Assessment of Toxicity of Green Synthesized Silver Nanoparticle-coated Titanium Mini-implants with Uncoated Mini-implants: Comparison in an Animal Model Study.

AIM: To assess the potential for systemic toxicity when silver nanoparticle-coated mini-implants were implanted in Wistar albino rats conducted as a comparative study in the animal model by assessing the blood biochemistry, liver and kidney function, and histology of the implanted site. MATERIALS AND METHODS: The surface of the mini-implant was coated with a green-mediated silver nanoparticle. Uncoated mini-implants were placed in two groups of eight Wistar albino rats, and silver nanoparticle-coated mini-implants were placed in another eight rats. The bone's general conditions, blood biochemistry assessing for ALT, AST, GPT, GOT, and histological sections using H and E stain and Masson's Trichrome stain were examined at 7, 14, and 28-day intervals. RESULTS: The creatinine, urea, ALP, and ALT showed no signs of systemic toxicity during the 28-day follow-up period in the Wistar rats both in the test and control groups. The histological evaluation, which was conducted using HE and MTS stain, revealed osteogenesis and adequate healing of the insertion site in the group where coated mini-implant was placed. The bone sample revealed no abnormalities in the control group with uncoated mini-implants. CONCLUSION: Green synthesized silver nanoparticle-coated mini-implant does not cause systemic toxicity as indicated by no abnormalities in the levels of creatinine, urea, ALT, ALP, GPT, and GOT. The bone histology indicates that the coated mini-implants placed in animal bone healed with adequate osteogenesis. CLINICAL SIGNIFICANCE: Silver nanoparticles have potential for antimicrobial activity. Mini-implants placed as temporary anchorage devices in orthodontics often fail due to inflammation and plaque. Silver nanoparticle-coated mini-implants would reduce the risk of mini-implant failure as it would have antimicrobial potential and eliminate this cause for failure of mini-implants. How to cite this article: Sreenivasagan S, Subramanian AK, Mohanraj KG, et al. Assessment of Toxicity of Green Synthesized Silver Nanoparticle-coated Titanium Mini-implants with Uncoated Mini-implants: Comparison in an Animal Model Study. J Contemp Dent Pract 2023;24(12):944-950.

A comprehensive update on the use of optical coherence tomography angiography in glaucoma.

PURPOSE: The primary purpose of this review is to provide a comprehensive summary on the technical principles of OCTA and to enumerate vascular parameters being explicated for glaucoma diagnosis and progression with emphasis on recent studies. In addition, the authors also summarize the future clinical potentials of OCTA in glaucoma and enumerate the limitations of this imaging modality in the present-day scenario. METHODS: The index study is a narrative review on OCTA in glaucoma. The authors searched the PubMed database using the key phrases ''optical coherence tomography angiography" AND "glaucoma,'' AND/OR "vascular parameters" AND/OR "ocular perfusion." Being a relatively recent development in ocular imaging, studies in which OCTA imaging had been used for glaucoma evaluation since 2012 were included until March 2022. The literature search included original studies and previous review articles, while case reports were excluded. Preliminary search was based on relevant articles with search keywords in the title and abstract. The second screening was performed by reading the full text of the literature. RESULTS: Recent studies indicate reduction in microcirculation in glaucomatous eyes compared to the normal subjects. The area of interest for glaucoma evaluation using OCTA varies among the different studies. Based on the literature reviewed here, (1) OCTA parameters measured in the peripapillary; ONH and macular area have been shown to differentiate between glaucoma and normal eyes with a discriminatory power comparable to OCT parameters used routinely in clinics, (2) monitoring of peripapillary and macular vessel density may provide important information to the evaluation of glaucoma progression and prediction of rates of disease worsening, (3) studies suggest strong correlation between the OCTA parameters, the OCT parameters and visual function, measured by visual field testing, in glaucomatous eyes, (4) future prospects of OCTA in glaucoma evaluations using AI predicting structural and functional features and prognosis based on early vascular findings would open up scope for early detection of high-risk suspects and fast progressors in glaucoma. CONCLUSION: OCTA can be useful in quantifying vascular parameters in the optic disc, peripapillary and the macular regions for glaucoma evaluation. OCTA shows potential to become a part of everyday glaucoma management.

The Singapore Asymptomatic Narrow Angles Laser Iridotomy Study: Five-Year Results of a Randomized Controlled Trial.

