Demyelination precedes axonal loss in the transneuronal spread of human neurodegenerative disease.

The spread of neurodegeneration through the human brain network is reported as underlying the progression of neurodegenerative disorders. However, the exact mechanisms remain unknown. The human visual pathway is characterized by its unique hierarchical architecture and, therefore, represents an ideal model to study trans-synaptic degeneration, in contrast to the complexity in neural connectivity of the whole brain. Here we show in two specifically selected patient cohorts, including (i) glaucoma patients with symmetrical bilateral hemifield defects respecting the horizontal meridian (n = 25, 14 females, 64.8 ± 10.1 years; versus 13 normal controls with similar age/sex distributions); and (ii) multiple sclerosis patients without optic radiation lesions (to avoid potential effects of lesions on diffusivity measures) (n = 30, 25 females, 37.9 ± 10.8 years; versus 20 controls), that there are measurable topographic changes in the posterior visual pathways corresponding to the primary optic nerve defects. A significant anisotropic increase of water diffusion was detected in both patient cohorts in the optic radiations, characterized by changes in perpendicular (radial) diffusivity (a measure of myelin integrity) that extended more posteriorly than those observed in parallel (axial) diffusivity (reflecting axonal integrity). In glaucoma, which is not considered a demyelinating disease, the observed increase in radial diffusivity within the optic radiations was validated by topographically linked delay of visual evoked potential latency, a functional measure of demyelination. Radial diffusivity change in the optic radiations was also associated with an asymmetrical reduction in the thickness of the calcarine cortex in glaucoma. In addition, 3 years longitudinal observation of the multiple sclerosis patient cohort revealed an anterograde increase of radial diffusivity in the anterior part of optic radiations which again was retinotopically associated with the primary damage caused by optic neuritis. Finally, in an animal model of optic nerve injury, we observed early glial activation and demyelination in the posterior visual projections, evidenced by the presence of myelin-laden macrophages. This occurred prior to the appearance of amyloid precursor protein accumulation, an indicator of disrupted fast axonal transport. This study demonstrated strong topographical spread of neurodegeneration along recognized neural projections and showed that myelin and glial pathology precedes axonal loss in the process, suggesting that the mechanism of trans-synaptic damage may be at least partially mediated by glial components at the cellular level. The findings may have broad biological and therapeutic implications for other neurodegenerative disorders.

Diagnostic value and safety of medical thoracoscopy in undiagnosed pleural effusions-a prospective observational cohort study.

Background: With the need for "actionable histology" in the current era of targeted cancer treatment, and the increasing practice of upfront thoracoscopy (without a prior diagnostic thoracentesis) or a "biopsy first" approach in suspected malignant pleural effusions (MPEs), we sought to prospectively evaluate the diagnostic accuracy, including full molecular profiling of cancer, and safety of medical thoracoscopy (MT) at a tertiary referral hospital. Methods: Patients with MT performed for an undiagnosed pleural effusion between January 2020 and December 2022 were included in this observational cohort study. All procedures were performed with a semirigid thoracoscope under conscious sedation. Clinical outcomes and adverse events were recorded prospectively. Results: We evaluated 141 patients, with a mean age of 67±12 years. Talc poudrage was performed in 67 (47.5%) patients with a median of 2 [interquartile range (IQR), 1-4] hospitalisation days after MT. Upfront thoracoscopy was performed in approximately half (55.3%) of patients. The overall diagnostic accuracy of MT was 95.7% in our cohort. A final diagnosis of cancer was made in 116 (82.3%) patients, with lung (67.2%) and breast cancer (8.6%) the most common. The diagnostic sensitivity of MT for malignancy was 94.8%, and molecular profiling of relevant cancer types for oncogenic mutations was achieved in all patients with malignancy seen on histopathology. The most common non-malignant diagnosis was tuberculous pleuritis in 14 patients (9.9%). Major complications occurred in 3 (2.1%) patients. Two patients had re-expansion pulmonary edema that resolved with low flow oxygen supplementation in the general ward, and one patient required intensive care unit admission for cardiac tamponade from a malignant pericardial effusion. There were no cases of mortality, bleeding complications or persistent air leaks. Conclusions: MT is a well-tolerated and effective option for the evaluation of undiagnosed pleural effusions. With expanding utility and expertise with MT and other pleural interventions, the challenge for respiratory physicians is integrating these into expeditious diagnostic and effective therapeutic pathways, individualised to patients' needs.

