Corneal Collagen Cross-linking For The Treatment Of Keratoconus Dr. A. Arafat, M.D., Al-Noor Eye Center, Specialized Arab Hospital Nablus, Palestine

An Everyday Story حالة نصادف مثلها يوميا A 17-year old female patient presented for changing her glasses. She last changed them 6 months ago.

Corneal cross linking uncorrected visual acuity Right eye : 6/60 Left eye: 6/24

Corneal cross linking Autorefractor Readings Right : -2.50/-0.75 Axis 51 Left : -2.25/-4.50 Axis 141

Corneal cross linking Best spectacle corrected visual acuity Right eye: -2.25/-0.50 Cyl. Axis 65 = 6/6 Left eye: -1.00/-1.00 Cyl. Axis 95 = 6/6

Corneal cross linking Clinical Examination No detectable anterior segment abnormality in either eye No fundus abnormality in either eye

Introduction Methods of Management of Keratoconus Classical Methods: Glasses Rigid gas-permeable contact lenses Penetrating keratoplasty

Methods of Management of Keratoconus New Methods: Glasses Rigid gas-permeable contact lenses Corneal cross linking Intracorneal rings Phakic intraocular lenses Deep Lamellar keratoplasty Penetrating keratoplasty

Corneal cross linking Useful to stop the progression of the disease Minimal improvement in vision Minimal decrease in K-readings Can be done till age of 38 years The earlier the keratoconus the better Corneal thickness <400 microns

Corneal cross linking Work-up Complete ophthalmologic examination Uncorrected visual acuity [UCVA], Best spectacle-corrected visual acuity [BSCVA] Keratometry Corneal topography & tomography (Pentacam)

Patient Inclusion Criteria Pachymetry >400 microns K readings <60D No central scarring No herpes simplex keratitis

Corneal cross linking Study Procedure Topical anaesthesia & povodine iodine Corneal epithelium is removed Riboflavin eye drops are applied Q 3 minutes for 30 minutes flare in A.C. is checked Pachymetry: if less than 400 microns hypotonic riboflavin is used Q 15 seconds till thickness is 400 or more

Corneal cross linking Study Procedure-continued Cornea is exposed to ultraviolet rays for 30 minutes (10 minutes in new machines) Riboflavin still applied Q 2 minutes using UV-X machine A bandage contact lens is applied Antibiotic & steroid eye drops are applied Patient is seen next day

Patient Treatment

Corneal cross linking Follow up Contact lenses are removed after 3-4 days Eye drops are tapered over one month Further management by glasses, RGP contact lenses or intracorneal rings

Corneal cross linking Complications Infection: Rare Corneal haze: Temporary Corneal oedema: Transient Corneal endothelial decompensation: Not seen in our series

Conclusions The procedure is effective & safe The main effect is stabilising Probably best for recent onset, milder, younger, progressive cases

Recommendations Evidence of progression Make use of : serial refractions,medical records and old glasses) Any change greater than 0.50 D from the above could point to unstable refraction Below 20 years of age: No need for evidence of progression