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Purpose: To evaluate the incidence of shallow anterior chamber in the early postoperative period following Ahmed glaucoma valve (AGV) implantation and its effect on the hypertensive phase (HP), intermediate-term intraocular pressure (IOP) control, and success rate. Methods: A retrospective analysis of 369 eyes of 360 patients who underwent AGV implantation between January 2005 and January 2020 with a minimum follow-up of 2 months was performed. Twenty-six patients developed shallow anterior chamber (AC) within 8 weeks following surgery (cases). They were compared with 39 randomly selected controls (no shallow AC post AGV). HP (IOP spike >21 mmHg), use of ocular hypotensive medications, and other associations were compared. Results: Incidence of shallow AC post AGV was 7% (95% confidence interval [CI] 4, 9). The onset of shallow AC was 3 ± 2.1 days and resolved within 6 ± 4.7 days. Hypotony (12 [47%] vs. 1 [2.5%], P 0.0001) and choroidal detachment (CD; 7 [27%] vs. 3 [8%], P 0.03) were more common in cases compared to controls. The HP occurred in 11 (43%) cases versus 13 (34%) controls (P 0.4). Cases required more ocular hypotensive medications than controls at the end of 8 weeks (1.1 ± 1 vs. 0.5 ± 0.5, P 0.01). There was no significant difference in the qualified success between the groups at 1 year. Conclusion: The development of postoperative shallow AC post AGV implantation was not detrimental to IOP control at 1 year. However, there is a need to monitor the occurrence of HP in these eyes.

Background/aims To assess pupillary light responses (PLRs) in eyes with high myopia (HM) and evaluate the ability of handheld chromatic pupillometry (HCP) to identify glaucomatous functional loss in eyes with HM. Methods This prospective, cross-sectional study included 28 emmetropes (EM), 24 high myopes without glaucoma (HM) and 17 high myopes with confirmed glaucoma (HMG), recruited at the Singapore National Eye Center. Monocular PLRs were evaluated using a custom-built handheld pupillometer that recorded changes in horizontal pupil radius in response to 9 s of exponentially increasing blue (469.1 nm) and red (640.1 nm) lights. Fifteen pupillometric features were compared between groups. A logistic regression model (LRM) was used to distinguish HMG eyes from non-glaucomatous eyes (EM and HM). Results All pupillometric features were similar between EM and HM groups. Phasic constriction to blue (p<0.001) and red (p=0.006) lights, and maximum constriction to blue light (p<0.001) were reduced in HMG compared with EM and HM. Pupillometric features of melanopsin function (postillumination pupillary response, PIPR area under the curve (AUC) 0-12 s (p<0.001) and PIPR 6 s (p=0.01) to blue light) were reduced in HMG. Using only three pupillometric features, the LRM could classify glaucomatous from non-glaucomatous eyes with an AUC of 0.89 (95% CI 0.77 to 1.00), sensitivity 94.1% (95% CI 82.4% to 100.0%) and specificity 78.8% (95% CI 67.3% to 90.4%). Conclusion PLRs to ramping-up light stimuli are unaltered in highly myopic eyes without other diagnosed ocular conditions. Conversely, HCP can distinguish glaucomatous functional loss in eyes with HM and can be a useful tool to detect/confirm the presence of glaucoma in patients with HM. [ABSTRACT FROM AUTHOR]

AIMS:To determine the diagnostic performance of macular ganglion cell-inner plexiform layer (GCIPL) thickness measured by spectral-domain optical coherence tomography (SD-OCT) for glaucoma detection in a Chinese population in comparison with optic nerve head (ONH) and retinal nerve fiber layer (RNFL) parameters measured by both SD-OCT and Heidelberg Retina Tomography 3 (HRT-3). METHODS:Adults aged 40 to 80 years were recruited from the population-based study (n = 3353, response rate 72.8%). Macular cube 200x200 scan was performed with Cirrus SD-OCT (version 6.0, Carl Zeiss Meditec Inc, Dublin, CA) for GCIPL thickness measurement. ONH and RNFL imaging was performed with Cirrus SD-OCT and HRT-3 (Heidelberg Engineering, Heidelberg, Germany). Glaucoma was defined according to International Society for Geographical and Epidemiological Ophthalmology criteria. RESULTS:In total, 86 eyes of 60 subjects with glaucoma and 1709 eyes of 1001 non-glaucoma participants were included. The best performing parameters for Cirrus SD-OCT GCIPL, Cirrus SD-OCT ONH and HRT-3 were minimum GCIPL thickness (Area under receiver-operating curve [AUC] = 0.89, 95% CI 0.83-0.95), vertical cup-disc ratio (CDR) (AUC = 0.94, 0.91-0.98) and vertical CDR (AUC = 0.86, 0.81-0.92), respectively. At 85% specificity, vertical CDR measured using Cirrus OCT ONH scan showed the highest sensitivity (88.64%, 95% CI 75.4-96.2) compared to minimum GCIPL thickness with sensitivity of 60.53% (95% CI 46.4-73.0) (p

