CHOROIDAL GRANULOMAS VISUALIZED BY SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To assess the visualization of choroidal granulomas with swept-source optical coherence tomography angiography (OCTA). METHODS: Consecutive patients with granulomatous choroiditis due to tuberculosis, sarcoidosis, or Vogt-Koyanagi-Harada disease underwent baseline OCTA images using a 12 × 12-mm field of view, and the choroidal slabs were analyzed by two independent examiners who counted the oval areas of flow void. Simultaneously, indocyanine green angiography (ICGA) and enhanced-depth imaging OCT were performed to mark visible choroidal changes corresponding to granulomatous lesions. The lesion areas on OCTA and ICGA were assessed using the in-built caliper tool. RESULTS: Three hundred and one round-shaped areas of flow void on OCTA, 209 hypofluorescent round lesions on ICGA, and 42 hyporeflective choroidal lesions on enhanced-depth imaging OCT were identified in 23 eyes from 14 patients. Of the 209 ICGA granulomas, 197 (94.3%) had a corresponding round area of flow void on OCTA that was interpreted as a granuloma. One hundred and four additional round flow voids were identified on OCTA that did not correspond to any hypofluorescent lesion on ICGA. The mean area of the 197 granulomas detected with both imaging modalities was significantly larger on ICGA (mean 0.33 mm2) than that on OCTA (mean 0.28 mm2). CONCLUSION: Optical coherence tomography angiography seems to be an optimal imaging method for the visualization of choroidal granulomas.

Wide-field optical coherence tomography angiography for the detection of proliferative diabetic retinopathy.

PURPOSE: To compare the ability of wide-field optical coherence tomography angiography (WF-OCTA) to that of ultra-wide field fluorescein angiography (UWF-FA) and ultra-wide-field color fundus photography (UWF-CP) to detect retinal neovascularization (NV) in eyes with proliferative diabetic retinopathy (PDR). METHODS: In this cross-sectional study, naïve patients with active PDR underwent UWF-FA and UWF-CP using the Optos 200Tx and WF-OCTA with 12 × 12 mm fields of five visual fixations using the PLEX Elite 9000. NV was defined on OCTA when the co-registered B-scan with flow overlay of the vitreoretinal interface (VRI) segmentation showed extraretinal proliferation. Three masked readers examined the UWF-FA, UWF-CP, and WF-OCTA independently for the presence of NV. Statistical analysis was performed to compare the diagnostic accuracy of the 3 wide-field imaging modalities using OCT B-scan as the reference standard. RESULTS: In 82 eyes with PDR, neovascularization of the disc (NVD) was detected in 13 eyes by UWF-CP, 35 eyes with UWF-FA, and 37 eyes with OCTA using the VRI slab. Upon review of the 2500 OCT B-scans with superimposed flow overlay of each eye, NVD was confirmed in 37 eyes. The sensitivity and specificity of NVD detection were 35.1% and 97.8%, respectively for UWF-CP; 94.6% and 100%, respectively, for UWF-FA; and 100% and 100% for WF-OCTA. One hundred ninety-six foci of neovascularization elsewhere (NVE) were identified with the OCT B-scan with superimposed flow overlay. UWF-CP analysis was able to detect 62 foci of NVE of the 196 confirmed by B-scan (31.6% detection rate). An additional 11 foci of NVE seen on UWF-CP were not confirmed by B-Scan (15% false positive rate). There were 182 foci of NVE identified by UWF-FA (detection rate 91.3%), while WF-OCTA detected 196 retinal NVEs (detection rate 100%). The rate of false positives for both UWF-FA and WF-OCTA was low (< 2%). CONCLUSION: WF-OCTA can identify NV that is not evident in UWF-CP and represents a faster and safer alternative to UWF-FA for surveillance of PDR with comparable diagnostic accuracy.

The influence of dissolved organic matter (DOM) on sodium regulation and nitrogenous waste excretion in the zebrafish (Danio rerio).

