Burden of undiagnosed and suboptimally controlled diabetes in selected regions of India: Results from the SMART India population-level diabetes screening study.

AIMS: To estimate the prevalence of undiagnosed diabetes and suboptimally controlled diabetes and the associated risk factors by community screening in India. METHODS: In this multi-centre, cross-sectional study, house-to-house screening was conducted in people aged ≥40 years in urban and rural areas across 10 states and one union territory in India between November 2018 and March 2020. Participants underwent anthropometry, clinical and biochemical assessments. Capillary random blood glucose and point-of-care glycated haemoglobin (HbA1c ) were used to diagnose diabetes. The prevalence of undiagnosed diabetes and suboptimal control (HbA1c ≥53 mmol/mol [≥7%]) among those with known diabetes was assessed. RESULTS: Among the 42,146 participants screened (22,150 urban, 19,996 rural), 5689 had known diabetes. The age-standardised prevalence of known diabetes was 13.1% (95% CI 12.8-13.4); 17.2% in urban areas and 9.4% in rural areas. The age-standardised prevalence of undiagnosed diabetes was 6.0% (95% CI 5.7-6.2); similar in both urban and rural areas with the highest proportions seen in the East (8.0%) and South (7.8%) regions. When we consider all people with diabetes in the population, 22.8% of individuals in urban areas and 36.7% in rural areas had undiagnosed diabetes. Almost 75% of the individuals with known diabetes had suboptimal glycaemic control. CONCLUSIONS: High prevalence of undiagnosed diabetes and suboptimally controlled diabetes emphasises the urgent need to identify and optimally treat people with diabetes to reduce the burden of diabetes.

Anatomical and functional features of photic retinopathy: a spectral domain optical coherence tomography-based longitudinal study.

BACKGROUND: Photic retinopathy may lead to permanent foveal structural injury, leading to irreversible visual acuity loss. METHOD: This prospective observational study evaluated 51 eyes of 30 patients with photic retinopathy. Optical coherence tomography (OCT) imaging was performed for all the eyes at baseline and final follow-up. All the eyes showed a focal outer retinal defect on spectral-domain OCT (SD-OCT) at the junction of the inner and outer photoreceptor segments. SD-OCT was used to measure central macular thickness, maximum horizontal dimension of the defect, maximum defect thickness, and the photic retinopathy index (PRI) through the foveal raster scan. RESULTS: Although PRI improved significantly at the final follow-up from baseline with a 17% improvement in PRI after a period of 6 months in photic retinopathy eyes, visual acuity declined for 14% of the patients and was stable for 84%. There was mild correlation of visual acuity with baseline PRI. Baseline PRI was significantly higher in eyes with poorer presenting visual acuity (VA). In total, 33.3% of the eyes showed partial ellipsoid zone recovery at 6 months. The area under curve of the receiver operator characteristic curve for partial ellipsoid zone recovery with the mean baseline PRI as the independent variable was poor at 0.612. CONCLUSION: OCT-based ultrastructural features in photic retinopathy seem to have poor correlation with presenting or final visual acuity. To the best of our knowledge, this is the largest study on longitudinal OCT evaluation of photic retinopathy eyes in literature.

Retinal manifestations in patients with SARS-CoV-2 infection and pathogenetic implications: a systematic review.

INTRODUCTION: The pandemic of COVID-19 has been caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Apart from respiratory malfunction, COVID-19 causes a system-wide thromboembolic state, leading to serious cardiovascular, cerebrovascular and peripheral vascular manifestations. However, our knowledge regarding retinal manifestations due to systemic COVID-19 is minimal. This systematic review has comprehensively summarized all retinal manifestations secondary to COVID-19 disease recorded till date since the beginning of the pandemic. METHODS: All studies published till November 27, 2020, which have reported retinal manifestations in COVID-19 patients were systematically reviewed using the PRISMA statement. RESULTS: We included 15 articles: 11 case reports and four cross-sectional case series. The most commonly reported manifestations which did not affect visual acuity were retinal hemorrhages and cotton wool spots. The most common vision threatening manifestation was retinal vein occlusion with associated macular edema. Rarely, patients may also present with retinal arterial occlusions and ocular inflammation. These manifestations may occur from as soon as within a week after the onset of COVID-19 symptoms to more than 6 weeks after. CONCLUSION: Mostly causing milder disease, COVID-19 may however lead to severe life-threatening thromboembolic complications, and systemic antithrombotic therapy has been suggested as a prophylactic and therapeutic management strategy for patients affected with serious systemic disease. However, both sick and apparently healthy patients may suffer from various retinal complications which may lead to loss of vision as well. No consensus regarding management of retinal complications with anticoagulants or anti-inflammatory medications have been proposed; however, they may be tackled on individual basis.

