Surgical outcomes of vitrectomy surgery for proliferative diabetic retinopathy in patients with abnormal renal function.

PURPOSE: To analyse the influence of renal function on the outcomes of vitrectomy for tractional-related complications in cases of severe proliferative diabetic retinopathy (PDR). METHODS: Retrospective consecutive case series of 109 eyes that underwent vitreoretinal interventions for traction-related complications of severe PDR from 2014 to 2017. Data collected included patient demographics, best-corrected visual acuity (BCVA), surgical complications, and systemic markers including HbA1c and estimated glomerular filtration rate (eGFR). Renal function categories were defined as low (eGFR < 30 mL/min/1.73 m2), medium (eGFR 30-60 mL/min/1.73 m2), and normal (eGFR > 60 mL/min/1.73m 2). RESULTS: A total of 109 eyes (56% (n = 61) female) were included in the study. Overall, mean baseline BCVA improved from 1.33 logMAR to 0.91 logMAR (p < 0.001) postoperatively. Patients with low eGFR had significantly worse baseline BCVA (p = 0.039) and demonstrated greater improvement in mean BCVA (p = 0.059). Multivariate regression analysis indicated that seven predictors explained 65.5% of the variance (R2 = 0.655, F(11,97) = 16.7, p < 0.01). CONCLUSIONS: Reduced renal function does not adversely affect visual outcomes of vitrectomy for traction-related complications of PDR.

Spectral domain ocular coherence tomography findings pre- and post vitrectomy with fibrovascular membrane delamination for proliferative diabetic retinopathy.

PurposeTo describe the intraretinal microstructure using serial spectral domain optical coherence tomography (SD-OCT) preceding and following pars plana vitrectomy and delamination of fibrovascular membranes in patients with proliferative diabetic retinopathy (PDR).MethodsThis retrospective, interventional case series includes 28 eyes. Outcome measures included LogMAR distance best-corrected visual acuity (BCVA), SD-OCT integrity of photoreceptor inner and outer segments junction (IS/OS), and integrity of external limiting membrane (ELM).ResultsPre-operative central macular thickness (CMT) was significantly correlated with the final post-operative LogMAR BCVA (Pearson's coefficient r=0.89; P=0.001). The eyes were categorised into three groups based on post-operative IS/OS integrity (group 0: IS/OS intact; group 1: IS/OS irregular but not completely disrupted; group 2: IS/OS completely disrupted). Mean BCVA improved significantly in group 0 (n=9) from 1.13±0.75 preoperatively to 0.34±0.21 (Student's t-test: P=0.06), in group 1 (n=10) the BCVA improved from 0.88±0.56 to 0.58±0.31 (Student's t-test: P=0.053) and in group 2 (n=9) the BCVA improved from 1.64±0.53 to 1.53±0.75 (Student's t-test: P=0.652).IS/OS integrity and ELM integrity at 3 months post operatively, were significantly and positively correlated with final BCVA (Pearson's coefficient: r=0.83, P<0.001 and r=0.72, P<0.001, respectively).ConclusionsPre-operative CMT and post-operative disruption of the IS/OS and ELM are useful prognostic indicators in fibrovascular delamination surgery for patients with PDR.

Enhanced depth imaging-OCT of the choroid: a review of the current literature.

BACKGROUND: With the advent of enhanced depth imaging optical coherence tomography (EDI-OCT), detailed visualisation of the choroid in vivo is now possible. Measurements of choroidal thickness (CT) have also enabled new directions in research to study normal and pathological processes within the choroid. The aim of the present study is to review the current literature on choroidal imaging using EDI-OCT. METHODS: Studies were identified by a systematic search using Medline ( http://www.ncbi.nlm.nih.gov/pubmed ). Papers were also identified based on the reference lists of relevant publications. Papers were included in the review if the focus of the study involved imaging of the choroid using EDI-OCT. RESULTS: Recent studies have demonstrated successful imaging of the choroid and high reproducibility of measurements of CT using EDI-OCT. There are much data confirming that abnormalities in choroidal structure and function contribute to major ocular diseases and patterns of CT variation may be observed in certain disease states and may be influenced by treatment. However, it is not clear whether these variations are a contributing factor or a consequence of the disease. CONCLUSION: While more invasive methods such as indocyanine green (ICG) angiography remain the gold standard for detecting abnormalities of the choroidal vasculature in normal eyes and disease states, EDI-OCT has become an important adjunctive clinical tool in providing three-dimensional anatomical information of the choroid.