Bleb vascularity following post-trabeculectomy subconjunctival bevacizumab: a pilot study.

BACKGROUND: To determine whether postoperative subconjunctival bevacizumab significantly alters bleb vascularity. DESIGN: A randomized, prospective interventional study. PARTICIPANTS: Forty-three eyes from 39 patients were recruited, with 21 eyes randomized to subconjunctival injections of 5-fluorouracil, and 22 eyes to combined 5-fluorouracil/bevacizumab. METHODS: All patients who underwent uncomplicated primary antimetabolite augmented trabeculectomy who subsequently required postoperative subconjunctival 5-fluorouracil injection within 4 weeks of surgery were eligible. Patients were randomized to receive subconjunctival 5-fluorouracil only (7.5 mg/0.15 mL) or 5-fluorouracil plus bevacizumab (1.25 mg/0.05 mL). MAIN OUTCOME MEASURES: Primary outcome was bleb vascularity with secondary endpoints including visual acuity, intraocular pressure, bleb morphology, complications and total numbers of 5-fluorouracil injections were recorded at baseline, week 12 and 18 months. RESULTS: At week 12, there was no significant difference between groups for visual acuity, intraocular pressure, bleb vascularity and morphology, or total number of 5-fluorouracil injections. By 18 months, 47.4% of the 5-fluorouracil/bevacizumab group exhibited central bleb avascularity compared with 21.1% of the 5-fluorouracil group (Fisher's exact test, P = 0.17). Two bleb complications (one blebitis; one suture abscess) recorded in the 5-fluorouracil/bevacizumab group. CONCLUSIONS: After a single combined injection, a trend for increased central bleb avascularity was observed, although this effect was not sufficient to reach statistical significance. This, in addition to the occurrence of two bleb-related complications in the bevacizumab group, suggests the need for a larger clinical trial to further evaluate the safety and efficacy of bevacizumab as a modulating agent in glaucoma filtration surgery.

Bilateral homonymous superior quadrantanopia after traumatic attempts to remove a cockroach impacted in the external auditory canal.

Visual field defects typically caused by lesions in the optic nerve or optic chiasm may be caused indirectly by subdural haematomas. A 61-year-old man survived transtentorial herniation caused by subdural haematomas that resulted from shaking his head in an attempt to remove a cockroach impacted in his external auditory canal. Bilateral incomplete posterior cerebral artery infarction of both inferior tips of the occipital lobe resulted in bilateral superior quadrantanopia. There are no previous reports of tentorial herniation causing this permanent outcome.

A geometric morphometric assessment of the optic cup in glaucoma.

The morphologic appearance of the optic disc is of interest in glaucoma. In contrast to descriptive classification systems that are currently used, a quantitative approach to the analysis of optic disc morphology is required. Our goal was to determine the optimal method for quantifying optic cup shape by comparing traditional (ovality, form-factor and neuroretinal rim (NRR) width ratio) and geometric morphometric approaches. Left optic disc stereophotographs of 160 (80 normal and 80 glaucomatous (stratified by severity)) subjects were examined. The optic cup margins were stereoscopically delineated with a custom tracing system and saved as a series of discrete points. The geometric morphometric methods of elliptic Fourier analysis (EFA) and sliding semi-landmark analysis (SSLA) were used to eliminate variation unrelated to shape (e.g. size) and yield a series of shape variables. Differences in optic cup shape between normal and glaucoma groups were investigated. Discriminant functions were computed and the sensitivity and specificity of each technique determined. Receiver operator characteristic (ROC) curves were calculated for all methods and evaluated in their potential to discriminate between normal and glaucomatous eyes based on the shape variables. All geometric morphometric methods revealed differences between normal and glaucomatous eyes in optic cup shape, in addition to the traditional parameters of ovality, form-factor and NRR width ratio (p<0.0005). SSLA (minimum bending energy criterion--18 points) had the best sensitivity (83%) and area under the curve (AUC) (0.91). EFA (72 points) performed similarly well (74%, 0.89) as did the set of traditional shape-based variables (76%, 0.86). This study demonstrated that a geometric morphometric approach for discriminating between normal and glaucomatous eyes in optic cup shape is superior to that provided by traditional single parameter shape measures. Such analytical techniques could be incorporated into future automated optic disc screening modalities.