Correlating the patterns of diabetic macular edema, optical coherence tomography biomarkers and grade of diabetic retinopathy with stage of renal disease.

PURPOSE: To correlate optical coherence tomography (OCT)-based morphological patterns of diabetic macular edema (DME), biomarkers and grade of diabetic retinopathy (DR) in patients with various stages of chronic kidney disease (CKD) secondary to diabetes. DESIGN: Multicentric retrospective cross-sectional study was conducted at seven centers across India. METHODS: Data from medical records of patients with DME and CKD were entered in a common excel sheet across all seven centers. Staging of CKD was based on estimated glomerular filtration rate (eGFR). RESULTS: The most common morphological pattern of DME was cystoid pattern (42%) followed by the mixed pattern (31%). The proportion of different morphological patterns did not significantly vary across various CKD stages (p = 0.836). The presence of external limiting membrane-ellipsoid zone (ELM-EZ) defects (p < 0.001) and foveal sub-field thickness (p = 0.024) showed a direct correlation with the stage of CKD which was statistically significant. The presence of hyperreflective dots (HRD) and disorganization of inner retinal layers (DRIL) showed no significant correlation with the stage of CKD. Sight threatening DR was found to increase from 70% in CKD stage 3 to 82% in stages 4 and 5 of CKD, and this was statistically significant (p = 0.03). CONCLUSION: Cystoid morphological pattern followed by mixed type was the most common pattern of DME on OCT found in patients suffering from stage 3 to 5 of CKD. However, the morphological patterns of DME did not significantly vary across various CKD stages. ELM-EZ defects may be considered as an important OCT biomarker for advanced stage of CKD.

Comparison of two ultra-widefield imaging for detecting peripheral retinal breaks requiring treatment.

AIM: To compare the sensitivity of Optomap Panoramic 200 and Clarus 500 in detecting peripheral retinal breaks that required treatment. METHODS: This prospective study enrolled consecutive patients undergoing laser for treatment-requiring peripheral retinal breaks from May 2019 to July 2019. The patients first underwent indirect ophthalmoscopy examination with scleral indentation by a retinal consultant and then ultra-widefield imaging by a single trained technician on Optomap 200 and Clarus 500 in all nine ocular gazes. The images were analysed by two independent investigators to look for the number and location of the breaks. The sensitivity of each platform was calculated as the number of treatment-requiring breaks identified by the system divided by the number of breaks identified on clinical examination. RESULTS: Clinical examination of 49 eyes (41 patients) showed 116 treatment-requiring breaks. Overall sensitivity for identifying such breaks for Optomap and Clarus was 80.2% (n = 93) and 74.1% (n = 86) respectively (p = 0.274). The sensitivities in superior (p = 0.665), temporal (p = 0.146) and inferior (p = 0.889) quadrants were statistically similar for both the platforms. The sensitivity of Optomap was slightly higher than Clarus in emmetropic (p = 0.046) and phakic (p = 0.061) eyes, but similar in myopic (p = 0.448) and pseudophakic (p = 0.191) eyes. CONCLUSION: The ability to detect treatment-requiring retinal breaks is similar for both Optomap and Clarus systems.

Real-world outcomes of intravitreal anti-vascular endothelial growth factor monotherapy in proliferative type 2 macular telangiectasia.

