Ophthalmology: AIIMS Nov 2014

Q-1. Gene commonly indicated in congenital cataract
b) PAX6
c) PITX3
d) LMX1B

Answer: CRYGS3
CRYGS3 mutation causes progressive cortical cataract in human.

Q-2. The light peak/dark trough (L/D) ratio in normal electro-oculogram reading
a) 1
b) 1.5
c) > 185 %
d) < 185 %

Answer: > 185 %
The electro-oculogram (EOG) is an electro-physiologic test that measures the existing resting electrical potential between the cornea and Bruch’s membrane.
The smaller amplitudes are recorded when the eyes make the saccadic eye movements in the dark (dark trough); the peak amplitude is recorded against a steady light background (light peak).
The light peak/dark trough (L/D) ratio is an index (Arden index) used to assess retinal function.
An Arden ratio of 1.80 or greater is normal, 1.65 to 1.80 is subnormal, and < 1.65 is significantly subnormal.

Q-3. Young male presents with intra-ocular foreign body. What is the best investigation for monitoring vision?
a) ERG
b) Arden index
c) Dark index
d) Serial evoked potentials

Answer: ERG
CT scans are the imaging study of choice for IOFB localization.
Electro-retinography is useful if a chronic IOFB is found.
Important point:
MRI is generally not recommended for metallic IOFBs.

Q-4. Which of the following procedure do not need dilatation of pupil?
a) Fundus examination
b) Gonioscopy
c) Laser Infero-metry
d) Electro-retinography

Answer: Gonioscopy
Gonioscopic procedure doesn’t need dilatation of pupil.
Use to examine the angle of anterior chamber

Q-5. Which is not a feature of fungal ulcer?
a) Fixed hypopyon
b) Ulcer with sloughing margins
c) Symptoms are more pronounced than signs
d) Hyphae are seen on KOH mount

Answer: Symptoms are more pronounced than signs

Q-6. Laser Trabeculoplasty is indicated in which of the following?
a) Neo-vascular glaucoma
b) Chronic angle closure glaucoma
c) Pseudo-exfoliative glaucoma
d) Uveitic glaucoma

Answer: Pseudo-exfoliative glaucoma
Indications of Laser Trabeculoplasty:
Pseudo-exfoliative glaucoma
Pigmentary glaucoma
Primary open angle glaucoma
Important point:
Laser Trabeculoplasty is performed with Argon or Nd-YAG laser.

Q-7. A patient presents with painless red eye with an IOP of 60 mmHg. What is the likely diagnosis?
a) Acute anterior uveitis
b) Glaucomatocyclitic crisis
c) Angle closure glaucoma
d) Chronic papillo-edema

Answer: Glaucomatocyclitic crisis
Posner Schlossman Syndrome (Glaucomatocyclitic crisis):
Glaucomatocyclitic crisis is a condition with self-limited recurrent episodes of markedly elevated intraocular pressure (IOP) with mild non-granulomatous anterior uveitis.

Q-8. A distortion increases in both direction on wearing a lens. Which of the following is not true about this?
a) It is type of Aniseikonia
b) it is called as Pin Cushion effect
c) Seen on wearing a convex lenses
d) Cylindrical lenses increases the distortion

Answer: Cylindrical lenses increases the distortion
Pincushion distortion:
Magnification increases as distances from axis increases in the transverse plane.
Barrel distortion:
Magnification decreases as distances from axis increases.
Important point:
Pincushion distortion occurs in practically all spectacle corrected aphakes and is occasionally seen in high myopes after clear lens extraction.

Q-9. Which is not on absolute contraindication of corneal transplantation?
a) TB meningitis
b) Rabies
d) Death due to unknown cause

Answer: TB meningitis
Absolute contra-indication of corneal transplantation:
Viral Hepatitis
Human immunodeficiency virus (HIV)
Creutzfeldt-Jakob disease
Sub-acute sclerosing pan-encephalitis (SSPE)
Death due to unknown cause

Q-10. Which of the following is used as a self tonometer?
a) Perkins
b) Diaton
c) Rebound
d) Dynamic contour

Answer: Rebound Tonometer
Rebound Tonometer:
The ability to evaluate intra-ocular pressure without the use of topical anesthesia potentially provides the opportunity to monitor intra-ocular pressure by patient at home.

Q-11. Sub-retinal demarcation lies (High water marks) indicate
a) Fresh rhegmatogenous RD
b) Old rhegmatogenous RD
c) Retinopathy of prematurity
d) Retinitis pigmentosa

Answer: Old rhegmatogenous RD
Rhegmatogenous or primary retinal detachment:
Usually associated with a retinal break through which sub-retinal fluid seep and separate the sensory retina from pigmentary epithelium.
Old retinal detachment is characterized by retinal thinning due to atrophy, formation of sub-retinal demarcation (High water marks) and formation of secondary intra-retinal cysts in very old retinal detachment.

Q-12. Which is not true about rhegmatogenous RD?
a) It is caused due to fibrous bands in the vitrous
b) Presents as floaters
c) Surgery is the primary treatment
d) Can extend up-to ora serrata

Answer: It is caused due to fibrous bands in the vitrous
Rhegmatogenous or primary retinal detachment:
It is usually associated with a retinal break or hole through which sun-retinal fluid seeps and separates the sensory retina from the pigmentary epithelium.
The final shape and position of retinal detachment is determined by location of retinal break and anatomical limit of optic disc and ora serrata.
Prodromal symptoms: Floaters and Photopsia
Tractional retinal detachment:
It occurs due to retina being mechanically pulled away from its bed by the contraction of fibrous tissue in vitreous called vitreo-retinal fractional bands.
Exudative or solid retinal detachment:
Due to retina being pushed away by a neoplasm or fluid beneath the retina following inflammatory or vascular lesion

Q-13. Corneal edema in hypoxic condition due to accumulation of
a) Lactate
b) Pyruvate
c) Glycogen
d) Carbon dioxide

Answer: Lactate
Stromal lactate accumulation can account for corneal edema osmotically following epithelial hypoxia.

Q-14. Which one of following is used in retinal sealing?
a) CO
b) SF6
c) Nitrous oxide
d) So2

Answer: SF6
Pneumatic retinopexy (PR) is an alternative to scleral buckling for the surgical repair of selected retinal detachments.
A gas bubble is injected into the vitreous cavity, and the patient is positioned so that the bubble closes the retinal break (s), allowing absorption of the sub-retinal fluid.
Cryotherapy or laser photocoagulation is applied around the retinal break(s) to form a permanent seal.
Sulfur hexafluoride (SF6) is the gas most frequently used for PR, followed by per-fluoro-propane (C3F8).

  1. Which of the following antibiotics can be used in the treatment of fungal kerato-mycosis?
    a) Linezolid
    b) Vancomycin
    c) Silver sulphadiazine
    d) Doxycycline

Answer: Silver sulphadiazine
Ocular anti-fungal agents:
Polyene anti-bacterial
Iodine and sulphadiazine
Important point:
Silver sulfadiazine is a topical antimicrobial agent with both antifungal and antibacterial activity and may also be useful in kerato-mycosis