Some observations on the macula of pesticide workers

To study the retinal changes in occupationally exposed pesticide workers, 79 subjects exposed to an organophosphate, fenthion, and 18 exposed to an organochlorine pesticide DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane], were subjected to a detailed study, including history taking, physical examination and ophthalmic evaluation. Fluorescein angiography was performed in selected cases. Serum cholinesterase level in 22 workers and serum DDT residue in 17 workers of the respective groups were also estimated. Fifteen workers (19%), who were exposed to fenthion had macular changes (P less than 0.01). The macular lesions were characterized by perifoveal irregularity of pigmentation and areas of hypopigmentation of 1/8-1/3 disc diameter. Mean age of the subjects having macular involvement was 30.6 years and mean duration of exposure 7.9 years. The symptoms reported by them were diminution of vision (8), dislike for bright light, flash of light, black dots in front of the eyes (2 each) and visual blurring (1). Paracentral scotoma and constriction of peripheral field were present in three workers each. Fluorescein angiography suggested pigment epithelium defect. Other causes of macular involvement in these workers were excluded; a possible role of pesticides in the genesis of these macular changes is suggested.