BACKGROUND: To study the effect of anti-VEGFs in proliferative MacTel 2 METHODS: Sixty-four eyes of 51 patients of MacTel 2 with subretinal neovascular membrane (SRNVM) undergoing intravitreal anti-VEGF monotherapy at our institution between January 2015 and December 2018 were evaluated for visual acuity, central macular thickness (CMT) and total macular volume (TMV) using optical coherence tomography (OCT). Repeat investigations were performed at the final follow-up. RESULTS: Location of SRNVM was foveal (F) in 65.6% eyes and extrafoveal (EF) in 34.4% eyes. Both CMT and TMV were lower significantly at baseline in EF-SRNVM. Fifty-six eyes received intravitreal bevacizumab and 8 eyes received ranibizumab. Average 2.14 ± 1.21 injections (range, 1-6) were administered. After a mean follow-up duration of 16.01 ± 12.96 months, the final visual acuity (VA) improved in 35.9% eyes, reduced in 28.1% and remained unchanged in 35.9% eyes. Significant improvement of VA was seen in F-SRNVM; however, overall, there was no significant improvement in visual acuity. Significant reduction in CMT was seen in F-SRNVM from 391.73 ± 152.45 µm to 293.33 ± 114.77 µm (p < 0.05) while EF-SRNVM did not show significant reduction. Total macular volume overall changed significantly from 8.79 ± 1.69 to 8.05 ± 1.27 (p < 0.05) and individually in F- and EF-SRNVM (p < 0.05). Intravitreal bevacizumab and ranibizumab monotherapy both had similar efficacy. CONCLUSIONS: Anti-VEGF agents can be successfully used to treat proliferative MacTels. Macular volume measurement on OCT may be a useful parameter for evaluating EF-SRNVM and as a prognostic marker of management outcomes.

Clinico-demographic profile and outcomes of 25-gauge vitrectomy in advanced stage 5 retinopathy of prematurity.

BACKGROUND: Stage 5 retinopathy of prematurity is a difficult condition to treat despite technological advances in vitreous surgery. METHODS: A retrospective chart review of all consecutive cases of stage 5 ROP was performed between December 2016 and December 2018, and 21 babies were included for assessment of surgical outcomes using a modified vitrectomy technique. Data extracted from documents included demography, ROP screening status, preoperative prophylactic therapy, clinical presentation, surgery performed, and postsurgical outcomes. RESULTS: Out of the 21 babies, ophthalmologist screening was done in 42.9%. Mean birth weight was 1185 ± 222.4 g with a mean gestational age of 29.86 ± 2.0 weeks and mean post-menstrual age of 44.55 ± 9.82 weeks. Lesser than stage 5 disease was seen in 16.7% of eyes and they were managed accordingly. Seventy percent of babies had bilateral disease. 21 eyes underwent 25-gauge pars plicata vitrectomy using a modified technique. After an average follow-up duration of 6.33 ± 2.18 months, the final macular attachment rate was 19%. Anteriorly closed-posteriorly closed type configuration of retinal detachments had a poorer outcome. Fix and follow visual acuity was achieved in 23.8% of eyes, while 57.1% of eyes had a perception of light. CONCLUSIONS: Management of stage 5 ROP is mostly surgical; however, the risk of ending up with a poor vision or vision loss is high, irrespective of whether surgery is performed. The modified surgical technique with a spacer described in this study may help in better manipulation of instruments inside the vitreous cavity.

A comparison of using digitally assisted vitreoretinal surgery during repair of rhegmatogenous retinal detachments to the conventional analog microscope: A prospective interventional study.

