Helen K. Li

Retinal Thickness on Stratus Optical Coherence Tomography in People with Diabetes and Minimal or No Diabetic Retinopathy

PURPOSE To evaluate optical coherence tomography (OCT) thickness of the macula in people with diabetes but minimal or no retinopathy and to compare these findings with published normative data in the literature from subjects reported to have no retinal disease. DESIGN Cross-sectional study. METHODS In a multicenter community- and university-based practices setting, 97 subjects with diabetes with no or minimal diabetic retinopathy and no central retinal thickening on clinical examination and a center point thickness of 225 microm or less on OCT (Stratus OCT; Carl Zeiss Meditec, Dublin, California, USA) were recruited. Electronic Early Treatment of Diabetic Retinopathy Study best-corrected visual acuity, seven-field stereoscopic color fundus photographs, and Stratus OCT fast macular scan were noted. Main outcome measures were central subfield (CSF) thickness measured on Stratus OCT. RESULTS On average, CSF thickness was 201 +/- 22 microm. CSF thickness was significantly greater in retinas from men than retinas from women (mean +/- standard deviation, 209 +/- 18 microm vs 194 +/- 23 microm; P < .001). After adjusting for gender, no additional factors were found to be associated significantly with CSF thickness (P > .10). CONCLUSIONS CSF thicknesses on Stratus OCT in people with diabetes and minimal or no retinopathy are similar to thicknesses reported from a normative database of people without diabetes. CSF thickness is greater in men than in women, consistent with many, but not all, previous reports. Studies involving comparisons of retinal thickness with expected norms should consider different mean values for women and men.

Telemedicine and ophthalmology

Technology to create and move multimedia medical information is creating alternatives to physically transporting patients and health care professionals. Teletechnology is a physician extender, both supplementing and reinventing traditional health care delivery systems. The potential of comprehensive teleophthalmology is compelling. This article provides a historical perspective of telemedicine, describes various teleophthalmology systems, and surveys teleophthalmology in clinical consultation, research, and education programs around the world. It also discusses basic issues in applying teleophthalmology to public health.

Comparison of time-domain OCT and fundus photographic assessments of retinal thickening in eyes with diabetic macular edema.

PURPOSE To explore the correlation between optical coherence tomography (OCT) and stereoscopic fundus photographs (FP) for the assessment of retinal thickening (RT) in diabetic macular edema (DME) within a clinical trial. METHODS OCT, FP, and best corrected visual acuity (VA) measurements were obtained in both eyes of 263 participants in a trial comparing two photocoagulation techniques for DME. Correlation coefficients (r) were calculated comparing RT measured by OCT, RT estimated from FP, and VA. Principal variables were central subfield retinal thickness (CSRT) obtained from the OCT fast macular map and DME severity assessed by a reading center using a seven-step photographic scale combining the area of thickened retina within 1 disc diameter of the foveal center and thickening at the center. RESULTS Medians (quartiles) for retinal thickness within the center subfield by OCT at baseline increased from 236 (214, 264) microm in the lowest level of the photographic scale to 517 (455, 598) microm in the highest level (r = 0.67). However, CSRT interquartile ranges were broad and overlapping between FP scale levels, and there were many outliers. Correlations between either modality and VA were weaker (r = 0.57 for CSRT, and r = 0.47 for the FP scale). OCT appeared to be more reproducible and more sensitive to change in RT between baseline and 1 year than was FP. CONCLUSIONS There was a moderate correlation between OCT and FP assessments of RT in patients with DME and slightly less correlation of either measure with VA. OCT and FP provide complementary information but neither is a reliable surrogate for VA.

