How Ophthalmologists Can Decarbonize Eye Care: A Review of Existing Sustainability Strategies and Steps Ophthalmologists Can Take.

TOPIC: Understanding approaches to sustainability in cataract surgery and their risks and benefits. CLINICAL RELEVANCE: In the United States, health care is responsible for approximately 8.5% of greenhouse gas (GHG), and cataract surgery is one of the most commonly performed surgical procedures. Ophthalmologists can contribute to reducing GHG emissions, which lead to a steadily increasing list of health concerns ranging from trauma to food instability. METHODS: We conducted a literature review to identify the benefits and risks of sustainability interventions. We then organized these interventions into a decision tree for use by individual surgeons. RESULTS: Identified sustainability interventions fall into the domains of advocacy and education, pharmaceuticals, process, and supplies and waste. Existing literature shows certain interventions may be safe, cost-effective, and environmentally friendly. These include dispensing medications at home to patients after surgery, multi-dosing appropriate medications, training staff to properly sort medical waste, reducing the number of supplies used during surgery, and implementing immediate sequential bilateral cataract surgery where clinically appropriate. The literature was lacking on the benefits or risks for some interventions, such as switching specific single-use supplies to reusables or implementing a hub-and-spoke-style operating room setup. Many of the advocacy and education interventions have inadequate literature specific to ophthalmology but are likely to have minimal risks. CONCLUSIONS: Ophthalmologists can engage in a variety of safe and effective approaches to reduce or eliminate dangerous GHG emissions associated with cataract surgery. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Normative Data and Conversion Equation for Spectral-Domain Optical Coherence Tomography in an International Healthy Control Cohort.

BACKGROUND: Spectral-domain (SD-) optical coherence tomography (OCT) can reliably measure axonal (peripapillary retinal nerve fiber layer [pRNFL]) and neuronal (macular ganglion cell + inner plexiform layer [GCIPL]) thinning in the retina. Measurements from 2 commonly used SD-OCT devices are often pooled together in multiple sclerosis (MS) studies and clinical trials despite software and segmentation algorithm differences; however, individual pRNFL and GCIPL thickness measurements are not interchangeable between devices. In some circumstances, such as in the absence of a consistent OCT segmentation algorithm across platforms, a conversion equation to transform measurements between devices may be useful to facilitate pooling of data. The availability of normative data for SD-OCT measurements is limited by the lack of a large representative world-wide sample across various ages and ethnicities. Larger international studies that evaluate the effects of age, sex, and race/ethnicity on SD-OCT measurements in healthy control participants are needed to provide normative values that reflect these demographic subgroups to provide comparisons to MS retinal degeneration. METHODS: Participants were part of an 11-site collaboration within the International Multiple Sclerosis Visual System (IMSVISUAL) consortium. SD-OCT was performed by a trained technician for healthy control subjects using Spectralis or Cirrus SD-OCT devices. Peripapillary pRNFL and GCIPL thicknesses were measured on one or both devices. Automated segmentation protocols, in conjunction with manual inspection and correction of lines delineating retinal layers, were used. A conversion equation was developed using structural equation modeling, accounting for clustering, with healthy control data from one site where participants were scanned on both devices on the same day. Normative values were evaluated, with the entire cohort, for pRNFL and GCIPL thicknesses for each decade of age, by sex, and across racial groups using generalized estimating equation (GEE) models, accounting for clustering and adjusting for within-patient, intereye correlations. Change-point analyses were performed to determine at what age pRNFL and GCIPL thicknesses exhibit accelerated rates of decline. RESULTS: The healthy control cohort (n = 546) was 54% male and had a wide distribution of ages, ranging from 18 to 87 years, with a mean (SD) age of 39.3 (14.6) years. Based on 346 control participants at a single site, the conversion equation for pRNFL was Cirrus = -5.0 + (1.0 × Spectralis global value). Based on 228 controls, the equation for GCIPL was Cirrus = -4.5 + (0.9 × Spectralis global value). Standard error was 0.02 for both equations. After the age of 40 years, there was a decline of -2.4 µm per decade in pRNFL thickness ( P < 0.001, GEE models adjusting for sex, race, and country) and -1.4 µm per decade in GCIPL thickness ( P < 0.001). There was a small difference in pRNFL thickness based on sex, with female participants having slightly higher thickness (2.6 µm, P = 0.003). There was no association between GCIPL thickness and sex. Likewise, there was no association between race/ethnicity and pRNFL or GCIPL thicknesses. CONCLUSIONS: A conversion factor may be required when using data that are derived between different SD-OCT platforms in clinical trials and observational studies; this is particularly true for smaller cross-sectional studies or when a consistent segmentation algorithm is not available. The above conversion equations can be used when pooling data from Spectralis and Cirrus SD-OCT devices for pRNFL and GCIPL thicknesses. A faster decline in retinal thickness may occur after the age of 40 years, even in the absence of significant differences across racial groups.