BACKGROUND: To compare outcomes and complications of pars plana vitrectomy (PPV) using a three-dimensional heads-up visualisation system (digitally assisted vitreoretinal system, DAVS) versus conventional analog microscope (CAM) in primary rhegmatogenous retinal detachment (RRD). METHODS: This prospective interventional institutional study evaluated 60 eyes of 60 subjects with primary RRD undergoing PPV between September 2017 and February 2018. Subjects were randomly put into DAVS and CAM group and pre-operative ocular characteristics and final outcomes recorded at each visit. All subjects were followed up for a duration of 6 months. Main outcome measures recorded were post-operative retinal status, visual acuity (VA), intraocular pressure (IOP) and surgical complications. RESULTS: Overall final retinal attachment at 6 months was 91.7% (90% in DAVS eyes and 93.3% in CAM eyes; p = 0.999). Final VA improved significantly from baseline in both groups (p < 0.001). Overall, VA improved to > = 20/40 in 18.3% eyes (6 DAVS, 5 CAM). Median duration of silicone oil endotamponade was 3.5 months (3.5 months in DAVS, 3 months in CAM). Redetachment rate in the series was 25% (20% in DAVS, 30% in CAM). Post-operative proliferative vitreoretinopathy grade C and more was present in 15% of eyes (10% in DAVS, 20% in CAM). Average duration of surgery was 37 ± 6.2 min in DAVS group and 39.8 ± 6.6 min in CAM group (p = 0.09). All steps of vitrectomy could be performed with relative ease and comfort with the DAVS platform. CONCLUSION: Anatomical and functional outcomes of RRD were favourable with DAVS and comparable to that with conventional microscope surgery.

Two-staged surgery as an alternative to buckle-vitrectomy for rhegmatogenous retinal detachment complicated by choroidal detachment.

AIM: To evaluate the outcome and safety profile of short-term perfluorocarbon liquids (PFCL) tamponade in comparison with buckle-vitrectomy in case of rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD). METHODS: Records of patients who underwent surgery for RRD/CD from January 2016 to July 2019 were reviewed retrospectively. The patients were allocated into two groups-group 1 patients underwent buckle-vitrectomy, while those in group 2 underwent a two-staged vitrectomy with short-term (5 days) PFCL tamponade. RESULTS: The study included 33 eyes (33 patients) with mean age of 50.3 ± 17.2 years. Group 1 included 15 patients, while group 2 included 18. The pre-operative characteristics were similar in both the groups. The mean pre-operative intraocular pressure in group 1 and 2 was 9.1 ± 4.0 and 8.6 ± 5.2 mmHg, respectively (p = 0.755). Retinal re-attachment after single surgery was achieved in 10 (66.7%) and 14 eyes (77.8%), respectively. All the eyes achieved retinal re-attachment after repeat surgery in both the groups (1.40 vs 1.39 surgeries, p = 0.963). Post-surgery visual improvement was seen in 13 (86.7%) and 17 eyes (94.4%), respectively (p = 0.579). Final visual acuity of ≥ 6/60 was obtained in 7 (46.7%) and 9 eyes (50.0%), respectively (p > 0.999). None of the patients needed retinectomy during repeat surgery. None of the patients experienced exaggerated inflammation or intractable raised IOP spike which could not be controlled with medications. CONCLUSION: Surgical outcomes were similar in both the groups. No clinically apparent toxicity was seen with post-operative short-term PFCL tamponade. Two-staged surgery is a good alternative to buckle-vitrectomy for eyes with RRD associated with CD.

Ten-year trends in the incidence, clinical profile and outcomes of acute-onset endophthalmitis following combined pars plana vitrectomy and sutureless, glueless and flapless scleral fixation of intraocular lenses.

PURPOSE: To evaluate the frequency and outcomes of acute-onset endophthalmitis following combined pars plana vitrectomy and scleral fixation of intraocular lens. METHODS: We evaluated patients undergoing a sutureless, glueless, flapless technique of scleral fixation of intraocular lenses (SFIOL) implantation for various causes of aphakia and documented the clinico-demographic data, microbiological profile and final outcome after acute endophthalmitis in this cohort of eyes. RESULTS: The frequency of suspected acute endophthalmitis diagnosed post-surgery was 0.112% (4/3541 eyes), with culture-positive endophthalmitis frequency being 0.028% (1 eye), showing growth of Pseudomonas aeruginosa. Mean age of patients with endophthalmitis was 51.75 ± 9.28 years, and mean interval between surgery and acute endophthalmitis presentation was 10.25 ± 9.6 days. Patients were managed with intravitreal antibiotics with or without core vitrectomy. Visual acuity of patients increased from baseline 1.43 ± 0.32 logMAR (Snellen equivalent = 6/150) to 0.79 ± 0.16 logMAR (Snellen equivalent = 6/36) after an average follow-up of 11 ± 2 weeks. CONCLUSION: Endophthalmitis is a rare complication following SFIOL surgery, and all ophthalmic surgeons must be aware of this inadvertent possibility, since SFIOLs are gaining wider acceptability recently. Moreover, these cases of endophthalmitis may show a different pattern of microorganisms than post-cataract surgery endophthalmitis; however, with prompt diagnosis and effective timely management, favorable outcomes can be achieved.

