Diabetic retinopathy screening can sometimes unveil other conditions, such as uveal melanoma. A study published in Retina shows that these routine screenings can help provide earlier detection, and treatment, of the common intraocular malignancy, reducing 5-year mortality rates.
Roughly 23% of patients with advanced uveal melanoma report that their tumor was missed on initial screening, despite presenting with symptoms. To address this, researchers investigated how routine diabetic retinopathy screening might promote early detection and treatment.
A retrospective, case-control study reviewed 132 patients from the United Kingdom with uveal melanoma, and660 controls. Uveal melanoma diagnosis was established via either clinical malignancy signs — thickness greater than 2 mm, orange pigment, serous retinal detachment, or documented growth — or biopsy.
The majority of patients were male (444 and 96 in the control and screening groups, respectively), and age at detection of uveal melanoma was higher in the screening group than in the control group (mean, 67.5 years; range, 27-88 years vs mean, 62.8 years; range 22 years to 92 years). Significant differences in systemic comorbidities existed between both groups, including higher rates of hypertension, ischemic heart disease, hypercholesterolemia, and concurrent systemic malignancies among screening group patients. Additionally, 6% of the patients in this group had diabetes.
Visual acuity was slightly better and initial tumor dimensions were smaller among screening group patients (11.1 mm vs 12.5 mm diameter and 3.4 mm vs 4.3 mm thickness). Ruthenium-106 plaque radiotherapy was the primary treatment for nearly half of all patients in this group (47% vs 31% in the control group; P =.001). Patients in the control group had higher rates of enucleation and transscleral resection (32% vs 23% and 11% vs 0%; P =.05 and <.001, respectively), and poorer visual outcomes due to a higher rate of enucleations.
Within the screening group, 69 and 22 patients were available for 5- and 10-year follow-ups, respectively. Although screening patients presented with higher rates of comorbidities, a slightly lower 5-year, all-cause mortality rate was noted (17% vs 20%). Metastatic mortality was noticeably lower in the screening group (8% vs 16%).
Cox proportional hazard regression indicated that patients in the screening group had half the risk for death from metastatic mortality (hazard ratio [HR], 0.49; P =.03), decreasing slightly when adjusted for age at diagnosis. A regression analysis focused on competing risks further confirmed these findings (HR, 0.41; P =.003).
Study limitations include potential lead time and length time bias.
“Earlier detection and therefore treatment of malignant uveal melanoma may influence metastatic risk and survival by enabling treatment of these lesions at a lower risk stage,” according to the researchers. “The detection of tumors at an earlier stage is therefore the only modality at present of treating the disease before higher risk factors for metastatic disease develop.”
Hussain R, Czanner G, Taktak A, Damato B, Praidou A, Heimann H. Mortality of patients with uveal melanoma detected by diabetic retinopathy screening. Retina. 2020;40(11):2198-2206.