Interplay between intraocular and intracranial pressure effects on the optic nerve head in vivo.

Intracranial pressure (ICP) has been proposed to play an important role in the sensitivity to intraocular pressure (IOP) and susceptibility to glaucoma. However, the in vivo effects of simultaneous, controlled, acute variations in ICP and IOP have not been directly measured. We quantified the deformations of the anterior lamina cribrosa (ALC) and scleral canal at Bruch's membrane opening (BMO) under acute elevation of IOP and/or ICP. Four eyes of three adult monkeys were imaged in vivo with OCT under four pressure conditions: IOP and ICP either at baseline or elevated. The BMO and ALC were reconstructed from manual delineations. From these, we determined canal area at the BMO (BMO area), BMO aspect ratio and planarity, and ALC median depth relative to the BMO plane. To better account for the pressure effects on the imaging, we also measured ALC visibility as a percent of the BMO area. Further, ALC depths were analyzed only in regions where the ALC was visible in all pressure conditions. Bootstrap sampling was used to obtain mean estimates and confidence intervals, which were then used to test for significant effects of IOP and ICP, independently and in interaction. Response to pressure manipulation was highly individualized between eyes, with significant changes detected in a majority of the parameters. Significant interactions between ICP and IOP occurred in all measures, except ALC visibility. On average, ICP elevation expanded BMO area by 0.17 mm2 at baseline IOP, and contracted BMO area by 0.02 mm2 at high IOP. ICP elevation decreased ALC depth by 10 µm at baseline IOP, but increased depth by 7 µm at high IOP. ALC visibility decreased as ICP increased, both at baseline (-10%) and high IOP (-17%). IOP elevation expanded BMO area by 0.04 mm2 at baseline ICP, and contracted BMO area by 0.09 mm2 at high ICP. On average, IOP elevation caused the ALC to displace 3.3 µm anteriorly at baseline ICP, and 22 µm posteriorly at high ICP. ALC visibility improved as IOP increased, both at baseline (5%) and high ICP (8%). In summary, changing IOP or ICP significantly deformed both the scleral canal and the lamina of the monkey ONH, regardless of the other pressure level. There were significant interactions between the effects of IOP and those of ICP on LC depth, BMO area, aspect ratio and planarity. On most eyes, elevating both pressures by the same amount did not cancel out the effects. Altogether our results show that ICP affects sensitivity to IOP, and thus that it can potentially also affect susceptibility to glaucoma.

Adipose-derived stem cells integrate into trabecular meshwork with glaucoma treatment potential.

The trabecular meshwork (TM) is an ocular tissue that maintains intraocular pressure (IOP) within a physiologic range. Glaucoma patients have reduced TM cellularity and, frequently, elevated IOP. To establish a stem cell-based approach to restoring TM function and normalizing IOP, human adipose-derived stem cells (ADSCs) were induced to differentiate to TM cells in vitro. These ADSC-TM cells displayed a TM cell-like genotypic profile, became phagocytic, and responded to dexamethasone stimulation, characteristic of TM cells. After transplantation into naive mouse eyes, ADSCs and ADSC-TM cells integrated into the TM tissue, expressed TM cell markers, and maintained normal IOP, outflow facility, and extracellular matrix. Cell migration and affinity results indicated that the chemokine pair CXCR4/SDF1 may play an important role in ADSC-TM cell homing. Our study demonstrates the possibility of applying autologous or allogeneic ADSCs and ADSC-TM cells as a potential treatment to restore TM structure and function in glaucoma.

ASSESSING THE ABILITY OF PREOPERATIVE QUANTITATIVE SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS TO PREDICT VISUAL OUTCOME IN IDIOPATHIC MACULAR HOLE SURGERY.

