Severe Visual Field Defects Associated With Blood Vessel Absence

Visual field defects are worse in patients with optic disc melanocytomas (ODMs) and incomplete blood vessel network (BVN) formation vs those with complete BVN formation, according to a case series published in British Journal of Ophthalmology. Visual field defect is more closely associated with the area of BVN absence rather than the tumor area, the study reports.

Researchers in South Korea conducted a retrospective review of medical records and image studies of 32 eyes of 32 patients with ODMs. All patients were diagnosed with ODM in the Department of Ophthalmology, Yonsei University College of Medicine, between May 2018 and September 2020. The investigators used optical coherence tomography angiography (OCT-A) to evaluate the association between visual field defects and BVN formation. Eyes were separated into 2 groups based on complete and incomplete BVN formations.

The median age at diagnosis was 51.5 years (range: 18-65 years) and 18 (56%) of the patients were women. OCT-A showed incomplete BVN formation in 16 of 32 ODMs. The location of BVN absence corresponded to the location of hypofluorescence angiography (FA) in 12 (75%) as well as the location of visual field defect in 13 (81%) ODMs in the incomplete BVN group, the researchers note.

Perimetric indices were notably worse in the incomplete BVN group compared with the complete BVN group. In the area of BVN absence, linear regression of mean deviation (MD) and visual field index (VFI) were statistically significant (P =.01 and P =.003). In the tumour area, linear regression of MD and VFI were not statistically significant (both P =.09) in the incomplete BVN group.

Limitations of the case series include small study population, retrospective design and insufficient number of follow-up data. Additionally, the investigators say that certain visual field defects cannot be fully explained by the location of BVN absence or tumour. 

“We believe that the results of this study would contribute to the knowledge regarding the pathogenesis of ODMs and may lead to the development of new treatment strategies for patients with ODM with severe visual field defect,” according to the researchers.  

Disclosure: This research was supported by the Basic Science Research Program. Please see the original reference for a full list of disclosures. 

Reference

Kwak JJ, Lee DH, Lee SC, Lee CS. Evaluation of blood vessel network formation and visual field defect in optic disc melanocytoma.Br J Ophthalmol. Published online September 27, 2021. doi:10.1136/bjophthalmol-2021-319630