Factors affecting anatomical and visual outcome after macular hole surgery: findings from a large prospective UK cohort.

OBJECTIVES: To reassess the definition of a large macular hole, factors predicting hole closure and post-surgery visual recovery. DESIGN: Database study of 1483 primary macular hole operations. Eligible operations were primary MH operations treated with a vitrectomy and a gas or air tamponade. Excluded were eyes with a history of retinal detachment, high myopia, previous vitrectomy or trauma. RESULTS: A higher proportion of operations were performed in eyes from females (71.1%) who were 'on average' younger (p < 0.001), with slightly larger holes (p < 0.001) than male patients. Sulfur hexafluoride gas was generally used for smaller holes (p < 0.001). From 1253 operations with a known surgical outcome, successful hole closure was achieved in 1199 (96%) and influenced by smaller holes and complete ILM peeling (p < 0.001), but not post-surgery positioning (p = 0.072). A minimum linear diameter of ~500 µm marked the threshold where the success rate started to decline. From the 1056 successfully closed operations eligible for visual outcome analysis, visual success (defined as visual acuity of 0.30 or better logMAR) was achieved in 488 (46.2%) eyes. At the multivariate level, the factors predicting visual success were better pre-operative VA, smaller hole size, shorter duration of symptoms and the absence of AMD. CONCLUSIONS: Females undergoing primary macular hole surgery tend to be younger and have larger holes than male patients. The definition of a large hole should be changed to around 500 µm, and patients should be operated on early to help achieve a good post-operative VA.

Genetic algorithm based feature selection combined with dual classification for the automated detection of proliferative diabetic retinopathy.

Proliferative diabetic retinopathy (PDR) is a condition that carries a high risk of severe visual impairment. The hallmark of PDR is the growth of abnormal new vessels. In this paper, an automated method for the detection of new vessels from retinal images is presented. This method is based on a dual classification approach. Two vessel segmentation approaches are applied to create two separate binary vessel map which each hold vital information. Local morphology features are measured from each binary vessel map to produce two separate 4-D feature vectors. Independent classification is performed for each feature vector using a support vector machine (SVM) classifier. The system then combines these individual outcomes to produce a final decision. This is followed by the creation of additional features to generate 21-D feature vectors, which feed into a genetic algorithm based feature selection approach with the objective of finding feature subsets that improve the performance of the classification. Sensitivity and specificity results using a dataset of 60 images are 0.9138 and 0.9600, respectively, on a per patch basis and 1.000 and 0.975, respectively, on a per image basis.

Automated detection of proliferative diabetic retinopathy using a modified line operator and dual classification.

Proliferative diabetic retinopathy (PDR) is a condition that carries a high risk of severe visual impairment. The hallmark of PDR is neovascularisation, the growth of abnormal new vessels. This paper describes an automated method for the detection of new vessels in retinal images. Two vessel segmentation approaches are applied, using the standard line operator and a novel modified line operator. The latter is designed to reduce false responses to non-vessel edges. Both generated binary vessel maps hold vital information which must be processed separately. This is achieved with a dual classification system. Local morphology features are measured from each binary vessel map to produce two separate feature sets. Independent classification is performed for each feature set using a support vector machine (SVM) classifier. The system then combines these individual classification outcomes to produce a final decision. Sensitivity and specificity results using a dataset of 60 images are 0.862 and 0.944 respectively on a per patch basis and 1.00 and 0.90 respectively on a per image basis.

Visual acuity outcomes following surgery for idiopathic epiretinal membrane: an analysis of data from 2001 to 2011.