Pilot randomised controlled trial of face-down positioning following macular hole surgery.

OBJECTIVE: This was a pilot randomised controlled trial (RCT) to investigate the effect of post-operative face-down positioning on the outcome of macular hole surgery and to inform the design of a larger definitive study. METHODS: In all, 30 phakic eyes of 30 subjects with idiopathic full-thickness macular holes underwent vitrectomy with dye-assisted peeling of the ILM and 14% perfluoropropane gas. Subjects were randomly allocated to posture face down for 10 days (posturing group) or to avoid a face-up position only (non-posturing group). The primary outcome was anatomical hole closure. RESULTS: Macular holes closed in 14 of 15 eyes (93.3%; 95% confidence interval (CI) 68-100%) in the posturing group and in 9 of 15 (60%; 95% CI 32-84%) in the non-posturing group. In a subgroup analysis of outcome according to macular hole size, all holes smaller than 400 µm closed regardless of posturing (100%). In contrast, holes larger than 400 µm closed in 10 of 11 eyes (91%; 95% CI 58-99%) in the posturing group and in only 4 of 10 eyes (40%; 95% CI 12-74%) in the non-posturing group (Fisher's exact test P=0.02). CONCLUSION: Post-operative face-down positioning may improve the likelihood of macular hole closure, particularly for holes larger than 400 µm. These results support the case for a RCT.

Recent trends in the management of maculopathy secondary to pathological myopia.

BACKGROUND: Pathological myopia is a frequent cause of secondary visual disturbance in young individuals worldwide. Myopic maculopathy describes a spectrum of clinical changes that comprise the main cause of visual loss among highly myopic individuals. Our aim is to describe current trends in the medical and surgical management of maculopathy secondary to pathological myopia. METHODS: The epidemiology, natural history, medical and surgical treatment modalities for choroidal neovascular membrane (CNV) and vitreomacular disorders secondary to pathological myopia (PM) are reviewed and evaluated. RESULTS: The medical and surgical treatment modalities in the management of myopic maculopathy have evolved over time. Laser photocoagulation, photodynamic therapy with verteporfin and other medical treatments have been superseded by the use of anti-vascular endothelial growth factor in the management of CNV secondary to PM. Surgical treatments are beneficial in the treatment of vitreomacular interface disorders such as macular hole retinal detachment and macular traction; however, primary success rates remain lower than those for non-myopic individuals. CONCLUSIONS: This updated clinical perspective demonstrates that CNV and vitreomacular disorders in pathological myopia are treatable conditions. There are numerous medical and surgical interventions that have significantly improved the outcome of myopic maculopathy and several others currently under investigation. Nonetheless, as technology advances, further well-designed studies are necessary to establish a uniform evidence-based approach for classification and treatment.

Pseudophakic macular edema and oral acetazolamide: an optical coherence tomography measurable, dose-related response.

PURPOSE: Although uncommon after phacoemulsification surgery, cystoid macular edema (CME) is an important cause of postoperative reduction of vision after cataract surgery. To demonstrate an optical coherence tomography (OCT) measurable, dose-related response to orally administered acetazolamide in a patient presenting with pseudophakic CME. METHODS: A 76-year-old woman with reduced vision in right eye due to cataract had uneventful phacoemulsification. Surgery was complicated by early onset endophthalmitis that was treated with intravitreal antibiotics with good visual recovery. At 6 months follow-up, she presented with further reduction of vision (0.5 LogMAR) due to CME and a central foveal thickness (CFT) of 587 microm. RESULTS: Acetazolamide treatment was started in combination with topical ketorolac. At a daily dose of 500 mg, CFT and visual acuity were 262 microm and 0.34 LogMAR, respectively. Dose reduction of acetazolamide to 250 mg/day was associated with worsening of the CFT to 335 microm. CFT was subsequently measured at 230 microm on increasing the acetazolamide dose to 500 mg/day and measured 353 microm when acetazolamide dose was halved. CFT was 478 microm when acetazolamide was ceased.CONCLUSIONS. In this report, the authors have shown a dose-related response of pseudophakic CME to oral acetazolamide. This would suggest that the clinical response to oral acetazolamide may be titrated to the extent of CME and monitored by OCT.