PURPOSE: To examine the efficacy of laser peripheral iridotomy (LPI) in patients who received a diagnosis of primary angle-closure suspect (PACS). DESIGN: Prospective, randomized controlled trial. PARTICIPANTS: This multicenter, randomized controlled trial (ClinicalTrials.gov identifier, NCT00347178) enrolled 480 patients older than 50 years from glaucoma clinics in Singapore with bilateral asymptomatic PACS (defined as having ≥2 quadrants of appositional angle closure on gonioscopy). METHODS: Each participant underwent prophylactic LPI in 1 randomly selected eye, whereas the fellow eye served as a control. Patients were followed up yearly for 5 years. MAIN OUTCOME MEASURES: The primary outcome measure was development of primary angle closure (PAC; defined as presence of peripheral anterior synechiae, intraocular pressure [IOP] of >21 mmHg, or both or acute angle closure [AAC]) or primary angle-closure glaucoma (PACG) over 5 years. RESULTS: Of the 480 randomized participants, most were Chinese (92.7%) and were women (75.8%) with mean age of 62.8 ± 6.9 years. Eyes treated with LPI reached the end point less frequently after 5 years (n = 24 [5.0%]; incidence rate [IR], 11.65 per 1000 eye-years) compared with control eyes (n = 45 [9.4%]; IR, 21.84 per 1000 eye-years; P = 0.001). The adjusted hazard ratio (HR) for progression to PAC was 0.55 (95% confidence interval [CI], 0.37-0.83; P = 0.004) in LPI-treated eyes compared with control eyes. Older participants (per year; HR, 1.06; 95% CI, 1.03-1.10; P < 0.001) and eyes with higher baseline IOP (per millimeter of mercury; HR, 1.35; 95% CI, 1.22-1.50; P < 0.0001) were more likely to reach an end point. The number needed to treat to prevent an end point was 22 (95% CI, 12.8-57.5). CONCLUSIONS: In patients with bilateral asymptomatic PACS, eyes that underwent prophylactic LPI reached significantly fewer end points compared with control eyes over 5 years. However, the overall incidence of PAC or PACG was low.

Inverse Calculation of Composite Kink-Band Toughness from Open-Hole Compression Strength.

Fiber-reinforced polymer matrix composite materials can fail by kink-band propagation mechanism when subjected to in-plane compressive loading. This mode of failure is especially prevalent in compressive loading of laminates with holes, cut-outs, or impact damage. Most of the successful models for predicting compressive strength of such laminates require "fracture" toughness associated with kink-band propagation under in-plane compression. However, this property is difficult to measure experimentally, limiting the use of such models in design practice. In this paper an inverse method is proposed to estimate the kink-band toughness of the laminate from its open-hole compression strength data, which is an easier property to measure experimentally. Furthermore, a scaling relationship is proposed to estimate kink-band toughness for other laminate configurations of the same material.

Use of Wavefront Imaging Technology to Demonstrate Improvement in Corneal Aberrations Using Piggyback Contact Lens in a Keratoconus Eye With Intrastromal Corneal Ring Segment Implantation: A Case Report.

OBJECTIVE: To quantify short-term changes in corneal high-order aberrations (HOA) with piggyback contact lens use in an eye with keratoconus that had undergone intrastromal ring segment (Intacs) implantation. METHODS: A patient with keratoconus reporting of distorted images after Intacs surgery was found to have HOA (trefoil, point spread function [PSF], and modulation transfer function [MTF]) as measured using wavefront technology (Nidek OPD-Scan III) and evidenced by her cylindrical correction. She underwent piggyback contact lens (silicone hydrogel and fluoroperm rigid gas-permeable lenses) fitting in an attempt to improve the HOA. RESULTS: After piggyback contact lens fitting, her visual acuity improved and all her visual symptoms resolved. High-order aberrations reduced from 3.152 to 0.490 after the lens fitting and was noted to be 0.447 at 6 months; trefoil also significantly improved (0.360-0.096; it was 0.031 at 6 months). The cylinder decreased from -4.50 to -0.75 and was stable at 6 months (-1.00). There was also significant improvement in PSF and MTF. CONCLUSIONS: Visual acuity and symptoms along with HOA and cylinder improved after fitting of piggyback contact lens in our patient with keratoconus who had undergone Intacs.

Preparation and Evaluation of Antimicrobial Properties and Cytotoxic Potentials of Nutmeg and Tulsi Gel.