PURPOSE: To determine which spectral domain optical coherence tomography biomarkers of idiopathic macular hole (MH) correlate with the postoperative best-corrected visual acuity (BCVA) in anatomically closed MH. METHODS: Retrospective analysis of spectral domain optical coherence tomography scans of 44 patients presenting with MH followed for a mean of 17 months. Widths of MH aperture, base, and ellipsoid zone disruption were calculated from presenting foveal spectral domain optical coherence tomography B-scans. Macular hole base area and ellipsoid zone disruption area were calculated through the custom in-house software. RESULTS: Poorer postoperative BCVA correlated with increased preoperative choroidal hypertransmission (r = 0.503, P = 0.0005), minimum diameter (r = 0.491, P = 0.0007), and base diameter (r = 0.319, P = 0.0348), but not with preoperative ellipsoid zone width (r = 0.199, P = 0.2001). Applying en-face analysis, the BCVA correlated weakly with preoperative ellipsoid zone loss area (r = 0.380, P = 0.013), but not with preoperative MH base area (r = 0.253, P = 0.1058). CONCLUSION: Increased MH minimum diameter, base diameter, base area, and choroidal hypertransmission are correlated with a poorer postoperative BCVA. Ellipsoid zone loss measurements were not consistently correlated with a BCVA. Choroidal hypertransmission width may be an easy-to-visualize predictive imaging biomarker in MH surgery.

Novel combination therapy reduces subconjunctival fibrosis after glaucoma filtration surgery in the rabbit model.

BACKGROUND: Glaucoma filtration surgery (GFS) is limited by subconjunctival, episcleral and scleral fibrosis sealing the trabeculectomy and scarring the filtering bleb. Mitomycin-C (MMC) is commonly applied intraoperatively to the subconjunctival and/or intrascleral space to reduce scarring and promotes GFS success but is associated with postoperative scleral melting and bleb leaks. IP-10 peptide (IP-10p), an ELR-negative CXC chemokine mimetic and inhibitor of fibroblast function, may be an alternative or adjunct to current postoperative GFS treatments. This study sought to determine if IP-10p produces histological changes in tissue remodelling, vascularity and fibrosis that enhance bleb survival after GFS. METHODS: Rabbits underwent tube-assisted filtration surgery on the right eye with either: (a) IP-10p injected into bleb at time of surgery and postoperative days 2, 4 and 7, (b) intraoperative MMC or (c) intraoperative MMC plus IP-10p injected into bleb at time of surgery and postoperative days 2, 4 and 7. Left contralateral eyes were treated with balanced salt solution (BSS). RESULTS: IP-10p-treated blebs demonstrated reduced collagen deposition, cellularity and overall reduction of scar formation compared to BSS-control. Bleb vascularity was reduced compared to BSS-control and MMC treatment groups. Additionally, IP-10p/MMC treated eyes demonstrated an increased number of conjunctival goblet cells in bleb histology compared to the dramatic loss seen with MMC treatment alone. CONCLUSIONS: This study demonstrates that IP-10p significantly reduces histological scarring compared to BSS or MMC alone, does not damage the conjunctiva to the extent of current standards, and may be an alternative or adjunct to MMC for those undergoing GFS.

Role of radially aligned scleral collagen fibers in optic nerve head biomechanics.

Collagen fibers organized circumferentially around the canal in the peripapillary sclera are thought to provide biomechanical support to the sensitive tissues within the optic nerve head (ONH). Recent studies have demonstrated the existence of a family of fibers in the innermost sclera organized radially from the scleral canal. Our goal was to determine the role of these radial fibers in the sensitivity of scleral canal biomechanics to acute increases in intraocular pressure (IOP). Following the same general approach of previous parametric sensitivity studies, we created nonlinear generic finite element models of a posterior pole with various combinations of radial and circumferential fibers at an IOP of 0 mmHg. We then simulated the effects of normal and elevated IOP levels (15 and 30 mmHg). We monitored four IOP-induced geometric changes: peripapillary sclera stretch, scleral canal displacement, lamina cribrosa displacement, and scleral canal expansion. In addition, we examined the radial (maximum tension) and through-thickness (maximum compression) strains within the ONH tissues. Our models predicted that: 1) radial fibers reduced the posterior displacement of the lamina, especially at elevated IOP; 2) radial fibers reduced IOP-induced radial strain within the peripapillary sclera and retinal tissue; and 3) a combination of radial and circumferential fibers maintained strains within the ONH at a level similar to those conferred by circumferential fibers alone. In conclusion, radial fibers provide support for the posterior globe, additional to that provided by circumferential fibers. Most importantly, a combination of both fiber families can better protect ONH tissues from excessive IOP-induced deformation than either alone.

