Miguel A. Zapata

Topical anesthesia: Possible risk factor for endophthalmitis after cataract extraction

PURPOSE: To assess the relationship between the risk for acute endophthalmitis after cataract extraction and whether certain factors, such as surgeon qualification, numerical order, duration of surgery, operating theater, and type of anesthesia (topical or retrobulbar), could be modified to decrease the risk. SETTING: Single‐center academic practice. METHODS: Two epidemiological studies were performed: a case‐control study and a retrospective cohort study. The surgical records of all patients with clinically diagnosed endophthalmitis within 30 days after cataract surgery performed between February 2002 and September 2003 were reviewed. The endophthalmitis cases were compared with 108 randomly selected controls (4 controls per case). The global incidence of endophthalmitis and the incidence according to type of anesthesia were calculated. RESULTS: Of 5011 cataract extractions performed, 27 cases of endophthalmitis occurred. The incidence was 5.39 per 1000 procedures. An independent statistically significant relationship was found between endophthalmitis and the use of topical anesthesia (odds ratio [OR], 11.8; 95% confidence interval [CI], 2.4‐58.7) and surgery longer than 45 minutes (OR, 7.2; 95% CI, 1.7‐29.7) but not between the other variables. The incidence of endophthalmitis was 1.8 per 1000 cataract extractions with retrobulbar anesthesia and 6.76 per 1000 with topical anesthesia (relative risk [RR], 3.76; 95% CI, 0.89‐15.85). After the start of the study period was extended to May 2001, the incidence of endophthalmitis was 1.3 per 1000 cataract extractions with retrobulbar anesthesia and 8.7 per 1000 with topical anesthesia (RR, 6.72; 95% CI, 1.63‐27.63). CONCLUSION: Results suggest that there may be an association between topical anesthesia and endophthalmitis after cataract extraction.

Endoresection in high posterior choroidal melanomas: long-term outcome

Background: Eyes with high posterior choroidal melanomas are frequently enucleated because of the potential complications of radiotherapy. The aim of this study was to evaluate the safety and efficacy of endoresection at long-term follow-up. Methods: Retrospective, non-randomised, interventional case series. Thirty-eight patients underwent endoresection. For primary procedures, inclusion criteria were tumour thickness ⩾8 mm, base <15 mm, tumours not exceeding the equatorial area. Endoresection was also undertaken as the salvage procedure in four patients. Main outcomes measured were metastatic disease, survival, local recurrences, visual acuity, enucleation rate, and surgical complications. Results: Follow-up time ranged from 23 to 129 months (mean 70.63 months). Preoperative visual acuity ranged from “hand-movements” to 20/20 (mean, 20/60). In primary cases, mean tumour thickness was 10.1 mm and mean base diameter 9.9 mm. At the latest visit, 92.1% patients still retained the eye. Final visual acuity ranged from “no light perception” to 20/30 (mean 20/300). Two patients experienced local recurrence before 3 years of follow-up. Melanoma metastatic disease was found in two patients at 5 years of follow-up. Kaplan–Meier survival analysis for all causes was 88.2% at 5 years. Specific survival was 90.9% at 5 years. Conclusions: At long-term follow-up, the risk of metastasis or local recurrence, and survival rates were similar to other techniques, although comparisons are difficult because of the unusual presentation of this type of melanoma. Further studies and longer follow-up are needed.

Epiretinal Membrane After Pars Plana Vitrectomy For Primary Pseudophakic Or Aphakic Rhegmatogenous Retinal Detachmentincidence and outcomes

Purpose: To compare outcomes of eyes that did or did not develop an epiretinal membrane (ERM) after repair of primary pseudophakic or aphakic rhegmatogenous retinal detachment by pars plana vitrectomy alone. Methods: Interventional, prospective, consecutive case series. Of 312 consecutive eyes that underwent pars plana vitrectomy for primary rhegmatogenous retinal detachment, 28 (8.97%) developed ERM during the postoperative period. Best-corrected visual acuity (BCVA) and fundus examinations were performed 1 month and 3, 6, and 12 months postoperatively. Results: Eyes with an ERM more often had a break at the equator (odds ratio, 3.92; 95% confidence interval, 1.3–11.2; P < 0.011). At ERM diagnosis, BCVA ranged from 20/400 to 20/25 with a mean of 20/100 (0.75 logarithm of the minimum angle of resolution), and BCVA at the final visit ranged from 20/200 to 20/25 with a mean of 20/63 (0.53 logarithm of the minimum angle of resolution). Of the 22 eyes that underwent surgical removal of the ERM, BCVA was ≥20/40 in 5 (22.7%) before the surgical procedure and in 13 (59%) at the final follow-up visit. Conclusion: The incidence of ERM after pars plana vitrectomy alone for the repair of primary pseudophakic or aphakic rhegmatogenous retinal detachment was similar to reported incidences after scleral buckling. Best-corrected visual acuity improved after surgical removal of ERM, although eyes with the macula detached had lower final BCVA.

