsy is common.
D. Low intra ocular pressure with dilated episcleral blood vessels.
E. Exaggerated ocular pulsation is seen in tonometry.
A, B: True; C- False, 6th nerve palsy; D- False, high IOP; E- True.
12. Regarding tonometers
A. Accuracy of non contact is only in low and middle range.
B. Pulsair tonometer is a non contact tonometer and provides clinically useful measurements comparable to Goldmann.
C. Tonopen overestimates a low IOP and underestimates a high IOP.
D. Tonopen is useful in distorted and oedematous cornea and also through bandage contact lens.
E. Perkins is a hand held tonometer useful in bed bound patients.
A - E: True
13. Torsion can be measured by
A. Synaptophore
B. Maddox wing
C. Adapted Lees screen
D. Awaya cyclo test
E. Bagolini glasses
A - E: True; also used are Maddox double rods
14. Ultrasound examination of eye
A. Helps in diagnosis and determining the tumour size.
B. In choroidal melanoma, is characterized by anterior border of tumour, acoustic hollowness, choroidal excavation and orbital shadowing.
C. In retinoblastoma detects presence of calcification.
D. Useful in detection of intra ocular foreign body, globe rupture, suprachoroidal haemorrhage in cases of trauma to the globe.
E. T sign in posterior scleritis is due to thickening of posterior sclera and fluid in sub tenon’s space.
A - E: True
15. Frequency doubling perimetry
A. Portable table top instrument
B. Requires dim illumination with patching
C. Stimuli are presented in 17/19 sectors in central 20*/ 30* depending on the program used.
D. Low spatial frequency sinusoidal gratings undergoes high temporal frequency counter phase flicker.
E. Reliability indices, probabilities, mean deviation and PSD are present in the print out.
A: True; B- False, normal lighting, viewing canopy automatically covers the eye not being tested so no need for occlusion. C - E: True
16. Dark adaptation
A. Retina and pupil react to decreased illumination and is useful in patients with nyctalopia.
B. Performed using Goldmann-Weekes adaptometer.
C. Sensitive curve is tripartite.
D. Alpha point occurs 20 min after dark adaptation.
E. Flash focused on foveola, only a cone plateau is recorded.
A - B: True
C: False; Curve is bipartite. The subject is pre-adapted to a standard amount of illumination and presented with series of flashes of light 11* below fixation. The intensity of flashes are controlled by neutral density filter and threshold plotted against time. The curve is obtained wherein initial rapid segment is cone followed by slower rod segment function.
D: False; Alpha point is inflection of curve where rod limit begins, rod-cone break”. Healthy eyes have it in 7-10 minutes of dark adaptation.
E: True; May be more sensitive than electroretinogram in certain disorders.
17. Electrophysiology in retinitis pigmentosa
A. Amplitude of scotopic and later photopic b wave is reduced in early stages with minimal fundus changes.
B. Delay in implicit time.
C. Electrooculogram shows absence of light rise.
D. Patients with loss of cone mediated response have poorer visual acuity and visual field scotoma encroaching closer to fixation compared to typical rod- cone type.
E. determination of any rod mediated response in electroretinogram is critical for diagnosis in any young patient suspected of retinitis pigmentosa.
A - E: True
18. MRI scans
A. Could be axial, saggital or coronal.
B. T1 weighted image of vitreous is dark
C. T1 weighted images are preferred for studying pathological changes
D. Gadolinium is a contrast taken up for tumours and appears bright white on T1
E. Good for orbital apex lesions
A - B: True; T2 is bright. Orbital fat T1 is bright T2 is dark
C: False; T1 is for normal anatomy and T2 for pathological changes.
D: True; Paramagnetic substance.
E: True
19. Aberrant regeneration of third cranial nerve
A. Trauma or aneurysms may cause it
B. Central or peripheral response may occur
C. Lid may rise on attempted depression, adduction or occasionally abduction
D. Pupil may constrict on attempted adduction, elevation or depression
E. Convergence may occur on attempted elevation
A - E: True
B- Central response involves mass response of damaged nerve resulting in growth to the wrong muscle. Peripheral response abnormal growth of damaged axons may occur locally.
