Efficacy of sub-Tenon's capsule injection of triamcinolone acetonide for refractory diabetic macular edema after vitrectomy

Management of Cystoid Macular Edema After Vitrectomy for Proliferative Vitreoretinopathy

BACKGROUND AND OBJECTIVE

To assess therapies for cystoid macular edema (CME) following pars plana vitrectomy for proliferative vitreoretinopathy (PVR).

PATIENTS AND METHODS

Retrospective analysis of 42 eyes developing CME after PVR surgery. Treatments included topical therapy, sub-Tenon's triamcinolone acetonide (STTA), intravitreal bevacizumab and combinations thereof. Best-corrected visual acuity (BCVA) as well as central subfield thickness (CST) were tracked.

RESULTS

Mean Snellen BCVA improved from 20/598 to 20/297 (logMAR change -0.21; confidence interval [CI], -0.39 to -0.03; P = .03). Mean CST improved from 448 µm to 260 µm (CI, -248.70 to -126.06; P < 0.01). There was no difference in efficacy between treatment subgroups (analysis of variance, P = 0.16, 0.43), but STTA yielded statistically significant improvement in both categories (CI, -0.79 to -0.11; P = 0.01; and CI, -333.74 to 166.51; P < .01).

CONCLUSIONS

Treatment of CME following PVR surgery is possible with a variety of different options. STTA appears to yield anatomical and visual improvement. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:436-443.].

Comparison of vitrectomized with nonvitrectomized eyes after subtenon injection of triamcinolone acetonide to treat diabetic macular edema: Retrospective comparative Analysis of an interventional case series

PURPOSE

Triamcinolone acetonide (TA) is an alternative option for diabetic macular edema thanks to its cost-benefit ratio and unique delivery route. We performed this study to compare vitrectomized with nonvitrectomized eyes treated with subtenon TA injection for diabetic macular edema.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of patients who had undergone subtenon TA injection for diabetic macular edema treatment. The patients were divided into two groups: Vitrectomized and nonvitrectomized. Visual acuity and central subfield macular thickness (CSMT) were analyzed before injection, at 1 and 3 months after injection.

RESULTS

Visual acuity in vitrectomized group improved significantly at 1 month (P = 0.002), but this improvement regressed after 3 months. In the nonvitrectomized group, visual acuity did not improve significantly after 1 month, but it did after 3 months (P = 0.019). The CSMT decreased significantly in both groups at 1 and 3 months (P < 0.001). There were no significant differences between the groups at either 1 or 3 months with regard to either visual improvement or change in CSMT.

CONCLUSION

Subtenon TA injection could be an alternative treatment option for diabetic macular edema, both in vitrectomized and in nonvitrectomized eyes. TA seems to take effect earlier and decay faster in vitrectomized eyes.

Intravitreal pharmacokinetics after posterior subtenon triamcinolone acetonide injection in vitrectomized rabbit eyes

PURPOSE

To investigate the intraocular pharmacokinetics of triamcinolone acetonide (TA) injected into the posterior subtenon of vitrectomized rabbit eyes.

METHODS

Vitrectomy was performed on the right eyes of 35 rabbits. Triamcinolone acetonide (40 mg/mL) was injected into the posterior subtenon space of both eyes. Five rabbits each were killed at days 1, 3, 7, 14, 28, 56, and 84. Both eyes were enucleated. The vitreous was isolated, and TA concentration was measured.

RESULTS

In vitrectomized eyes, the intravitreal concentrations of TA were 1763, 822.9, 321.5, 113.3, 35.5, 14.4, and 6.7 ng/mL, respectively, at the time points indicated above; the concentrations in nonvitrectomized eyes were 397.8, 360.4, 154.4, 48.5, 30.7, 15.2, and 8.0 ng/mL, respectively. Triamcinolone acetonide concentrations were significantly higher in the vitrectomized eyes at days 1, 3, 7, and 14. The terminal half-life of intravitreal TA was 23.3 days in the vitrectomized eyes and 28.9 days in the nonvitrectomized eyes.

CONCLUSION

Intravitreal absorption and excretion of TA in the posterior subtenon space are increased after vitrectomy. Although the terminal half-life of TA was shorter, higher early concentration and similar effective duration were achieved in the vitrectomized eyes.

Inflammation and macular oedema after pars plana vitrectomy

Cystoid macular oedema (CMO) is a major cause of reduced vision following intraocular surgery. Although the aetiology of CMO is not completely clarified, intraocular inflammation is known to play a major role in its development. The macula may develop cytotoxic oedema when the primary lesion and fluid accumulation occur in the parenchymatous cells (intracellular oedema) or vasogenic oedema when the primary defect occurs in the blood-retinal barrier and leads to extracellular fluid accumulation (extracellular oedema). We report on the mechanisms of CMO formation after pars plana vitrectomy and associated surgical procedures and discuss possible therapeutic approaches.

Steroid eye drop treatment (difluprednate ophthalmic emulsion) is effective in reducing refractory diabetic macular edema

PURPOSE

To evaluate the efficacy of treatment of refractory diabetic macular edema (DME) after vitrectomy with difluprednate ophthalmic emulsion 0.05% (Durezol(TM)), and to compare this treatment with sub-Tenon's injection of triamcinolone (STTA).

METHODS

This study enrolled patients with refractory diabetic macular edema that persisted despite pars plana vitrectomy in our clinic. In all subjects, more than 3 months had passed since prior treatment. Eleven eyes in ten subjects were treated with STTA (STTA group), and 11 eyes in seven subjects were treated with difluprednate ophthalmic emulsion 0.05% (Durezol(TM), Sirion Therapeutics Inc., USA) 4 times daily for the first month and then twice daily for 2 months (eye drop group).

RESULTS

In the eye drop group, mean VA (+/- SD) was 0.67 +/- 0.35 logMAR and mean retinal thickness was 500.6 +/- 207.7 mum at baseline. After 3 months of treatment, mean VA was 0.67 +/- 0.29 and mean retinal thickness had decreased to 341.2 +/- 194.8 mum. The mean minimum value of RT during the treatment period was 300.6 +/- 123.2 mum, and significantly lower than that at baseline (Mann-Whitney U test: P = 0.003). In the STTA group, mean VA (+/- SD) was 0.67 +/- 0.35 logMAR, and mean retinal thickness was 543.3 +/- 132.6 mum at baseline. After 3 months of treatment, mean VA was 0.49 +/- 0.67, and mean retinal thickness had decreased to 378.6 +/- 135 mum. The mean minimum value of RT during the treatment period was 349.9 +/- 113.8 mum, and significantly lower than at baseline (Mann-Whitney U test: P = 0.003). The rate of effective improvement in RT did not differ between the eye drop group (73%) and STTA group (84%) (Fisher's exact test: P = 1).

CONCLUSIONS

Comparable improvements of retinal thickness were observed in the STTA and eye drop groups. Instillation of difluprednate ophthalmic emulsion 0.05% is a safe and effective treatment that does not require surgical intervention and does not produce severe side-effects.