Trends in contact lens-associated microbial keratitis in Southern India.

OBJECTIVE: To review the microbiologic profile, clinical course, treatment, and outcome in patients with contact lens-associated microbial keratitis in the setting of a tertiary eye care center in a developing country in the Tropics.

DESIGN: Retrospective noncomparative case series selected from an ongoing prospective series.

PARTICIPANTS: Twenty-eight subjects examined in the contact lens clinic of L. V. Prasad Eye Institute, Hyderabad, south India, between February 1991 and September 2000, who presented with corneal stromal infiltrate on slit-lamp examination, were included in the study.

INTERVENTION: All patients underwent standard diagnostic microbiologic evaluation and smear and culture-guided topical antimicrobial therapy. Penetrating keratoplasty was performed in some patients.

MAIN OUTCOME MEASURES: Culture results and clinical response to antimicrobial therapy.

RESULTS: Twenty eight (0.11%) of 23,889 contact lens-wearing patients presented with laboratory-proven infectious keratitis; this constituted 0.56% of 4967 corneal ulcer patients seen during the same period. Most (15/28) of the patients wore soft contact lenses on a daily basis. Rigid gas-permeable lenses were worn by six patients, therapeutic bandage contact lenses by four, and Silsoft lenses by four. Laboratory results showed bacterial infections in 25 patients (89.2%); Pseudomonas was the most common organism (13/25; 52%). Acanthamoeba, herpes simplex virus, and Aspergillus niger were isolated in one case each. Laboratory-based medical therapy led to the healing of ulcers in 24 (85.7%) of 28 patients, whereas 4 patients required penetrating keratoplasty. Most of the organisms were sensitive to antibiotics.

CONCLUSIONS: Contact lens-associated microbial keratitis is rare in southern India. Soft contact lens wear is the most common risk factor; Pseudomonas keratitis is the predominant causative agent. Fungal, viral, and Acanthamoeba keratitis are rare. The offending bacteria are usually sensitive to antibiotics, and the treatment outcome with medical therapy is good.