C- Pseudo Graefe’s phenomenon
D- Pseudo Argyll Robertson pupil.
Widening of palpebral fissure on adduction and narrowing on abduction- Inverse Duane
20. Injury to occipital poles may result
A. Altitudinal defects
B. Upper portion damage leads to entire inferior field of vision
C. Lower portion damage is usually managed conservatively
D. Homonymous paramacular scotoma is the normal area adjoining the scotoma
E. Riddoch phenomenon is characterized by dense homonymous hemianopia in which stationary object is not perceived but a small moving object can be perceived.
A-B: True
C: False; associated with laceration of dural sinuses and results in intracranial bleeding and is fatal.
D: False, this area is characterized by defect for colour and emphasizes the importance of examining the central fields.
E: True.
21. Occipital lobe lesions are associated with
A. Visual hallucinations
B. Colour field defects
C. Vascular injury
D. Cortical blindness
E. Macular sparing
A-E: True
A- Visual hallucinations though can occur from any part of visual system and not specific to occipital lobe. But hallucinations in occipital lobe are unformed (scintillating scotoma)
B- Cerbral dyschromatopsia
Select group of cells involved in colour stimuli are involved
Colour defect is random and does not fall into deuteran/protan types
Make errors while reading pseudo isochromatic plates of Ishihara/ colour sorting
Vascular insult is the most common cause
D- Cortical blindness
Loss of all sensations including dark and light adaptation
Loss of menace reflex
Normal pupillary reaction (pupil pathway is related to third nerve)
Normal extraocular motility
Normal fundus
Hypoxia to the striate cortex is the main cause.
No associated CNS manifestations like motor/sensory/speech disorders
22. Error with Goldmann applanation tonometer
A. Thin corneas produce falsely low readings
B. Thick cornea due to oedema produce low readings
C. For every 3D of increase in corneal power the IOP increases by 1mm Hg
D. Marked corneal astigmatism will produce an elliptical area of contact.
E. For every 4D of increase in astigmatism the IOP increases by 1mm Hg
A-E: True
When biprism is in the usual orientation, with mires horizontally, IOP will be underestimated for with-the rule astigmatism and overestimated for against the rule astigmatism. To minimize this error, the biprism may be rotated until the dividing line between the prisms is 45* to the major axis of the ellipse or an average of vertical and horizontal readings may be taken.
23. Biometry in special conditions
A. Immersion technique is the method of choice in aphakes.
B. Pseudophakic eyes needing IOL exchange have extremely high spikes at the lens followed by reduplication of echoes.
C. System gain is increased in eyes with silicone oil
D. IOL required by eyes with silicone oil is usually 2-3D weaker than indicated by standard power calculation
E. In paediatric biometry in children less than 6 months of age undercorrection has to be done by 60-75% to account for myopic shift later in life.
A-C: True; Newer biometry machines have options for aphakic/ pseudophakic modes
In an aphakic eye sound travels at the speed of 1532m/s and in a phakic eye at 1550m/s.
In a pseudophakic eye sound speed depends on sound transmission characteristic and centre thickness of IOL
Holladay formula for pseudophakic biometry
True axial length = 0.988 apparent axial length +thickness of IOL(1-1532/velocity of sound in IOL)
TAL= 0.988(AAL)+T(1-1532/V)
Velocity of sound in silicone oil is 990m/s
Shammus formula for a cataractous lens with silicone oil
TAL=1133/1550 AAL
Further adjustment for IOL power is required as silicone oil causes a hyperopic shift in aphakic eye.