PURPOSE: Pars plana vitrectomy (PPV) is commonly used to remove the epiretinal membrane (ERM), but the timing of surgical intervention guided by visual acuity (VA) performance at presentation is uncertain. PATIENTS AND METHODS: Prospectively entered clinical data of 237 patients on an electronic patient record from 2001 to 2011 were analysed to determine visual outcomes, in particular in relation to pre-operative VA. RESULTS: The mean age of the patients was 68.8 years and 54.4% were female. Median follow-up was 0.55 years. The median pre-operative logMAR VA was 0.60 (SD 0.48-0.78, Snellen equivalent 6/36) and post-operative VA was 0.30 (SD 0.18-0.60, 6/12, P<0.005). Pre-operative VA correlated with post-operative VA (linear R(2)=0.22, P<0.0001). In all, 69.6% of patients showed an improvement in VA, 15.2% showed no change, and the condition of 15.2% worsened. The number of patients with an improvement in logMAR VA of more than 0.3 was greatest in those who had a pre-operative VA of 1.0 (6/60) or worse, followed by those in the range of 0.6-0.9 and then those with pre-operative VA of 0.5 or better (P<0.001). The proportion of patients with visual improvement of logMAR VA of more than 0.3 increased statistically with progressing years (P=0.019). CONCLUSION: In conclusion, this study shows improvement in VA after PPV and ERM removal. Patients with better initial VA achieve higher levels of visual outcome but those with poorer pre-operative VA show a greater change in VA following ERM surgery. Results of surgery improved over the time period of the study.

Characteristics of rhegmatogenous retinal detachment and their relationship to visual outcome.

AIMS: To examine pre-operative characteristics of rhegmatogenous retinal detachment (RRD) and their relationship to visual acuity (VA) following surgery. METHODS: Review of prospectively completed electronic database. Baseline characteristics, retinal drawings and outcomes were analysed. RESULTS: In all, 847 eyes from 847 patients with a mean age of 62.2 years, 60% males, and 56% right eyes were studied. Mean follow-up was 9.6 months. Preoperative VA correlated with final VA (r(2)=0.21, P<0.0001). Median postoperative VA was 6/9 (Logmar 0.18, quartiles=0.0-0.48) and was significantly related to anatomical success: 70.15% achieved 0.18 or better with fully attached retina and primary success, whereas only 8.33% achieved this when the retina was not fully attached at final follow-up (failure) (P<0.0001). Univariate analysis found multiple variables associated with achieving 0.18 postoperative vision, however, multivariate analysis revealed only primary anatomical success with surgery; absence of proliferative vitreo-retinopathy (PVR), better-presenting VA and fewer quadrants of detachment were associated with a better visual outcome (r(2)=0.26, P<0.0001). Patients with a clinically attached fovea achieved better vision than patients with a clinically detached fovea, independent of the visual loss duration. With foveal detachment however, postoperative VA was better in patients with 1-3 days of visual loss compared with 4-6 days (P=0.013). CONCLUSIONS: Failure of primary surgery, PVR, extensive RRD and poor-presenting VA are risk factors for poorer visual outcome following surgery for RRD. Fovea off RRD at presentation achieved poorer postoperative VA than fovea attached and visual outcome was poorer when there was a longer duration of visual symptoms.

Characteristics of rhegmatogenous retinal detachment in pseudophakic and phakic eyes.

AIMS: To investigate whether pseudophakic and phakic rhegmatogenous retinal detachment (RRD) patterns differ. METHODS: Retrospective review of electronic database of patients, aged 50 years or over, presenting to our vitreoretinal service. Data included baseline characteristics, digital drawings, and outcomes. Retinal drawings were analysed in a masked fashion for site, size, and number of retinal breaks. Comparisons were made between the following groups and subgroups: pseudophakic eyes, phakic eyes, phakic eyes with cataract, and phakic eyes without cataract. RESULTS: Of 500 eyes included, 146 were pseudophakic; 177 of the phakic eyes had cataract. The following were significant by univariate analysis: pseudophakic patients were older than phakic patients in general, but the same age as patients with cataract; in the pseudophakic group, there were lower proportions of females and of patients presenting with vitreous haemorrhage or with large or superotemporal breaks; higher proportions of pseudophakic eyes had small breaks and inferonasal breaks. Some differences remained significant when comparing pseudophakia eyes with cataract. Multivariate analysis comparing pseudophakia with phakia confirmed a lower chance in pseudophakia of large breaks, vitreous haemorrhage and superotemporal breaks, but higher chance of detached inferior breaks. Some variables were age dependent. CONCLUSION: Differences were found between pseudophakic and phakic RRD patterns. These suggest special pathogenetic mechanisms in pseudophakic retinal detachment, which could help explain increased incidences of RRD after cataract surgery.

