Late Hyperbaric Oxygen Treatment of Cilioretinal Artery Occlusion With Nonischemic Central Retinal Vein Occlusion Secondary to High Altitude Gokcen Gokce, 1 Suleyman Metin, 2 Uzeyir Erdem, 3 Gungor Sobaci, 3 Ali Hakan Durukan, 3 Halil Huseyin Cagatay, 4 and Metin Ekinci 4 Abstract Gokce, Gokcen, Suleyman Metin, Uzeyir Erdem, Gungor Sobaci, Ali Hakan Durukan, Halil Huseyin Cagatay, and Metin Ekinci. Late hyperbaric oxygen treatment of cilioretinal artery occlusion with nonischemic central retinal vein occlusion secondary to high altitude. High Alt Med Biol. 15:84–88, 2014.—Aim: To report a case of cilioretinal artery occlusion (CRAO) with central retinal vein occlusion (CRVO) after a journey to high altitude region and the use of late period hyperbaric oxygen (HBO) therapy successfully. Case Report: A previously healthy 48-year-old lowlander woman was admitted to our department for sudden blurred vision in her right eye started at 2 weeks prior to examination. The patient had a history of 1-month exposure to high altitude that finished a day before the onset of her complaints. The best corrected visual acuity (BCVA) was 10/20 in the right eye (RE) and 10/10 in the left eye. Fundus examination of the RE revealed whitening of the retina along the distribution of cilioretinal artery, sparing fovea, flame-shaped hemorrhages, and roth spots with minimally dilated and tortuous retinal veins. Visual field analysis revealed centrocecal scotoma. The patient was treated by a daily session of 2 h of HBO at 2.5 atmosphere absolute for 11 days. BCVA rised to a level of 20/20 for the RE and the scotomas were disappeared immediately after using of the HBO treatment. Conclusion: CRVO related CRAO should be regarded as a rare complication of exposure to high altitude and HBO seems to be the treatment of choice of high altitude related co-occurence of CRVO and CRAO in the late period. Key Words: central retinal vein occlusion, cilioretinal artery occlusion, high altitude, hyperbaric oxygen therapy. Introduction T he frequency of retinal vein occlusion (RVO), which is the most common retinal vascular disease after diabetic retinopathy, ranges from 2/1000 to 8/1000 in popu- lation studies, and this frequency is expected to increase with life expectancy (Bearelly et al., 2004). Exposure to high al- titude has been described as a risk factor for various retinal changes, including RVOs (Arora et al., 2011; Gupta et al., 2011; Hutton et al., 2012). The higher ascents and the longer durations at high altitudes are more associated with retinal vaso-occlusive events (Barthelmes et al., 2011). Cilioretinal artery usually originates from short posterior ciliary arteries and it has a critical role for blood supply of the macular area (Hayreh et al., 2008). Coexistance of central retinal vein occlusion (CRVO) and cilioretinal artery occlusion (CRAO) is a rare disorder that can be easily overlooked. In this report we present a case of CRAO with nonischemic CRVO in a 48-year-old woman after a journey to high alti- tude region and the use of late period hyperbaric oxygen (HBO) therapy successfully. Case Report A previously healthy 48-year-old lowlander (Bayrakli, Izmir, Turkey. 25 meters/82 ft above mean sea level) woman was admitted to our department for sudden blurred vision in her right eye, started at 2 weeks prior to our examination. The 1 Department of Ophthalmology, Sarikamis Military Hospital, Kars, Turkey. 2 Department of Aerospace and Hyperbaric Medicine, Gulhane Military Medical Academy, Eskisehir, Turkey. 3 Department of Ophthalmology, Gulhane Military Medical Academy, Ankara, Turkey. 4 Department of Ophthalmology, Kafkas University, Kars, Turkey. HIGH ALTITUDE MEDICINE & BIOLOGY Volume 15, Number 1, 2014 ª Mary Ann Liebert, Inc. DOI: 10.1089/ham.2013.1086 84