Intravitreal and subtenon depot triamcinolone as treatment of retinitis pigmentosa associated cystoid macular edema

Efficacy of additional topical betamethasone in persistent cystoid macular oedema after carbonic anhydrase inhibitor treatments in retinitis pigmentosa

Objective

We investigated the efficacy of additional topical betamethasone in persistent cystoid macular oedema (CMO) after carbonic anhydrase inhibitors (CAIs) therapy.

Methods and analysis

This retrospective cohort study included 16 eyes of 10 patients with retinitis pigmentosa (RP). All patients were previously administered CAI for at least 3 months to treat CMO secondary to RP and lacking an effective reduction (≥11%) of central foveal thickness (CFT). We administered topical 0.1% betamethasone daily in each affected eye following a preceding course of the CAI medication as a first treatment. CMO was diagnosed using spectral-domain optical coherence tomography. CFT was regarded as the average of vertical and horizontal foveal thickness. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were obtained from patient medical records. We compared the CFT and BCVA between baseline and the average of 1-3, 5-7, 10-14 and 16-20 months period.

Results

In treatments with brinzolamide in 14 eyes, dorzolamide in 2 eyes and bromfenac in 2 eyes, CFT effectively decreased in 12 of 16 eyes (81%). CFT decreased significantly in 1-3 months (326±102 µm; n=16; P=0.029) and 5-7 months (297±102 µm; n=12; P=0.022) compared with baseline but not within 10-14 months (271±96 µm; n=9; P=0.485) or 16-20 months (281±134 µm; n=9; P=0.289). There were no significant intergroup differences in BCVA throughout the study. Betamethasone treatment was stopped in three patients because of IOP elevation.

Conclusion

Our data suggested that additional betamethasone might improve treatments for persistent CMO. Topical steroids could be an alternative option for managing persistent CMO in RP.

Retinitis pigmentosa-associated cystoid macular oedema: pathogenesis and avenues of intervention

Hereditary retinal diseases are now the leading cause of blindness certification in the working age population (age 16–64 years) in England and Wales, of which retinitis pigmentosa (RP) is the most common disorder. RP may be complicated by cystoid macular oedema (CMO), causing a reduction of central vision. The underlying pathogenesis of RP-associated CMO (RP-CMO) remains uncertain, however, several mechanisms have been proposed, including: (1) breakdown of the blood-retinal barrier, (2) failure (or dysfunction) of the pumping mechanism in the retinal pigment epithelial, (3) Müller cell oedema and dysfunction, (4) antiretinal antibodies and (5) vitreous traction. There are limited data on efficacy of treatments for RP-CMO. Treatments attempted to date include oral and topical carbonic anhydrase inhibitors, oral, topical, intravitreal and periocular steroids, topical non-steroidal anti-inflammatory medications, photocoagulation, vitrectomy with internal limiting membrane peel, oral lutein and intravitreal antivascular endothelial growth factor injections. This review summarises the evidence supporting these treatment modalities. Successful management of RP-CMO should aim to improve both quality and quantity of vision in the short term and may also slow central vision loss over time.

Treatment of Retinitis Pigmentosa-Associated Cystoid Macular Oedema Using Intravitreal Aflibercept (Eylea) despite Minimal Response to Ranibizumab (Lucentis): A Case Report

BACKGROUND

We present an interesting case of bilateral retinitis pigmentosa (RP)-associated cystoid macular oedema that responded on two separate occasions to intravitreal injections of aflibercept, despite previously demonstrating only minimal response to intravitreal ranibizumab. This unique case would support a trial of intravitreal aflibercept for the treatment of RP-associated cystoid macular oedema.

CASE PRESENTATION

A 38-year-old man from Dubai, United Arab Emirates, presented to the UK with a 3-year history of bilateral RP-associated cystoid macular oedema. Previous treatment with topical dorzolamide, oral acetazolamide, and intravitreal ranibizumab had demonstrated only minimal reduction of cystoid macular oedema. Following re-confirmation of the diagnosis by clinical examination and optical coherence tomography imaging, bilateral loading doses of intravitreal aflibercept were given. Central macular thickness reduced and the patient returned to Dubai. After 6 months, the patient was treated with intravitreal ranibizumab due to re-accumulation of fluid and the unavailability of aflibercept in Dubai. Only minimal reduction of central macular thickness was observed. Once available in Dubai, intravitreal aflibercept was administered bilaterally with further reduction of central macular thickness observed. Visual acuity remained stable throughout.

CONCLUSIONS

This is the first case report to demonstrate a reduction of RP-associated CMO following intravitreal aflibercept, despite inadequate response to ranibizumab on two separate occasions. Aflibercept may provide superior action to other anti-VEGF medications due to its intermediate size (115 kDa) and higher binding affinity. This is worthy of further investigation in a large prospective cohort over an extended time to determine the safety and efficacy of intravitreal aflibercept for use in this condition.

The effects of VEGF-A-inhibitors aflibercept and ranibizumab on the ciliary body and iris of monkeys

PURPOSE

To investigate the effects of intravitreal ranibizumab (Lucentis®) and aflibercept (Eylea®) on the ciliary body and the iris of 12 cynomolgus monkeys with regard to the fenestrations of their blood vessels.

MATERIALS AND METHODS

Structural changes in the ciliary body and in the iris were investigated with light, fluorescent, and transmission electron microscopy (TEM). The latter was used to specifically quantify fenestrations of the endothelium of blood vessels after treatment with aflibercept and ranibizumab. Each of the two ciliary bodies treated with aflibercept and the two treated with ranibizumab and their controls were examined after 1 and 7 days respectively. Ophthalmological investigations including funduscopy and intraocular pressure measurements were also applied.

RESULTS

Ophthalmological investigations did not reveal any changes within the groups. Both drugs reduced the VEGF concentration in the ciliary body pigmented epithelium. The structure of the ciliary body was not influenced, while the posterior pigmented epithelium of the iris showed vacuoles after aflibercept treatment. Ranibizumab was mainly concentrated on the surface layer of the ciliary epithelium, in the blood vessel walls and the lumen of some of the blood vessels, and in the cells of the epithelium of the ciliary body. Aflibercept was more concentrated in the stroma and not in the cells of the epithelium, but as with ranibizumab, also in the blood vessel walls and some of their lumina, and again on the surface layer of the epithelium. Both aflibercept-and ranibizumab-treated eyes showed a decreased number of fenestrations of the capillaries in the ciliary body compared to the untreated controls. On day 1 and day 7, aflibercept had fewer fenestrations than the ranibizumab samples of the same day.

CONCLUSIONS

Both aflibercept and ranibizumab were found to reach the blood vessel walls of the ciliary body, and effectively reduced their fenestrations. Aflibercept might eliminate VEGF to a greater extent, possibly due to a higher elimination of fenestrations in a shorter time. Moreover, the vacuoles found in the iris need further research, in order to evaluate whether they carry a possible pathological potential.