Dissolved organic matter (DOM) is both ubiquitous and diverse in composition in natural waters, but its effects on the branchial physiology of aquatic organisms have received little attention relative to other variables (e.g. pH, hardness, salinity, alkalinity). Here, we investigated the effects of four chemically distinct DOM isolates (three natural, one commercial, ranging from autochthonous to highly allochthonous, all at ∼6 mg C l(-1)) on the physiology of gill ionoregulation and nitrogenous waste excretion in zebrafish acclimated to either circumneutral (7.0-8.0) or acidic pH (5.0). Overall, lower pH tended to increase net branchial ammonia excretion, net K(+) loss and [(3)H]PEG-4000 clearance rates (indicators of transcellular and paracellular permeability, respectively). However, unidirectional Na(+) efflux, urea excretion and drinking rates were unaffected. DOM sources tended to stimulate unidirectional Na(+) influx rate and exerted subtle effects on the concentration-dependent kinetics of Na(+) uptake, increasing maximum transport capacity. All DOM sources reduced passive Na(+) efflux rates regardless of pH, but exerted negligible effects on nitrogenous waste excretion, drinking rate, net K(+) loss or [(3)H]PEG-4000 clearance, so the mechanism of Na(+) loss reduction remains unclear. Overall, these actions appear beneficial to ionoregulatory homeostasis in zebrafish, and some may be related to physico-chemical properties of the DOM sources. They are very different from those seen in a recent parallel study on Daphnia magna using the same DOM isolates, indicating that DOM actions may be both species and DOM specific.

The effects of fundus photography on the multifocal electroretinogram.

PURPOSE: To determine the effect of flash fundus photography (FFP) on the multifocal electroretinogram (mfERG). METHODS: Ten subjects underwent mfERG testing on three separate dates. Subjects received either mfERG without FFP, mfERG at 5 and 15 min after FFP, or mfERG at 30 and 45 min after FFP on each date. The FFP groups received 10 fundus photographs followed by mfERG testing, first of the right eye then of the left eye 10 min later. Data were averaged and analyzed in six concentric rings at each time point. Average amplitude and implicit times of the N1, P1, and N2 peaks for each concentric ring at each time point after FFP were compared to baseline. RESULTS: Flash fundus photography did not lead to a significant change of amplitude or implicit times of N1, P1, or N2 at 5 min after light exposure. CONCLUSIONS: These findings suggest that it is acceptable to perform mfERG testing without delay after performance of FFP.

Pediatric glaucoma surgery: a report by the American Academy Of Ophthalmology.

OBJECTIVE: To review the current published literature to evaluate the success rates and long-term problems associated with surgery for pediatric glaucoma. METHODS: Literature searches of the PubMed and Cochrane Library databases were last conducted in May 2012. The search yielded 838 potentially relevant citations, of which 273 were in non-English languages. The titles and abstracts of these articles were reviewed by the authors, and 364 were selected for possible further review. Members of the Ophthalmic Technology Assessment Committee Glaucoma Panel reviewed the full text of these articles and used the 36 that met inclusion and exclusion criteria for this Ophthalmic Technology Assessment. There were no studies on the topic that provided level I evidence. The assessment included only level II and level III studies. RESULTS: Surgeons treat pediatric glaucoma most commonly with goniotomy, trabeculotomy, trabeculectomy, combined trabeculotomy and trabeculectomy, tube shunt surgery, cyclodestruction, and deep sclerectomy. Certain surgical options seem better for specific diagnoses, such as primary congenital glaucoma, aphakic glaucoma, and glaucomas associated with other ocular or systemic anomalies. CONCLUSIONS: There are many surgical options for the treatment of the pediatric glaucomas. The relative efficacy of these various procedures for particular diagnoses and clinical situations should be weighed against the specific risks associated with the procedures for individual patients.

Retinal blood vessel positional shifts and glaucoma progression.

