Comparative study of intravitreal dexamethasone implant in the treatment of macular edema secondary to central retinal vein occlusion with different ages

Objective

To compare the efficacy of intravitreal dexamethasone implant (OZURDEX^®) in the treatment of macular edema (ME) caused by central retinal vein occlusion (CRVO) in different ages.

Methods

A retrospective case observation study was performed.Forty eyes of 40 patients diagnosed with ME secondary to CRVO were enrolled in the study.According to patient’s age, all of the 40 eyes were divided into <40 years old group (20 eyes) and ≥40 years old group (20 eyes). All eyes went through best corrected visual acuity (BCVA), intraocular pressure (IOP) and optic coherence tomography (OCT) examinations.Early Treatment Diabetic Retinopathy Study chart was used to test visual acuity, and central macular thickness (CMT) was measured by OCT.Fundus fluorescein angiography (FFA) was proceeded selectively.All eyes went through intravitreal injections of intravitreal dexamethasone implant and BCVA, IOP, OCT were tested 1 month, 2, 3, 6, 9 and 12 months after injection.After 3 months follow-up, intravitreal dexamethasone implant or ranibizumab would be injected again for patients with ME recurrence or poor treatment effects.Changes of BCVA, IOP and CMT before and after injection were observed.

Results

BCVA and CMT in the <40 years old group and ≥40 years old group were compared at different time points, and the differences were significantly different (BCVA: F_group=2.071, P=0.044; F_time=9.551, P<0.001.CMT: F_group=2.402, P=0.034; F_time=13.175, P<0.001), compared with before injection, the BCVA at each time point of post-injection was improved, and CMT was thinner than that before injection; at 2 months after injection, the BCVA was improved and CMT was thinner than those 1 month after injection, the differences were statistically significant (all at P<0.05); at 12 months after injection, the BCVA in the <40 years old group was obviously better than that in the ≥40 years old group, the CMT was much thinner than that in the ≥40 years old group, the differences were statistically significant (both at P<0.05). Compared with before injection, the IOP at 1 month, 2 and 3 months after injection was increased, the IOP at 2 months after injection was higher than that at 1 month after injection, the differences were statistically significant (both at P<0.05). The mean number of injections was (1.8±0.9) times in the <40 years old group and (2.7±1.4)times in the ≥40 years old group, with a statistical difference between them (t=2.569, P=0.014).

Conclusions

In different age groups, patients with ME caused by CRVO can be effectively treated by intravitreal dexamethasone implant, the therapeutic effect is significant at 1 month post-injection and most improvement is shown at 2 months post-injection.Compared with patients over 40 years of age, patients under 40 years of age have better long-term results, better visual improvement, thinner CMT and less intravitreal injections.

Key words:

Dexamethasone/therapeutic use; Central retinal vein occlusion; Macular edema