Optics

Question 1

Light converges between which two surfaces of eye

Light divergence between which two surfaces of eye

Answer 1

Air-cornea
Aquous humour- lens

Cornea- aquous humor
Lens-vitreous humor

Question 2

Two models of reduced eye

Nodal point of reduced eye

Visually most significant cataract is located at

Answer 2

Donders model
Listings model

Posterior subcapsular location

Posterior subcapsular cataract

Question 3

Myopia vs hypermetropia

Size of eye
Anterior chamber depth

Which one has which type of glaucoma

Answer 3

Longer eye -myopia
smaller eye- hypermetropia

Deep anterior chamber- myopia
shallow anterior chamber- hypermetropia

Angle closure glaucoma - hypermetropia

Question 4

Fundus features of myopia (pathological)

Answer 4

1) tilted myopic optic disc
2) temporal crescent
3) foster fuchs spot(HGE/Pigmentation -fovea)
4) tessellated tegroid fundus (choroidal vessels)
5) peripheral retinal degeneration ( MC lattice)
6) Rhegmatogenous RD
7) Lacquer cracks ( Bruchs memb)
8) posterior staphyloma
9) complicated cataract

Question 5

Fundus features of hypermetropia

Answer 5

1) silk shot retina (shiny)

2) pseudopapilledema/ pseudopapillitis

Question 6

Examples of irregular astigmatism

Answer 6

keratoconus

Scar

Question 7

Criteria for refractive surgery

Answer 7

Age >18 yr
Stable refractive error for > 1 yr
-nce of any other eye disease
>500 micrometer cornea (for LASIK only)
-nce of CTD
-nce of factors impairing corneal healing Eg DM

Question 8

Refractive surgery for thin cornea

Refractive surgery completely based on femto laser

Refractive surgery where corneal flap is cut with femtolaser, type of which laser?, nm?

Laser used in LASIK, nm?

Answer 8

PRK, photorefractive keratectomy

SMILE, SMALL INCISION LENTICULE EXTRACTION

Femtosecond LASIK, type of Nd YAG laser, 1053 nm

Excimer, 193 nm

Question 9

Anisocoria

Anisometropia

Anisokonia

Answer 9

Difference in size of pupil

Difference in refractive error between eyes

Difference in size of image formed