D: False; stronger lens is required
E: True
For every 1mm axial length the IOL power needs to be increased by +2.5 (considering +23.0 as adult standard)
70% undercorrection of the extra power
24. Wollaston prism
A. Incorporated in the viewing telescope of the keratometer.
B. Consists of two rectangular quartz prisms cemented together.
C. Quartz prisms allow two emergent beams by a fixed angle
D. Dispersion by two prisms causes image blurring
E. Corneal curvature is measured by distance between the mires when the doubled images of the prism just touch
A-C: True; D: False; cancel dispersion of each other allowing sharp images
E- True
25.Javal Schiotz keratometer
A. Calibration is in terms of corneal radius of curvature and not dioptric refracting power of cornea
B. Each step of mire is equivalent to 1D of corneal power
C. In an astigmatic cornea two images are displaced vertically in all meridians of cornea
D. Measures axis of astigmatism as well as its magnitude
E. The mires of Haag- Streit Javal Schiotz incorporate avertical line to facilitate horizontal alignment.
A: False; Also includes dioptric refracting power of cornea.
B. True
C. False; Except in two principal meridians where there is no displacement.
D. True
E. False; Horizontal line for vertical alignment.
26. Fresnel prism/lenses
A. Sheets of polyvinyl chloride, 1mm thick with an refractive index equal to that of crown glass
B. Available in the range between +1 to +20D and -1 to -14 D
C. Patched on the convex surface of lens wetting both surfaces.
D. Temporary trial prisms to evaluate prism corrections for heterophoria
E. Temporary management of recovering muscle paresis.
A-B: True; also 30D, and 25- 18D.
C: False; D-E: True
27. Absorptive lenses
A. Clear crown glass transmits 20% of the UV overall.
B. Clear crown glass increases transmission towards visible spectrum (85% at 350nm)
C. CR-39 no UV transmission at 350 nm and 35% at 375 nm
D. UV filter coatings block all UV rays below 400 nm
E. Glass and CR-39 transmit highly in near IR
A - E: True
28. Anti reflective coatings (ARC)
A. Film of manganese fluoride in a thickness one quarter the wavelength of light
B. Improves light transmission to 100% based on wavelight interference
C. Greatest effect in red green region
D. Coating reduces glare, “ghost veiling” in plus lenses and visibility of thick edge in minus lenses.
E. Reduces shiny appearance of high index glass and plastic lenses
A: False; Magnesium chloride
B: False; 98%
C: False: Yellow green region of spectrum
D- E: True
29. Tinted lenses
A. Pink lenses transmit at high end of spectrum. Comfortable under fluorescent lighting
B. Green good absorption at both ends of spectrum, protect against UV and IR
C. Gray produces maximum colour distortion
D. Brown produces “warm” appearance
E. Yellow tints used for outdoor activities
A: True
B: True; maximum transmission is at luminosity peak of photopic spectrum
C: False; Least distortion
D: True
E: True
No Infra red (NoIR) absorptive lenses absorb between UV 400nm to IR 800 to 1500nm. Their light transmission is variable from 1-40%. Available in gray and yellow colours.
30. Intraocular lens
A. Harold Ridley performed the first successful surgical operation
B. A + 20D lens tilt of 10* induces an astigmatism of 2D
C. Contrast decreases in linear fashion as the amount of implant dislocation increases.
D. A +20D lens in air is 3 times its power in aqueous
E. Magnifying power in air is 15x
A. True
B. True
C. True
D. True;
E. True
If the IOL tilts, a refractive astigmatism results. The effect of tilting IOLs was measured in the laboratory using laser beams. Tilting of the lens caused a spherical error in addition to any astigmatic error. The spherical error was always in the plus direction and, with higher degrees of tilting, became larger than the astigmatic error. With a 20-D lens, a 10° tilt resulted in an increase of spherical power of about 1 D and an astigmatic error of 2 D; a 20° tilt increased spherical power about 4 D; and a 30° tilt increased spherical power about 12 D, increasing astigmatic error to 6.5 D.
