Volume 19, Number 45Monday, November 11, 2019November is Diabetic Eye Disease Awareness Month In this issue: (click heading to view article)Using OCTA to Distinguish Intraretinal Microvascular Abnormalities from Retinal NeovascularizationResearchers evaluated the utility of optical coherence tomography angiography to characterize intraretinal microvascular abnormalities (IRMAs) and retinal neovascularization.They imaged individuals with severe non-proliferative diabetic retinopathy or PDR with fluorescein angiography and widefield swept-source OCTA (Zeiss Plex Elite 9000). And they identified regions suspicious for IRMAs or retinal NV, and two masked readers graded the OCTA images, including flow overlay on the co-registered structural OCT and fluorescein angiography images. (Two of the study’s authors are consultants for Carl Zeiss.) Researchers analyzed 96 foci of irregular vasculatures, including 70 IRMAs and 26 retinal NV lesions from 14 eyes. Here were some of the findings: • Compared with fluorescein angiography, OCTA with flow overlay demonstrated a specificity of 99 percent and sensitivity of 92 percent in identifying IRMAs and NV. • Neovascularization differed from IRMAs on OCTA by demonstrating supraretinal flow breaching the internal limiting membrane and posterior hyaloid (p<0.001). • IRMAs were distinguished from NV by outpouching of the internal limiting membrane (p=0.035). • Vascular flow was reduced in the presence of fibrosis. Researchers concluded that OCTA, through flow overlay, had utility in imaging and differentiating IRMA—a key feature distinguishing severe non-PDR; and NV—a key feature distinguishing PDR. They added that noninvasive widefield OCTA may be a useful tool to diagnose high-risk diabetic retinopathy eyes. Source: Arya M, Sorour O, Chaudhri J, et al. Distinguishing intraretinal microvascular abnormalities from retinal neovascularization using optical coherence tomography angiography. Retina 2019; Oct 14. [Epub ahead of print]. Autologous DSAEK to Reduce Endothelial Rejection in High-risk EyesInvestigators aimed to determine whether autologous Descemet’s stripping endothelial keratoplasty was technically feasible and whether it reduced the risk of endothelial rejection in eyes at high risk for immunological rejection.The prospective, observational, interventional study from 2016 to 2018, had a 24-month follow-up in a tertiary-level corneal referral center in Forlì, Italy. One 25-year-old woman with failed penetrating keratoplasty after endothelial rejection in the context of chronic panuveitis and a blind fellow eye due to retinal detachment underwent autologous Descemet’s stripping automated keratoplasty. Investigators harvested an endothelial graft from the fellow eye by performing a hinged, microkeratome-assisted superficial stromal flap, with removal of the central posterior stromal bed. The posterior lamellar graft that was created was then transplanted into the other eye using a standardized Descemet’s stripping automated endothelial keratoplasty technique. Main outcome measures were endothelial rejection, best spectacle-corrected visual acuity and endothelial cell density. Investigators observed no endothelial rejection during the two-year follow-up duration. They reported stable improvement in best spectacle-corrected visual acuity from 0.2 to 0.4 (decimal Snellen). And they recorded an endothelial cell density of 1,465 cells/mm2 at the final follow-up. They found that the use of this repeatable technique to harvest and transplant an autologous DSAEK graft helped to eliminate endothelial rejection in high-risk eyes. SOURCE: Myerscough J, Friehmann A, Bovone C, et al. Autologous Descemet stripping automated endothelial keratoplasty to eliminate endothelial rejection in eyes at high risk. Cornea 2019; Oct 30. [Epub ahead of print]. Cost-effectiveness of IVR vs. Panretinal Photocoagulation for PDRStudy authors wrote that the DRCR Retina Network Protocol S randomized clinical trial suggested that the mean visual acuity of eyes with proliferative diabetic retinopathy treated with ranibizumab wasn’t worse at five years than that of eyes treated with panretinal photocoagulation. They added that the ranibizumab group had fewer new cases of diabetic macular edema with vision loss or vitrectomy, but had four times the number of injections and three times the number of visits. Although two-year cost-effectiveness results of Protocol S were previously identified, incorporating five-year data from Protocol S could alter the longer-term cost-effectiveness of the treatment strategies from the perspective of the health care system, the study authors suggested.Scientists evaluated 5- and 10-year cost-effectiveness of therapy with ranibizumab 0.5 mg compared with PRP for treating PDR. They initiated a preplanned secondary analysis of the Protocol S randomized clinical trial using efficacy, safety and resource utilization data through five years of