SUCCESSFUL CLOSURE OF FULL-THICKNESS MACULAR HOLES SECONDARY TO MACULAR VITELLIFORM LESIONS.

PURPOSE: To describe the first reported cases of full-thickness macular holes secondary to vitelliform lesions that were successfully closed with vitrectomy surgery and gas tamponade. METHODS: Two female patients developed visual loss secondary to bilateral vitelliform lesions and associated full-thickness macular holes. The patients underwent 25-gauge pars plana vitrectomy, internal limiting membrane peeling, and 26% sulfur hexafluoride gas, followed by 3 days of face-down positioning. RESULTS: In both patients, the macular holes remain closed 3 and 25 months postoperatively. CONCLUSION: Vitrectomy surgery with gas tamponade may successfully close full-thickness macular holes secondary to macular vitelliform lesions.

Elevated activated partial thromboplastin time-based clot waveform analysis markers have strong positive association with acute venous thromboembolism.

INTRODUCTION: A hypercoagulable state is a predisposition for venous thromboembolism (VTE). The activated partial thromboplastin time (aPTT)-based clot waveform analysis (CWA) is a global haemostatic measure but its role in assessment of hypercoagulability and thrombotic disorders is uncertain. We aimed to study the changes of CWA parameters in acute VTE. We hypothesized that patients with acute VTE would demonstrate higher CWA values than control patients without VTE and having elevated CWA parameters is associated with acute VTE. MATERIALS AND METHODS: Clot waveform analysis data from patients (N = 45) with objectively proven acute VTE who had an aPTT performed prior to initiation of anticoagulation were compared with controls (N = 111). The CWA parameters measured were min1, min2, max2 and delta change. RESULTS: While the mean aPTT between VTE patients and controls did not differ (P = 0.830), the mean CWA parameters were significantly higher among VTE patients than controls (min1, P < 0.001; min2, P = 0.001; max2, P = 0.002; delta change, P < 0.001). There were significantly more cases within the VTE group exhibiting CWA values above their reference intervals than the control group (all P < 0.001), with the odds ratios for VTE of 8.0, 5.2, 4.8 and 18.6 for min1, min2, max2 and delta change, respectively (all P < 0.001). CONCLUSIONS: Patients with acute VTE had elevated aPTT-based CWA parameters than controls. Higher CWA parameters were significantly associated with acute VTE.

Positive association between plasma homocysteine level and chronic kidney disease.

BACKGROUND: Increasing experimental evidence, including recently developed animal models, supports a role for homocysteine in the development of chronic kidney disease (CKD). However, relatively few clinical/epidemiological studies have examined this hypothesis in humans. We examined the relationship between plasma homocysteine level and CKD in a population-based study of older Australians. METHODS: Community-based study (1992-1994) among 2,609 individuals (58.6% women), aged 49-98 years, free of clinical cardiovascular disease in the Blue Mountains region, west of Sydney, Australia. The main outcome-of-interest was CKD (n = 461), defined as estimated glomerular filtration rate of <60 ml/min/1.73 m(2). RESULTS: Higher plasma homocysteine levels were positively associated with CKD, independent of smoking, body mass index, diabetes mellitus, hypertension, cholesterol levels, and other confounders. The multivariable odds ratio (OR; 95% confidence intervals, CI) comparing quartile 4 of plasma homocysteine (>14 micromol/l) to quartile 1 (< or =9 micromol/l) was 10.44 (6.99-15.60), p-trend <0.0001. This association persisted in both men and women separately. The results were also consistent in subgroup analyses by categories of diabetes mellitus and hypertension. CONCLUSIONS: Higher plasma homocysteine levels are associated with CKD in a community-based sample of older Australians. This association appeared to be independent of diabetes mellitus and hypertension.

