MICROBIAL KERATITIS FOLLOWING EPI-OFF CORNEAL COLLAGEN

CROSSLINKING PROCEDURE

Dr. K V SatyamurthyDr. Jaysheel V N

Cornea-Refractive Surgery Dept

MM Joshi Eye InstituteHubli

Authors have no financial or proprietary interest in any material or methods

Introduction Keratoconus is a degenerative, noninflammatory ectasia of

the cornea characterized by progressive corneal thinning

and irregular astigmatism.

Corneal collagen crosslinking (CXL) with riboflavin

and ultraviolet-A light (UVA) technique has been used

to increase the corneal rigidity of keratoconic eyes and

prevent further progression of keratoconus.

We report a case of microbial keratitis which developed

following collagen crosslinking with riboflavin and UVA

for the treatment of keratoconus

20 year old female was referred to the Cornea Department

of MM Joshi eye institute in March 2013 for treatment of

Progressive keratoconus.

She was intolerant for contact lens wear.

OD OS

BSCVA 6/18, N8 6/9, N6

Manifest Refraction

-4DS -5DC@30º -1DS -1DC@ 130º

Anterior segment

Severe keratoconus

Mild keratoconus

IOP (mmHg) 12 14

Pachymetry 414µ 495µ

Kf 49.01@ 28º 45.25@ 167º

Ks 53.35@ 118º 45.81@ 77º

The patient was scheduled for CXL with riboflavin–UVA light in the right eye. The risk and potential complications of the surgery were fully explained to the patient.

Standard surgical procedure with sterile techniques with topical

anesthesia was performed.

Epithelium was removed by 20% alcohol-assisted method in the

central 8mm area followed by instillation of hypotonic riboflavin 0.1%

(K-link) solution eye drop once every 3 minutes for 30 minutes.

This was followed by UV irradiation for 25 minutes to the central 8mm

of cornea. Riboflavin 0.1% solution eye drops were instilled once

every 5 minutes for 25 minutes.

Bandage contact lens was used for dressing the cornea.

Patient was started on gatifloxacin 0.5% ophthalmic solution 6 times a

day, homatropine eye drops 2 times a day and Carboxymethylcellulose

sodium eye drops 6 times a day.

At the first follow-up visit , 2 days after surgery, patient complained

of pain, redness, photophobia and decreased vision in operated eye

White nodular infiltrates

Hypopyon

Stromal infiltrates

Ciliary congestion

Immediate management started with scraping the corneal stromal infiltrates with 15No. BP blade and sending the samples for Gram stain;Blood agar and thioglycolate broth for bacterial culture.

Smears revealed no micro-organisms

Satellite lesions

Hourly fortified Vancomycin (50mg/ml) , fortified Amikacin (20mg/ml) were started on the same day along with atropine sulphate eye drops twice daily.

Cultures were subsequently (after 48hours of incubation) positive for Staphylococcal epidermidis

On 4th Post-operative day ocular inflammation and corneal infiltrates had regressed.

Topical antibiotic agents were reduced to 4 times a day for 2 more weeks. Topical flourometholone 0.10% (FML) 3 times a day was added to the antibiotic regimen.

15days after CXL, an eye examination revealed moderate leucomas surrounded by stromal haze in the upper and lower central cornea.

Topical flourometholone was continued twice a day for 1 additional month.

POST 15DAYS

1 MONTH after treatment, the UCVA in the right eye was 6/60 and

BSCVA was 6/18, manifest refraction -4.50DS -2.50DC@ 30º

Slit-lamp evaluation shows a central leucomatous opacity and the central

corneal thickness was 381µm

POST 30DAYS

Discussion Conventional C3R requires epithelial removal for surgery and

epithelial defect takes 2-4 days to heal completely.

Compromised epithelium predisposes to bacterial keratitis,

hence epi-on C3R may lower the risk of same.

Coagulase-negative staphylococci, including S epidermidis, are

usually present in normal ocular flora.

These microorganisms are very common etiologic agents of bacterial

keratitis and usually cause opportunistic infection when the

epithelium is compromised.

Use of bandage soft contact lens could be a risk factor since it can

harbour micro-organisms.

Corneal scraping to obtain enough material for detailed

microbiological evaluation is very much emphasized in

order to detect and expedite the treatment.

This case report emphasizes the importance of conducting

collagen crosslinking procedure under sterile precautions.

Informed consent should include occurrence of microbial

keratitis and the related outcomes

Postoperative counselling to report any early signs of

microbial keratitis is a must.

Conclusion