Intensive topical interferon therapy in uveitic macular edema

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.

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.

Two Cases of Chronic Central Serous Chorioretinopathy Successfully Treated with Systemic Interferon Alpha

Chronic central serous chorioretinopathy (CSCR) is a sight threatening disease that can lead to legal blindness. Verteporfin photodynamic therapy is the main treatment for chronic CSCR, however, there has been a critical worldwide shortage of verteporfin. Other medical treatments have been attempted with variable efficacy. Interferons have shown efficacy in treating uveitis and associated macular edema. We report 2 cases of treatment refractory chronic CSCR successfully treated with subcutaneous injection of interferon alpha with significant anatomical and functional improvement. To our knowledge, this is the first report observing the therapeutic potential of systemic interferon alpha in the treatment of chronic CSCR. A large randomized controlled clinical trial would help to better evaluate the safety and efficacy of systemic PEG-IFNα2a in treating chronic CSCR, and further define the optimal dose, treatment interval and duration.

Choroidal Involvement and Chronic Macular Edema in Acute Retinal Necrosis: A Novel Finding and a Novel Treatment

Acute retinal necrosis (ARN) as the term suggests is recognized as necrotic inflammation of retina, in contrast to toxoplasma retinochoroiditis where involvement of choroid can be appreciated as choroidal thickening on optical coherence tomography scan during active stage. Secondly, sequelae of ARN, such as chronic anterior uveitis and cystoid macular edema, could be challenging to manage as steroid use in various forms poses a risk of virus reactivation. We present a case of ARN caused by varicella zoster virus with an initial confusing clinical picture with toxoplasma retinochoroiditis, documented with choroidal involvement. The patient also developed a chronic anterior uveitis with macular edema after resolution of ARN which was treated with topical interferon (IFN) alfa 2b therapy with successful outcome. This report supports the recently described choroidal involvement in ARN and suggests topical IFN as a novel treatment in management of chronic macular edema post ARN.

Evaluation of the additive effect of interferon α 2b with monthly intravitreal injection of bevacizumab in refractory diabetic macular edema

Background

To evaluate the additive effect of topical or sub-tenon injection of interferon (IFN)-α 2b in the treatment of refractory diabetic macular edema.

Methods

In this prospective study patients with center-involved DME who were unresponsive to 3 monthly consecutive IVB injections were recruited. Patients were divided into three groups: group1, received IFN- α 2b topical drop at a dose of 1mIU/ml four times a day for 3 months. Group 2, received a single sub-tenon injection of 1mIU/ml IFN- α 2b at the enrollment. Group 3 received artificial tears four times a day for 3 months (control group). All groups received three consecutive monthly IVB injections and were evaluated monthly up to 1 month following the last IVB injection.

Results

In this study, 59 eyes of 35 patients with refractory DME were assessed. The final follow-up showed that although CMT decreased in all groups, only patients in Group 2 had statistically significant lower CMT compared to their baseline values (change in CMT: − 117 ± 213 µm; p-value = 0.025). Comparison of CMT changes between three groups showed no statistically significant difference, although it was higher in group 2 (change in CMT: − 117 ± 213 µm (Group2) vs. − 49 ± 173 (Group 1) vs. − 36 ± 86 (Group 3); p-value = 0.085). Considering eyes with baseline CMT > 400 µm, sub-tenon injection of IFN α2b led to a significant reduction of CMT at the first month and final follow-up visit (CMT change: − 166 ± 210, − 145 ± 231 µm; p-value = 0.018 and 0.035, respectively). In this subgroup, eyes in Group 2 had lower CMT at the first month following treatment in comparison with the control group (CMT: 444 ± 123 µm vs. 544 ± 96 µm, p-value = 0.042). Alterations of CDVA were not statistically significant among groups, although patients in Group 1 had a significant improvement in vision at second and last follow up (CDVA change: − 0.23 ± 0.39, − 0.20 ± 0.43 logMAR; p-value = 0.030 and 0.010, respectively).

Conclusions

In short term, Sub-tenon injection of IFN might have an additive anatomical effect in eyes with refractory DME. Validation of this observation requires further prospective controlled studies.