The eye as a window to a rare disease: ectopia lentis and homocystinuria, a Pakistani perspective.

Non-traumatic ectopia lentis has been associated with genetic diseases in a European population; however, no data are present in regards to this in a Pakistani demographic. In third world countries such as Pakistan, due to the lack of screening tests, this disease has the potential to remain undiagnosed till a later age, at which point the eye through the finding of ectopia lentis has potential to lead to the right diagnosis. Our purpose was to investigate Pakistani patients presenting with ectopia lentis who have underlying homocystinuria and establish a relationship between the two. Additionally, we elicited various systemic and ophthalmic features in these settings. Ten Pakistani patients presenting with decreased vision and ectopia lentis with concomitant homocystinuria were included in the study. Assessment of systemic and ophthalmic features was performed. All patients presented with visual deterioration. All 20 (100 %) eyes had ectopia lentis, of which, 15 (75 %) eyes had inferior subluxation, whereas five (25 %) eyes had anterior subluxation of the crystalline lens. Ectopia lentis and homocystinuria appear to have a strong correlation in Pakistani population. Ectopia lentis has the potential to serve as an important clue to its diagnosis, which may in turn lead to decreased morbidity if diagnosed in a timely fashion.