PURPOSE: To determine the characteristics and significance of retinal blood vessel (RBV) positional shifts over time in a cohort of patients with progressive glaucoma. DESIGN: Retrospective cohort study. PARTICIPANTS: Baseline and serial stereophotographs from 1 eye of 125 patients with open-angle glaucoma with ≥8 reliable Swedish interactive threshold algorithm standard visual fields (VFs) were included. On the basis of global rates of threshold sensitivity change, patients with glaucoma were divided into groups of minimal (<-0.02 decibels [dB]/year), moderate (-0.02 to -0.65 dB/year), or fast (≥-0.65 dB/year) progression. To determine whether graders' assessments of RBV positional shifts were false-positives, a control group consisting of 33 patients with glaucoma with 2 sets of photographs taken on the same day was included. METHODS: Masked graders reviewed serial photographs aligned with automated alternation flicker (EyeIC, Narbeth, PA) and assessed them for the presence of any discrete RBV positional shifts (2 graders) and for traditional measures of structural progression (2 graders), including neuroretinal rim loss, parapapillary atrophy progression, and disc hemorrhage (DH). MAIN OUTCOME MEASURES: Presence or absence of RBV positional shifts, rates of VF progression, and presence or absence of traditional measures of structural progression. RESULTS: A total of 158 image sets (125 longitudinal and 33 same-day controls) from patients with glaucoma were included. Retinal blood vessel shifts were noted in 33 of 125 (26.4%) longitudinally followed glaucomatous eyes and 2 of 33 (6%) same-day control patients (P = 0.01). Agreement between graders I and II was 90.4% (kappa=0.77; P< 0.001). Eyes with RBV positional change progressed more rapidly than those without (-0.55 vs. -0.29 dB/year; 95% confidence interval [CI], 0.03-0.48); P = 0.03). Retinal blood vessel shift was present in 12.1% of minimal progressors versus 31.5% of moderate and fast progressors (P = 0.04). Rate of VF progression was statistically associated with RBV shift (odds ratio [OR], 2.2; 95% CI, 1.1-4.5; P = 0.03). Other variables significantly associated with RBV shift included neuroretinal rim loss (OR, 21.9; 95% CI, 5.7-83.6; P< 0.001) and DH (OR, 4.6; 95% CI, 1.5-15.5; P< 0.01). A multivariable model revealed that rim loss and DH, but not rate of functional change, were significantly associated with RBV shift. CONCLUSIONS: Retinal blood vessel positional shifts occurred in eyes with functionally progressive glaucoma, neuroretinal rim loss, and DH. This is a novel clinical finding that could help identify glaucoma progression or individuals at higher risk for future progression.

Effect of patient positioning on cerebrospinal fluid opening pressure.

BACKGROUND: Prone is the preferred patient position for fluoroscopic-guided lumbar puncture (LP). Normative data for cerebrospinal fluid (CSF) opening pressure (OP) exist for lateral decubitus (LD) positioning only and have not been defined for the prone position. This study compares CSF OP values in the prone and LD positions and examines the effect of body mass index (BMI) on OP. METHODS: Patients undergoing diagnostic or therapeutic fluoroscopic-guided LP were recruited prospectively at 2 tertiary care centers from 2009 to 2012. Following prone fluoroscopic-guided LP, patients were rolled to the LD position for repeat CSF OP measurement. In addition to comparing the mean OP in each position, the relationships between OP, body position, and BMI were also explored. RESULTS: Fifty-two patients were enrolled. A mean OP difference of 1.2 cm H2O was observed (prone: 26.5 cm H2O; LD: 27.7 cm H2O; P = 0.07). No correlation between CSF OP and BMI was seen in either position. CONCLUSIONS: No statistically or clinically significant difference between prone and LD OP was identified. BMI does not appear to affect CSF OP measurement in either position.

The Humira in Ocular Inflammations Taper (HOT) Study.