The effect of pars plana vitrectomy on cystoid macular oedema associated with chronic uveitis: a randomised, controlled pilot study.

AIM: To evaluate the efficacy of pars plana vitrectomy (PPV) in the management of chronic uveitic cystoid macular oedema (CMO). METHODS: A prospective, interventional, randomised, controlled, pilot study. 23 eyes of 23 patients with CMO secondary to chronic intermediate or posterior uveitis unresponsive to medical treatment were randomised into a surgical (group S) or medical group (group M). 12 patients in group S underwent PPV as opposed to 11 patients in group M who received systemic corticosteroid and/or immunosuppressive treatment during the study period. The primary outcome measures of the study were change in visual acuity and angiographic appearance of CMO at 6 months. RESULTS: Mean visual acuity in group S improved significantly from 1.0 (0.62) at baseline to 0.55 (0.29) at 6 months following vitrectomy (p = 0.011), with five (42%) eyes reaching vision of 20/40 or better. Conversely, mean visual acuity in group M improved only marginally by 0.03 (0.27) (p = 0.785). CMO after vitrectomy was angiographically improved in four (33%) eyes, remained unchanged in seven (58%) eyes, and deteriorated in one (8%) eye. In the medical group, fluorescein leakage decreased in one eye, did not alter in four eyes, and deteriorated in two eyes. CONCLUSION: PPV for macular oedema secondary to chronic uveitis despite angiographic improvement in only one third of the patients, seems to have a significant beneficial effect on visual function. This study provides enough evidence to justify a large scale trial which would define the role of vitrectomy in uveitic macular oedema.

High resolution imaging of fluorescein patterns in RCS rat retinae and their direct correlation with histology.

To assess the progressive changes in the retinal vascular bed of dystrophic and non-dystrophic Royal College of Surgeons (RCS) rats, retinae, were visualised correlating in vivo fundus fluorescein angiography (FA) with histology. FA was performed in rats aged 5 weeks to 2 years, using a Zeiss confocal scanning laser ophthalmoscope (cSLO). After the final imaging session, a subset of retinae were prepared for flat-mount histology and the vascular bed was visualised using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) staining. While non-dystrophic rat retinae showed no substantive changes in vascular patterns with age and no demonstrable fluorescein leakage up to at least 1 year, dystrophic rat retinae showed abnormal vascular formations, demonstrable on FA and NADPH-d staining, which could be correlated in single retinae. Hyperfluorescent spots and late angiographic leakage were evident beginning at 10 weeks and progressed in severity with time: they were coincident in distribution with abnormal histological vascular complexes. The ability to monitor the same retina serially makes this approach a valuable tool for studying the dynamics of vascular change in the diseased retina, not only during the course of degeneration but also when assessing efficacy of potential therapeutic approaches.

Vitrectomy and radial optic neurotomy for central retinal vein occlusion: effects on visual acuity and macular anatomy.

BACKGROUND: Central retinal vein occlusion (CRVO) is a common retinal vascular disorder and a leading cause of visual loss. It is thought to arise from vascular obstruction at the level of the lamina cribrosa. The purpose of the study reported here was to evaluate the potential benefit of radial optic neurotomy (RON) and determine its effect on foveal thickness and macular volume in patients with CRVO. METHODS: We conducted a prospective pilot study of ten patients with CRVO. Visual acuity (VA) score measured with the Early Treatment Diabetic Retinopathy Study chart and the corresponding Snellen equivalent were assessed before and 6 months after surgery. Colour fundus photography, fluorescein angiography (FA) and optical coherence tomography (OCT) were carried out before and at 2, 6, 12 and 24 weeks after surgery. Foveal thickness and macular volumes were assessed using OCT. RESULTS: Visible reperfusion was observed in four of the ten patients at the time of surgery. VA score improved in eight of the ten patients from a median score of 11.50 (range 0-68) to a median score of 35.00 (range 3-79). Macular volumes decreased in six of seven patients from a median of 4.99 mm3 (range 2.68-6.77) to a median of 3.11 mm3 (range 1.11-5.02). Foveal thickness decreased in six of seven patients from a median of 596.50 microm (range 338.50-745.50) to a median of 330.50 microm (range 118-634.50). Six of ten patients developed a chorioretinal venous anastomosis. Macular oedema on OCT persisted in six of ten patients. CONCLUSIONS: We observed an improvement in VA score and a corresponding reduction in foveal thickness and macular volume following RON, but macular oedema persisted in 60% of patients. Whilst optimisation of patient selection criteria remains a challenge, this pilot study suggests that RON has a beneficial effect on VA in patients presenting with CRVO.