31. A compound microscope is used in
A. Slit lamp
B. Keratometer
C. Pachymeter
D. Applanation tonometer
E. Gonioscopy lens
A-E: True
32. Regarding compound microscope
A. Consists of two concave lenses for objective and eye piece
B. Object to be studied is placed just outside the anterior focal length
C. Real, inverted, magnified image is formed behind the objective
D. Porro prisms are incorporated to obtain an erect, non inverted image and also to shorten the physical length of the instrument
E. Zoom lens allows for smooth change in magnification without change in position of object or image.
A: False; convex lens
B-E: True
33. Regarding Hruby lenses
A. used to examine the posterior vitreous and fundus with slit lamp biomicroscope
B. Powerful plano convex lens having a -58.6D
C. Forms virtual, erect, diminished image of the retina
D. Lens placed with plano surface towards the eye.
E. Best view is obtained with lens near the eye, when retinal image is found in pupillary plane.
A: True
B: False; Plano concave
C: True
D: False; Concave surface
E: True
34. Regarding Bausch and Lomb keratometer
A. Principle of constant object size and variable image size
B. Object is a circular mire with one plus and two minus signs
C. Contains 4 aperture diaphragm and two doubling prisms
D. Image doubling is unique in that it is produced side by side as well as 90* from each other.
E. Rotation is required to measure the power of cornea in other principal meridian
A: True
B: False; Two plus and two minus
C: True
D: True
E: False; -One position keratometer. In oblique astigmatism the entire instrument need to be rotated until + signs are aligned.
35. Regarding keratometers
A. The range is 36-52 D (6.5-9.38mm)
B. By interposing a lens of -1D and +1.25 D the lower limit can be extended to 30D (5.6mm) and upper limit to 61 D(10.9mm)
C. Useful in calculation of IOL power
D. Very accurate in flat or steep cornea
E. Measure refractive status in central 3mm cornea.
A-C: True
D: False
E: True
36. Regarding Goldman contact lens
A. Plano concave contact lens with higher RI compared to eye
B. Equatorial mirror(longest and oblong) enables visualization from 30* to equator
C. Smaller the mirror more peripheral the view
D. Illumination column of the slit lamp is always tilted except for viewing 12’o clock fundus (mirror at 6’0 clock)
E. For a more peripheral view of retina, tilt the lens to opposite side and ask the patient to move the eyes to the same side.
A-E: True
For a 12’oclock view , tilt lens down and patient looks up
37. Argon blue-green laser
A. Mixture of 70%(488 nm blue) and 30%(514 nm green) light
B. Argon green well absorbed by melanin and haemoglobin
C. Argon green contra indicated in macular area as it is absorbed by inner retinal layers
D. Scattering of laser light by crystalline lens in elderly necessitates higher power settings
E. Newer lasers are air cooled and limit emission to green
A,B: True
C: False; Argon blue, green is not absorbed
D,E: True
38. Diode lasers
A. 810 nm, infra red, continuous wave mode by semiconductor chip
B. Light is absorbed by melanin
C. Good for oedematous retina and also penetrates sclera
D. Photocoagulation enhanced by ICG with an absorption peak of 800- 810 nm
E. Used in endoscopic DCR
A-E: True
39. Nd:YAG laser
A.1064 infra red, usually continuous wave, but Q switched when used in the eye.
B. Laser energy emitted from neodymium molecules suspended in clear YAG crystal
C. Invisible laser, requires Helium-Neon aiming beam(632.8nm)
D. Photodisruption of capsule
E. Laser beam and aiming beam focused at same spot before starting
A-E: True
40. Blepharophimosis syndrome
A. Autosomal dominant with moderate to severe ptosis
B. Poor levator function, amblyopia is a possibility
C. Short horizontal palpebral fissure
D. Telecanthus, epicanthus inversus and lateral ectropion of lower lid
E. Poorly developed nasal bridge and hypoplasia of superior orbital rims
A-E: True
I made these MCQ's while reading and with the hope I can remember very well next time I revise..
Wednesday, January 10, 2007
MRCS ophthalmology exams
Preparing for Part-2 MRCS Ophthalmology of Royal college of surgeons of Edinburgh requires lots of effort, patience and dedication.
It is a test of one's patience and perseverance which helps one carry through..
I will be posting few salient tips, questions which I made while preparing for the exams..
