Impact of Prophylactic Ranibizumab to Prevent Neovascular Age-Related Macular Degeneration on Eyes With Intermediate Age-Related Macular Degeneration.

Purpose: The purpose of this study was to determine the impact of prophylactic ranibizumab (PR) injections given every 3 months in eyes with intermediate nonexudative age-related macular degeneration (AMD) on drusen volume, macular layer thicknesses, and progression of geographic atrophy (GA) area over 24 months in the PREVENT trial. Methods: This post hoc analysis of the prospective PREVENT trial compared eyes with intermediate AMD randomized to PR versus sham injections to determine rates of conversion to neovascular AMD over 24 months. Drusen area and volume, macular thickness and volume, and retinal layer thicknesses were measured on spectral-domain optical coherence tomography images and analyzed. Masked grading of GA area and subretinal drusenoid deposits (SDDs) using fundus autofluorescence images was performed. Results: There were no statistical differences in drusen area and volumes between groups, and similar reductions in central subfield thickness, mean cube thickness, cube volume, and retinal sublayer thickness from baseline to 24 months (P = 0.018 to < 0.001), with no statistical differences between groups in any of these anatomic parameters. These findings were not impacted by the presence or absence of SDD. Among the 9 eyes with GA in this study, mean GA growth rate from baseline to 24 months was 1.34 +/- 0.79 mm2/year after PR and 1.95 +/- 1.73 mm2/year in sham-treated eyes (P = 0.49), and similarly showed no statistical difference with square root transformation (P = 0.61). Conclusions: Prophylactic ranibizumab given every 3 months did not appear to affect drusen volume, macular thinning, or GA progression in eyes with intermediate AMD. Translational Relevance: This work investigates the impact of PR on progressive retinal degeneration in a clinical trial.

CRISPR-based VEGF suppression using paired guide RNAs for treatment of choroidal neovascularization.

Clustered regularly interspaced short palindromic repeats (CRISPR)-based genomic disruption of vascular endothelial growth factor A (Vegfa) with a single gRNA suppresses choroidal neovascularization (CNV) in preclinical studies, offering the prospect of long-term anti-angiogenesis therapy for neovascular age-related macular degeneration (AMD). Genome editing using CRISPR-CRISPR-associated endonucleases (Cas9) with multiple guide RNAs (gRNAs) can enhance gene-ablation efficacy by augmenting insertion-deletion (indel) mutations with gene truncations but may also increase the risk of off-target effects. In this study, we compare the effectiveness of adeno-associated virus (AAV)-mediated CRISPR-Cas9 systems using single versus paired gRNAs to target two different loci in the Vegfa gene that are conserved in human, rhesus macaque, and mouse. Paired gRNAs increased Vegfa gene-ablation rates in human cells in vitro but did not enhance VEGF suppression in mouse eyes in vivo. Genome editing using paired gRNAs also showed a similar degree of CNV suppression compared with single-gRNA systems. Unbiased genome-wide analysis using genome-wide unbiased identification of double-stranded breaks (DSBs) enabled by sequencing (GUIDE-seq) revealed weak off-target activity arising from the second gRNA. These findings suggest that in vivo CRISPR-Cas9 genome editing using two gRNAs may increase gene ablation but also the potential risk of off-target mutations, while the functional benefit of targeting an additional locus in the Vegfa gene as treatment for neovascular retinal conditions is unclear.

NATURAL HISTORY AND PREDICTORS OF VISION LOSS IN EYES WITH DIABETIC MACULAR EDEMA AND GOOD INITIAL VISUAL ACUITY.

PURPOSE: To identify clinical and anatomic factor-associated vision loss in eyes with treatment-naïve diabetic macular edema and good initial visual acuity. METHODS: Retrospective cohort study after long-term history of eyes with untreated center-involving diabetic macular edema and baseline visual acuity ≥ 20/25 seen at the University of California, Davis Eye Center between March 2007 and March 2018. We collected characteristics including diabetes type, hemoglobin A1c, presence of visual symptoms, visual acuity, and diabetic retinopathy severity; and spectral-domain optical coherence tomography biomarkers including central subfield thickness, intraretinal cyst size, intraretinal hyperreflective foci, disorganization of retinal inner layers, and outer layer disruptions to determine factors associated with vision loss as defined by DRCR Protocol V as threshold for initiating aflibercept therapy. RESULTS: Fifty-six eyes (48 patients) with untreated diabetic macular edema and mean baseline visual acuity of logMAR 0.05 ± 0.05 (Snellen 20/22) were followed for an average of 5.1 ± 3.3 years, with a median time to vision loss of 465 days (15 months). Older age (hazard ratio [HR] 1.04/year, P = 0.0195) and eyes with severe NPDR (HR 3.0, P = 0.0353) or proliferative diabetic retinopathy (HR 7.7, P = 0.0008) had a higher risk of a vision loss event. None of the spectral-domain optical coherence tomography biomarkers were associated with vision loss except central subfield thickness (HR 0.98, P = 0.0470) and cyst diameter (HR 1.0, P = 0.0094). CONCLUSION: In eyes with diabetic macular edema and good initial vision, those with older age and worse diabetic retinopathy severity should be monitored closely for prompt treatment initiation when vision loss occurs.

Patterns and Predictors of Successful Treatment Discontinuation in Retinal Vein Occlusions With Macular Edema in the Real World.

BACKGROUND AND OBJECTIVE: To identify factors associated with successful treatment discontinuation in eyes with retinal vein occlusions (RVOs) and macular edema (ME) in real-world settings. PATIENTS AND METHODS: Retrospective study of 214 eyes with RVO and ME with 24-month follow-up at five academic centers. Regression analyses identified factors associated with (1) successful treatment discontinuation for at least 6 months without fluid recurrence and (2) best-corrected visual acuity (BCVA) at 24 months. RESULTS: Forty percent of eyes with branch RVO and 35% with central RVO (CRVO) / hemi-retinal RVO (HRVO) successfully discontinued therapy without fluid recurrence, with median time to discontinuation of 6 and 7 months, respectively. Lower 6-month central subfield thickness was associated with greater likelihood of treatment discontinuation within 24 months for eyes with CRVO/HRVO (P = .001), whereas better 6-month BCVA was associated with better 24-month BCVA for all RVO subtypes (P < .001). CONCLUSION: Early anatomic response at 6 months is associated with greater likelihood of stopping treatments. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:84-92.].

Emerging Concepts in the Treatment of Diabetic Retinopathy.

PURPOSE OF REVIEW: Diabetic retinopathy (DR) is the leading cause of vision loss in working-age adults in the developed world. This review discusses the current approach to managing the disease, such as glycemic and blood pressure control, as well as laser photocoagulation, as well as emerging concepts and controversies on novel therapies. RECENT FINDINGS: In recent years, the rise of intraocular anti-angiogenesis treatments is changing the paradigm of classic laser photocoagulation in the management of DR, but its long-term benefits remain an area of controversy. We also discuss new targets including anti-inflammation, neuroprotection, and novel laser technologies. Finally, we discuss new advances in retinal imaging that has vastly improved the diagnosis and management of DR. Diagnosis and management of diabetic retinopathy is a rapidly progressing field. Emerging concepts in ophthalmic imaging, medical treatments, and surgical approaches provide insights into how DR management will evolve in the near future.