A Deep Learning-Based Algorithm Identifies Glaucomatous Discs Using Monoscopic Fundus Photographs.

PURPOSE: To develop and test the performance of a deep learning-based algorithm for glaucomatous disc identification using monoscopic fundus photographs. DESIGN: Fundus photograph database study. PARTICIPANTS: Four thousand three hundred ninety-four fundus photographs, including 3768 images from previous Sydney-based clinical studies and 626 images from publicly available online RIM-ONE and High-Resolution Fundus (HRF) databases with definitive diagnoses. METHODS: We merged all databases except the HRF database, and then partitioned the dataset into a training set (80% of all cases) and a testing set (20% of all cases). We used the HRF images as an additional testing set. We compared the performance of the artificial intelligence (AI) system against a panel of practicing ophthalmologists including glaucoma subspecialists from Australia, New Zealand, Canada, and the United Kingdom. MAIN OUTCOME MEASURES: The sensitivity and specificity of the AI system in detecting glaucomatous optic discs. RESULTS: By using monoscopic fundus photographs, the AI system demonstrated a high accuracy rate in glaucomatous disc identification (92.7%; 95% confidence interval [CI], 91.2%-94.2%), achieving 89.3% sensitivity (95% CI, 86.8%-91.7%) and 97.1% specificity (95% CI, 96.1%-98.1%), with an area under the receiver operating characteristic curve of 0.97 (95% CI, 0.96-0.98). Using the independent online HRF database (30 images), the AI system again accomplished high accuracy, with 86.7% in both sensitivity and specificity (for ophthalmologists, 75.6% sensitivity and 77.8% specificity) and an area under the receiver operating characteristic curve of 0.89 (95% CI, 0.76-1.00). CONCLUSIONS: This study demonstrated that a deep learning-based algorithm can identify glaucomatous discs at high accuracy level using monoscopic fundus images. Given that it is far easier to obtain monoscopic disc images than high-quality stereoscopic images, this study highlights the algorithm's potential application in large population-based disease screening or telemedicine programs.

Optical coherence tomography findings of acute traumatic maculopathy following motor vehicle accident.

PURPOSE: To describe two cases of acute traumatic maculopathy using optical coherence tomography (OCT) following high-speed motor vehicle accidents. DESIGN: Case reports. METHODS: Patients were examined soon after the accident using Snellen visual acuity (VA), dilated fundus examination, and OCT. Re-examination was conducted two weeks to one month later. RESULTS: Both patients experienced an immediate reduction in VA of between 20/120 and 20/200. An abnormal yellow foveal reflex was noted at fundus examination in both cases. OCT revealed outer retinal thickening under the fovea and of the neurosensory retina with preservation of the inner retinal architecture and foveal pit. These OCT changes resolved approximately within two weeks of the accidents with near resolution of the visual disturbance in both cases. CONCLUSIONS: We describe two cases of acute traumatic maculopathy, including its appearance on OCT imaging.

Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration.