follow-up for 213 adults diagnosed with PDR and simulated results through 10 years. Interventions included intravitreous ranibizumab 0.5 mg at baseline and as frequently as every four weeks, based on a structured retreatment protocol vs. PRP at baseline for PDR; eyes in both groups could receive ranibizumab for concomitant DME with vision loss. Scientists evaluated incremental cost-effectiveness ratios (ICERs) of ranibizumab therapy compared with PRP for those with and without center-involved DME (CI-DME) and vision loss (Snellen equivalent, 20/32 or worse) at baseline. The study included 213 adults with a mean (SD) age of 53 (12) years, of whom 92 (43 percent) were women and 155 (73 percent) were white. Here were some of the findings: • The ICER of the ranibizumab group compared with PRP for patients without CI-DME at baseline was $582,268 per quality-adjusted life-year (QALY) at five years, and $742,202/QALY at 10 years. • For patients with baseline CI-DME, ICERs were $65,576/QALY at five years and $63,930/QALY at 10 years. Scientists determined that, during five to 10 years of treatment, ranibizumab 0.5 mg as given in the studied trial compared with PRP may be within the frequently cited range considered cost-effective in the United States for PDR eyes with vision-impairing CI-DME, but not for PDR eyes without vision-impairing CI-DME. They added that substantial reductions in anti-vascular endothelial growth factor expense may make the ranibizumab therapy cost-effective within this range even for patients without baseline CI-DME. SOURCE: Hutton DW, Stein JD, Glassman AR, et al. Five-year cost-effectiveness of intravitreous ranibizumab therapy vs panretinal photocoagulation for treating proliferative diabetic retinopathy: A secondary analysis of a randomized clinical trial. JAMA Ophthalmol 2019; Oct 24:1-9. Repeat SLT in Medication-naïve OAG & OHT During LiGHT TrialResearchers assessed the efficacy of repeat selective laser trabeculoplasty in medication-naïve open-angle glaucoma and ocular hypertensive (OHT) patients requiring repeat treatment for early- to medium-term failure during the Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. (One of the researchers has received grants from laser-makers in the past.)The post hoc analysis of the SLT treatment arm of the multicenter, prospective randomized controlled trial included treatment-naïve OAG or OHT requiring repeat 360-degree SLT within 18 months. Retreatment was triggered by pre-defined IOP and disease-progression criteria (using objective individualized target IOPs) After SLT at baseline, researchers followed individuals for a minimum of 18 months after a second (“repeat”) SLT. They performed a mixed-model analysis with the eye as the unit of analysis, and crossed random effects to adjust for correlations between fellow eyes and repeated measures within eyes. Kaplan-Meier curves helped plot the duration of effect. Outcome measures included initial (“early”) IOP lowering at two months and duration of effect following initial and repeat SLT. Here were some of the findings: • A total of 115 eyes of 90 individuals received repeat SLT during the first 18 months of the trial. • Pre-treatment IOP prior to initial SLT was significantly higher than that prior to pre-retreatment IOP of repeat SLT (mean difference: 3.4; CI, 2.6 to 4.3, mmHg; p<0.001). • Absolute IOP reduction at two months was greater following initial, compared with repeat, SLT (mean difference: 1; CI, 0.2 to 1.8 mmHg; p=0.02). • Adjusted absolute IOP reduction at two months (adjusting for IOP prior to initial or repeat laser) was greater following repeat SLT (adjusted mean difference: -1.1; CI, -1.7 to -0.5 mmHg; p=0.001). • Thirty-four eyes were “early failures” (retreated two months after initial SLT) vs. 81 “later failures” (retreatment beyond two months following initial SLT). • No significant differences in early absolute IOP reduction at two months following repeat SLT were noted between “early” and “later” failures’ (mean difference: 0.3; CI, -1.1 to 1.8 mmHg; p=0.655). • Repeat SLT helped maintain drop-free IOP control in 67 percent of 115 eyes at 18 months, with no clinically relevant adverse events. Researchers wrote that the exploratory analysis demonstrated that repeat SLT could maintain IOP at or below target IOP in medication-naive OAG and OHT eyes requiring retreatment with at least an equivalent duration of effect to initial laser. SOURCE: Garg A, Vickerstaff V, Nathwani N, et al. Efficacy of repeat selective laser trabeculoplasty in medication-naïve open angle glaucoma and ocular hypertension during the LiGHT Trial. Ophthalmology 2019; Oct. 29. [Epub ahead of print]. BRIEFLY Cedars-Sinai to Test Stem Cells for RP Treatment AGTC Announces Stargardt’s as Second Preclinical Program Review of Ophthalmology® Online is published by the Review Group, a Division of Jobson Medical Information LLC (JMI), 11 Campus Boulevard, Newtown Square, PA 19073. |