Early Treatment of Posterior Retinopathy of Prematurity: A Controlled Trial

OBJECTIVE The purpose of the study is to assess the possible benefits of early laser treatment for posterior retinopathy of prematurity (ROP) and to provide data concerning the natural history of posterior ROP. DESIGN The study design was a prospective, multicenter, randomized trial. PARTICIPANTS A total of 19 infants with prethreshold posterior ROP were studied. INTERVENTION Randomization to immediate indirect laser photocoagulation or observation, with application of laser photocoagulation for those control eyes reaching threshold disease, was performed. MAIN OUTCOME MEASURES Patients were assessed at 3 months and the anatomic outcome recorded along with any adverse treatment effects. RESULTS An unfavorable structural outcome developed in 3 (16%) of 19 early treatment eyes compared with 3 (18%) of 17 for those treated only if threshold disease was reached. Of the 17 control eyes, 15 (88%) reached threshold disease. Progression to threshold occurred within 1 week in all but two eyes. All 12 control eyes with posterior ROP and any amount of extraretinal fibrovascular proliferation progressed to threshold disease. CONCLUSIONS Although the number of patients studied is too small to reach statistical significance, the likelihood of a favorable outcome for eyes with prethreshold posterior ROP treated immediately with laser photocoagulation is comparable to that obtained by withholding treatment until threshold disease is reached. There is a high probability of progression from prethreshold to threshold disease, usually within 1 week or less.

Reversal of Visual Loss with Hyperbaric Oxygen Treatment in a Patient with Susac Syndrome

PURPOSE The purpose of the study is to report on a 34-year-old woman with Susac syndrome who presented on two separate occasions with visual acuity loss from a recurrent branch retinal artery occlusion and underwent hyperbaric oxygen treatment with favorable outcome. METHODS Visual acuity was 20/400 in the left eye and count fingers in the right eye after separate occlusive events. The patient underwent hyperbaric oxygen treatment on each occasion of visual acuity loss. The patient subsequently was diagnosed with Susac syndrome (microangiopathy of the retina, brain, and middle ear). The authors present visual fields, photographs, angiograms, and ancillary tests documenting diagnosis and course of treatment. RESULTS On each occasion, visual acuity improved to 20/25 during and was maintained after hyperbaric oxygen treatment. Visual fields showed improvement immediately after treatment. CONCLUSION This is the first report of hyperbaric oxygen treatment for Susac syndrome. Dramatic post-treatment visual field and acuity changes suggest benefit of treatment. Hyperbaric oxygen treatment can be considered a treatment option for visual complications of this syndrome. Susac syndrome should be included in the differential diagnosis of recurrent branch retinal artery occlusion.

Sub-tenon’s injection for local anesthesia in posterior segment surgery

OBJECTIVE To determine whether the sub-Tenons parabulbar approach for local anesthesia is a safe and effective choice for posterior segment surgery. DESIGN Prospective, noncomparative case series. PARTICIPANTS Two hundred seventy-six consecutive patients underwent posterior segment surgery at the University of Texas Medical Branch. INTERVENTION Two hundred patients received sub-Tenons parabulbar anesthesia containing an 11 -ml mixture of 5-ml 2% lidocaine (Xylocaine), 5-ml 0.5% bupivacaine (Marcaine), and 1 ml of 150 hyaluronidase (Wydase) units as primary anesthesia. The method did not involve a separate transcutaneous lid nerve or subconjunctival injection. MAIN OUTCOME MEASURES The proportion of cases receiving supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both) was estimated. Its relationship to duration of surgery and surgical procedures deemed painful was assessed. Surgery lasting 3 hours or more was considered a long duration. Both scleral buckle and cryotherapy were considered painful procedures. The proportion of cases receiving additional local anesthesia preoperatively was also evaluated. Complications associated with sub-Tenons parabulbar injection were monitored. RESULTS There were 101 instances of patients receiving additional anesthesia. Nineteen received additional preoperative sub-Tenons anesthesia, 12 received intraoperative local anesthesia supplementation, and 70 received intravenous medication. Of these 70, 19 required what the authors defined as a significant amount of intravenous medication, three of whom also received intraoperative local anesthesia supplementation. Consequently, 28 of 200 patients (14%; 95% confidence interval: 9.5, 19.6) received supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both). The proportion of cases receiving supplementation was directly related to duration of surgery. Patients involved in longer cases (51.7% vs. 7.6%; P < 0.001) and those involved in more painful procedures (48.2% vs. 8.7%; P < 0.001) were more likely to receive supplementation. Adjusting for surgery duration, a greater proportion of patients undergoing painful procedures required supplementation (31.3% vs. 0.5% for surgery < 3 hours, P = 0.003; 72.7% vs. 38.9% for surgery > or = 3 hours, P = 0.13). No associated ocular or systemic complications were observed. CONCLUSIONS The results of this large study demonstrate that a single injection of sub-Tenons anesthesia is relatively safe and effective for achieving local anesthesia during vitrectomies, with or without other intraocular procedures, lasting less than 3 hours. Other types of posterior segment surgery may require supplementation if they are more painful procedures, such as scleral buckle or cryotherapy, or last longer than 3 hours.