AIM: The aim of this article is to evaluate the rate of patients developing sustained elevated intraocular pressure (IOP) after ranibizumab (Lucentis) intravitreal (IVT) injections. DESIGN: This is a retrospective study. PARTICIPANTS: Charts of 192 consecutive patients receiving Lucentis for age-related macular degeneration (AMD) were retrospectively reviewed. MATERIALS AND METHODS: We enrolled patients with at least two IOP measurements between injections. Elevated IOP was defined as >21 mm Hg with an increase of at least 20% from baseline. Noninjected contralateral eyes of the same patient cohort were used as control. MAIN OUTCOME MEASURES: Primary outcome was defined as elevated IOP. Secondary outcomes were presence and type of glaucoma, number of injections, and time to IOP elevation. RESULTS: Elevated IOP occurred at a significantly higher rate in eyes receiving IVT ranibizumab (7.47%; n = 9) compared with control (0.93%; n = 1). Patients with preexisting glaucoma or ocular hypertension (OHT) were more likely to develop elevated IOP after IVT ranibizumab injection. CONCLUSION: Intravitreal ranibizumab injections are associated with sustained IOP elevation in some eyes. HOW TO CITE THIS ARTICLE: Reis GMSM, Grigg J, Chua B, Lee A, Lim R, Higgins R, Martins A, Goldberg I, Clement CI. The Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration. J Curr Glaucoma Pract 2017;11(1):3-7.

Dietary fatty acids and the 5-year incidence of age-related maculopathy.

OBJECTIVE: To assess longitudinal associations between dietary fat and incident age-related maculopathy (ARM) in an older, population-based, historical cohort. METHODS: A total of 3654 persons, 49 years or older, participated in the Blue Mountains Eye Study (1992-1994); 2335 (75.1% of survivors) were reexamined after 5 years (1997-1999). Dietary data were collected from 2895 people (79%) at baseline by means of a semiquantitative food frequency questionnaire to calculate dietary fat intakes. Presence of ARM was graded from retinal photographs (Wisconsin ARM Grading System). Logistic regression adjusted for age, sex, vitamin C intake, and smoking. RESULTS: Participants with the highest vs lowest quintiles of n-3 polyunsaturated fat intake had lower risk of incident early ARM (odds ratio [95% confidence interval], 0.41 [0.22-0.75). A 40% reduction of incident early ARM was associated with fish consumption at least once a week (odds ratio [95% confidence interval], 0.58 [0.37-0.90]), whereas fish consumption at least 3 times per week could reduce the incidence of late ARM (odds ratio [95% confidence interval], 0.25 [0.06-1.00]). We found no association between incident ARM and butter, margarine, or nut consumption. CONCLUSIONS: A regular diet high in n-3 polyunsaturated fat, especially from fish, suggests protection against early and late ARM in this older Australian cohort. Our study could not confirm deleterious effects of higher polyunsaturated fat intakes reported by other clinic-based studies.

Homocysteine and retinal emboli: the Blue Mountains Eye Study.

PURPOSE: To examine the association between serum homocysteine and retinal emboli in a general older population. DESIGN: Cross-sectional population-based study. METHODS: Homocysteine level was determined from fasting venous blood collection at the second Blue Mountains Eye Study (BMES) (n = 3509, age > or =49 years, 1997 to 2000). Retinal emboli were graded from retinal photographs. Using logistic regression, we analyzed associations between serum homocysteine and retinal emboli adjusting for age, gender, hypertension, body mass index, and lipid levels. RESULTS: After multivariable adjustment, serum homocysteine was associated with presence of retinal emboli (odds ratio (OR) 1.2; 95% confidence interval (CI), 1.0 to 1.6 per standard deviation [4.8 micromol/l] increase in serum homocysteine). CONCLUSION: Elevated serum homocysteine is weakly associated with increased odds of retinal emboli in this older population-based study.

Homocysteine and retinal vein occlusion: a population-based study.

PURPOSE: To report population data on the association between homocysteinemia and retinal vein occlusion (RVO). DESIGN: Cross-sectional, population-based study. METHODS: Total serum homocysteine (tHcy) was estimated in subjects attending the second Blue Mountains Eye Study (BMES) (n = 3509, aged >49 years). Its association with RVO (graded from retinal photographs) was examined. RESULTS: Homocysteine was more strongly associated with RVO in younger than older participants. In those aged <70 years, homocysteine levels >15 micromol/l were associated with increased odds of RVO, odds ratio (OR) 3.76; 95% confidence interval (CI) 1.06-13.40, in multivariable-adjusted analyses. Each 1 micromol/l increase in homocysteine was associated with a 7% increased odds of RVO, OR 1.07; CI 0.99-1.17 (P = .08). CONCLUSION: This population-based study showed that elevated serum homocysteine is associated with the presence of RVO, independent of other risk factors.

