Retrospective, controlled observational case study of patients with central retinal vein occlusion and initially low visual acuity treated with an intravitreal dexamethasone implant.

BACKGROUND: Patients with initially low visual acuity were excluded from the therapy approval studies for retinal vein occlusion. But up to 28 % of patients presenting with central retinal vein occlusion have a baseline BCVA of less than 34 ETDRS letters (0.1). The purpose of our study was to assess visual acuity and central retinal thickness in patients suffering from central retinal vein occlusion and low visual acuity (<0.1) in comparison to patients with visual acuity (≥0.1) treated with Dexamethasone implant 0.7 mg for macular edema. METHODS: Retrospective, controlled observational case study of 30 eyes with macular edema secondary to central retinal vein occlusion, which were treated with a dexamethasone implantation. Visual acuity, central retinal thickness and intraocular pressure were measured monthly. Analyses were performed separately for eyes with visual acuity <0.1 and ≥0.1. RESULTS: Two months post intervention, visual acuity improved only marginally from 0.05 to 0.07 (1 month; p = 0,065) and to 0.08 (2 months; p = 0,2) in patients with low visual acuity as compared to patients with visual acuity ≥0.1 with an improvement from 0.33 to 0.47 (1 month; p = 0,005) and to 0.49 (2 months; p = 0,003). The central retinal thickness, however, was reduced in both groups, falling from 694 to 344 µm (1 month; p = 0.003,) to 361 µm (2 months; p = 0,002) and to 415 µm (3 months; p = 0,004) in the low visual acuity group and from 634 to 315 µm (1 month; p < 0,001) and to 343 µm (2 months; p = 0,001) in the visual acuity group ≥0.1. Absence of visual acuity improvement was related to macular ischemia. CONCLUSIONS: In patients with central retinal vein occlusion and initially low visual acuity, a dexamethasone implantation can lead to an important reduction of central retinal thickness but may be of limited use to increase visual acuity.

Retrobulbar hemodynamics before and after oculopression with and without dorzolamide.

PURPOSE: To investigate the effect of intraocular pressure (IOP) reduction by oculopression and topical dorzolamide on retrobulbar hemodynamics. METHODS: Sixty patients (70 ± 8.5) solely with cataract diagnosis solely were included in this prospective study. Patients with other systemic and ocular diseases affecting ocular circulation were excluded. On 30 patients (71 ± 8.5), solely oculopression (Honan IOP reducer) was performed. The other half of the patients (69 ± 8.3) additionally received 2 h prior to oculopression additionally topical dorzolamide. Before and after oculopression, IOP was measured and color Doppler imaging (CDI) was performed for the ophthalmic artery (OA), the central retinal artery, and the short posterior ciliary arteries (PCA). Furthermore, blood pressure and heart rate were monitored. RESULTS: At baseline there was no significant IOP difference between both groups (p = 0.54). IOP, measured prior to oculopression, was significant lower (p < 0.0001) in the group treated with dorzolamide (15.2 mmHg) compared to the other group (17.8 mmHg). Oculopression then led to a significant IOP reduction in all patients (p < 0.0001). There was no significant difference of the delta of IOP reduction between both groups observed (p = 0.47). In either group CDI showed a significant increase of peak systolic velocity (PSV) (p < 0.0001) and end-diastolic velocity (EDV) (p < 0.0001) after oculopression in all vessels. In both groups ocular perfusion pressure increased significantly by 6% (p < 0.0001). After oculopression the PSV of the OA was significantly higher (14%; p < 0.0001) after dorzolamide application than after oculopression alone. Furthermore, in the group with oculopression and dorzolamide treatment EDV of the PCA was significantly higher (21%; p < 0.0001) and resistive index of the PCA was significantly lower (-5.6%; p = 0.001). CONCLUSION: IOP reduction by a pure mechanical procedure like oculopression leads to a significant increase of flow velocities of the retrobulbar vessels. This effect can significantly be increased by using dorzolamide prior to oculopression.