A splicing mutation in aryl hydrocarbon receptor associated with retinitis pigmentosa.

Retinitis pigmentosa (RP) refers to a group of retinal degenerative diseases, which often lead to vision loss. Although 70 genes have been identified in RP patients, the genetic cause of approximately 30% of RP cases remains unknown. We aimed to identify the cause of the disease in a cohort of RP families by whole exome sequencing. A rare homozygous splicing variant, c.1160 + 1G>A, which introduced skipping of exon 9 of the aryl hydrocarbon receptor (AHR), was identified in family RD-134. This variant is very rare in several exome databases and leads to skipping of exon 9 in the transcript. AHR is expressed in the human retina and is a ligand-activated transcription factor with multiple functions. Mutant AHR failed to promote 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-induced xenobiotic responsive element (XRE) luciferase activity. In parallel, mutation in AHR abolished activation of its downstream target gene, such as CYP1A1 and CYP1A2. To investigate the in vivo roles of Ahr in the retina, we generated a retina-specific conditional knockout mouse model of Ahr. Comparing with wild-type mouse, Ahr knockout mice exhibited reduced electroretinogram responses at 9 months of age. Retinal histology revealed retinal histology showed the degeneration of photoreceptors with a thinner outer nuclear layer. Thus, our data demonstrate that AHR is associated with RP.

Treatment of retinopathy of prematurity (ROP) outside International Classification of ROP (ICROP) guidelines.

AIM: To evaluate the incidence and clinical indications for which eyes were treated for retinopathy of prematurity (ROP) outside the guidelines set by International Classification of ROP (ICROP). METHODS: Medical records of the patients treated at a single tertiary care ophthalmology hospital for ROP from January 2016 to December 2019 were retrospectively analysed to evaluate the indications for which they were treated. RESULTS: Out of 241 eyes, 33 eyes (13.7%) were treated outside the guidelines. The reasons for the treatment outside the guidelines were structural changes (n = 24, 72.7%), persistent stage 3 ROP that did not show any sign of regression for 6 weeks (n = 7, 21.2%) and active ROP with fellow eye being treated (n = 2, 6.1%). The recorded specific structural changes were tangential traction with temporal vessel straightening concerning for macular distortion and ectopia (n = 5, 15.2%), and stage 3 neovascularisation or ridge with anteroposterior traction with risk of progression to stage 4 disease (n = 19, 57.6%). Pre-plus disease was present in 11 eyes (33.3%).After the treatment, ROP stages regressed and retinal vessels grew either until the ora or at least into zone III in all the treated eyes. None of the eyes showed worsening of structural changes after treatment. The mean follow-up of the patients was 12.4 ± 11.7 months. CONCLUSION: Experts occasionally recommend treatment in eyes with disease milder than type 1 ROP. This study may help paediatric retinal practitioners in decision-making in borderline cases.

Distribution of peripheral lesions identified by mydriatic ultra-wide field fundus imaging in diabetic retinopathy.