Management of Duane retraction syndrome.

BACKGROUND: Duane retraction syndrome is the most common cause of congenital aberrant ocular innervation. We report referral practices, clinical characteristics and complications, prevalence of congenital and familial anomalies, and management outcomes from a clinic-based series. METHODS: Retrospective clinic-based study of 65 patients with Duane retraction syndrome seen between January 1994 and March 2004. RESULTS: The majority of patients were girls with type I Duane retraction syndrome associated with esotropia in primary gaze. Twenty percent of cases were complicated by absent binocular stereoacuity and 16.9% had amblyopia. Family history of any ocular disorder was reported in 38.5% of cases, while an associated congenital abnormality was found in 46% of patients. There was a significant delay between the age when ocular abnormalities were first noticed and the age when patients presented at our tertiary referral center (P < .001). Twenty-two percent of patients underwent surgical correction at a mean age of 6 years. Most procedures were unilateral or bilateral medial or lateral rectus recessions. Postoperative ocular alignment < or = 15 prism diopters (PD) was achieved in 86% of cases, with 50% of cases having < or = 5 PD. CONCLUSIONS: Amblyopia and absent binocular stereo vision affected one in five patients with Duane retraction syndrome. There was significant delay between identification of an abnormality and presentation at the eye clinic.

Does Chronic Hypotony following Trabeculectomy Represent Treatment Failure?

PURPOSE: To measure the rate of complications from chronic hypotony following trabeculectomy and clarify the definition of postoperative hypotony. MATERIALS AND METHODS: In this retrospective case-control study, the rate of complications was compared between 34 eyes with chronic hypotony and 34 eyes without hypotony. Chronic hypotony was defined as those eyes with an intraocular pressure (IOP) of less than 6 mm Hg on two consecutive clinic visits at least 3 months after trabeculectomy. Cases were identified from a database of two glaucoma surgeons between 2010 and 2013. Outcomes measured included visual acuity, presence of choroidal effusion, hypotensive maculopathy and cataract development/progression. Factors associated with the development of hypotony were considered using analysis of variance (ANOVA) multivariate regression. RESULTS: Maculopathy was seen in 23.5% of hypotony eyes but not in controls (p < 0.01). No significant difference in the rate of choroidal effusion or cataract was documented between groups. Control eyes were more likely to remain complication free (58.8 vs 32.4%, p < 0.03). Spontaneous recovery from hypotony occurred in 32.4% of hypotony eyes. CONCLUSION: Sight threatening complications occur more frequently in eyes with chronic hypotony following glaucoma surgery. However, not all eyes with chronic hypotony develop sight threatening complications. A definition of hypotony that combines IOP criteria with the presence of structural and/or functional changes is recommended. How to cite this article: Yun S, Chua B, I Clement C. Does Chronic Hypotony following Trabeculectomy Represent Treatment Failure? J Curr Glaucoma Pract 2015;9(1):12-15.

Corneal arcus and hyperlipidemia: findings from an older population.

PURPOSE: To quantify the association between arcus and hyperlipidemia in an older population. DESIGN: Cross-sectional population-based study. METHODS: Arcus and serum lipids were measured in the Blue Mountains Eye Study (n = 3,654, aged >49 years). Arcus was graded as absent, partial (<180 degrees) or circumferential (> or =180 degrees). Associations between arcus and hyperlipidemia were assessed using logistic regression, adjusting for age and vascular risk factors. RESULTS: Arcus was strongly associated with age (P <.0001). After age adjustment, arcus was associated with male sex (P <.01) and diabetes (P <.02) but not with hypertension or smoking. Corneal arcus was significantly associated with progressively higher levels of total cholesterol over 5 mmol/l. Adjusted odds increased from 1.6 for cholesterol 6.0 to 6.9 mmol/l to 4.6 for cholesterol >8.0 mmol/l, and was 1.9 for high triglyceride >3.0 mmol/l. CONCLUSION: This population-based finding confirms that corneal arcus was associated with hypercholesterolemia and hypertriglyceridemia in older persons.