The incidence and the risk factors for iatrogenic retinal breaks during pars plana vitrectomy.

PURPOSE: To establish the frequency and the risk factors for iatrogenic retinal breaks during three-port pars plana vitrectomy (PPV). METHODS: A total of 2471 PPV operations were included in the study. The study period was between 2001 and 2010, all the data were entered in an electronic patient record database. All 270 consecutive eyes of 270 patients developing iatrogenic retinal breaks during primary PPV were matched to 270 controls. Univariate and multivariate analysis were performed to establish the risk factors. RESULTS: The median age of the patients with iatrogenic breaks was 60.06 years; male to female ratio was 140/130. The overall frequency of iatrogenic retinal breaks was 10.09%. The frequency of iatrogenic retinal breaks for eyes undergoing PPV for tractional retinal detachment (TRD) was 32.45%. The lens status was phakic in 79.6% of the eyes, with iatrogenic breaks compared with 34.4% of the eyes in control group (P<0.001). Posterior vitreous was attached in 58.9% of the eyes with iatrogenic breaks compared with 50.4% of the eyes in control group (P=0.04). Internal limiting, epiretinal, proliferative, or fibrovascular membrane removing manoeuvers were performed in 71.1% of the eyes with iatrogenic breaks compared with 61.9% of the eyes in control group (P=0.052). CONCLUSION: Eyes undergoing PPV for TRD had significantly higher frequency of iatrogenic retinal breaks compared with other subgroups (P=0.0001). Phakia and absence of PVD were found to be risk factors for iatrogenic retinal breaks.

Surgical and visual outcome following 20-gauge vitrectomy in proliferative diabetic retinopathy over a 10-year period, evidence for change in practice.

INTRODUCTION: The study reports 10-year anatomical and visual outcome in patients who underwent pars plana vitrectomy (PPV) for complications due to proliferative diabetic retinopathy (PDR). METHODS: Retrospective analysis of patients undergoing 20 G PPV from January 1999 to May 2010 for tractional retinal detachment (TRD) and non-clearing vitreous hemorrhage (NCVH) secondary to PDR recorded prospectively on an electronic patient record. The primary aim was to study anatomical success and eyes with visual acuity (VA) of ≤ 0.3 logMAR at last follow-up. RESULTS: There were 346 eyes of 249 patients with mean age of 55.63 years and follow-up of 1.44 years. In all, 95.3% of eyes had a flat retina at final follow-up. Overall 136/346 (39.4%) eyes had final VA of logMAR ≤ 0.3 (Snellen 6/12) and 129 (37.3%) had logMAR ≥ 1.0 (Snellen 6/60). In all, 50/181 (27.6%) eyes with TRD and 84/165 (50.9%) with NCVH achieved final VA of ≤ 0.3 logMAR (Snellen 6/12). A total of 218 (63.1%) showed ≥ 0.3 logMAR improvement from baseline to last follow-up. Both preoperative VA and final postoperative (post-op) VA (P<0.001) improved significantly with each year from 1999 to 2010. The commonest peroperative complication was iatrogenic retinal tear formation (28.4%). This was a risk factor for the development of post-op retinal detachment, odds ratio: 3.90 (95% confidence interval: 1.91-7.97, P = 0.0002). Silicone oil was used in 5.2% of patients at the primary procedure. In all, 9.2% required removal of non clearing post vitrectomy hemorrhage. CONCLUSIONS: Outcomes from vitreoretinal surgery for complications of diabetic retinopathy have improved. In addition, the visual outcome after diabetic vitrectomy steadily improved over the 10-year period, which may in part be due to the move to operate on patients with better vision.

