Characterization of Autofluorescense Emitted From Pinguecula and Pterygium: - A Statistical Report of an Ophthalmic Survey in Shanxi, China

Abstract

Purpose: : To investigate autofluorescence in eyes with pinguecula and pterygium by ultraviolet fluorescence photography (UVFP).

Methods: : One experienced observer diagnosed 444 eyes of 222 farmers aged ≥50yrs with pinguecula or pterygium if conjunctival tissue was hyperplasic or covered the periphery of the corneal surface, respectively. And graded the lesions using UVFP ultraviolet excitation with peak wavelength of 365 nm as follows- pinguecula: 0 (asymptomatic); 1 (small); 2 (medium); 3 (large); and pterygium: 0 (asymptomatic); 1 (extending <1/3 of the cornea radius), 2 (extending 1/3-2/3 of the cornea radius), 3 (extending >2/3 of the cornea radius). Fluorescence intensity was rated from slit images as follows: 0 (no brightness); 1 (a little, 2 medium); 3 (obvious). There were no exclusion criteria. For statistical analysis, Χ²-test, or logistic regression adjusting for age were applied.

Results: : Overall prevalence of pinguecula and pterygium was 67.9% and 29.7%, respectively. Complication of both together was found in 21.2% of all eyes. Fluorescence was detected in 70.0% of all eyes, 61.3% of normal eyes, 82.5% of eyes with only pinguecula, 55.3% of eyes with only pterygium, and 58.5% of complication eyes. Fluorescence intensity was positively correlated with pinguecula grade (p=0.0001), and negatively correlated with pterygium grade (p=0.0248) and age (p=0.0004).

Conclusions: : Fluorescence intensity was strongly associated with size of pinguecula and pterygium lesions. UVFP may provide important information to help solve the pathogenesis or understand the mechanisms of pinguecula and pterygium.

Keywords: pterygium • conjunctiva