Aim To investigate the association between the extent of iridotrabecular contact and other quantitative anterior segment dimensions measured by swept-source optical coherence tomography (SS-OCT; CASIA SS-1000, Tomey, Nagoya, Japan) with intraocular pressure (IOP). Methods Cross-sectional study. All subjects who were ≥50 years with no history of glaucoma, ocular surgery or trauma, underwent SS-OCT imaging (eight equally spaced radial scans), Goldman applanation tonometry and gonioscopy on the same day. We measured iridotrabecular contact (ITC) index and area, total volume of trabeculo-iris space area and angle opening distance at 500 and 750 from the scleral spur (TISA 500 and 750, AOD 500 and 750, respectively), anterior chamber depth (ACD), volume, area and width, pupil diameter, lens vault and iris volume.Their relationship with IOP (dependent variable) was assessed by locally weighted scatterplot smoothing (Lowess) regression with change-point analysis and generalised additive models adjusted for confounders. Results 2027 right eyes of mostly Chinese Singaporeans (90%) were analysed. ITC index above a threshold of ~60% (95% CI 34% to 92%) was significantly associated with higher IOP. Independent of the extent of ITC, ACD was also significantly associated with higher IOP below a threshold of 2.5 mm (95% CI 2.33 mm to 2.71 mm). Greater ITC index and shallower ACD had a joint association with IOP. A model including ACD and ITC index was more predictive of IOP than a model considering these variables separately, particularly for women with gonioscopically closed angles (R2 52.7%, p<0.05). Conclusions The extent of angle closure and the ACD below a certain threshold had a significant joint association with IOP. These parameters, as biometrical surrogates of mechanical obstruction of the aqueous outflow, may jointly contribute to elevated IOP, particularly in women with gonioscopic angle closure. [ABSTRACT FROM AUTHOR]

Purpose: To determine agreement between diurnal variation testing (DVT) of intraocular pressure (IOP) with Goldmann applanation tonometer (GAT) and iCare HOME (IH) by an optometrist (OP) and home monitoring by participants (PT). Methods: Patients (18-80 years) with glaucoma and suspects were enrolled. IH IOP and GAT were taken by an OP at 2 h intervals from 8 AM to 4 PM on Day 1 and PT between 6 AM and 9 PM, for the next 2 days. IOP, date, and time were viewed via iCare LINK software. Results: In total, 72.9% (51/70) PT trained were able to take reliable readings. One hundred two eyes (51 patients, age 53 ± 16 yrs) were analyzed. Correlation between optometrist (OP) and participants (PT) was strong and positive {IH OP-IH PT-r = 0.90, p-0.0001;IH PT-GAT- r = 0.79, p-0.0001}. Agreement by Bland Altman plots was limited {IH OP-IH PT mean 0.1 mmHg (95% LOA -5.3 to 5.5), IH PT-GAT 2.2 mmHg (-5.7 to 10.1)}. Intraclass correlation coefficient for IH OP-IH PT was 1.18 (95% CI 1.37-1.09). Intradevice {0.95 (95% CI 0.94-0.97)} and interrater repeatability {0.91 (0.79-0.96)} were good. 37% of eyes had a synchronous peak on GAT and IH during the day DVT. Conclusion: Home tonometry by iCare HOME is easy, feasible, but due to limited agreement cannot substitute GAT DVT. [ABSTRACT FROM AUTHOR]