Evaluation of macular retinal ganglion cell-inner plexiform layer thickness after vitrectomy with internal limiting membrane peeling for idiopathic macular holes.

Purpose. To evaluate macular retinal ganglion cell-inner plexiform layer (GCIPL) thickness changes after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole repair using a high-resolution spectral-domain optical coherence tomography (SD-OCT). Methods. 32 eyes from 32 patients with idiopathic macular holes who underwent vitrectomy with internal limiting membrane peeling between January 2011 and July 2012 were retrospectively analyzed. GCIPL thickness was measured before surgery, and at one month and at six months after surgery. Values obtained from automated and semimanual SD-OCT segmentation analysis were compared (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA). Results. No significant differences were found between average GCIPL thickness values between preoperative and postoperative analysis. However, statistical significant differences were found in GCIPL thickness at the temporal macular quadrants at six months after surgery. Quality measurement analysis performed by automated segmentation revealed a significant number of segmentation errors. Semimanual segmentation slightly improved the quality of the results. Conclusion. SD-OCT analysis of GCIPL thickness found a significant reduction at the temporal macular quadrants at 6 months after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole.

Macular holes after rhegmatogenous retinal detachment repair: surgical management and functional outcome.

Purpose: To review the surgical management and functional outcome of macular holes (MHs) developing after rhegmatogenous retinal detachment repair. Methods: Retrospective, interventional, noncomparative case series. Twenty patients with MH developing after rhegmatogenous retinal detachment repair were included. Pars plana vitrectomy with internal limiting membrane peeling and gas tamponade was performed. Macular attachment status and number of best-corrected visual acuity lines of improvement after MH repair were evaluated. Results: The fovea had been detached in all eyes at the time of rhegmatogenous retinal detachment repair. Six MHs developed after scleral buckling surgery and 14 MHs after vitrectomy with an encircling band. In 5 of the 20 patients, ≥2 operations had been required to achieve retinal reapplication. The mean time to MH diagnosis was 38 weeks. Preoperative best-corrected visual acuity was ≤20/100 in all but one case. Single-operation MH closure rate was 100%, with a mean of 4 Early Treatment Diabetic Retinopathy Study lines of visual improvement (P < 0.001). Mean postoperative Snellen best-corrected visual acuity was 20/70 (±0.15) (P < 0.001). Conclusion: In this small retrospective study, standard surgical treatment for idiopathic MH was effective in achieving anatomical closure of these secondary MHs, but visual acuity gain was limited by the previous macula-involving rhegmatogenous retinal detachment status.

Vitreoretinal surgery without schisis cavity excision for the management of juvenile X linked retinoschisis

Juvenile X linked retinoschisis (XLRS) is a congenital X linked recessive retinal disorder characterised by cystic maculopathy and peripheral schisis. This study presents the case of an 8-month-old boy with a documented positive family history of XLRS, with a large retinoschisis cavity affecting the macula, first in the left eye and 1 year later in the right eye. The patient underwent pars plana vitrectomy in both eyes using 23-G instruments, posterior hyaloid dissection, a small retinotomy, fluid drainage with a 42-G cannula, infrared diode laser and silicone oil as internal tamponade. The anatomical and functional outcomes at 3 years following the first surgery are described. To the authors’ knowledge, there is no previously reported experience with this technique in patients with XLRS.

