Volume 20, Number 7Monday, February 10, 2020FEBRUARY IS AGE-RELATED MACULAR DEGENERATION AWARENESS MONTH VF Changes in Patients Treated with PRP or Ranibizumab for PDRPreservation of peripheral visual fields is considered an advantage for anti-vascular endothelial growth factor agents compared with panretinal photocoagulation for treatment of proliferative diabetic retinopathy, researchers wrote. Since long-term data on VF are important when considering either treatment approach, researchers aimed to evaluate VF changes through five years among eyes enrolled in the Protocol S clinical trial, conducted by the DRCR Retina Network.This post hoc analysis of an ancillary study within a multicenter, randomized clinical trial included individuals with proliferative diabetic retinopathy enrolled in Protocol S. Data were collected from February 2012 to February 2018, and analysis began in June 2018. Subjects received panretinal photocoagulation or intravitreous injections of 0.5-mg ranibizumab. Diabetic macular edema, whenever present, was treated with ranibizumab in both groups. Panretinal photocoagulation could be administered in eyes in the ranibizumab group when failure or futility criteria were met. Main outcomes and measures included mean change in total point score on VF testing with the Humphrey Field Analyzer 30-2 and 60-4 test patterns. Of 394 eyes enrolled in Protocol S, 234 (59.4 percent) were targeted for this ancillary study. Of these, 167 (71.4 percent) had VFs meeting acceptable quality criteria at baseline (median age: 50 [interquartile range: 43 to 58] years; 90 participants were men [53.9 percent]). At five years, 79 (33.8 percent) had results available. Here were some of the findings: • The mean change in total point score was -305 ±521 dB in the PRP group and -36 ±486 dB in the ranibizumab group at one year, increasing to -527 ±635 dB in the PRP group and -330 ±645 dB in the ranibizumab group at five years (p=0.04). • After filtering VF results post-PRP treatment in the ranibizumab group, the five-year mean change in total point score was -201 (442) dB. • In a longitudinal regression analysis of change in total point score including both treatment groups, laser treatment was associated with a mean point decrease of 208 (CI, 112 to 304) dB for the initial PRP session, 77 (CI, 21 to 132) dB for additional PRP sessions and 325 (CI, 211 to 439) dB for endolaser. • No association was found between the change in point score and the number of ranibizumab injections during the previous year (-9 per injection [CI, -22 to three]). Researchers wrote that the limited data available from Protocol S suggested that factors besides PRP were associated with VF loss in eyes treated with PDR. They added that further clinical research is needed to clarify the finding. SOURCE: Maguire MG, Liu D, Glassman AR, et al. Visual field changes over 5 years in patients treated with panretinal photocoagulation or ranibizumab for proliferative diabetic retinopathy. JAMA Ophthalmol 2020; Jan 30. [Epub ahead of print]. OCTA Macula Vessel Density for Glaucoma DiagnosisScientists evaluated the diagnostic accuracy of 3 mm2 and 6 mm2 macula OCTA scans for classifying healthy, mild glaucoma, and moderate to severe glaucoma eyes. SOURCE: Penteado RC, Bowd C, Proudfoot J, et al. Diagnostic ability of optical coherence tomography angiography macula vessel density for the diagnosis of glaucoma using difference scan sizes. J Glaucoma 2020; Jan 21. [Epub ahead of print]. DMEK with a Pull-through Insertion DeviceInvestigators described a surgical technique for Descemet’s membrane endothelial keratoplasty using a pull-through, endothelium-in insertion device, the DMEK EndoGlide. They evaluated the endothelial cell loss associated with the EndoGlide-DMEK (E-DMEK) technique in ex vivo and prospective clinical studies. (Two of the study authors disclose that they are inventors of the EndoGlide and receive royalties from the device’s maker.)The ex vivo study involved calcein acetoxymethyl staining and preparation of DMEK grafts, which were trifolded endothelium-in, loaded into the EndoGlide, pulled through and unfolded in imaging dishes. Investigators performed inverted fluorescent microscopy, and quantified ECL using trainable segmentation software. The prospective clinical series described the outcomes of consecutive surgeries using technique. Grafts were pulled through the EndoGlide with