Comparative study on the incidence and outcomes of pigmented versus non pigmented keratomycosis

PURPOSE: To determine the incidence, outcomes and establish factors determining visual prognosis of keratomycosis due to pigmented fungi in comparison with nonpigmented fungi. MATERIALS AND METHODS: All culture-proven cases of fungal keratitis from January 2006 to August 2008 were drawn from a computerized database and cases with adequate documentation were analyzed for predisposing factors, clinical characteristics, microbiology and treatment methods. Outcomes of keratitis due to pigmented and nonpigmented fungi were compared using t-test and χ(2) test. RESULTS: Of 373 cases of keratomycosis during the study period, pigmented fungi were etiological agents in 117 eyes (31.3%) and nonpigmented fungi in 256 eyes (68.7%). Eyes with nonpigmented keratitis had significantly larger ulcers (14.96 mm(2) ) and poorer vision (1.42 logMAR) at presentation compared to those with keratomycosis due to pigmented fungi (P=0.01). The characteristic macroscopic pigmentation was seen in only 14.5% in the pigmented keratitis group. Both groups responded favorably to medical therapy (78.1% vs. 69.1%) with scar formation (P=0.32) and showed a significant improvement in mean visual acuity compared with that at presentation (P<0.01). Visual improvement in terms of line gainers and losers in the subgroup of eyes that experienced healing was also similar. Location of the ulcer was the only factor that had significant predictive value for visual outcome (P=0.021). CONCLUSION: Incidence of keratomycosis due to pigmented fungi may be increasing as compared to previous data. These eyes have similar response to medical therapy and similar visual outcome compared to nonpigmented keratitis. Central ulcers have a poor visual outcome.