PURPOSE: To assess factors that impact the risk of relapse in patients with noninfectious uveitis (NIU) who undergo adalimumab tapering after achieving remission. DESIGN: Retrospective study. METHODS: In this multicenter study, patients with NIU were treated with adalimumab and subsequently tapered. Patient demographics, type of NIU, onset and duration of disease, the period of inactivity before tapering adalimumab, and the tapering schedule were collected. The primary outcome measures were independent predictors of the rate of uveitis recurrence after adalimumab tapering. RESULTS: Three hundred twenty-eight patients were included (54.6% female) with a mean age of 34.3 years. The mean time between disease onset and initiation of adalimumab therapy was 35.2 ± 70.1 weeks. Adalimumab tapering was commenced after a mean of 100.8 ± 69.7 weeks of inactivity. Recurrence was observed in 39.6% of patients at a mean of 44.7 ± 61.7 weeks. Patients who experienced recurrence were significantly younger than those without recurrence (mean 29.4 years vs 37.5 years, P = .0005), and the rate of recurrence was significantly higher in younger subjects (hazard ratio [HR] = 0.88 per decade of increasing age, P = .01). The lowest rate of recurrence was among Asian subjects. A faster adalimumab taper was associated with an increased recurrence rate (HR = 1.23 per unit increase in speed, P < .0005). Conversely, a more extended period of remission before tapering was associated with a lower rate of recurrence (HR = 0.97 per 10-weeks longer period of inactivity, P = .04). CONCLUSIONS: When tapering adalimumab, factors that should be considered include patient age, race, and duration of disease remission on adalimumab. A slow tapering schedule is advisable.

Evaluation of the anterior chamber angle in glaucoma: a report by the american academy of ophthalmology.

OBJECTIVE: To assess the published literature pertaining to the association between anterior segment imaging and gonioscopy and to determine whether such imaging aids in the diagnosis of primary angle closure (PAC). METHODS: Literature searches of the PubMed and Cochrane Library databases were last conducted on July 6, 2011. The searches yielded 371 unique citations. Members of the Ophthalmic Technology Assessment Committee Glaucoma Panel reviewed the titles and abstracts of these articles and selected 134 of possible clinical significance for further review. The panel reviewed the full text of these articles and identified 79 studies meeting the inclusion criteria, for which the panel methodologist assigned a level of evidence based on a standardized grading scheme adopted by the American Academy of Ophthalmology. Three, 70, and 6 studies were rated as providing level I, II, and III evidence, respectively. RESULTS: Quantitative and qualitative parameters defined from ultrasound biomicroscopy (UBM), anterior segment optical coherence tomography (OCT), Scheimpflug photography, and the scanning peripheral anterior chamber depth analyzer (SPAC) demonstrate a strong association with the results of gonioscopy. There is substantial variability in the type of information obtained from each imaging method. Imaging of structures posterior to the iris is possible only with UBM. Direct imaging of the anterior chamber angle (ACA) is possible using UBM and OCT. The ability to acquire OCT images in a completely dark environment allows greater sensitivity in detecting eyes with appositional angle closure. Noncontact imaging using OCT, Scheimpflug photography, or SPAC makes these methods more attractive for large-scale PAC screening than contact imaging using UBM. CONCLUSIONS: Although there is evidence suggesting that anterior segment imaging provides useful information in the evaluation of PAC, none of these imaging methods provides sufficient information about the ACA anatomy to be considered a substitute for gonioscopy. Longitudinal studies are needed to validate the diagnostic significance of the parameters measured by these instruments for prospectively identifying individuals at risk for PAC. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Exploring patient perceptions of PSA screening for prostate cancer: risks, effectiveness, and importance.

OBJECTIVE: To study the beliefs of a group of Canadian men regarding the risks, effectiveness, and importance of routine prostate-specific antigen (PSA) testing when used as a screening tool for prostate cancer. DESIGN: A 1-page questionnaire designed to gauge patient beliefs about PSA screening. SETTING: Two primary care clinics in Kingston, Ont. PARTICIPANTS: Seventy-two men aged 41 to 80. MAIN OUTCOME MEASURES: Whether men believed that the PSA blood test was not risky when used as a screening test for prostate cancer, was effective at preventing death from prostate cancer, and was important for their health. RESULTS: Fifteen men reported having visited their physicians because of difficulty urinating in the past 2 years, or a personal history of prostate cancer, and were excluded; for these men, the use of the PSA blood test would not be for screening. Of the 57 men considered in the study, 54 (95%) believed that using the PSA blood test as a screening tool for prostate cancer was not risky, 39 (68%) believed that the PSA blood test was good or very good at preventing death from prostate cancer, and 45 (79%) believed that the routine use of the PSA blood test was important or very important for their health. Men in the suggested screening age group of 51 to 70 years (n = 32) had an equally positive impression of PSA screening. CONCLUSION: Despite a limited body of evidence showing its effectiveness, Canadian men continue to have a favourable impression of PSA screening and remain largely unaware of potential adverse events associated with PSA testing.