forceps and unfolded in the anterior chamber endothelium-down. The main outcome measure was ECL in both studies. In the ex vivo study with nine human donor corneas, mean ECL was 15.2 ±5.4 percent (n=9). In the clinical series of 69 eyes, the indications for surgery were pseudophakic/aphakic bullous keratopathy (47.8 percent), previous failed grafts (23.2 percent) and Fuchs’ endothelial dystrophy (18.8 percent). Here are some of the findings: • Rebubbling rates related to E-DMEK were 11.6 percent, and primary graft failure rates were 1.5 percent. • Among eyes with at least six months of follow-up, mean preoperative endothelial cell density was 2,772 (range: 2,457 to 3,448) cells/mm2, and postoperative endothelial cell density was 1,830 (range: 541 to 2,545) cells/mm2. • Mean ECL was 33.6 percent (range: 7.5 to 80.4; n=32) at the 7.1 (range: six to 11) months follow-up. Investigators determined that the ex vivo and pilot clinical studies suggested that E-DMEK showed acceptable rates of ECL, with safe and promising early clinical outcomes. Source: Tan TE, Devarajan K, Seah XY, et al. Descemet membrane endothelial keratoplasty with a pull-through insertion device: Surgical technique, endothelial cell loss, and early clinical results. Cornea 2020; Jan 28. [Epub ahead of print.] Non-exudative Macular Neovascularization Supporting Outer Retina in AMDResearchers wrote that type 1 macular neovascularization (MNV) secondary to age-related macular degeneration may compensatorily sustain hypoxic and micronutrient-insufficient outer retinal cells. They explored this hypothesis using the histology of an eye with a shallow irregular retinal pigment epithelial elevation (SIRE) on optical coherence tomography and good vision.The case study and clinicopathologic correlation included the imaging of untreated non-exudative neovascular AMD and 20/30 visual acuity (left eye) and neovascular AMD (right eye) in a white woman with nine years’ multimodal imaging before death at age 90. The left eye was preserved 6.25 hours after death and prepared for submicrometer epoxy resin sections and transmission electron microscopy aligned to clinical OCT B-scans. Researchers measured inside and outside the MNV area, layer thicknesses, phenotypes and vascular density of native choriocapillaris and new vessels with ImageJ. They measured the lengths of choriocapillaries and intervening gaps in the index eye, and in early AMD eyes and normal eyes with similar age (n=19 each) from the Project MACULA online histopathology resource with custom software (Caps and Gaps). Main outcome measures included descriptive light and electron microscopic morphology, vascular density, histologic and OCT layer thicknesses, and distribution of choriocapillaries and intervening gaps. Here were some of the findings: • The SIRE correlated to a type 1 MNV that expanded slowly without evidence of exudation and with numerous choroidal vessels traversing Bruch’s membrane defects, some visible on OCT. • Tissue layers in and adjacent to the MNV area showed continuous RPE and characteristic AMD deposits. • Capillary-like new vessels with fenestrations and caveolae resembling native choriocapillaris lined the RPE with a vascular density comparable to surrounding non-MNV areas. • Relative to early AMD and normal-aged eyes, the index case had similar capillary lengths but larger gaps between vessels, indicating drop-out. • ONL thickness was preserved and showed less photoreceptor degeneration over areas of relative choriocapillaris health, including the type 1 MNV. Researchers concluded that eyes with non-exudative type 1 MNV in AMD may progress to exudation; however, this stable MNV complex supported the outer retinal structure for nine years. Distinguishing features were numerous connecting vessels, high density of new vessels, continuous RPE and slow growth. Researchers concluded that maintaining beneficial type 1 MNVs may be a therapeutic strategy. SOURCE: Chen L, Messinger, Sloan KR, et al. Non-exudative macular neovascularization supporting outer retina in age-related macular degeneration, a clinicopathologic correlation. Ophthalmology 2020; Jan 28. [Epub ahead of print]. BRIEFLY Prevent Blindness and B+L Raise Awareness of AMD Product Pipeline Update Prevent Blindness Calls for Nominations Verana Health Acquires PYA Analytics; Announces $100 Million Financing 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. |