Central Retinal Artery Occlusion in Young Adults at High Altitude: Thin Air, High Stakes.

Rana, Vipin, Pradeep Kumar, Sandeepan Bandopadhyay, Vijay K. Sharma, Meenu Dangi, Dattakiran Joshi, Sanjay Kumar Mishra, Satyabrat Srikumar, and V.A. Arun. Central retinal artery occlusion in young adults at high altitude: thin air, high stakes. High Alt Med Biol. 00:000-000, 2024.-We present five cases of young security personnel who were posted at high altitude (HA) for a duration of at least 6 months and presented with a sudden decrease of vision in one eye. The diagnosis of central retinal artery occlusion (CRAO) was made in all patients. Fundus fluorescein angiography and optical coherence tomography of the macula supported the diagnosis. None of these cases had any preexisting comorbidities. Erythrocytosis was noticed in all patients, and two of them had hyperhomocysteinemia. Four out of five patients showed either middle cerebral artery or internal carotid artery (ICA) thrombosis on computed tomography angiography. The patients were managed by a team of ophthalmologist, hematologist, vascular surgeon, and neurologist. In cases of incomplete ICA occlusion, patients were managed surgically. However, in the case of complete ICA occlusion, management was conservative with antiplatelet drugs. This case series highlights HA-associated erythrocytosis and hyperhomocysteinemia as important risk factors for CRAO in young individuals stationed at HA.

Comparison of immediate versus deferred intravitreal Bevacizumab in macular oedema due to branch retinal vein occlusion: a pilot study.

PURPOSE: To compare visual and anatomical recovery of immediate versus deferred intravitreal Bevacizumab for the treatment of macular oedema secondary to branch retinal vein occlusion (BRVO). METHODS: In a pilot study, 40 treatment naïve patients of branch retinal vein occlusion with macular oedema and vision 6/12 or less presenting within one month of onset were randomised into 2 groups (20 each) to receive either immediate intravitreal Bevacizumab or deferred (after 3 months of observation). Outcome in terms of visual recovery and decrease in central macular thickness on the Optical Coherence Tomography (OCT) from pre-treatment level was analysed at 6 and 12 months from starting of treatment and compared between the two groups. RESULTS: The mean visual gain in the two groups early and delayed intervention was 0.38 log MARs and 0.15 log MAR units, respectively, and the superior vision gain in the early intervention group was statistically significant (p < 0.001). The difference in visual improvement between the two groups persisted till 1 year of follow-up. The early intervention group required fewer injections (2.6 ± 71 vs. 3.5 ± 0.51), and rescue laser treatment (15 vs. 25%) as compared to deferred group. Both groups showed significant decrease in central macular thickness (328 and 289 µ, respectively) from baseline thickness, but the difference between the two groups was not statistically significant (p = 0.45). CONCLUSIONS: Both early as well as deferred injection of Bevacizumab in macular oedema due to BRVO resulted in reduction of macular oedema and visual gain but immediate injection were associated with significantly greater visual gain with lesser number of injections fewer rescue laser treatment.