Purpose: To assess the visual outcome after cataract surgery in a south Indian population. Materials and Methods: Population-based cross-sectional study of subjects aged 40 years or more. Three thousand nine hundred and twenty-four rural subjects from 27 contiguous villages and 3850 urban subjects from five randomly selected divisions were studied. All subjects underwent a comprehensive ophthalmic examination that included visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, and dilated retinal examination. Statistical Analysis: Chi square test, t test and multivariate analysis were used. Results: Five hundred and twenty-eight (216 males, 312 females, 781 eyes) rural subjects (13.5%, 95% confidence interval (CI) 12.4% to 14.6%) and 406 (197 males, 209 females, 604 eyes) urban subjects (10.5%, 95% CI 9.6-11.5%) had undergone cataract surgery. Outcome of cataract surgery was defined based on visual acuity. Using best-corrected visual acuity for classification, the single most important cause for visual impairment was cystoid macular edema in the aphakic group and posterior capsule opacification in the pseudophakic group. Aphakia (visual acuity of < 20/60 to ≤ 20/400 - odds ratio (OR) 1.8; 95% CI 1.3 to 2.6%, visual acuity of < 20/400 - OR 6.2; 95% 4.0 to 9.8%), rural residence (visual acuity of < 20/60 to ≤ 20/400 - OR 3.2; 95% CI 2.2 to 4.5% and visual acuity of < 20/400 - OR OR 3.5; 95% CI 2.3 to 5.5%) were associated with visual impairment. The urban cataract-operated population had significantly more pseudophakics ( P < 0.001), men ( P = 0.02) and literates ( P < 0.001). In the rural group the prevalence of cataract surgery (13.5% vs. 10.5%, P < 0.001) and number of people that had undergone cataract surgery within three years prior to examination ( P < 0.001) were significantly greater. In 30% of rural and 16% of urban subjects uncorrected refraction was the cause of visual impairment. Conclusions: Surgery-related complications were major causes for visual acuity of < 20/60.

Purpose: The aim of this study was to compare the Humphrey MATRIX visual field (frequency doubling technology threshold) and Swedish interactive threshold algorithm (SITA) standard strategy white on white perimetry in detecting glaucomatous visual field loss. Material and Methods: Twenty-eight adult subjects, diagnosed to have glaucoma at a tertiary eye care hospital, who fulfilled the inclusion criteria, were included in this prospective study. All subjects underwent a complete ophthalmic examination. Subjects with glaucomatous optic disc changes underwent repeat perimetric examination on the same day with the Humphrey visual field analyzer (HFA II) and Humphrey MATRIX, the order of testing being random. Only reliable fields, where the HFA results corresponded to the disc changes were considered for analysis. A cumulative defect depth in each hemifield in both HFA and MATRIX reports was calculated. Results: Thirty-seven eyes of 24 subjects had reliable fields corresponding to optic disc changes. The mean age of the subjects was 56 ± 12 years. There were 12 males and 12 females. The test duration was significantly less on the MATRIX, mean difference in test duration was -81 ± 81.3 sec ( p < 0.001). The mean deviation and the pattern standard deviation between the two instruments showed no significant difference ( p = 0.55, p = 0.64 respectively) and a positive correlation coefficient of 0.63 and 0.72 respectively. Poor agreement was found with the glaucoma hemifield test. Conclusion: The Humphrey MATRIX takes less time in performing the test than SITA Standard and shows good correlation for mean deviation and pattern standard deviation. However, the glaucoma hemifield test showed poor agreement. The Humphrey MATRIX diagnoses were similar to established perimetric standards.

Aim: To assess the awareness and knowledge levels about glaucoma and its determinants in an urban population of Chennai in south India. Materials and Methods: Chennai glaucoma study (CGS) was a population based prevalence study to estimate the prevalence of glaucoma in a rural and urban south Indian population. A total of 3850 subjects aged 40 years or above participated in the urban arm of CGS. A systematic random sample of 1926 (50.0%) subjects completed a questionnaire that assesses their awareness and knowledge level of glaucoma. Respondents "having heard of glaucoma" even before they were contacted/recruited for the study were defined as "aware" and respondents having some understanding of the eye disease were defined as "knowledgeable". Results: Overall 13.5% were aware of glaucoma, the age-gender adjusted rate for awareness was 13.3% (95% CI: 11.57 to 15.03). Two clinicians graded knowledge on glaucoma, based on the subject′s knowledge of risk factors, definitions and treatment aspects of glaucoma. Overall 8.7% had some knowledge about glaucoma. Among those who had knowledge 0.5% had good knowledge about glaucoma, 4% had fair knowledge and 4.2% had poor knowledge. We observed a very good agreement between the clinicians in grading knowledge (k =0.92). Determinants of glaucoma awareness and knowledge were higher levels of education, females, age, religion and family history of glaucoma. Conclusion: Awareness and knowledge about glaucoma was very low among the urban population of Chennai. We have found that younger subjects and men were less aware of glaucoma. Subjects with lower levels of education were less aware and knew less about glaucoma than their counterparts. The study findings stress the need for health education for effective prevention of blindness due to glaucoma.