PURPOSE: To analyze the distribution of diabetic retinopathy (DR) lesions in an Indian population using ultra-wide field (UWF) fundus imaging. METHODS: Seven hundred fifteen subjects (1406 eyes) with diabetic retinopathy in India were enrolled in this multicenter, prospective, observational study using UWF pseudocolor imaging with Optos Daytona Plus (Optos plc, Dunfermline, Scotland, UK). Images were transmitted to Doheny Image Reading Center, Los Angeles, CA, for grading. The ETDRS grid was overlaid on stereographic projections of UWF images, and images were graded independently by 2 masked graders. Lesion distribution was graded as predominantly central (PCL) or predominantly peripheral (PPL) according to previous criteria, considering both lesion number and area. An image was graded as PPL if > 50% of the lesion area was seen in at least one peripheral field as compared with the corresponding ETDRS field. Diabetic retinopathy severity was also assessed based on the International Classification of Diabetic Retinopathy (ICDR) grading scale. The main outcome measures were lesion distribution (PPL versus PCL): overall and within specific fields in eyes with various grades of DR. RESULTS: Lesion distribution was rated to be PPL in 37% of eyes and PCL in 63% of eyes (P < 0.003). The frequency of a PPL distribution varied significantly across all ICDR severity levels, with frequencies of mild non-proliferative DR (NPDR) (30.9%), moderate NPDR (40.3%), severe NPDR (38.5%) and PDR (34.9%), P = 0.005. When assessing which individual fields were rated to show a PPL distribution, the frequency was greatest in field 4 and least in field 7. For any grade of DR, temporal fields showed the greatest PPL frequency, followed in order by the superior, inferior, and nasal fields (P < 0.001). Only 3.5% of eyes showed PPL distribution in all five peripheral fields. CONCLUSIONS: One-third of the UWF images showed a PPL distribution in this cohort with the temporal quadrant having the widest distribution of PPL. As the PPL distribution varied significantly between various grades of DR, UWF imaging may prove to be important for screening of referral warranted retinopathy.

Clinical presentation and prognostic factors affecting surgical outcomes of secondary macular holes after retinal vein occlusions.

PURPOSE: To describe clinical presentation, morphological features and surgical outcomes of macular hole (MH) secondary to retinal vein occlusion (RVO). METHOD: This prospective interventional study evaluated eight eyes with atypical MH (secondary to RVO) and data regarding medical management, pars plana vitrectomy, postoperative anatomical hole closure, visual acuity improvement, morphological features of hole were noted till the last follow-up. RESULTS: Eight eyes with full-thickness MH in an RVO eye were followed-up for a minimum period of 3 months postoperatively. Five subjects had a RVO episode which occurred more than 6 months before the onset of the recent symptoms (Group 1; 4 branch RVO and 1 central RVO), and 3 subjects had a recent onset branch RVO within 6 months (Group 2). All FTMH cases except one showed closure at the last follow-up. Visual acuity of all eyes improved from 0.91 ± 0.57 logMAR to 0.5 ± 0.3 logMAR (p = 0.093). At baseline, visual acuities of the two groups had no significant difference. Postoperatively, group 1 holes had better visual prognosis, than Group 2 holes, further substantiated by persistence of subretinal fluid in Group 2 eyes till last follow-up. Minimum hole diameter was higher in the recent RVO group, although anatomical closure was obtained in all of these eyes. Most holes had favorable morphological hole features like raised configuration with rounded edges. CONCLUSION: In the presence of favorable morphological features, secondary macular holes associated with retinal vein occlusion may show optimal outcomes after surgery. It is not clear whether acutely created holes in recent onset RVO should be operated early. Older holes may have better prognosis.

Comparative study of inverted internal limiting membrane (ILM) flap and ILM peeling technique in large macular holes: a randomized-control trial.

BACKGROUND: The anatomical success rate of macular hole surgery ranges around 93-98%. However, the prognosis of large macular holes is generally poor. The study was conducted to compare the anatomical and visual outcomes of Internal Limiting Membrane (ILM) peeling vis-a-vis inverted ILM flap for the treatment of idiopathic large Full-Thickness Macular Holes (FTMH). METHODS: This was a prospective randomized control trial. The study included patients with idiopathic FTMH, with a minimum diameter ranging from 600 to 1500 µm. The patients were randomized into Group A (ILM peeling) and Group B (inverted ILM flap). The main outcome measures were anatomical and visual outcome at the end of 6 months. Anatomical success was defined as flattening of macular hole with resolution of the subretinal cuff of fluid and neurosensory retina completely covering the fovea. RESULTS: There were 30 patients in each group. The mean minimum diameters in Group A and B were 759.97 ± 85.01 µm and 803.33 ± 120.65 µm respectively (p = 0.113). The mean base diameter in group A and B was 1304.50 ± 191.59 µm and 1395.17 ± 240.56 µm respectively (p = 0.112). The anatomical success rates achieved in Group A and B were 70.0 and 90.0% respectively (p = 0.125). The mean best-corrected visual acuity (BCVA) after 6 months was logMAR 0.65 ± 0.25 (Snellen equivalent, 20/89) in Group A and logMAR 0.53 ± 0.20 (Snellen equivalent, 20/68) in Group B (p = 0.060). The mean improvement in BCVA was 1.4 lines and 2.1 lines in groups A and B respectively (p = 0.353). BCVA≥20/60 was achieved by 13.3 and 20.0% in group A and B respectively (p = 0.766). CONCLUSION: The anatomical and functional outcome of Inverted ILM flap technique in large FTMH is statistically similar to that seen in conventional ILM peeling. TRIAL REGISTRATION: Clinical Trials Registry - India (Indian Medical Research) CTRI/2017/11/010474 .