Advanced OCT Analysis of Biopsy-proven Vitreoretinal Lymphoma.

PURPOSE: Although diagnosing vitreoretinal lymphoma (VRL) can be challenging, early detection is critical for visual prognosis. We analyzed the spectrum of optical coherence tomography (OCT) findings in patients with biopsy-proven VRL and correlate these features with clinical parameters. DESIGN: This retrospective cross-sectional study was a multicenter chart review from 13 retina, uveitis, and ocular oncology clinics worldwide from 2008 to 2019. We included patients with a diagnosis of biopsy-proven VRL imaged with OCT at presentation. Ocular information, systemic information, and multimodal retinal imaging findings were collected and studied. The main outcome measure was the characteristics of VRL on OCT. RESULTS: A total of 182 eyes of 115 patients (63 women, mean age 65 years) were included in this study. The disease was bilateral in 81 patients (70%), and mean baseline visual acuity was 0.2 ± 0.89 logMAR (Snellen equivalent, 20/32). At baseline, 38 patients (33%) presented with isolated ocular involvement, 54 (45%) with associated central nervous system involvement, and 11 (10%) with other systemic lymphomatous involvement; an additional 12 patients (10%) presented with central nervous system and other systemic involvement. On OCT, tumor infiltration was identified in various retinal layers, including lesions in the subretinal pigment epithelium compartment (91% of eyes), the subretinal compartment (43% of eyes), and the intraretinal compartment (7% of eyes). OCT analysis of eyes with VRL identified 3 main regions of retinal infiltration. Subretinal pigment epithelium location, with or without subretinal infiltration, was the most common pattern of involvement and isolated intraretinal infiltration was the least.

Intraocular pressure outcome of patients with fluocinolone acetonide intravitreal implant for noninfectious uveitis.

PURPOSE: To evaluate the intraocular pressure (IOP) outcomes of patients with noninfectious posterior uveitis treated with a fluocinolone acetonide (FA) intravitreal implant over an 8-year period. DESIGN: Retrospective clinical case series. PARTICIPANTS: Forty-seven eyes of 35 patients. METHODS: Retrospective review of medical records of all patients receiving FA implants between June 2001 and March 2009 was performed. Data were pooled to record visual acuity (VA) and to characterize the incidence and outcome of glaucoma surgical intervention. MAIN OUTCOME MEASURES: Incidence of glaucoma surgery and IOP before and after glaucoma surgical intervention. Visual acuity before and after FA implant placement. RESULTS: Nineteen of 42 eyes (45%) receiving FA implants over the course of the study period required glaucoma surgical intervention. Success of IOP-lowering surgery was achieved in 94%, 94%, and 92% of eyes at 6, 12, and 24 months postoperatively. No patient lost more than 1 line of VA. There was an average 2-line gain of acuity at 3 years after FA implant placement for those patients who underwent IOP-lowering surgery. CONCLUSIONS: Patients receiving FA implants have a significant risk of increased IOP that frequently necessitates glaucoma surgery. Glaucoma surgery, when necessary, offers an effective method to decrease IOP. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Novel glaucoma procedures: a report by the American Academy of Ophthalmology.