Assessing the Demand for Teleophthalmology in Florida Emergency Departments.

Background: Teleophthalmology programs are expanding, but have not been adapted into many emergency departments (EDs) in the United States. Introduction: Determining the potential demand for teleophthalmology services in the United States. EDs could enable development of new strategies to improve access to eye care in resource-limited regions. Methods: Telephone surveys were administered to ED physicians and nurses in Florida. Perceptions of ophthalmologist availability, equipment availability, and perceived utility of teleophthalmology services were measured. Results: Responses were from 104 of 207 facilities (50.2%); 88/181 (48.6%) designated as nonrural hospitals (NRHs) and 16/26 (61.5%) as rural hospitals (RHs). NRHs reported a median of 1 ophthalmologist available on call compared with a median of 0 at RHs (p < 0.001). NRHs were more likely to have a slit lamp (98.9% NRH, 50.0% RH; p < 0.001) and tonometer (100% NRH, 75.0% RH; p < 0.001). On a scale from 1 (lowest) to 5, most (68/93; 73.1%) perceived the value of teleophthalmology for remote consults as a 4 or 5. The most common perceived benefit of teleophthalmology use was to provide second/expert opinion (26.5% of responses). The most commonly cited perceived disadvantage was the physical unavailability of an ophthalmologist for examination and follow-up care (35.5% of responses). Discussion: RHs have less access to ophthalmologists and ophthalmic equipment when managing eye-related complaints in the ED. At both RHs and NRHs, providers face limitations in managing eye complaints and perceived teleophthalmology as a potentially valuable tool for remote expert consultation. Conclusions: Results suggest teleophthalmology services may be used to improve access to expert ophthalmic care, particularly in rural communities.

SALT Trial: Steroids after Laser Trabeculoplasty: Impact of Short-Term Anti-inflammatory Treatment on Selective Laser Trabeculoplasty Efficacy.

PURPOSE: This study examined whether short-term use of topical nonsteroidal anti-inflammatory drug (NSAID) or steroid therapy affected the efficacy of selective laser trabeculoplasty (SLT). DESIGN: Double-masked, randomized, placebo-controlled, dual-center, multisurgeon trial. PARTICIPANTS: Patients older than 18 years with intraocular pressure (IOP) of more than 18 mmHg for whom the clinician decided SLT was the appropriately indicated therapy were randomized to 1 of 3 groups in a ratio of 1:1:1 as follows: ketorolac 0.5%, prednisolone 1%, or saline tears. METHODS: After SLT, patients randomized into each group were instructed to use an unmarked drop 4 times daily starting the day of SLT and continuing for 4 additional days. The Kruskal-Wallis test and Wilcoxon rank-sum test were used for continuous variables when comparing 2 or 3 treatment groups, respectively. The Fisher exact test was used for categorical variables. MAIN OUTCOME MEASURES: The primary outcome of this study was IOP at 12 weeks. Secondary outcome measures included IOP at 1 and 6 weeks, patient-reported pain, and detectable anterior chamber inflammation. RESULTS: Ninety-six eyes of 85 patients fit inclusion criteria and were enrolled between the 2 sites. The NSAID, steroid, and placebo groups were similar in baseline demographics and baseline IOP (mean, 23.3±3.9 mmHg; P = 0.57). There was no statistically significant difference in IOP decrease among groups at week 6. Both the NSAID and steroid groups showed a statistically significantly greater decrease in IOP at week 12 compared with the placebo group (mean, -6.2±3.1 mmHg, -5.2±2.7 mmHg, and -3±4.3 mmHg, respectively; P = 0.02 [analysis of variance] and P = 0.002 [t test] for NSAID vs. placebo groups; P = 0.02 for steroid vs. placebo groups). CONCLUSIONS: Significantly better IOP reduction at 12 weeks was measured in eyes treated with steroid or NSAID drops after SLT. Short-term postoperative use of NSAID or steroid drops may improve IOP reduction after SLT. Longer-term follow-up studies are indicated.

