Israel Medical Association Journal

Uveal melanoma (UM) affects approximately six individuals per million per year in the United States, with similar rates in Mediterranean countries. Although it appears to have a low prevalence, it is the most common primary intraocular malignancy in adults. Clinically, it presents in most patients as a painless loss or distortion of vision, although it may also be accidentally discovered at routine ophthalmic examination. Associated risk factors include fair skin tone, light eye color, presence of a choroidal nevus, oculodermal melanocytosis (nevus of ota), dysplastic nevus syndrome, and germline BRCA-associated protein 1 mutations (BAP1 mutations) [1].

The prevalence of choroidal nevi associated with choroidal neovascular membrane (CNV) is estimated to range between 0.58% and 8.6% [1]. The pathogenesis of CNV is not completely understood. Researchers have suggested that damage caused to the choroid capillaries above the nevi affects the overlying retinal pigment epithelium and triggers production of angiogenic factors that, in turn, cause the development of CNV [2,3]. Hypoxia and inflammation may be involved in the process. Data have been inconsistent with both theories [4].

Objectives: To evaluate the long-term efficacy and safety of an intravitreal injection of triamcinolone acetonide for clinically significant diabetic macular edema.

Methods: In a retrospective case series 31 diabetic patients with persistent, recurrent or diffuse clinically significant diabetic macular edema received a single 4 mg (0.1 ml) intravitreal triamcinolone acetonide injection and were followed for at least 6 months. The main outcome measures evaluated were classified as primary: visual acuity and central macular thickness, and secondary: intraocular pressure and cataract progression. Statistical analyses included Student’s t-test, chi-square test and the McNamar test.

Results: Best visual acuity results were observed 2.6 ± 2.4 months post-injection. At that time the mean foveal thickness had decreased by 37% from a baseline of 455 ± 100 to 288 ± 99 µ (P < 0.001) and the mean visual acuity improved from 6/42 to 6/23 (P < 0.001). Final mean visual acuity after an average of 10 ± 1.8 months follow-up (range 6–13 months) was identical to the baseline, although mean foveal thickness was still significantly lower than the initial thickness (368 ± 166 vs. 455 ± 100 µ, P < 0.01). Statistical analysis did not identify any pre-injection prognostic factors for improved visual acuity. The only complications that occurred were elevated intraocular pressure in 42% of patients and cataract progression in 21%. There was no endophthalmitis.

Conclusions: Intravitreal injection of triamcinolone acetonide for clinically significant diabetic macular edema is effective in reducing foveal thickness and improving visual acuity in the short term. Longer follow-up revealed that visual acuity returned to pre-injection values, even though a modest decrease in the foveal thickness persisted. Further studies are needed to evaluate the long-term efficacy in conjunction with laser photocoagulation treatment.