Melanocytoma Associated with Significant Structural and Vascular Alterations

Optic disc melanocytoma has a slight female predominance and typically occurs in middle age; however, it can still be seen in children and adolescents. Photo: JRami Aboumourad, OD. Click image to enlarge.  A rare type of tumor, optic disc melanocytoma (ODM), luckily isn’t malignant, although it can result in some degree of vision loss. Due to its rarer nature, the structural alterations that underlie the visual field defects patients may experience is still poorly understood. In a new study published in American Journal of Ophthalmology, Chinese researchers used OCT and OCT angiography (OCT-A) to retrospectively analyze potential structural and vascular changes seen with the condition.Included in the investigation were 34 eyes diagnosed with ODM and 15 eyes with juxtapapillary choroidal melanoma who were referred to Beijing Tongren Hospital. After reviewing the imaging, it was found that ODM was characterized by hyperreflectivity on the anterior surface and dense posterior optic shadowing. Peripapillary hyperreflective ovoid mass-like structures (PHOMS) were seen in a majority (88.2%) of affected eyes vs. 17.1% in unaffected fellow eyes. Epiretinal membrane was present in 20.6%, while the fellow eyes also had a lower rate (2.9%). OCT-A determined that there was reduced optic nerve head vessel density in eyes with ODM, mostly affecting the radial peripapillary capillary (RPC) layer on the tumor surface—resulting in 14 cases of localized RPC atrophy and patchy non-perfusion areas on en face imaging. Non-perfusion in eyes was associated with worse visual acuity, larger tumor basal diameter and tumor thickness. However, ODM did not exhibit an intrinsic tumor vasculature, which is contrary to the disorganized vascular network observed in the 15 cases of juxtapapillary choroidal melanoma. For more on melanocytoma, see this recent  Retina Quiz column. The authors of the study explain in their paper that their findings are additive to the hallmark features of melanocytoma, which are a hyperreflective anterior surface with posterior shadowing. Also, because the flow signals were confined to the overlying retinal ODM layers, they add that this supports the idea that optic disc melanocytoma is benign with limited angiogenesis.ODM can cause instances of subretinal fluid, vitreous seeds, retinal edema and more. Interestingly, the authors highlight that the incidence of epiretinal membrane seems to be higher in East-Asian populations, as it occurred in 20.6% of this cohort, but another case series with 15 patients found no evidence of such.PHOMS, the authors explain, is a newly found anatomic marker of ODM. Since almost all patients presented with this manifestation, the authors suggest that “PHOMS may serve as an early marker of ODM-related optic nerve compression, leading to the possibility of progressive optic nerve fiber damage.”When dealing with patients, the authors relay that “these findings highlight the importance of OCT/OCT-A imaging in understanding the pathophysiology of ODM and suggest that PHOMS and non-perfusion areas can serve as imaging biomarkers for disease monitoring and prognosis.”Click here for the journal source. Zhang R, Dong J, Li Y, et al. OCT and OCTA features of optic disc melanocytoma: PHOMS, perfusion deficits, and association with vision loss. Am J Ophthalmol. August 20, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.