Macular microholes: pathogenesis and natural history.

AIMS: To study the natural history and evaluate optical coherence tomography (OCT) and the retinal thickness analyser (RTA) in patients with macular microholes. METHODS: The medical records of 22 patients with a well demarcated red intraretinal foveal or juxtafoveal defect were reviewed. Fluorescein angiography (FA), RTA, and OCT were performed. The main outcome measures were visual acuity (VA), and OCT and RTA characteristics of microholes. Long term follow up was available in 13 eyes of 12 patients. RESULTS: The patients had a mean age of 50 years and a mean refractive error of -0.93 dioptres. The presenting symptom was a central scotoma in 14 eyes and metamorphopsia in eight eyes. All patients had a corrected VA ranging from 20/16 to 20/125, with 20 out of 24 eyes (83%) having a VA > or =20/40. Symptoms remained stable or improved in 16 out of 22 patients (72%). OCT 2 findings were normal but an abnormality of the outer retina and/or a defect of the retinal pigment epithelium (RPE) were demonstrated on OCT 3 in 15 of 18 eyes (83%). The RTA topographic map demonstrated a defect at the site of the microhole in two out of 12 eyes. CONCLUSION: Although biomicroscopic examination suggested an inner foveal defect, the OCT 3 scans demonstrated a localised abnormality of the outer retina and/or RPE which could not be resolved using OCT 2. Macular microholes have a favourable long term prognosis with stable VA. Bilateral involvement is uncommon.

Successful treatment of varicella zoster virus retinitis with aggressive intravitreal and systemic antiviral therapy.

AIMS: To describe the successful treatment of varicella zoster virus retinitis (VZVR) using intravenous cidofovir as part of an aggressive management strategy. CASE REPORTS: Two patients with bilateral VZVR were treated with a combination of intravenous cidofovir and ganciclovir with adjuvant intravitreal foscarnet or ganciclovir. Both patients maintained good vision in the less severely affected eye. Retinal detachment did not occur in either patient. CONCLUSIONS: VZVR should be treated aggressively with a combination of intravenous and intravitreal therapy to improve visual prognosis. Intravenous cidofovir, in the absence of contra-indications, should be considered as part of this aggressive therapeutic approach, especially in patients with AIDS in whom the prognosis is particularly poor.

CMVR diagnoses and progression of CD4 cell counts and HIV viral load measurements in HIV patients on HAART.

AIM: To assess the impact of highly active antiretroviral therapy (HAART) on the prevalence and progression of CMV retinitis (CMVR) among AIDS patients with baseline CD4 cell counts <100 cells x 10(6)/l. METHODS: A longitudinal cohort study of 1292 patients. CD4 cell counts and HIV viral load measurements were obtained before commencing therapy, at 3 months, 1 year, 2 years, and at last follow up. The CMVR prevalence rate was measured for the subgroup with baseline CD4 cell counts <100 cells x 10(6)/l. CMVR adverse event (AE) rates per 100 person days at risk were calculated for the subgroup with CMVR and baseline CD4 cell counts <100 cells x 10(6)/l. RESULTS: 1292 patients were started on HAART. 8% of patients had CD4 counts <50 cells x 10(6)/l and 40% had detectable HIV viral load at last follow up. The prevalence of CMVR for the subgroup with baseline CD4 <100 cells x 10(6)/l was 10%. For those with baseline CD4 <100 cells x 10(6)/l, the mean CMVR AE rate was greatest during the first 6 months of follow up after HAART commencement (p <0.003). The mean AE rate per 100 person days at risk was 0.36 (95% CI 0.167 to 0.551) before starting HAART, and 0.14 (95% CI 0.085 to 0.199) after starting HAART (p = 0.03). CONCLUSIONS: HAART significantly prolongs the disease-free intervals in patients with pre-existing disease but recurrences persist within the first 6 months of starting therapy. AE were absent beyond 18 months of follow up in all patients including those with persistently low CD4 counts and detectable HIV viral load indicating clinical immunorestoration. New methods for monitoring the response to therapy are needed to identify those at risk.