Here is the first set on retinoscopy and subjective refraction..
History
1. Age
2. Occupation
3. Special requirements- hobbies
4. History of eye disease- glaucoma
5. Previous spectacle/contact lens
6. Previous eye surgery/laser
Examination
1. Visual acuity- uniocularly
Distance/near/ unaided
2. Fog the fellow eye with a nystagmus with high plus lens
3. Poor VA check with ophthalmoscope (too much light- photostress induced reduction of VA)
Objective refraction
1. Age
2. Occupation
3. Special requirements- hobbies
4. History of eye disease- glaucoma
5. Previous spectacle/contact lens
6. Previous eye surgery/laser
Examination
1. Visual acuity- uniocularly
Distance/near/ unaided
2. Fog the fellow eye with a nystagmus with high plus lens
3. Poor VA check with ophthalmoscope (too much light- photostress induced reduction of VA)
Objective refraction
1. Cover/uncover test
2. Convergence
3. IPD measurement
4. Fit trial frame, taking care lens apertures centred on the pupil, with patient gazing ahead.
a. Level across face
b. Close to face as much lashes allow
c. High power trial lens in the back cell of trial frame
5. Retinoscopy in patient’s visual axis in order to measure true optical length of eye
Avoid blocking patient’s distant fixation –patient may accommodate if examiner comes in the way
6. Fog patient’s fellow eye rather than occlude
In presence of manifest squint dominant eye may have to be occluded to achieve steady fixation of non dominant eye
Young children with latent/ manifest squint- cycloplegic before retinoscopy
7. Dioptric value of working distance (+1.5D for 2/3 m)
8. High refractive error too dim and diffuse initial reflex- use+/- &D to bring reflex in view(alternatively use ophthalmoscope to view the fundus)
9. Remove the working distance lens after neutralization
10. Cylinder to be moved only by a small amount before rechecking the retinoscopy
11. Minus cylinders to be used during retinoscopy
The use of plus cylinders when refracting young hypermetropes may stimulate acomodation as eye is fogged in both meridians
Minus cylinders may overcorrect hypermetropia in elderly
Some may prefer plus cylinders with plus and minus with minus
Retinoscopy reflexes with opposite movement wise to use minus spheres and plus cylinders as it is easy to find the axis of astigmatism with plus cylinder using the with movement than against movement that goes with use of plus spheres and minus cylinders.
Power cross is drawn in orientation of principal meridians and angle of one meridian is marked
If result is transposed to a lens prescription (corrected for working distance) the axis of cylinder lies at 90* to the line of meridian
Scissor shadows- moving away and towards each other due to difference in refraction between zones of pupillary aperture
Seen in
· Different zones of dilated pupil
· Near end point (one area is myopic and other is hypermetropic)
· Apex of cone is darker than periphery (oil drop sign) in keratoconus
Scissor shadows- moving away and towards each other due to difference in refraction between zones of pupillary aperture
Seen in
· Different zones of dilated pupil
· Near end point (one area is myopic and other is hypermetropic)
· Apex of cone is darker than periphery (oil drop sign) in keratoconus
Subjective refraction
Occlude the fellow eye/ fog the fellow eye
Two methods to check sphere power at this stage
Duochrome (6/9 or more)
i. R>G an extra 0.5 makes green clear
ii. R=G young and hypermetropes
iii. Green clearest if accommodation needs to be stimulated
iv. If there is not 0.5D interval between R& G best to abandon duochrome
v. Less reliable in presence of accommodation (children), uncorrected astigmatism, large or small pupil, media opacities and colour vision anomalies
Use small plus or minus until no further improvement can be made (those with poor VA may be given +/- 0.5(start with additional plus otherwise patient may accommodate and confuse the result)
i. + little noticeable effect (if patient is already forced to accommodate)
+ blurred (if too much plus in place or sufficient plus)
ii. - little noticeable effect (if previous lens was corrector too much minus in place)
- clearer (if too much plus in place)
- smaller(forced to accommodate with new lens)
Verify axis of cylinder
Insert a -0.25/-0.50 to + accommodation
When accommodation is active it may be assumed that circle of least confusion will be focused on the retina
Look at a circular letter near their acuity limit
End point is when both positions are equally blurred
Verify power of cylinder
If cylinder power is changed by + 0.5D, change sphere power by - 0.25D in the opposite direction to keep patient’s accommodation stable, if power is altered recheck the axis
Large change is found in cylinder, it is wise to go back and check the sphere
Myopic patient- Duochrome test –monocular and binocular
Red letters clearly binocularly and ensure patient will be comfortable and not accommodating, when wearing spectacles
Prescription and acuity of each eye with binocular VA
Binocular tests
Record BVD if power of spherical lenses is>5D
Lens should be in back cell of trial frame
Ruler beside the arm of trial frame, while viewing patient from side.
