Vitreo-retinal disorders at high altitude in Nepal

Abstract

Introduction: Nepal has many mountains including the highest one in the world. People living in high altitude are often involved in climbing mountains. Objective: To explore the pattern of vitreo-retinal disorders at high altitude in Nepal. Materials and methods: Consecutive patients aged 40 years and older who presented at the micro-surgical eye camp at Lukla of Solukhumbu district (2,860 metres) were included. Detailed ocular and systemic histories and ocular examination including dilated fundus evaluation were done. Results: There were a total 81 patients with the mean age of 56.7 years (S.D 11.15). Females (51.9 %) outnumbered males. Sherpa comprised of 76.5 % followed by Rai (9.8 %). The main occupation was agriculture (51.9 %) followed by mountain trekking (28.4 %). Smokers comprised of 13.5 %. Hypertension was the predominant systemic problem (28 %). The best corrected visual acuity of 6/18 and better was found in 86.4 % of cases and less than 3/ 60 in 3.6 % of cases. Age-related macular degeneration (AMD) was found in 19.6 % of cases with a predominant mild AMD (16 %), hypertensive retinopathy in 12.2 %, with grade I hypertensive change in 8.6 %, retinal vein occlusion (RVO) in 7.1 % of cases and with a branch RVO in 4.9 %. Dilated and tortuous retinal vessels were present in 25.9 % of cases; out of this, 9.8 % of the cases had concurrent AMD and/or hypertensive retinopathy. Other retinal problems were macular hole (2.46 %), solar retinopathy (2.46 %) and choroidal tear (1.2 %). Conclusion: AMD, hypertensive retinopathy, and RVO are the main vitreo-retinal disorders besides the dilated and tortuous retinal vessels in people living at high altitude in Nepal.

The eye in extreme environments

“…Indeed, hypoxia‐induced changes in the eye are less evident as acclimatization progresses (Bosch et al., 2010). A survey of vitreoretinal disorders of Sherpas living at high altitude in Nepal reported that high altitude retinopathy without and with dry, age‐related macular degeneration accounted for 16 and 3.7% of vitreoretinal disorders, respectively, in a population of 81 patients (Thapa, Paudyal, Crandall, & Tabin, 2013). Solar retinopathy accounted for only 2.5% of the disorders.…”

“…Indeed, hypoxia-induced changes in the eye are less evident as acclimatization progresses(Bosch et al, 2010). A survey of vitreoretinal disorders of Sherpas living at high altitude in Nepal reported that high altitude retinopathy without and with dry, age-related macular degeneration accounted for 16 and 3.7% of vitreoretinal disorders, respectively, in a population of 81 patients(Thapa, Paudyal, Crandall, & Tabin, 2013). Solar retinopathy accounted for only 2.5% of the disorders.The frequent high-altitude-related changes of the retina are commonly known as high-altitude retinopathy and may be the result of a combined effect of systemic hypoxia and increased blood viscosity (Barthelmes et al, 2011; Wiedman & Tabin, 1999).…”