key: cord-0864989-ja836ybs authors: Panigrahi, Pradeep K title: Comment on: Cilioretinal artery occlusion with paracentral acute middle maculopathy associated with COVID-19 date: 2021-10-03 journal: Indian J Ophthalmol DOI: 10.4103/ijo.ijo_1684_21 sha: 861de2006d8c5ab0c6527ae6e21df6c71f66e21f doc_id: 864989 cord_uid: ja836ybs nan Dear Editor, I went through the article titled "Cilioretinal artery occlusion with paracentral acute middle maculopathy associated with COVID-19" by Cemal O et al. [1] The authors have described a rare case of isolated cilioretinal artery occlusion (CILRAO) due to presumed COVID-19 infection. I have a few observations. The authors have mentioned that there are no reports of isolated CILRAO in young patients in the absence of significant medical history and systemic disease in the literature. Aktas S et al. [2] reported an isolated case of CILRAO in a 26-year-old healthy male who was treated with hyperbaric oxygen therapy. The patient presented with visual acuity of 20/200 in the left eye and was diagnosed with CILRAO in the left eye. Systemic examination and laboratory investigations were normal in the patient. The patient was treated with 5 sessions of hyperbaric oxygen. Two weeks following initial presentation, his vision had improved to 20/20 in left eye. Ugradar S et al. [3] reported isolated CILRAO in a 21-year-old healthy male with no previous medical history. As in the present case, systemic examination and laboratory markers for inflammation and pro-thrombotic states were normal. However, there was a history of patient smoking cannabis prior to vision loss on that day. Mechanisms underlying cannabis use and its effect on vascular pathology have not been clearly established. It seems the association in this case between CILRAO and cannabis use was more coincidental rather than causal. It will be interesting to know if there was any history of cannabis use in the present case. [1] Raised serum homocysteine level is an independent risk factor associated with retinal vascular occlusive disease. [4] Its assessment is important in the investigation, management, and follow-up of cases of retinal vascular occlusive diseases. In the present case, the authors have mentioned that laboratory tests for thrombophilia parameters and autoimmune antibodies were normal. There is no mention of whether serum homocysteine levels were normal. It would be good to highlight whether serum homocysteine was normal in this particular case as it can be independently associated with retinal vascular occlusion. Nil. Cilioretinal artery occlusion with paracentral acute middle maculopathy associated with COVID-19 Idiopathic isolated cilioretinal artery occlusion treated with hyperbaric oxygen therapy Unilateral cilioretinal artery occlusion following cannabis use Raised plasma homocysteine as a risk factor for retinal vascular occlusive disease