Visual and anatomical outcomes following vitrectomy for complications of diabetic retinopathy: the DRIVE UK study.

INTRODUCTION: End-stage diabetic eye disease is an important cause of severe visual impairment in the working-age group. With the increasing availability of refined surgical techniques as well as the early diagnosis of disease because of screening, one would predict that the prevalence of this condition is decreasing and the visual outcome is improving. AIM: To study the prevalence and visual outcome following vitrectomy for complications of diabetic retinopathy. MATERIALS AND METHODS: This study identified the patients who underwent vitrectomy from January 2007 to December 2009 because of diabetes-related complications in South East London. Data collected included baseline demographics, best-corrected visual acuity, indication for the vitrectomy, complication, outcome, and duration of follow-up. RESULTS: The prevalence of people requiring vitrectomy who are registered in the diabetes register of this region was 2 per 1000 people with diabetes. Vitrectomy was required in 185 eyes of 158 patients during this period. These included 83 Caucasians, 51 Afro-Caribbeans, 17 South Asians, and 7 from other ethnic groups. There were 58 patients with type I diabetes and 100 with type II, with a mean duration of diabetes of 23 and 16.5 years, respectively. The reason for vitrectomy included tractional retinal detachment (TRD) in 109 eyes, non-clearing vitreous haemorrhage (NCVH) in 68 eyes, and other causes in 8 eyes. In all, 50% of the eyes with TRD and NCVH, and 87% of the eyes with NCVH improved by at least three ETDRS lines at 12 months. Poor predictors of visual success included longer duration of diabetes (OR: 0.69), use of insulin (OR: 0.04), presence of ischaemic heart disease (OR: 0.04), delay in surgery (OR: 0.59), and the failure to attend clinic appointments (OR: 0.58). Preoperative use of intravitreal bevacizumab in eyes with TRD undergoing vitrectomy showed a marginal beneficial effect on co-existent maculopathy (P=0.08) and required less laser intervention post procedure, but did not affect the number of episodes of late-onset vitreous haemorrhage post vitrectomy (P=0.81). CONCLUSION: Visual outcome has improved significantly in eyes with complications due to diabetic retinopathy compared with the previously reported Diabetic Vitrectomy Study.

Predicting visual success in macular hole surgery.

AIM: Data on the outcome of surgery facilitate informed preoperative patient counselling. Most studies on the outcome of surgery for idiopathic full thickness macular hole surgery have concentrated on rates of anatomical closure. The aim of this study was to identify factors predicting visual success (better than 20/40; 6/12 Snellen) following macular hole surgery. METHODS: A retrospective study of 133 patients undergoing standardised macular hole surgery with at least 3 months of postoperative follow-up. All patients underwent preoperative measurement of the maximum macular hole diameter using optical coherence tomography. RESULTS: Multivariable regression analysis identified that age, preoperative visual acuity and macular hole size were significant predictors of visual success. The resulting model correctly classified the visual outcome of 80% of cases. Predicted rates of visual success varied from 93% in patients <60 years old with visual acuity better than 6/24 and a hole diameter of <350 mum, to 2% in patients those >79 years old with visual acuity of 6/60 or worse and hole diameter of >500 microm. CONCLUSION: The results provide a simple and clinically useful model to employ when counselling patients on macular hole surgery.

Vitreoretinal management of the complications of sickle cell retinopathy by observation or pars plana vitrectomy.