Outcome of 2 cc pure sulfur hexafluoride gas tamponade for macular hole surgery.

BACKGROUND: Isoexpansile concentrations of intraocular gases are typically used as tamponading agent in macular hole surgery. Using a small volume of the pure form of these gases may achieve the same result without increasing the incidence of postoperative complications. The purpose of this study was to evaluate the anatomical and visual outcomes following macular hole surgery with 2 cc pure (100 %) sulfur hexafluoride (SF6) gas tamponade. METHODS: A retrospective study of eyes with idiopathic macular holes that underwent 23-gauge pars plana vitrectomy with 2 cc pure SF6 gas tamponade. Macular hole surgery was performed alone or in combination with phacoemulsification in eyes with cataract. Preoperative and postoperative data including best corrected visual acuity recorded in LogMAR units, slit-lamp biomicroscopy, and optical coherence tomography were analysed. Surgical complications were also recorded. RESULTS: Seventy six eyes of seventy five patients were analysed. A closure rate of 100 % was achieved with reoperation in 4 eyes. There was a significant improvement in best-corrected visual acuity from a mean of 0.65 LogMAR preoperatively to 0.36 at 6 months (p value 0.004). Forty five (59 %) eyes gained at least 2 lines on the Snellen visual acuity chart. Postoperative elevation in intraocular pressure (≥30 mmHg) was documented in 3 eyes (4 %). CONCLUSION: Macular hole surgery with 2 cc pure SF6 gas tamponade achieved a high success rate with a low incidence of complications. The smaller volume of gas required makes it a cheaper technique.

Genome-wide association study for sight-threatening diabetic retinopathy reveals association with genetic variation near the GRB2 gene.

AIMS/HYPOTHESIS: Diabetic retinopathy is a serious complication of diabetes mellitus and can lead to blindness. A genetic component, in addition to traditional risk factors, has been well described although strong genetic factors have not yet been identified. Here, we aimed to identify novel genetic risk factors for sight-threatening diabetic retinopathy using a genome-wide association study. METHODS: Retinopathy was assessed in white Australians with type 2 diabetes mellitus. Genome-wide association analysis was conducted for comparison of cases of sight-threatening diabetic retinopathy (n = 336) with diabetic controls with no retinopathy (n = 508). Top ranking single nucleotide polymorphisms were typed in a type 2 diabetes replication cohort, a type 1 diabetes cohort and an Indian type 2 cohort. A mouse model of proliferative retinopathy was used to assess differential expression of the nearby candidate gene GRB2 by immunohistochemistry and quantitative western blot. RESULTS: The top ranked variant was rs3805931 with p = 2.66 × 10(-7), but no association was found in the replication cohort. Only rs9896052 (p = 6.55 × 10(-5)) was associated with sight-threatening diabetic retinopathy in both the type 2 (p = 0.035) and the type 1 (p = 0.041) replication cohorts, as well as in the Indian cohort (p = 0.016). The study-wide meta-analysis reached genome-wide significance (p = 4.15 × 10(-8)). The GRB2 gene is located downstream of this variant and a mouse model of retinopathy showed increased GRB2 expression in the retina. CONCLUSIONS/INTERPRETATION: Genetic variation near GRB2 on chromosome 17q25.1 is associated with sight-threatening diabetic retinopathy. Several genes in this region are promising candidates and in particular GRB2 is upregulated during retinal stress and neovascularisation.