OBJECTIVE: To review the published literature and summarize clinically relevant information about novel, or emerging, surgical techniques for the treatment of open-angle glaucoma and to describe the devices and procedures in proper context of the appropriate patient population, theoretic effects, advantages, and disadvantages. DESIGN: Devices and procedures that have US Food and Drug Administration clearance or are currently in phase III clinical trials in the United States are included: the Fugo blade (Medisurg Ltd., Norristown, PA), Ex-PRESS mini glaucoma shunt (Alcon, Inc., Hunenberg, Switzerland), SOLX Gold Shunt (SOLX Ltd., Boston, MA), excimer laser trabeculotomy (AIDA, Glautec AG, Nurnberg, Germany), canaloplasty (iScience Interventional Corp., Menlo Park, CA), trabeculotomy by internal approach (Trabectome, NeoMedix, Inc., Tustin, CA), and trabecular micro-bypass stent (iStent, Glaukos Corporation, Laguna Hills, CA). METHODS: Literature searches of the PubMed and the Cochrane Library databases were conducted up to October 2009 with no date or language restrictions. MAIN OUTCOME MEASURES: These searches retrieved 192 citations, of which 23 were deemed topically relevant and rated for quality of evidence by the panel methodologist. All studies but one, which was rated as level II evidence, were rated as level III evidence. RESULTS: All of the devices studied showed a statistically significant reduction in intraocular pressure and, in some cases, glaucoma medication use. The success and failure definitions varied among studies, as did the calculated rates. Various types and rates of complications were reported depending on the surgical technique. On the basis of the review of the literature and mechanism of action, the authors also summarized theoretic advantages and disadvantages of each surgery. CONCLUSIONS: The novel glaucoma surgeries studied all show some promise as alternative treatments to lower intraocular pressure in the treatment of open-angle glaucoma. It is not possible to conclude whether these novel procedures are superior, equal to, or inferior to surgery such as trabeculectomy or to one another. The studies provide the basis for future comparative or randomized trials of existing glaucoma surgical techniques and other novel procedures.

Laser trabeculoplasty for open-angle glaucoma: a report by the american academy of ophthalmology.

OBJECTIVE: To provide an evidence-based summary of the outcomes, repeatability, and safety of laser trabeculoplasty for open-angle glaucoma. METHODS: A search of the peer-reviewed literature in the PubMed and the Cochrane Library databases was conducted in June 2008 and was last repeated in March 2010 with no date or language restrictions. The search yielded 637 unique citations, of which 145 were considered to be of possible clinical relevance for further review and were included in the evidence analysis. RESULTS: Level I evidence indicates an acceptable long-term efficacy of initial argon laser trabeculoplasty for open-angle glaucoma compared with initial medical treatment. Among the remaining studies, level II evidence supports the efficacy of selective laser trabeculoplasty for lowering intraocular pressure for patients with open-angle glaucoma. Level III evidence supports the efficacy of repeat use of laser trabeculoplasty. CONCLUSIONS: Laser trabeculoplasty is successful in lowering intraocular pressure for patients with open-angle glaucoma. At this time, there is no literature establishing the superiority of any particular form of laser trabeculoplasty. The theories of action of laser trabeculoplasty are not elucidated fully. Further research into the differences among the lasers used in trabeculoplasty, the repeatability of the procedure, and techniques of treatment is necessary. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Assessment of visual function in glaucoma: a report by the American Academy of Ophthalmology.

OBJECTIVE: To review the published literature to summarize and evaluate the effectiveness of visual function tests in diagnosing glaucoma and in monitoring progression. METHODS: Literature searches of the PubMed and Cochrane Library databases were conducted last on May 7, 2010, and were restricted to citations published on or after January 1, 1994. The search yielded 1063 unique citations. The first author reviewed the titles and abstracts of these articles and selected 185 of possible clinical relevance for further review. The panel members reviewed the full text of these articles and determined that 85 met inclusion criteria. They conducted data abstraction of the 85 studies, and the panel methodologist assigned a level of evidence to each of the selected articles. One study was rated as level I evidence. The remaining articles were classified broadly as providing level II evidence. Studies deemed to provide level III evidence were not included in the assessment. RESULTS: Standard white-on-white automated perimetry remains the most commonly performed test for assessing the visual field, with the Swedish interactive threshold algorithm (SITA) largely replacing full-threshold testing strategies. Frequency-doubling technology and its refinement into Matrix perimetry, as well as short-wavelength automated perimetry, now available with SITA, have been evaluated extensively. Machine learning classifiers seem to be ready for incorporation into software to help distinguish glaucomatous from nonglaucomatous fields. Other technologies, such as multifocal visual-evoked potential and electroretinography, which were designed as objective measures of visual function, provide testing free of patient input, but issues prevent their adoption for glaucoma management. CONCLUSIONS: Advances in technology and analytic tools over the past decade have provided us with more rapid and varied ways of assessing visual function in glaucoma, but they have yet to produce definitive guidance on the diagnosis of glaucoma or its progression over time. Further research on an objective measure of visual function is needed.