Sensitivity and specificity of a new scoring system for diabetic macular oedema detection using a confocal laser imaging system.

AIM: To assess the use of the Heidelberg retina tomograph (HRT) in screening for sight threatening diabetic macular oedema in a hospital diabetic clinic, using a new subjective analysis system (SCORE). METHODS: 200 eyes of 100 consecutive diabetic patients attending a diabetologist's clinic were studied, all eyes had an acuity of 6/9 or better. All patients underwent clinical examination by an ophthalmologist. Using the HRT, one good scan was obtained for each eye centred on the fovea. A System for Classification and Ordering of Retinal Edema (SCORE) was developed using subjective assessment of the colour map and the reflectivity image. The interobserver agreement of using this method to detect macular oedema was assessed by two observers (ophthalmic trainees) who were familiarized with SCORE by studying standard pictures of eyes not in the study. All scans were graded from 0-6 and test positive cases were defined as having a SCORE value of 0-2. The sensitivity of SCORE was assessed by pooling the data with an additional 88 scans of 88 eyes in order to reduce the confidence interval of the index. RESULTS: 12 eyes in eight out of the 100 patients had macular oedema clinically. Three scans in three patients could not be analysed because of poor scan quality. In the additional group of scans 76 out of 88 eyes had macular oedema clinically. The scoring system had a specificity of 99% (95% CI 96-100) and sensitivity of 67% (95% CI 57-76). The predictive value of a negative test was 87% (95% CI 82-99), and that of a positive test was 95% (95% CI 86-99). The mean difference of the SCORE value between two observers was -0.2 (95% CI -0.5 to +0.07). CONCLUSIONS: These data suggest that SCORE is potentially useful for detecting diabetic macular oedema in hospital diabetic patients.

Assessment of the Heidelberg Retina Tomograph in the detection of sight-threatening diabetic maculopathy.

PURPOSE: To assess the potential role of the Heidelberg Retina Tomograph (HRT) in screening for sight-threatening macular oedema in diabetes. METHODS: One hundred and thirty-one eyes of 81 consecutive diabetic patients who fitted the inclusion criteria were included in the study. On HRT, the volume above the reference plane bound within a 2 mm diameter circle centred at the fovea was measured. The volumetric indices were compared with the mean measurement index in a group of 20 age-matched controls (mean score = 1, mean +2 SD score = 1.8). We also assessed the sensitivity of the subjective analysis of the intensity image and the addition of the three-dimensional map to the intensity image for detecting macular oedema and clinically significant macular oedema (CSMO). RESULTS: One hundred and twelve eyes of 71 patients had a corrected Snellen visual acuity of 6/9 or better. When considering eyes with 6/9 or better vision only, the system's sensitivity for detecting CSMO was 58.33% 'per eye' examined, and 81.82% 'per patient' examined using a cut-off volumetric index of 1.8. In our study eyes with 6/9 or better vision, we found a 21% prevalence of CSMO. The predictive values of a positive test were 38.89% and 45% (cut-off score 1.8, 'per eye' and 'per patient' respectively) for CSMO. The predictive values of a negative test were 86.84% and 90.48% (cut-off score 1.8, 'per eye' and 'per patient' respectively) for CSMO. CONCLUSIONS: The volumetric assessment of diabetic maculopathy by HRT is a potentially useful method for screening eyes at risk. A larger group of patients with a greater number of eyes with minimal or no maculopathy is required to establish the specificity of this technique.