Comparative study of human embryonic stem cells (hESC) and human induced pluripotent stem cells (hiPSC) as a treatment for retinal dystrophies

Retinal dystrophies (RD) are major causes of familial blindness and are characterized by progressive dysfunction of photoreceptor and/or retinal pigment epithelium (RPE) cells. In this study, we aimed to evaluate and compare the therapeutic effects of two pluripotent stem cell (PSC)-based therapies. We differentiated RPE from human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (hiPSCs) and transplanted them into the subretinal space of the Royal College of Surgeons (RCS) rat. Once differentiated, cells from either source of PSC resembled mature RPE in their morphology and gene expression profile. Following transplantation, both hESC- and hiPSC-derived cells maintained the expression of specific RPE markers, lost their proliferative capacity, established tight junctions, and were able to perform phagocytosis of photoreceptor outer segments. Remarkably, grafted areas showed increased numbers of photoreceptor nuclei and outer segment disk membranes. Regardless of the cell source, human transplants protected retina from cell apoptosis, glial stress and accumulation of autofluorescence, and responded better to light stimuli. Altogether, our results show that hESC- and hiPSC-derived cells survived, migrated, integrated, and functioned as RPE in the RCS rat retina, providing preclinical evidence that either PSC source could be of potential benefit for treating RD.

Retinal Venous Occlusions: Diagnosis and Choice of Treatments

Retinal vascular occlusive disorders constitute one of the major causes of blindness and impaired vision. There is marked controversy on their pathogeneses, clinical features and particularly their management. Recently, advances in clinical research added antivascular endothelial growth factor, corticosteroids and sustained-release implants to our armamentarium in the management of retinal vein occlusions. The purpose of our paper is to provide an update and a brief review on the current treatment options of retinal vein occlusions.

Retinal Sensitivity And Choroidal Thickness In High Myopia

Purpose: To estimate the association between choroidal thickness in the macular area and retinal sensitivity in eyes with high myopia. Methods: This investigation was a transversal study of patients with high myopia, all of whom had their retinal sensitivity measured with macular integrity assessment microperimetry. The choroidal thicknesses in the macular area were then measured by optical coherence tomography, and statistical correlations between their functionality and the anatomical structuralism, as assessed by both types of measurements, were analyzed. Results: Ninety-six eyes from 77 patients with high myopia were studied. The patients had a mean age ± standard deviation of 38.9 ± 13.2 years, with spherical equivalent values ranging from −6.00 diopter to −20.00 diopter (8.74 ± 2.73 diopter). The mean central choroidal thickness was 159.00 ± 50.57. The mean choroidal thickness was directly correlated with sensitivity (r = 0.306; P = 0.004) and visual acuity but indirectly correlated with the spherical equivalent values and patient age. The mean sensitivity was not significantly correlated with the macular foveal thickness (r = −0.174; P = 0.101) or with the overall macular thickness (r = 0.103; P = 0.334); furthermore, the mean sensitivity was significantly correlated with visual acuity (r = 0.431; P < 0.001) and the spherical equivalent values (r = −0.306; P = 0.003). Conclusion: Retinal sensitivity in highly myopic eyes is directly correlated with choroidal thickness and does not seem to be associated with retinal thickness. Thus, in patients with high myopia, accurate measurements of choroidal thickness may provide more accurate information about this pathologic condition because choroidal thickness correlates to a greater degree with the functional parameters, patient age, and spherical equivalent values.

Insulin resistance and diabetic macular oedema in type 2 diabetes mellitus.

Objective To evaluate the association between insulin resistance and diabetic macular oedema in type 2 diabetes. Methods Patients with type 2 diabetes who agreed to undergo blood sampling were enrolled into this cross-sectional study. Patients who had received treatment for macular oedema within the past 3 months and those with other retinal diseases were excluded. The following data were recorded: age, sex, time of diabetes evolution, HbA1c, ophthalmologic and systemic treatment, and lens status. Optical coherence tomography (OCT) was performed to determine the morphological patterns of macular oedema. Insulin resistance was established by a McAuley index of <6.3 and fasting insulin levels of >16 mU/l. Results A total of 177 eyes from 90 patients were included; 27.1% of eyes were from insulin-resistant patients. There were no differences in age, time of evolution, sex, HbA1c level or lens status between insulin-resistant and non-resistant patients. Insulin-resistant patients were more likely to have exogenous insulin therapy (p<0.05; OR=3.8). An association was found between diabetic cystoid macular oedema and insulin resistance (Fisher exact test p=0.007; OR=2.53, 95% CI 1.52 to 4.2). There were no associations between insulin resistance and the other morphological patterns of oedema. Patients undergoing insulin therapy were found to have an association with a diffuse retinal thickening pattern on OCT (p=0.036; OR=1.4). However, no association was found between insulin therapy and the presence of cystoid macular oedema. Conclusions The findings of this study indicate a relationship between insulin resistance and cystoid macular oedema that unrelated to the use of insulin. Insulin treatment was associated with diffuse macular oedema.