Telehealth practice recommendations for diabetic retinopathy, second edition.

Ocular telemedicine and telehealth have the potential to decrease vision loss from DR. Planning, execution, and follow-up are key factors for success. Telemedicine is complex, requiring the services of expert teams working collaboratively to provide care matching the quality of conventional clinical settings. Improving access and outcomes, however, makes telemedicine a valuable tool for our diabetic patients. Programs that focus on patient needs, consider available resources, define clear goals, promote informed expectations, appropriately train personnel, and adhere to regulatory and statutory requirements have the highest chance of achieving success.

Retinal changes associated with tamoxifen treatment for breast cancer

Purpose: This study was undertaken to estimate the incidence of retinal changes and determine the prevalence of ocular toxicity associated with tamoxifen treatment in a breast cancer population.Methods: The study was based on a population cross-sectional survey, including 290 patients taking tamoxifen from 6 months to 12 years; 274 patients were analysed. The main outcome measures were the incidence of retinal changes and visual impairment.Results: The incidence of retinal changes was 0.9% (3 of 274 patients). All 3 patients were asymptomatic. The length of tamoxifen treatment ranged from 39 months to 120 months in the affected patients, with cumulative tamoxifen doses ranging from 23.7 g to 73 g.Conclusions: Retinopathy in patients receiving low doses of tamoxifen is rare and, in our study, did not result in changes in visual acuity. We found no retinopathy in patients receiving tamoxifen within the first 3 years of treatment or in patients receiving a total tamoxifen dosage of less than 23.7 g. Although retinopathy can occur in a tamoxifen-treated population its low incidence and an associated good prognosis for vision does not merit special screening for this problem.

The significance of white-centered retinal hemorrhages in the shaken baby syndrome

Retinal hemorrhages in healthy children with or without a history of associated trauma are a strong indicator of child abuse. This report describes six cases of battered infants who presented with white-centered retinal hemorrhages. We discuss potential mechanisms for the presence of white-centered retinal hemorrhages in battered children.

Comparability of digital photography with the ETDRS film protocol for evaluation of diabetic retinopathy severity.

PURPOSE To evaluate digital photography parameters affecting comparability with the Early Treatment Diabetic Retinopathy Study (ETDRS) film protocol for diabetic retinopathy (DR) severity grading. METHODS ETDRS protocol photographs and four variations of digital images (uncompressed stereoscopic, compressed stereoscopic, uncompressed monoscopic, and uncompressed monoscopic wide-angle mosaic) of 152 eyes were independently evaluated by using ETDRS classifications. Digital formats were compared to film and each other for agreement on severity level, DR presence at ascending threshold, presence of the DR index lesion, and repeatability of grading. Study parameters included image resolution sufficient to distinguish small lesions, color balancing of digital images to film, documenting essential ETDRS classification retinal regions, similar magnification, and supplementary green-channel viewing. RESULTS The κ statistic was substantial or near substantial between all digital formats and film for classifying severity levels (κ = 0.59-0.62; κ(w) [linear weighted] = 0.83-0.87). The distribution of DR levels in all digital formats was not significantly different from that of the film (Bhapkar test, P = 0.09-0.44). The κ among digital formats for severity level was also substantial or near substantial (κ = 0.58-0.76, κ(w) = 0.82-0.92). Differences between digital formats and film for grading severity level, severity threshold, or index lesions were not significant. The repeatability of grading between readers using film and all digital formats was also similar. CONCLUSIONS Digital format variations compared favorably with film for DR classification. Translating film characteristics (resolution, color/contrast) and protocol (magnification, retinal regions) to digital equivalents and augmentation of full color with green-channel viewing most likely contributed to the results.