Glaucoma prevalence in Indigenous Australians.

AIM: Define the prevalence of glaucoma within the Indigenous Australian population. METHODS: Aboriginal and Torres Strait Islander adults aged ≥ 40 years were recruited from 30 randomly selected sample areas or communities. Participants were regarded to have glaucoma if they had a cup:disc ratio (CDR) of > 0.8, or missed ≥ 2 points on the Frequency Doubling Test and a CDR > 0.7 in at least one eye. RESULTS: 1189 eligible adult participants were examined, representing 72% of the target population. After excluding cases with missing or ungradable information, the authors found a 2.2% (95% CI 1.6% to 3.6%) overall prevalence of glaucoma. In univariate analyses, the odds of glaucoma increased with age (χ² trend=4.38, p < 0.001), male gender (OR 2.43, 95% CI 1.10 to 5.41), less than secondary education (OR 4.74, 95% CI 1.96 to 11.45) and self-reported history of glaucoma (OR 20.8; 95% CI 6.23 to 69.51). After a multivariate analysis, none of these attributes other than history of glaucoma remained significant. No cases of low vision (presenting visual acuity (VA) < 6/12 to ≤ 6/60) or blindness (presenting VA < 6/60) were solely attributable to glaucoma. The mean optic disc diameter was 1.93 mm (SD 0.19) for left and right eyes, while the mean CDR for right eyes was 0.44 (SD 0.15) and for left eyes 0.43 (SD 0.16). CONCLUSIONS: This population-based study examined the prevalence of glaucoma within the Indigenous Australian population, and although an infrequent cause of vision loss, definable rates of disease were seen. The results may suggest a potential introduction of Caucasian glaucoma-associated genes into this community, differently used diagnostic criteria or sampling bias compared with previous surveys.

Retinal vessel diameters and obesity: a population-based study in older persons.

OBJECTIVE: Obesity is linked with large vessel atherosclerosis and diabetes. Its association with microvascular changes is less clear. We investigated the associations among retinal vessel diameters, vessel wall signs, and BMI in an older population. RESEARCH METHODS AND PROCEDURES: Retinal photographs were taken on 3654 persons aged 49+ years at baseline of the Blue Mountains Eye Study in Australia. Arteriolar and venular diameters were measured from digitized retinal photographs of the right eyes. BMI was calculated as weight (kilograms)/height (meters2). Incident obesity was defined in persons with BMI < or = 30 at baseline but > 30 after 5 years. A significant weight gain was defined as an increase in BMI of 2+ SDs (4 or more units) over the 5-year period. RESULTS: At baseline, mean BMI was 26.1 (+/-4.6) in this population. At 5-year examinations, 177 (10.0% of 1773 at risk) developed incident obesity, and 136 (6.4% of 2143 at risk) had significant weight gain. After adjusting for age, sex, smoking, triglyceride levels, and mean arterial blood pressure, persons with wider retinal venular diameters had a higher risk of incident obesity (odds ratio, 1.8; 95% confidence interval, 1.0 to 3.1, comparing the highest with lowest venular diameter quintiles) and significant weight gain (odds ratio, 1.7; 95% confidence interval, 0.9 to 3.2). These associations were attenuated with further adjustment for baseline BMI. Arteriolar diameter was unrelated with baseline or change in BMI. DISCUSSION: Wider retinal venular diameter is associated with risk of obesity, independent of hypertension, diabetes, lipids, and cigarette smoking. These data may support a role for impaired microvascular function in the course of weight gain.