Lens vault, thickness, and position in Chinese subjects with angle closure.

PURPOSE: To investigate the association of lens parameters-specifically, lens vault (LV), lens thickness (LT), and lens position (LP)-with angle closure. DESIGN: Prospective, comparative study. PARTICIPANTS: One hundred two Chinese subjects with angle closure (consisting of primary angle closure, primary angle-closure glaucoma, and previous acute primary angle closure) attending a glaucoma clinic and 176 normal Chinese subjects with open angles and no evidence of glaucoma recruited from an ongoing population-based cross-sectional study. METHODS: All participants underwent gonioscopy and anterior-segment optical coherence tomography (AS OCT; Carl Zeiss Meditec, Dublin, CA). Customized software was used to measure LV, defined as the perpendicular distance between the anterior pole of the crystalline lens and the horizontal line joining the 2 scleral spurs, on horizontal AS OCT scans. A-scan biometry (US-800; Nidek Co, Ltd, Tokyo, Japan) was used to measures LT and to calculate LP (defined as anterior chamber depth [ACD] +1/2 LT) and relative LP (RLP; defined as LP/axial length [AL]). MAIN OUTCOME MEASURES: Lens parameters and angle closure. RESULTS: Significant differences between angle-closure and normal eyes were found for LV (901±265 vs. 316±272 µm; P<0.001), LT (4.20±0.92 vs. 3.90±0.73 mm; P = 0.01), LT-to-AL ratio (0.18±0.04 vs. 0.16±0.03; P<0.001), ACD (2.66±0.37 vs. 2.95±0.37 mm; P<0.001), and AL (22.86±0.93 vs. 23.92±1.37 mm; P<0.001), but no significant differences were found for LP (4.76±0.51 vs. 4.90±0.54 mm; P = 0.34) or RLP (0.21±0.02 vs. 0.20±0.02; P = 0.14). After adjusting for age, gender, ACD, LT, and RLP, increased LV was associated significantly with angle closure (odds ratio [OR], 48.1; 95% confidence interval [CI], 12.8-181.3, comparing lowest to highest quartile), but no association was found for LT (OR, 1.78; 95% CI, 0.76-4.16), LP (OR, 1.94; 95% CI, 0.59-6.31), or RLP (OR, 2.08; 95% CI, 0.66-6.57). There was low correlation between LV and LT (Pearson's correlation coefficient [PCC], 0.17), between LV and RLP (PCC, 0.08), or between LV and LP (PCC, 0.2). CONCLUSIONS: Eyes with angle closure have thicker lenses with greater LV compared with normal eyes. The LV, which represents the anterior portion of the lens, is a novel parameter independently associated with angle closure after adjusting for age, gender, ACD, and LT.

Novel mechanism of decreased iris vasculature density after cosmetic iris implants.

A 25-year-old man presented with decreased vision in both eyes, approximately 4 years following bilateral bright ocular cosmetic iris implantation. On examination, he was found to have bilateral elevated intraocular pressures, anterior chamber cells and flare, chronic peripheral anterior synechiae and significantly reduced endothelial cell counts. Ultrasound biomicroscopy demonstrated compression of the peripheral iris, resulting in synechial angle closure in both eyes. Surgical removal of the implants was performed without additional complication. On removal, bilateral iris atrophy was evident with non-reacting pupils and permanent mydriasis. Optical coherence tomography angiography showed a reduction in iris vasculature density that is more pronounced in the area of the iris atrophic defects. This case suggests that cosmetic iris implants may compress iris vasculature, resulting in decreased iris perfusion resulting in atrophic mydriasis and iris defects. This is a potential novel mechanism for complications in eyes with cosmetic iris implants.