Five-year clinical outcomes of combined phacoemulsification and trabectome surgery at a single glaucoma center.

PURPOSE: To analyze the 5-year results of trabectome ab interno trabeculectomy of a single glaucoma center. METHOD: In this retrospective interventional single-center case series, data of 93 patients undergoing ab interno trabeculotomy between September 2010, and December 2012 were included. Kaplan-Meier analysis was performed using success criteria defined as postoperative intraocular pressure (IOP) ≤ 21 mmHg, and > 20% reduction from preoperative IOP, and no need for further glaucoma surgery. Risk factors for failure were identified using Cox proportional hazards ratio (HR). RESULTS: The retention rate for 5-year follow-up was 66%. The cumulative probability of success at 1, 2, 3, 4, and 5 years was 82.6%, 76.7%, 73.9%, 72.3%, and 67.5%. Risk factors for failure were lower baseline IOP (HR = 0.27, P = 0.001), younger age (HR = 0.25, P = 0.02), and higher central corneal thickness (HR = 0.18, P = 0.01). Exfoliative glaucoma was associated with a higher success rate (HR = 0.39, P = 0.02). IOP was decreased significantly from 20.0 ± 5.6 mmHg at baseline to 15.6 ± 4.6 mmHg at 5-year follow-up (P = 0.001). The baseline number of glaucoma medications was 1.8 ± 1.2, which decreased to 1.0 ± 1.2 medications at 5 years. CONCLUSION: Trabectome surgery was associated with a good long-term efficacy and safety profile in this single-center case series with a high retention rate.

Clinical Prediction Performance of Glaucoma Progression Using a 2-Dimensional Continuous-Time Hidden Markov Model with Structural and Functional Measurements.

PURPOSE: Previously, we introduced a state-based 2-dimensional continuous-time hidden Markov model (2D CT HMM) to model the pattern of detected glaucoma changes using structural and functional information simultaneously. The purpose of this study was to evaluate the detected glaucoma change prediction performance of the model in a real clinical setting using a retrospective longitudinal dataset. DESIGN: Longitudinal, retrospective study. PARTICIPANTS: One hundred thirty-four eyes from 134 participants diagnosed with glaucoma or as glaucoma suspects (average follow-up, 4.4±1.2 years; average number of visits, 7.1±1.8). METHODS: A 2D CT HMM model was trained using OCT (Cirrus HD-OCT; Zeiss, Dublin, CA) average circumpapillary retinal nerve fiber layer (cRNFL) thickness and visual field index (VFI) or mean deviation (MD; Humphrey Field Analyzer; Zeiss). The model was trained using a subset of the data (107 of 134 eyes [80%]) including all visits except for the last visit, which was used to test the prediction performance (training set). Additionally, the remaining 27 eyes were used for secondary performance testing as an independent group (validation set). The 2D CT HMM predicts 1 of 4 possible detected state changes based on 1 input state. MAIN OUTCOME MEASURES: Prediction accuracy was assessed as the percentage of correct prediction against the patient's actual recorded state. In addition, deviations of the predicted long-term detected change paths from the actual detected change paths were measured. RESULTS: Baseline mean ± standard deviation age was 61.9±11.4 years, VFI was 90.7±17.4, MD was -3.50±6.04 dB, and cRNFL thickness was 74.9±12.2 µm. The accuracy of detected glaucoma change prediction using the training set was comparable with the validation set (57.0% and 68.0%, respectively). Prediction deviation from the actual detected change path showed stability throughout patient follow-up. CONCLUSIONS: The 2D CT HMM demonstrated promising prediction performance in detecting glaucoma change performance in a simulated clinical setting using an independent cohort. The 2D CT HMM allows information from just 1 visit to predict at least 5 subsequent visits with similar performance.

Can Macula and Optic Nerve Head Parameters Detect Glaucoma Progression in Eyes with Advanced Circumpapillary Retinal Nerve Fiber Layer Damage?