PURPOSE: To describe the management of vitreoretinal complications of sickle cell retinopathy. DESIGN: A retrospective interventional case series. METHODS: Review of an electronic patient record and clinical notes of 27 patients with vitreoretinal complications of sickle retinopathy. RESULTS: Six male patients and 21 female patients presented with a mean age of 41 years (range 28-67), 12 left eyes and 16 right eyes. The mean follow-up was 15.5 months (range: 3-60). Two patients were SS, and the remainders were doubly heterozygous (SC). In all, 10 were observed without surgery- three with vitreous haemorrhage, four tractional retinal detachments (TRD), and three rhegmatogenous retinal detachments (RRD). Two patients demonstrated spontaneous flattening of the retina- one RRD and one TRD. Eighteen eyes had pars plana vitrectomies (PPVs)- seven with vitreous haemorrhage, three RRD, three TRD, three ERM (one bilateral), and two macular holes. In all, 15 patients (83%) had improved vision postoperatively. The mean logMar preoperative visual acuity was 1.07 (Snellen equivalent 6/70), SD 0.62 was significantly improved postoperatively (mean 0.42 (6/15), SD 0.48, P=0.001). CONCLUSIONS: Sickle retinopathy occasionally presents with vitreoretinal complications. These can often be observed and may spontaneously regress. If surgery is required eyes respond to vitrectomy procedures with segmentation of sea fan proliferation.

Diurnal variation of macular oedema in CRVO: prospective study.

INTRODUCTION: Patients with central retinal vein occlusion (CRVO) may experience reduced vision in the morning. This may be due to increased cystoid macular oedema (CMO), which can be measured on optical coherence tomography (OCT). METHODS: A prospective study was performed on ten patients. Retinal thickness measurements were made with the Topcon 3D OCT-1000: at 9 A.M., 11 A.M., 1 P.M., 3 P.M., 5 P.M. In addition, at 9 A.M. and 5 P.M. visual acuity was recorded using ETDRS LogMAR. RESULTS: There were seven males and three females with average age of 59.4 years (range 40-80 years). The average duration of symptoms was 5.4 months (range 3-9 months). In eyes with CRVO, median central macular thickness (CMT) significantly reduced from 571 microm at 9 A.M. to 475 microm at 5 P.M. (p < 0.05). Comparison of CMT at 9 A.M. to each of the subsequent time intervals found that there was a significant reduction in the central macula thickness late in the day (p < 0.05). There was no statistical difference in the visual acuity and change in macular thickness did not correlate with change in visual acuity in eyes affected by CRVO. DISCUSSION: Patients with CRVO demonstrate increase in CMO in morning compared with late morning and afternoon. Possible causes are diurnal variation in blood pressure, retinal metabolism and erect posture. Interventions designed to influence these factors could be used to try to reduce CMO severity.

Severe folding of the inferior retina after relaxing retinectomy for proliferative vitreoretinopathy.

PURPOSE: Proliferative vitreoretinopathy (PVR) is a severe complication of retinal detachment, which can be treated surgically by relaxing retinectomy. In this study, we describe patients with severe inferior retinal folding after this surgical intervention (SIRF). METHODS: A retrospective review of the electronic patient records of 254 patients who received relaxing retinectomies was performed to identify patients with SIRF. RESULTS: Five patients (1.97% of those with retinectomy) were identified with SIRF, mean age, 51.4 years; mean follow-up, 36 months. Three patients had rhegmatogenous retinal detachment (RRD) with PVR, one had a dropped nucleus with RRD and PVR and one with giant retinal dialysis from ocular trauma. SIRF was noted from a mean 4.2 months after the retinectomy. All involved the macula and visions were hand movements or perception of light. CONCLUSIONS: SIRF is an uncommon but devastating complication of relaxing retinectomy with a poor visual outcome. This is the first description of this condition that we are aware of.

Combined removal of silicone oil plus internal search (ROSO-plus) following retinal detachment surgery.

