Sankha Amarakoon

A genetic case-control study confirms the implication of SMAD7 and TNF locus in the development of proliferative vitreoretinopathy.

PURPOSE Proliferative vitreoretinopathy (PVR) is still the major cause of failure of retinal detachment (RD) surgery and although the risk for developing this complication is associated with some clinical characteristics, the correlation is far from absolute, raising the possibility of genetic susceptibility. The objective of this study was to analyze the genetic contribution to PVR in patients undergoing RD surgery, the Retina 4 Project. METHODS A candidate gene association study was conducted in 2006 in a Spanish population of 450 patients suffering from primary rhegmatogenous RD. Replication was carried out in a larger population undergoing RD surgery at several European centers among 546 new patients. Single nucleotide polymorphism (SNP) of 30 genes known to be involved with inflammation were analyzed. For replication stage, those genes previously detected as significantly associated with PVR were genotyped. Distribution of allelic and haplotypic frequencies in case and control group were analyzed. Single and haplotypic analysis were assessed. The Rosenberg two-stage method was used to correct for single and multiple analyses. RESULTS After correction for multiple comparisons, four genes were significantly associated with PVR: SMAD7 (P = 0.004), PIK3CG (P = 0.009), TNF locus (P = 0.0005), and TNFR2 (P = 0.019) In the European sample, replication was observed in SMAD7 (P = 0.047) and the TNF locus (P = 0.044). CONCLUSIONS These results confirm the genetic contribution to PVR and the implication of SMAD7 and TNF locus in the development of PVR. This finding may have implications for understanding the mechanisms of PVR and could provide a potential new therapeutic target for PVR prophylaxis.

Bevacizumab in age-related macular degeneration: a randomized controlled trial on the effect of injections every 4 weeks, 6 weeks and 8 weeks

Purpose:  Several clinical trials have established the efficacy of ranibizumab therapy administered every 4 weeks to treat exudative age‐related macular degeneration (ARMD). Bevacizumab appears to be a cost‐effective alternative to ranibizumab, although an optimal injection schedule has not yet been determined. In this study, we set out to determine whether bevacizumab treatment in exudative ARMD every 6 or 8 weeks is non‐inferior to bevacizumab treatment every 4 weeks.

Predicting proliferative vitreoretinopathy: temporal and external validation of models based on genetic and clinical variables

Purpose To validate three models for predicting proliferative vitreoretinopathy (PVR) based on the analysis of genotypic data and relevant clinical characteristics. Methods The validation series consisted of data from 546 patients operated on from primary rhegmatogenous retinal detachment (RRD) coming from centres in the Netherlands, Portugal, Spain and the UK. Temporal and geographical validation was performed. The discrimination capability of each model was analysed and compared with the original series, using a receiver operating curve. Then, clinical variables were combined in order to improve the predictive capability. A risk reclassification analysis was performed with and without each one of the variables. Reclassification of patients was compared and models were readjusted in the original series. Readjusted models were further validated. Results One of the models showed good predictability in the temporal sample as well as in the original series (area under the curve (AUC) original=0.7352; AUC temporal=0.6457, 95% CI 50.17 to 78.97). When clinical variables were included, only pre-existent PVR improves the predictability of this model in the validation series (temporal and geographical samples) (AUC original=0.7940 vs AUC temporal=0.7744 and AUC geographical=0.7152). The other models showed acceptable AUC values when clinical variables were included although they were less accurate than in the original series. Conclusions Genetic profiling of patients with RRD can improve the predictability of PVR in addition to the well-known clinical biomarkers. This validated formula could be a new tool in our current clinical practice in order to identify those patients at high risk of developing PVR.

Prospective, Randomized Intervention Study Comparing Retinal Pigment Epithelium-Choroid Graft Surgery and Anti-VEGF Therapy in Patients with Exudative Age-Related Macular Degeneration

