Recent studies have suggested that intravitreal triamcinolone acetonide may be a treatment option for diffuse diabetic macular oedema.1 Since the duration of the effect of an intravitreal application of triamcinolone acetonide lasts between 4 weeks and up to 9 months,2,3 the purpose of this study was to evaluate the effect of a repeated intravitreal injection of triamcinolone acetonide.
Case reports
The clinical interventional case series study included four patients with diffuse diabetic macular oedema who consecutively received a second intravitreal injection of about 20 mg triamcinolone acetonide 7.6 (SD 3.9) months (median, 6.7 months; range, 4.1–13.1 months) after the first injection, and for whom follow up was longer than 3 months. The second injection was carried out, since visual acuity had decreased again after an initial increase following the first intravitreal injection. Mean follow up after the second injection was 5.6 (SD 4.2) months (median 5.6 months; range 1–10.5 months). Mean age of the patients was 62.0 (5.0) years (range 56.8–67.8 years; median 61.7 years), refractive error ranged between a mean of −0.75 (SD 1.19) dioptres and +2.50 (1.38) dioptres. All patients were fully informed about the experimental character of the therapy and had signed an informed consent. The ethics committee of the university had approved the study. All patients received an intravitreal injection of about 20 mg triamcinolone acetonide in 0.2 ml Ringer’s solution as previously described in detail.4
After the first injection, visual acuity increased from 0.12 (SD 0.05) (range 0.08–0.20) to a maximum of 0.23 (SD 0.14) (range 0.10–0.40). Converting visual acuity measurements into the logarithm of the minimum angle of resolution (logMAR) showed a change in the minimum angle of resolution from 0.95 (SD 0.17) logMAR units to 0.71 (SD 0.29) logMAR units. After the second injection, visual acuity increased from 0.12 (SD 0.06) (range 0.08–0.20) to a mean maximal visual acuity of 0.18 (SD 0.06) (range 0.10–0.25). The minimum angle of resolution changed from 0.97 (SD 0.19) logMAR units to 0.77 (SD 0.17) logMAR units. All eyes increased in visual acuity. After the first injection, and after the second injection, respectively, intraocular pressure increased to values higher than 21 mm Hg in three eyes. For all of these eyes, intraocular pressure could be normalised by topical antiglaucomatous treatment.
Comment
The data of this study may suggest that the repeated intravitreal injection of about 20 mg of triamcinolone acetonide as treatment of diffuse diabetic macular oedema can be associated with a increase in visual acuity again in those patients who as “triamcinolone responders” showed an improvement in visual acuity after a preceding intravitreal injection of triamcinolone acetonide. It is in agreement with a previous study on repeated intravitreal injections of triamcinolone acetonide for exudative age related macular degeneration.5
Proprietary interest: none.
References
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