PURPOSE: To evaluate the ability of OCT optic nerve head (ONH) and macular parameters to detect disease progression in eyes with advanced structural glaucomatous damage of the circumpapillary retinal nerve fiber layer (cRNFL). DESIGN: Longitudinal study. PARTICIPANTS: Forty-four eyes from 37 patients with advanced average cRNFL damage (≤60 µm) followed up for an average of 4.0 years. METHODS: All patients were examined with spectral-domain OCT and visual field (VF) assessment during at least 4 visits. MAIN OUTCOME MEASUREMENTS: Visual field mean deviation (MD) and VF index. OCT cRNFL (average, superior, and inferior quadrants), ganglion cell-inner plexiform layer (GCIPL) (average, superior, and inferior), rim area, cup volume, average cup-to-disc (C:D) ratio, and vertical C:D ratio. RESULTS: At baseline, patients had a median VF MD of -10.18 dB and mean cRNFL of 54.55±3.42 µm. The rate of change for MD and VF index were significant. No significant rate of change was noted for cRNFL, whereas significant (P < 0.001) rates were detected for GCIPL (-0.57±0.05 µm/year) and ONH parameters such as rim area (-0.010±0.001 mm2/year). CONCLUSIONS: Macula GCIPL and ONH parameters may be useful in tracking progression in patients with advanced glaucoma.

The Future of Imaging in Detecting Glaucoma Progression.

Ocular imaging has been heavily incorporated into glaucoma management and provides important information that aids in the detection of disease progression. Longitudinal studies have shown that the circumpapillary retinal nerve fiber layer is an important parameter for glaucoma progression detection, whereas other studies have demonstrated that macular parameters, such as the ganglion cell inner plexiform layer and optic nerve head parameters, also are useful for progression detection. The introduction of novel technologies with faster scan speeds, wider scanning fields, higher resolution, and improved tissue penetration has enabled the precise quantification of additional key ocular structures, such as the individual retinal layers, optic nerve head, choroid, and lamina cribrosa. Furthermore, extracting functional information from scans such as blood flow rate and oxygen consumption provides new perspectives on the disease and its progression. These novel methods promise improved detection of glaucoma progression and better insight into the mechanisms of progression that will lead to better targeted treatment options to prevent visual damage and blindness.

The Current State of Teleophthalmology in the United States.

Telemedicine services facilitate the evaluation, diagnosis, and management of the remote patient. Telemedicine has rapidly flourished in the United States and has improved access to care, outcomes, and patient satisfaction. However, the use of telemedicine in ophthalmology is currently in its infancy and has yet to gain wide acceptance. Current models of telemedicine in ophthalmology are largely performed via "store and forward" methods, but remote monitoring and interactive modalities exist. Although studies have examined the effects of telemedicine, few reports have characterized its current status. We perform a descriptive analysis of the current state of teleophthalmology in the United States. We describe the use of teleophthalmology in the hospital and outpatient settings. We also review the applications to retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration, and glaucoma, as well as anticipated barriers and hurdles for the future adoption of teleophthalmology. With ongoing advances in teleophthalmology, these models may provide earlier detection and more reliable monitoring of vision-threatening diseases.

Top-down influence on the visual cortex of the blind during sensory substitution.

Visual sensory substitution devices provide a non-surgical and flexible approach to vision rehabilitation in the blind. These devices convert images taken by a camera into cross-modal sensory signals that are presented as a surrogate for direct visual input. While previous work has demonstrated that the visual cortex of blind subjects is recruited during sensory substitution, the cognitive basis of this activation remains incompletely understood. To test the hypothesis that top-down input provides a significant contribution to this activation, we performed functional MRI scanning in 11 blind (7 acquired and 4 congenital) and 11 sighted subjects under two conditions: passive listening of image-encoded soundscapes before sensory substitution training and active interpretation of the same auditory sensory substitution signals after a 10-minute training session. We found that the modulation of visual cortex activity due to active interpretation was significantly stronger in the blind over sighted subjects. In addition, congenitally blind subjects showed stronger task-induced modulation in the visual cortex than acquired blind subjects. In a parallel experiment, we scanned 18 blind (11 acquired and 7 congenital) and 18 sighted subjects at rest to investigate alterations in functional connectivity due to visual deprivation. The results demonstrated that visual cortex connectivity of the blind shifted away from sensory networks and toward known areas of top-down input. Taken together, our data support the model of the brain, including the visual system, as a highly flexible task-based and not sensory-based machine.

Glaucoma Structural and Functional Progression in American and Korean Cohorts.