Purpose: To investigate whether patients with exudative age-related macular degeneration and a submacular hemorrhage, retinal pigment epithelium (RPE) tear or nonresponders to anti-vascular endothelial growth factor (VEGF) benefit more from a free RPE-choroid graft transplantation surgery than from (continuation of) anti-VEGF treatment. Procedures: A total of 20 patients were included in this prospective, international, multicenter, randomized intervention study. Results: The change in the mean number of Early Treatment of Diabetic Retinopathy Study (ETDRS) letters in the graft group 1 year postoperatively was -15 (range -54 to +26), whilst 2 patients experienced a gain of >10 letters. The median preoperative visual acuity (VA) was 0.75 logMAR (range 0.46-2.8), and the mean postoperative VA was 1.48 logMAR (range 0.14-2.8). The change in the mean number of ETDRS letters in the anti-VEGF group was -8 (range -26 to +6); no patients experienced a >10 letter gain. The median preoperative VA was 1.36 logMAR (range 0.58-1.6), and the median postoperative VA was 1.42 logMAR (range 0.44-1.66). Conclusions: The included patient group is far too small to draw conclusions. However, both gain and loss of VA may be experienced by patients undergoing either treatment method; more gain might be possible for patients with a graft in the absence of complications.

SF-6D utility values for the better- and worse-seeing eye for health states based on the Snellen equivalent in patients with age-related macular degeneration

Objective Economic evaluations in wet age-related macular degeneration (ARMD) is hampered as often utility values for solely one eye are used, mostly the better-seeing eye (BSE). Moreover, frequently chosen methods rely on patient values and/or disease specific measures, while economic evaluations prefer generic quality of life (QoL) measures based on societal preferences. The generic QoL utility instrument EQ-5D has shown to be insensitive for differences in visual acuity. The aim of this study was therefore to provide societal utility values, using the generic SF-6D, for health states acknowledging both BSE and worse-seeing eye (WSE). Methods SF-6D utility values of 191 ARMD patients (≥65 years) with 153 follow-up measures at 1 year were used to fill health states defined by the combination of BSE and WSE using Snellen equivalents; no visual loss (≥20/40), mild-moderate (<20/40–>20/200) and severe (≤20/200). Results QoL utilities were estimated for the SF-6D, ranging from 0.740 for ARMD patients without visual loss to 0.684 for patients with a combination of mild-moderate visual loss in their BSE and severe visual loss in their WSE. Conclusion Societal utility values are provided for ARMD patients using the generic QoL instrument SF-6D for visual acuity health states based on both BSE and WSE. The range of the values is smaller than previous elicited utilities with the disease-specific VisQoL. Besides, the utility values are placed on a more realistic position on the utility scale, and SF-6D utility values avoid the problem associated with the interpretation of disease-specific utility values.

Treatment Effects in Retinal Angiomatous Proliferation Imaged with OCT Angiography

Purpose: This prospective case series is aimed at exploring optical coherence tomographic angiography (OCT-A) as a treatment monitoring tool in patients treated for retinal angiomatous proliferation (RAP). Methods: Twelve treatment-naïve RAP patients were included, with a median age of 79 years (range 65–90). Patients were imaged with an experimental 1,040-nm swept-source phase-resolved OCT-A instrument before and after treatment. Treatment consisted of either intravitreal bevacizumab or triamcinolone injections with or without photodynamic therapy (PDT). Abnormal blood flow after treatment was graded as increased, unchanged, decreased, or resolved. Results: OCT-A images before and after treatment could be obtained in 9 patients. The median follow-up period was 10 weeks (range 5–19). After various treatments, the RAP lesion resolved in 7 patients, in 1 patient the OCT-A depicted decreased flow in the lesion, and 1 patient showed unchanged abnormal blood flow. Monotherapy with intravitreal bevacizumab injections resolved RAP in 1 out of 2 patients. Combined therapy of bevacizumab with PDT resolved RAP in 6 out of 7 patients. Conclusions: OCT-A visualized resolution of abnormal blood flow in 7 out of 9 RAP patients after various short-term treatment sequences. OCT-A may become an important noninvasive monitoring tool for optimizing treatment strategies in RAP patients.

Bevacizumab in age-related macular degeneration: a randomized controlled trial on the effect of on-demand therapy every 4 or 8 weeks

Intravitreal anti‐vascular endothelial growth factor (VEGF) injections are an effective treatment for neovascular age‐related macular degeneration (nARMD). Bevacizumab appears to be a cost‐effective off‐label anti‐VEGF alternative to ranibizumab, but an optimal injection schedule has not yet been determined. In this study, we investigate whether on‐demand bevacizumab treatment every 8 weeks is non‐inferior to on‐demand bevacizumab every 4 weeks in treating nARMD.