A case report of branch retinal artery occlusion in a teenager due to hyperhomocysteinaemia; the interplay of genetic and nutritional defects

Clare Shute

doi:10.1186/s12886-018-0859-2

Abstract

BackgroundRetinal vascular occlusions are uncommon in young people and require more in-depth investigation into the cause. Studies have revealed that a high level of circulating homocysteine poses a risk for retinal vaso-occlusive events across a wide age range. This case report reflects on how the interplay of genetic mutation and vitamin deficiency can cause a pathological level of homocysteine with resultant branch retinal artery occlusion in a young patient.Case presentationA 16-year-old boy presented to eye casualty with acute inferior visual field loss in the left eye. Visual acuity remained normal at 6/6 each eye and the event was painless. Initial assessment, and retinal photography revealed a left superior hemi-field branch retinal artery occlusion with macular sparing. Given the patient’s age, extensive investigation into the cause was carried out. Positive findings were of an elevated level of homocysteine as a result of vitamin B12 and folic acid deficiency as well as a genetic mutation in the MTHFR gene (encoding MTHFR enzyme which is vital in normal homocysteine metabolism). Vitamin B12 and folic acid were replaced which in turn normalized the patient’s homocysteine levels. At two months, the patient’s visual fields had also improved, and no further vascular event had occurred.ConclusionsThis case report has highlighted the link between hyperhomocysteinaemia and retinal artery occlusion. However, despite vitamin replacement being shown to normalize homocysteine levels, no evidence exists to date as to whether this will reduce the risk of further retinal vascular occlusion.

Highlights

Retinal vascular occlusions are uncommon in young people and require more in-depth investigation into the cause
This case report has highlighted the link between hyperhomocysteinaemia and retinal artery occlusion
Despite vitamin replacement being shown to normalize homocysteine levels, no evidence exists to date as to whether this will reduce the risk of further retinal vascular occlusion

Summary

Conclusions

Thorough but directed investigation revealed a number of potential causes for this patient’s retinal artery occlusion including migraine (known to cause vasospasm) and a bicuspid aortic valve (with the potential to generate emboli). Research is limited as to whether reducing homocysteine levels lowers the risk of further retinal vascular occlusive events This represents a potential area for future research and could guide treatment for patients like the one described in this case report. It is important for ophthalmologists to have knowledge of these conditions allowing for appropriate multidisciplinary team communication and correct ongoing management Funding This supplement and the meeting on which it was based were sponsored by Novartis (tracking number OPT17-C041). Availability of data and materials All data generated or analysed during this case report are included in this published article. About this supplement This article has been published as part of BMC Ophthalmology Volume 18 Supplement 1, 2018: The Novartis Ophthalmology Case Awards 2017. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations

Background

Findings

Discussion