Improvement of pseudophakic cystoid macular edema with subconjunctival injections of interferon α2b:a case report

Prevention and management of postcataract cystoid macular edema

PURPOSE OF REVIEW

This review highlights treatment options, both under investigation and currently available, for treating postcataract macular edema. An update on current clinical studies for postcataract macular edema has been summarized.

RECENT FINDINGS

Pseudophakic cystoid macular edema (PCME) is a common complication of cataract surgery leading to decreased visual acuity due to inflammation promoting vascular permeability and macular edema. There is no gold standard protocol for treatment with physicians choosing topical NSAIDs and corticosteroids most commonly. Recent developments in a therapeutic approach to PCME include improved delivery methods via implantation and improved drugs and combinational therapies.

SUMMARY

While PCME treatments are poorly studied due to their common sudden resolution without medical intervention, chronic PCME is debilitating for patients. Clinical studies show hope for improved drug delivery methods, practices to prevent potential PCME, and improved therapeutics.

Pseudophakic cystoid macular edema

PURPOSE OF REVIEW

Pseudophakic cystoid macular edema (PCME) is the most common postoperative complication of cataract surgery, resulting in visual decline. In this review, we discuss its pathophysiology, epidemiology, clinical presentation, and the current available evidence on therapeutic management.

RECENT FINDINGS

Patients with diabetes mellitus have twice the risk of developing PCME as compared to nondiabetic individuals. Recent large database studies have revealed an increased risk among young, male, and black patients. A previous history of PCME is perhaps the strongest risk factor for fellow eye involvement.

SUMMARY

PCME generally occurs around 6 weeks postoperatively and is likely a consequence of postoperative inflammation with disruption of the blood-queous and blood-retina barriers. Optical coherence tomography of the macula servers as a key diagnostic tool. There is a lack of large controlled clinical trials to guide treatment approaches. We recommend a stepwise approach for PCME that includes observation if not visually significant versus treatment with topical nonsteroidal anti-inflammatory drugs and steroids if symptomatic. Refractory cases can be treated with a periocular steroid injection, followed by intravitreal steroids if still nonresponsive.

Topical and Subcutaneous Interferon-Alpha for the Treatment of Refractory Inflammatory Macular Edema

PURPOSE

To evaluate the efficacy of topical interferon alpha-2b (tIFN a2b) and subcutaneous pegylated interferon alpha-2a (peg-IFN a2a) in the treatment of refractory pseudophakic (PME) and uveitic (UME) macular edema.

METHODS

Retrospective case series of patients with PME or UME that was non-responsive to conventional therapies. Topical IFN a2b drops (1 MIU/ml) were commenced four times a day. Non-responders were offered treatment with subcutaneous peg-IFN a2a starting at 180 mcg weekly.

RESULTS

Seven eyes of seven patients (three UME and four PME) were treated with tIFN a2b. Three eyes had complete ME resolution with tIFN treatment after a mean of 2.66 weeks (range 1-4 weeks) and no recurrence after a mean total course of 11.33 weeks (range 5-20 weeks). Two cases (both PME) had partial responses to tIFN treatment and two cases (both UME) failed to respond. Of the four eyes that incompletely responded to tIFN (treatment range 6 weeks to 4 months), three were treated with peg-IFN a2a, which invariably led to complete and sustained ME resolution. Adverse effects from topical treatment were mild and consisted mainly of superficial irritation. Adverse effects of subcutaneous treatment included nausea, vomiting, anorexia, and leukopenia, though none limited treatment.

CONCLUSIONS

Topical IFNa-2b appears safe and effective in isolation or in conjunction with topical steroids for the treatment of inflammatory macular edema (IME) in about half of patients in our small series. All partial and non-responders had complete disease resolution with systemic IFN. Topical IFN a2b should be considered in patients with refractory IME.

Current management options for the treatment of refractory postoperative cystoid macular edema: A systematic review

Post-operative cystoid macular edema (PCME) is an important complication following intraocular surgery that often resolves spontaneously without treatment. In some cases, PCME may persist despite initial medical therapy, which can adversely impact visual outcomes. Various topical, intraocular and systemic treatments exist for the prevention and management of cystoid macular edema; however, there is no consensus on treatment of refractory cases in the postoperative setting. In accordance with the PRISMA guidelines, we systematically reviewed 68 articles describing management options and their outcomes for treatment-resistant cases of PCME. The most commonly reported treatments included steroid (39 studies) and biological-based (17 studies) therapies. We provide an overview of the treatment options for refractory PCME.

Interferons in vitreoretinal diseases; a review on their clinical application, and mechanism of action

PURPOSE

This review investigates the therapeutic benefits of interferons (IFNs) in vitreoretinal diseases, focusing on their regulatory roles in innate immunological reactions and angiogenesis. The study aims to categorize the clinical outcomes of IFN applications and proposes a molecular mechanism underlying their action.

METHODS

A systematic review was conducted using MEDLINE/PubMed, Web of Science, EMBASE, and Google Scholar databases to identify randomized clinical trials, case series, and case-control studies related to IFNs' impact on vitreoretinal diseases (1990-2022). The data synthesis involved an in-depth analysis of the anti-inflammatory and anti-angiogenesis effects of IFNs across various studies.

RESULTS

Our findings indicate that IFNs exhibit efficacy in treating inflammation-associated vitreoretinal disorders. However, a lack of sufficient evidence exists regarding the suitability of IFNs in angiogenesis-associated vitreoretinal diseases like choroidal neovascularization and diabetic retinopathies. The synthesis of data suggests that IFNs may not be optimal for managing advanced stages of angiogenesis-associated disorders.

CONCLUSION

While IFNs emerge as promising therapeutic candidates for inflammation-related vitreoretinal diseases, caution is warranted in their application for angiogenesis-associated disorders, especially in advanced stages. Further research is needed to elucidate the nuanced molecular pathways of IFN action, guiding their targeted use in specific vitreoretinal conditions.

Intensive topical interferon therapy in uveitic macular edema

Purpose

To evaluate the efficacy of intensive topical interferon alfa-2b (IFN) therapy in uveitic macular edema (UME).

Methods

This is a prospective, interventional case study of eyes with UME. Commercially available injection IFN for subcutaneous use was reconstituted to form eye drops and a dose of 6 times/day for 2 weeks, 5 times/day for next 2 weeks, followed by 4, 3, 2, 1 taper per month was prescribed. Optical coherence tomography (OCT) and clinical examination was done at 0, 2, 4, 8 weeks, and further as required.

Results

Nine eyes of 9 patients with UME were studied. Mean central macular thickness (CMT) at presentation was 522.2 μm (range: 408-803 μm). At 2-week, 1-month, and 2-month follow-up, mean CMT decreased to 451.6 μm (range: 322-524 μm), 375.8 μm (range: 287-480 μm), and 360.3 μm (range: 260-485 μm), respectively. Four eyes which showed inadequate response to previous topical IFN therapy (4 times/day) showed significant improvement with intensive therapy at 1 month follow-up. In 4 eyes, UME resolved completely with mean CMT 285.5 μm (range: 260-312 μm) at 7.5 weeks (range: 4-12 weeks). Study exit was seen in 2 cases due to inadequate response and relapse of uveitis. Mean follow up was 3.38 months (range: 1-5 months).

Conclusion

Intensive topical IFN therapy can be an alternative therapeutic option in the treatment of UME. Study of intraocular penetration, combination with other drugs, and the efficacy of IFN separately for different uveitic entities may explore new avenues in treatment of UME.