Maddox rod for muscle balance for distance
Occlude each eye to ascertain if spot and light are visible
Uncover both eyes to see if able to perceive them simultaneously (uniocularly seen but binocularly absent- BSV absent or defective)
Presbyopic
Rule of thumb addition
Accommodation monocularly and binocularly(RAF rule) amplitudes should be equal in both eyes)
Addition = working distance (in dioptres)- 0.5 (amplitude)
Eg: WD= 33cm, amplitude is 4D, addition is
100/33= 3D; 3-0.5(4)= 3-2=1D
Near duochrome (if available)
Maddox wing near muscle balance
Convergence weakness by convergence excercises
Steps in cross-cylinder refraction
Adjust the sphere to give most plus/least minus that gives best VA
Use test figures ½ lines larger than patient’s best VA as cross cylinder causes blur
If no cylindrical correction look for astigmatism by testing with cross cylinder at 90*& 180* and subsequently 45* &135*
Refine axis first
Cross cylinder 45* from principal meridian
Plus cylinder to plus axis of the cross cylinder
Minus cylinder to minus axis
Refine cylinder power
Keep track of cylinder power added/subtracted
Compensate for change in position of circle of least confusion by adding half sphere in opposite direction
Eg: -0.5D cyl/+0.25D sph
After cross cylinder technique Sturms conoid is collapsed to a point on retina
Refine sphere again add + 0.25 till patient reports ê in vision.
If +0.25 not accepted then add –0.25 until maximum acuity-least minus
End point verified by duochrome test.
Binocular balancing
1. Fogging
2. Duochrome with fogging
3. Prism dissociation
Fogging
1. BCVA add + 2.0 both eyes, patient reports ¯ in vision (6/60-6/36) íHumphriss method (+0.75/+1.0) swap the other eye not possible if large squint.ý
a. Binocular addition once prescribed balance in place+0.25 in front of both eyes, ask if smallest letters are clear if prescription correct letters blur if not incorporate extra positive power and repeat tests)
2. Add –0.25 do alternate cover test and see which eye is clear
a. Eye is balanced eye with 0.25 clearer
b. Eye not balanced add/ subtract in 0.25 until clear
Duochrome with fogging
BCVA add +1.0 in one eye observe red green preference
Prism dissociation
1. BCVA add +1.0 both eyes, 4 D is placed in front of one eye
2. Project 6/12, patient able to see same line with both eyes simultaneously
3. Add +0.25 before one eye and then before another eye
4. Balanced- Eye with +0.25 blurred
5. Prism removed when balance is obtained and fog is reduced binocularly until maximum vision with highest plus/ least minus
Pinhole test
Any stage of refraction
+1D test
if VA is 6/6 +1DS should blur 6/12 to 6/18.
Books to read for the part-2
1. MCQ's and OSCE's in Optics and refraction by A Bhan
2. Success in part-2 MRCOphth by Chua CN
3. Clinical optics-Elkington
4. AAO- Clinical optics 2006-2007
5. The Opthalmology Examinations Review by Wong TY
6. Clinical orthoptics- Rowe F
Great website
Yahoo groups
health.groups.yahoo.com/group/FRCOphth
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