The study conducted in a real-life setting shows functional and anatomical improvement after treatment of postoperative macular edema with an Ozurdex® intravitreal implant. With a 6-month follow-up, an average improvement in visual acuity (VA) from 0.40 to 0.22 logMAR, in central macular thickness (CMT) from 431 to 322 μm, and in central area thickness (CAT) from 316 to 299 μm was observed. Moreover, our results also indicate that greater structural improvement in CMT is associated with better functional recovery in VA.
Among the risk factors for cystoid macular edema after rhegmatogenous retinal detachment, complex retinal detachment repairs that require multiple surgeries and pseudophakic or aphakic status are prominent [13]. The literature presents conflicting results, with some studies showing no anatomical improvement [13] and a recent publication finding significant differences in best corrected visual acuity and central macular thickness before and after the Ozurdex® injection, with at least an 18-month follow-up [14]. Pignatelli et al. demonstrated that Ozurdex implantation had a statistically significant effect at the time of silicone oil removal in 24 eyes previously undergoing vitreoretinal surgery for the treatment of rhegmatogenous retinal detachment, showing a reduction in mean macular thickness and improved visual acuity after 6 months. Favorable results and an acceptable safety profile were achieved, with intraocular pressure (IOP) elevation in only one eye, which was managed clinically. Macular status was significantly associated with visual acuity after Dexamethasone implantation [15]. It should be noted that the intraoperative implant must be performed safely when the eye is filled with balanced salt solution (BSS) to avoid retinal trauma due to the kinetic energy of the implant [16].
Other corticosteroids, such as Triamcinolone, also show benefits in terms of visual acuity improvement and anatomical macular changes [17]; however, they have a less favorable safety profile, with a higher risk of elevated IOP, and should not be used as an alternative treatment in randomized studies [18]. Furthermore, the use of Ozurdex is associated with a lower need for retreatments, as recently demonstrated in cases of Irvine-Gass syndrome refractory to topical therapy with nonsteroidal anti-inflammatory drugs and corticosteroids [19, 20], as well as in vitrectomized eyes [21], with functional improvement through microperimetry already documented [22].
We found no significant effect of sex or age on the differences observed between pre- and postoperative parameters. Preoperative CMT and CAT values have shown a significant impact in the outcomes, such that the worse the baseline parameter, the greater the observed improvement. The timing of the implant was also significantly associated with the functional improvement, with cases where the implant was placed at the time of oil removal showing less improvement. It is important to emphasize that patients with silicone oil tamponade presented with severe retinal detachment, with surgical indication due to significant functional and/or anatomical impairment, especially in the presence of macular involvement and vitreoretinal proliferation. Some of these patients underwent complex procedures and re-operations, which negatively affect the final visual prognosis due to irreversible damage to the photoreceptors, despite the improvement in macular edema after surgery. In that sense, the observed finding on functional improvement associated with time of implant can be confounded by the case severity and have to be interpreted with caution.
Approximately 25% of patients required additional treatment, with two-thirds of them needing an additional injection of Ozurdex. The need for a new implant primarily occurred due to the absence of a complete anatomical response after 90 days of treatment, although there was a decrease in macular thickness and intraretinal cysts compared to baseline. Surgical intervention was indicated in four cases due to the development of an epiretinal membrane with a tangential traction component, causing anatomical distortion and macular thickening. This progression can be attributed to the inflammatory component intrinsic to surgical trauma, leading to fibrocellular proliferation along the inner limiting membrane.
Real-life scenarios provide important insights but also illustrate the challenges of maintaining regular follow-up. Patient attrition posed a significant challenge in this study, reflecting real-world constraints in delivering care to a diverse patient population. Among the 82 eyes pre-selected for the study, 33 patients missed scheduled follow-ups due to treatment abandonment or delays. This was often attributed to logistical barriers such as long travel distances from rural areas to the reference center in São Paulo, compounded by socioeconomic constraints and cultural factors influencing health-seeking behaviors. Despite clear guidance, adherence to follow-up schedules remained difficult for some patients, emphasizing the need for tailored interventions. Additionally, attrition included losses due to clinical complications. One patient experienced implant migration to the anterior chamber, one had retinal detachment, and another developed a myopic neovascular membrane, leading to treatment cessation. These cases highlight the challenges associated with managing severe underlying eye conditions and the inherent risks of intravitreal implants. To address attrition in future studies, we recommend strategies such as providing transportation support, enhancing patient education on the importance of follow-ups, and using telemedicine for interim evaluations to reduce the burden of in-person visits. Furthermore, employing reminders through digital platforms or community health workers may improve adherence. To evaluate the potential impact of attrition on our findings, we conducted sensitivity analyses. By comparing baseline characteristics of patients who completed follow-ups with those lost to attrition, we found no significant differences in demographics or baseline clinical parameters, suggesting minimal bias introduced by attrition. However, we acknowledge that the reduced sample size may have limited the generalizability of our findings. In that sense, controlled clinical trials with comprehensive follow-up mechanisms remain crucial for producing more robust evidence.
The retrospective design of the study imposes further limitations. Although confounding factors were minimized by considering the study’s exclusion criteria, it is known that more complex procedures with longer surgical times—such as vitreoretinal surgeries—tend to have higher rates of macular edema and greater severity, particularly when the macula is affected by the primary disease or in the presence of vitreoretinal proliferation. The poorer outcomes associated with Ozurdex implantation at the time of silicone oil removal reinforce this hypothesis, as these eyes had previously undergone complex surgical procedures.
Leave a Reply