Purpose: To compare the prevalence of refractive errors and factors associated with spectacle use in a rural and urban south Indian population. Materials and Methods: Four thousand eight hundred subjects (age> 39 years) each from rural and urban Tamil Nadu were enumerated for a population-based study. All participants underwent a complete ophthalmic evaluation including best-corrected visual acuity (BCVA), objective and subjective refraction. Out of 3924 rural responders 63.91% and out of 3850 urban responders 81.64% were phakic in the right eye with BCVA of 20/40 or better and were included in the study. Association of spectacle use and refractive errors with different parameters were analysed using logistic regression. Statistical Analysis: Chi square, t test, Chi square for trend and Pearson′s correlation coefficient were used for analysis. Results: Spectacle use was significantly higher and positively associated with literacy and employment in the urban population. The age and gender-adjusted prevalence of emmetropia, myopia of spherical equivalent (SE) ≤-0.50 diopter sphere (DS), high myopia (SE ≤-5.00DS), hyperopia (SE> 0.50DS) and astigmatism &#8804 0.50 diopter cylinder (DC) were 46.8%, 31.0%, 4.3%, 17.9% and 60.4% respectively in the rural population and 29.0%, 17.6%, 1.5%, 51.9%, 59.1% respectively in the urban population. The prevalence of emmetropia decreased with age ( p < 0.001); prevalence of myopia and high myopia increased with age ( p = 0.001) and were associated with nuclear sclerosis ( p = 0.001) in both populations. Hyperopia was commoner among women than men ( p = 0.001); was positively associated with diabetes mellitus ( p = 0.008) in the rural population and negatively with nuclear sclerosis ( p = 0.001) in both populations. Conclusion: Spectacle use was found to be significantly lower in the rural population. The pattern of refractive errors was significantly different between both populations.

Aims To validate a deep learning (DL) algorithm (DLA) for 360° angle assessment on swept-source optical coherence tomography (SS-OCT) (CASIA SS-1000, Tomey Corporation, Nagoya, Japan). Methods This was a reliability analysis from a cross-sectional study. An independent test set of 39 936 SS-OCT scans from 312 phakic subjects (128 SS-OCT meridional scans per eye) was analysed. Participants above 50 years with no previous history of intraocular surgery were consecutively recruited from glaucoma clinics. Indentation gonioscopy and dark room SS-OCT were performed. Gonioscopic angle closure was defined as non-visibility of the posterior trabecular meshwork in =180° of the angle. For each subject, all images were analysed by a DL-based network based on the VGG-16 architecture, for gonioscopic angle-closure detection. Area under receiver operating characteristic curves (AUCs) and other diagnostic performance indicators were calculated for the DLA (index test) against gonioscopy (reference standard). Results Approximately 80% of the participants were Chinese, and more than half were women (57.4%). The prevalence of gonioscopic angle closure in this hospital-based sample was 20.2%. After analysing a total of 39 936 SS-OCT scans, the AUC of the DLA was 0.85 (95% CI:0.80 to 0.90, with sensitivity of 83% and a specificity of 87%) to classify gonioscopic angle closure with the optimal cut-off value of >35% of circumferential angle closure. Conclusions The DLA exhibited good diagnostic performance for detection of gonioscopic angle closure on 360° SS-OCT scans in a glaucoma clinic setting. Such an algorithm, independent of the identification of the scleral spur, may be the foundation for a non-contact, fast and reproducible 'automated gonioscopy' in future. [ABSTRACT FROM AUTHOR]