PURPOSE: To report the rate of retinal redetachment and intervention with combined removal of silicone oil plus internal search (ROSO-plus) and to report the pathology identified. METHODS: Preoperative and peroperative findings were related to postoperative failure of the surgery defined as retinal redetachment postoperatively or silicone oil in situ at the final follow-up. RESULTS: Sixty-three patients were included in the study. Mean follow-up was 13 months. Retinopexy and further tamponade were used in 22 patients. Overall 'ROSO-plus' failed in 13 (21%) patients. Patients with subretinal fluid (SRF) in the inferior quadrants of the fundus during 'ROSO-plus' were particularly at risk of failure at 86% (six of seven patients) vs 12.5% (7/56) for the remainder (P=0.0002, relative risk=6.9, 95% confidence interval 3.2-14.6). The overall success rate at final follow-up (after any further surgery) for a flat retina without oil in situ was 83%. CONCLUSION: The 'ROSO-plus' procedure allowed identification of problems expected to result in anatomical failure. Treatment did not prevent a high rate of postoperative retinal detachment. Refinement of the treatment algorithm is required with perhaps more use of silicone oil reinsertion in high-risk eyes.

How effective is macula-off retinal detachment surgery. Might good outcome be predicted?

PURPOSE: To determine factors associated with anatomical and functional outcomes of macula-off retinal detachment surgery in a modern vitreoretinal unit. METHODS: A retrospective casenote review of 185 patients presenting with macula-off retinal detachment was performed. Demographic and ocular characteristics were determined. Logistic regression analysis was used to determine (1) the effect of these factors on visual outcome and (2) their effect on primary and final anatomical success. RESULTS: Primary and ultimate anatomical success were achieved in 76 and 84% of cases. Patients with oil in at final follow-up were considered to be anatomical failures. Statistically significant factors predicting primary anatomical success using a multiple variable model were preoperative logMAR visual acuity, preoperative PVR and number of breaks. Preop logMAR visual acuity and duration of macular detachment were the statistically significant factors predicting ultimate success. In all, 44% of patients regained 6/12 Snellen or better with a median improvement of 0.78 logMAR. For prediction of visual outcome (in patients with no ocular comorbidity) only preoperative logMAR visual acuity achieved statistical significance (P=0.001) at the P=0.05 level. CONCLUSION: In all, 76% of macula-off detachments may be repaired with one operation and 44% of patients regain at least 6/12 Snellen. The median logMAR acuity increment of 0.78 far exceeds that seen in cataract surgery. Preoperative visual acuity is the most important factor predicting primary and final anatomical success as well as visual outcome. Preoperative PVR, number of breaks and duration of detachment also affect outcomes.

Central scotoma associated with intraocular silicone oil tamponade develops before oil removal.

BACKGROUND: Unexplained sudden visual loss after removal of silicone oil from the eye has recently been described. We report the occurrence and features of unexplained central scotoma developing with silicone oil in situ in the vitreous cavity. METHODS: A retrospective case series of five patients (from two centres) who reported a central scotoma commencing during silicone oil tamponade was studied. All patients had vitrectomy for macula-on retinal detachment, with ultra-purified silicone oil tamponade (four out of five had giant retinal tear). Investigations included visual acuity, intraocular pressure, optical coherence tomography, fluorescein angiography, visual fields and electrophysiology. RESULTS: All patients reported a central scotoma that appeared during oil tamponade. Visual acuity fell by a mean of 0.93 LogMAR units after onset of the scotoma. After cataract extraction and oil removal, vision remained reduced by a mean of 0.8 units. The mean duration of oil in the eye was 2.7 months when the scotoma was noted by the patient. Investigations were performed after removal of oil. Fluorescein angiography (FFA) was performed in two cases and optical coherence tomography (OCT) in five patients. No abnormality was demonstrated. Electrophysiology was performed in five patients with pattern electroretinography suggestive of macular dysfunction in four patients. CONCLUSION: This is the first case series describing central scotoma associated with silicone oil in situ. Electrophysiology indicated macular dysfunction in most cases. We suggest that early removal of oil in cases with good visual potential should be considered to avoid this sight-threatening complication.