October 14, 2020
An 82 year-old man was referred to the retina service for loss of the vision in the left eye for several months. The patient reported he had fallen 9 months ago, and he lost vision in the left eye around that time. He had a past medical history of hypertension, diabetes, hypothyroidism, and coronary artery disease with prior coronary artery bypass graft. His medications included metformin, enalapril, synthroid, atorvastatin and baby aspirin.
On presentation, his best corrected visual acuity was 20/25 OD and hand motion OS.
Anterior segment examination was remarkable for PCIOL OU which were clear and well positioned in the capsular bags. IOP was 19 OD and 11 OS.
The patient’s pupils were dilated. While the patient was dilating we acquired some imaging:
Here is the SD-OCT od the right and left eyes:
Here is another cut through the macula of the left eye:
The OCT showed subretinal fluid in the left eye and elevation of the retina consistent with retinal detachment.
The right eye had macular drusen and RPE changes indicative of macular degeneration.
This was not a case of a typical rhegmatogenous retinal detachment, however. Bscan of the left eye revealed a surprising finding.
Dilated funduscopic examination of the right eye was remarkable for drusen. The right retina was flat for 360 degrees. The left eye DFE revealed the following. Here is a widefield photo:
The patient has a choroidal melanoma with a secondary exudative retinal detachment.
Measurement of the mass on bscan revealed it to be 9.6mm in apical height and 10.2mm in width at its widest points.
The patient was referred to an ocular oncologist, who evaluated the patient 4 days later.
The patient is scheduled to receive plaque radiotherapy next week for the melanoma.
Choroidal melanoma is the most common primary intraocular malignancy in adults. It typically occurs unilaterally. Small melanomas are generally asymptomatic, however larger melanomas can cause visual symptoms. Patients may complain of scotoma in the vision, metamorphopsia, or photopsias.
The diagnosis of choroidal melanoma is made clinically based on the characteristics of the lesion. Lesions may appear gray or dark. They may have associated orange pigment (lipofuscin) which is indicative of high metabolic activity. There may also be associated subretinal fluid. Melanomas may arise from choroidal nevii. Shields et al published a useful mnemonic to help determine clinical features that should raise suspicion for transformation of a choroidal nevus to a melanoma. “To find small ocular melanoma using helpful hints daily.”
T: Thickness greater than 2mm
F: Fluid (subretinal fluid)
M: Margin within 3mm of optic disc
UH: Ultrasonographic hollowness
H: absence of halo
D: absence of drusen
Ultrasound is an important tool in the diagnosis of melanoma. Ultrasound is utilized to measure the lesion, evaluate internal reflectivity, and to evaluate for the presence of subretinal fluid. Size of the lesion is important in determining treatment. The Collaborative Ocular Melanoma Study (COMS) classifies melanomas into three groups (small, medium and large) based on measurement of the lesion’s apical height and basal dimension. Based on the study, our patient’s melanoma falls into the medium category.
Stay tuned next month for a follow up on how our patient is doing after his plaque radiotherapy treatment.