Opthalmology vision correction

Question 1

Refractive keratoplasty

Answer 1

a general term for surgical procedures on the cornea to improve vision by changing the shape a thus the refractive index of the corneal surface.

Question 2

What are the layers of the cornea from outside in

Answer 2

Epithelium, bowman’s membrane, stroma, descemet’s membrane, endothelium

Question 3

What are the 4 most common types of keratoplasties?

Answer 3

Radial keratotomy (RK), photorefractive keratectomy (PRK), automated lamellar keratoplasty (ALK) and laser in-situ keratomileusis (LASIK)

Question 4

What are some facts about radial keratotomy (RK)

Answer 4

incisions create a bulge in the peripheral cornea which flattens the central cornea, not used much any more, been replaced by PRK and LASIK

Question 5

Photorefractive keratectomy (PRK)

Answer 5

for myopic and hyperopic patients, a laser removes part of the outside cornea to correct refractive layers. Outside removed for hyperopia and middle for myopia. Preferred in patients with thin or irregular shaped corneas

Question 6

Laser in-situ keratomileusis (LASIK)

Answer 6

most common, for both myopia and hyperopia, similar to PRK but the corneal epithelium remains intact (a flap of the cornea is cut and the cornea is reshaped underneath), faster recovery, 90% patients have desired vision. Irreversible.

Question 7

What are some potential side effects of LASIK?

Answer 7

discomfort 12-24hrs, glare, halos, difficult driving at night, dry eyes, fluctuating vision

Question 8

Automated Lamellar keratoplasty

Answer 8

used for sever nearsightedness and slight farsightedness. A flap is created in the cornea and then another incision is made underneath. Replaced by LASIK in almost all cases.

Question 9

Conductive keratoplasty (CK)

Answer 9

for hyperopia and presbyopia, non surgical procedure where low energy radio frequency light is used to increase the curvature of the cornea by shrinking the collagen around it. Safe and effective but results not always permanent.

Question 10

Crystalens

Answer 10

for hyperopia or presbyopia and cataracts, lens is replaced by a plastic one, artificial lens is able to focus like the natural one, most common eye surgery

Question 11

Orthokeratology

Answer 11

special contact lens is worn at night that reshapes the cornea, takes several weeks, appealing to adolescents who are not eligible for LASIK

Question 12

eye exercises

Answer 12

no evidence based finding but helpful to be familiar with if patients have questions

Question 13

what are some vitamins that are beneficial to the eyes?

Answer 13

Vitamin A, beta-carotene (night vision and wound healing)
Vitamin B complex, folic acid, biotin, choline-may help prevent elevated homocystein in the blood which has been associated with vascular problems affecting the retina. May also reduce the risk of macular degeneration and the treatment of uveitis.
Vitamin C-reduced risk of cataracts
Vitamin D-lower risk of macular degeneration
Vitamin E-lower risk of cataracts