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.

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.

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.

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.

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.

Medium to long-term intraocular pressure control following small flap trabeculectomy (microtrabeculectomy) in relatively low risk eyes.

AIM: To determine the long-term efficacy of small flap trabeculectomy (microtrabeculectomy) in terms of intraocular pressure (IOP) control in relatively low risk eyes. METHOD: A review of a case series of small flap trabeculectomy procedures performed on 36 eyes from 36 patients with a minimum follow up of 24 months (mean 50.8). RESULTS: The mean (SD) intraocular pressures at presentation and preoperatively were 33.7 (7.5) and 24.6 (4.5) mm Hg. At 6 months, 1, 2, 3, 4, 5, and 6 years the mean (n, SD) IOPs (mm Hg) of those eyes followed to each time point were 11.9 (36, 4.6), 12.6 (36, 4.7), 13.2 (36, 4.6), 13.7 (29, 4.1), 13.2 (22, 4.0), 12.7 (15, 4.8), and 12.3 (8, 4.7) respectively. There was no significant difference in IOP levels at any of the analysis points by one way ANOVA. Kaplan-Meier analysis revealed survival rates of 80% at 4 years and 75% at 5 years when any postoperative IOP > 20 mm Hg is considered a failure, and 50% at 6 years when any IOP > 15 mm Hg is classed as a failure. CONCLUSION: Small flap trabeculectomy (microtrabeculectomy) is effective at reducing IOP in low risk glaucoma eyes with IOP control similar to previous reports of filtering surgery utilising larger scleral trapdoors.

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.

Reproducibility of volumetric measurements of normal maculae with the Heidelberg retina tomograph.

AIMS: The Heidelberg retina tomograph (HRT) is a scanning laser ophthalmoscope with confocal optics. The reproducibility of the optic nerve head topography is accurate and reliable. The authors describe a new technique for the assessment of macular thickening by volumetric quantification and present the results of its reproducibility in normal subjects. METHODS: Topographic images of the macula, centred on the fovea were obtained in one eye of 44 normal subjects. The volumes above the reference plane bound by a 1 mm, 2 mm, and 3 mm diameter circle were measured. The reference plane was adjusted to the lowest point of the height variation of the contour line at each examination. The reproducibility of repeated measurements within a 2 mm diameter circle was assessed in 20 eyes selected at random. Three HRT scans of each eye were obtained. The measurements of volume above reference plane of each scan were repeated three times on three separate days. RESULTS: The intrascan coefficients of variability measured 7.12-9.57%. The 95% confidence interval for the geometric mean ratio of single volume measurements was 0.92 to 1.24 for scans 1 and 2, 0.89 to 1.17 for scans 1 and 3, and 0.81 to 1.12 for scans 2 and 3. When the mean of three measurements of one scan were compared with the mean of three measurements of a second scan, the 95% confidence interval for their geometric mean ratio was 0.89 to 1.20 for scans 1 and 2, 0.89 to 1.16 for scans 1 and 3, and 0.84 to 1.13 for scans 2 and 3. The average standard deviation (SD) for one measurement per scan was 0.02 mm3, and 0.019 mm3 for two or three measurements per scan. Linear regression demonstrated a significant increase in SD as volumetric measurements increased (p = 0.003). Age did not significantly affect the SD of volumetric measurements (p = 0.797). The authors found no significant differences in volumetric measurements across all ages for all three circles (p = 0.314, p = 0.471, p = 0.267). CONCLUSION: Good reproducibility for volumetric measurements at the macula was found with the HRT using the above technique in normal subjects. This method may be extremely useful for the identification and quantification of diabetic macular oedema and for monitoring the effects of argon laser photocoagulation.

Topographic and keratometric astigmatism up to 1 year following small flap trabeculectomy (microtrabeculectomy).

AIM: To determine the induced corneal astigmatism by measuring the changes in manual keratometry and computerised corneal videokeratoscopy up to 1 year following small flap trabeculectomy (microtrabeculectomy). METHOD: A prospective study of a case series of small flap trabeculectomy procedures performed at the 90 degree meridian on 16 eyes of 16 patients, all followed to 1 year postoperatively. Changes in manual keratometry and computerised videokeratoscopy (Eyesys) readings were analysed by vector analysis and vector decomposition techniques. RESULTS: By vector analysis, the mean surgically induced refractive change (SIRC) cylinder power vectors induced at 1, 3, 6, and 12 months as measured by manual keratometry were 0.68, 0.38, 0.52, and 0.55 dioptres, and by keratography 0.75, 0.66, 0.59, and 0.64 dioptres. Vector decomposition on the induced vector cylinders on manual keratometry resulted in a "with the rule" mean vector of 0.52 and 0.22 dioptres at 1 and 3 months and an "against the rule" mean vector of 0.16 and 0.16 dioptres at the same time points (p=0.03 and 0.28 respectively). Vector decomposition at 6 and 12 months revealed no significant with the rule changes induced. Similar analysis on the videokeratoscopy results revealed significant induced with the rule astigmatism until 3 months, but not at 6 and 12 months postoperatively. CONCLUSION: Small flap trabeculectomy (microtrabeculectomy) produces smaller changes in corneal curvature that resolve sooner than previous reports of larger flap techniques.

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.

Cataract formation in the Cronkhite-Canada syndrome.

A 69-year-old man with Cronkhite-Canada syndrome presented with a 6 month history of gradually blurring vision resulting from early lens opacities that 1 month later had reduced visual acuity to hand movement in both eyes. Extracapsular cataract extraction with intraocular lens implantation resulted in good visual rehabilitation.

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.

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.