Screening for Keratoconus in a High-Risk Adolescent Population.

PURPOSE: To estimate the prevalence of keratoconus (KC) in a majority-Emirati adolescent population and to demonstrate the feasibility of screening using a dual Scheimpflug and Placido imaging device. METHODS: Adolescent subjects from two secondary schools in Abu Dhabi, UAE underwent corneal imaging with the Galilei tomographer (Ziemer Ophthalmic Systems AG, Port, Switzerland). The prevalence of KC and KC suspects was determined using a combination of both subjective and objective criteria. Objective criteria included these KC indices: percent probability of keratoconus, inferior-superior index, asphericity asymmetry index, maximum keratometry and thinnest pachymetry. Subjective pattern analysis was performed by four experienced cornea specialists. Subjects were classified by each cornea specialist into three groups: normal, KC and KC suspect. The final classification was made by group reconciliation of cases where disagreement was present. Inter-observer agreement was assessed with the kappa statistic. RESULTS: A total of 839 eyes of 420 students between 10 and 19 years of age underwent corneal tomography. After the exclusion of 251 eyes due to insufficient scan quality based on internal instrument-derived standards, 588 eyes of 339 subjects were included in the analysis. The prevalence of KC and KC suspect was estimated to be 2.7% (95% CI [1.2%, 5.0%]) and 19.8% (95% CI [15.7%, 24.4%]), respectively. There was a strong inter-observer agreement between examiners' classification of the subjects' KC status (kappa = 0.84). CONCLUSION: KC is highly prevalent in Emirati adolescents. Screening secondary school students for keratoconus appears to be feasible and may be indicated in this population to improve early detection and intervention.

Comparing the detection and agreement of parapapillary atrophy progression using digital optic disk photographs and alternation flicker.

PURPOSE: Parapapillary atrophy (PPA) progression has been associated with progressive glaucoma, but has proven to be difficult to assess clinically. We compared inter- and intra-observer agreement using a novel automated alternation flicker technology and side-by-side digital photography inspection for the evaluation of PPA progression. METHODS: Consecutive patients with serial digital optic nerve photographs at least 1 year apart were included. Two graders (NR, BV) masked to image chronology assessed a set of photographs for progressive PPA using predefined criteria based on reference photographs containing mild, moderate, extensive or no PPA progression. At a separate session, the graders evaluated photographs using alternation flicker (EyeIC, Narberth, PA, USA) applying the same criteria. The order of patients and technique was randomized. Graders then assessed the same set of flickers and photographs a second time with the order of presentation reversed. The main outcome measure was the assessment of progressive PPA as identified by alternation flicker and digital photography inspection. Inter- and intra-observer agreement using each technique was assessed using the kappa statistic. A bootstrap method for comparing correlated kappa coefficients was used to assess statistical significance. RESULTS: Serial photographs from 131 eyes of 68 patients were evaluated. Both graders identified significantly more cases of PPA progression using flicker compared to photography (27-34% vs 8-13%; both p< or =0.003). Inter-observer agreement using flicker was better than using photographs (kappa=0.52 vs 0.18, p=0.02). Intra-observer agreement was similar for both graders (photos: kappa=0.58 vs 0.57, p=0.97; flicker: kappa=0.61 vs 0.70, p=0.37). When progression was assessed by the number of progressive quadrants identified by each grader using a weighted kappa statistic, flicker inter-observer agreement was still moderate (kappa=0.45) and significantly better (p=0.01) than photography, which showed poor agreement (kappa=0.15). Intra-observer agreement with a weighted kappa for quadrant progression was also similar for both graders (photos: grader 1 kappa=0.53 vs grader 2 kappa=0.52, p=0.92; flickers: grader 1 kappa=0.58 vs grader 2 kappa=0.69, p=0.22). Conclusion Flicker identified more cases of progressive PPA than photographic review. Agreement between observers was significantly higher when using the automated flicker technology.