PURPOSE: To compare the rate of glaucoma structural and functional progression in American and Korean cohorts. DESIGN: Retrospective longitudinal study. PARTICIPANTS: Three hundred thirteen eyes from 189 glaucoma and glaucoma suspects, followed up for an average of 38 months. METHODS: All subjects were examined semiannually with visual field (VF) testing and spectral-domain optical coherence tomography. All subjects had 5 or more reliable visits. MAIN OUTCOME MEASUREMENTS: The rates of change of retinal nerve fiber layer (RNFL) thickness, cup-to-disc (C/D) ratios, and VF mean deviation (MD) were compared between the cohorts. Variables affecting the rate of change for each parameter were determined, including ethnicity, refraction, baseline age and disease severity, disease subtype (high- vs. normal-tension glaucoma), clinical diagnosis (glaucoma vs. glaucoma suspect), and the interactions between variables. RESULTS: The Korean cohort predominantly demonstrated normal-tension glaucoma, whereas the American cohort predominantly demonstrated high-tension glaucoma. Cohorts had similar VF parameters at baseline, but the Korean eyes had significantly thicker mean RNFL and larger cups. Korean glaucoma eyes showed a faster thinning of mean RNFL (mean, -0.71 µm/year vs. -0.24 µm/year; P < 0.01). There were no detectable differences in the rate of change between the glaucoma cohorts for C/D ratios and VF MD and for all parameters in glaucoma suspect eyes. Different combinations of the tested variables significantly impacted the rate of change. CONCLUSIONS: Ethnicity, baseline disease severity, disease subtype, and clinical diagnosis should be considered when comparing glaucoma progression studies.

Clinical Considerations for Vascularized Composite Allotransplantation of the Eye.

Vascularized composite allotransplantation represents a potential shift in approaches to reconstruction of complex defects resulting from congenital differences as well as trauma and other acquired pathology. Given the highly specialized function of the eye and its unique anatomical components, vascularized composite allotransplantation of the eye is an appealing method for restoration, replacement, and reconstruction of the nonfunctioning eye. Herein, we describe conventional treatments for eye restoration and their shortcomings as well as recent research and events that have brought eye transplantation closer to a potential clinical reality. In this article, we outline some potential considerations in patient selection, donor facial tissue procurement, eye tissue implantation, surgical procedure, and potential for functional outcomes.

Ethical Considerations of Whole-Eye Transplantation.

Whole eye transplantation (WET) remains experimental. Long presumed impossible, recent scientific advances regarding WET suggest that it may become a clinical reality. However, the ethical implications of WET as an experimental therapeutic strategy remain largely unexplored. This article evaluates the ethical considerations surrounding WET as an emerging experimental treatment for vision loss. A thorough review of published literature pertaining to WET was performed; ethical issues were identified during review of the articles.

New developments in optical coherence tomography.

PURPOSE OF REVIEW: Optical coherence tomography (OCT) has become the cornerstone technology for clinical ocular imaging in the past few years. The technology is still rapidly evolving with newly developed applications. This manuscript reviews recent innovative OCT applications for glaucoma diagnosis and management. RECENT FINDINGS: The improvements made in the technology have resulted in increased scanning speed, axial and transverse resolution, and more effective use of the OCT technology as a component of multimodal imaging tools. At the same time, the parallel evolution in novel algorithms makes it possible to efficiently analyze the increased volume of acquired data. SUMMARY: The innovative iterations of OCT technology have the potential to further improve the performance of the technology in evaluating ocular structural and functional characteristics and longitudinal changes in glaucoma.

Lymphoma of the orbit masquerading as Tolosa-Hunt syndrome.

BACKGROUND: Tolosa-Hunt syndrome is a rare clinical syndrome characterized by painful ophthalmoplegia and ipsilateral cranial neuropathies. It is caused by an inflammatory process of unknown etiology. CASE PRESENTATION: We present a case of a 77-year-old white man with history of Waldenstrom's macroglobulinemia transforming to large B-cell lymphoma who presented to a community physician complaining of 4 months of isolated right retro-orbital pain and later with diplopia, ptosis, 6th nerve and pupil-sparing partial 3rd nerve palsies as well as progressive neurological findings. His clinical course was complicated by debilitating neurological symptoms and multiple hospitalizations leading to a delay in diagnosis caused by incomplete initial workup. CONCLUSION: This case is a reminder that lymphoproliferative disorders often mimic other neurologic disorders and that Tolosa-Hunt is a rare diagnosis that must be considered a diagnosis of exclusion.