AIM: The aim of the study is to prepare the dual gel using nutmeg and Tulsi and then the evaluation of the antimicrobial properties and cytotoxic potential. MATERIALS AND METHODS: The Nutmeg Tulsi gel preparation has been done with a mixture of equal amounts of nutmeg and Tulsi powder. To the above-mentioned mixture, 5 mL of the concentrate is added and mixed thoroughly until the gel formation is done. The antimicrobial property is checked in the Porphyromonas gingivalis organism (p>0.05). The cytotoxic potential is checked in the Brine variety of the shrimp. The statistical analysis is done using a Paired t-test. RESULTS: The results stated that the Nutmeg Tulsi gel at a concentration of 100 microgram/mL showed a greater zone of inhibition (4.1±0.09 mm) when compared with doxycycline and has high antimicrobial potential in both Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Conclusion: The antimicrobial property of Nutmeg Tulsi gel has been demonstrated to be effective against P. gingivalis and A. actinomycetemcomitans. This suggests that it could be used as an affordable and effective "adjunct" alongside standard care for managing periodontal conditions.

Diagnostic Accuracy of Frequency-Doubling Technology and the Moorfields Motion Displacement Test for Glaucoma.

PURPOSE: Portable perimetric testing could be useful for community-based glaucoma screening programs. Frequency-doubling technology (FDT) and the Moorfields motion displacement test (MDT) are portable perimeters that have shown promise as potential screening tools for glaucoma. This study's goal was to determine the diagnostic accuracy of FDT and MDT for visual field defects and glaucoma. DESIGN: Prospective, cross-sectional, diagnostic accuracy study. PARTICIPANTS: A consecutive series of patients aged ≥ 50 years who presented to a glaucoma clinic in South India and had never undergone Humphrey field analyzer (HFA) visual field testing in the past. METHODS: Participants underwent 24-2 Swedish Interactive Thresholding Algorithm (SITA) Standard HFA perimetry, FDT perimetry, MDT perimetry, and iPad perimetry using visualFields Easy in random order. Ophthalmologist grades of HFA and optic nerve head photographs were used as reference standards for glaucoma and field defect presence. Receiver operating characteristic curves were constructed to assess the diagnostic accuracy of various parameters for each test. MAIN OUTCOME MEASURES: Sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC). RESULTS: Overall, 292 eyes from 173 participants were included, with 112 eyes classified as moderate or worse glaucoma. For moderate or worse glaucoma detection, the best parameter on FDT was mean deviation (MD) (AUROC, 0.84; 95% confidence interval [CI], 0.79-0.89) and the best parameter on MDT was global probability of true damage (GPTD) (AUROC, 0.87; 95% CI, 0.82-0.91). When specificity was set to 90%, the sensitivity for detection of moderate or worse glaucoma was 55% (95% CI, 39%-68%) for FDT MD and 62% (95% CI 52%-71%) for MDT GPTD. CONCLUSIONS: Frequency-doubling technology and MDT perimetry had fair diagnostic accuracy for glaucoma detection when administered to naïve test takers in this South Indian population. Although not appropriate for use as a sole glaucoma screening test, these perimetric tests may be useful as ancillary tests. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Diagnostic accuracy of an iPad application for detection of visual field defects.

BACKGROUND/OBJECTIVES: Tablet-based perimetry could be used to test for glaucomatous visual field defects in settings without easy access to perimeters, although few studies have assessed diagnostic accuracy of tablet-based tests. The goal of this study was to determine the diagnostic accuracy of iPad perimetry using the visualFields Easy application. SUBJECTS/METHODS: This was a prospective, cross-sectional study of patients undergoing their first Humphrey Field Analyser (HFA) visual field test at a glaucoma clinic in India. Participants underwent 24-2 SITA Standard HFA testing and iPad-based perimetry with the visualFields Easy application. Reference standards for both visual field loss and suspected glaucoma were determined by ophthalmologist review of HFA results and optic disc photographs. Receiver operating characteristic curves were constructed to assess diagnostic accuracy at various test thresholds. RESULTS: 203 eyes from 115 participants were included, with 82 eyes classified as moderate or worse glaucoma. iPad perimetry had an area under the receiver operating characteristic (AUROC) curve of 0.64 (95% CI 0.57 to 0.71) for detection of any visual field defect relative to HFA and an AUROC of 0.68 (0.59 to 0.76) for detection of moderate or worse glaucoma relative to ophthalmologist examination. At a set specificity of 90%, the sensitivity of iPad perimetry for detection of moderate or worse glaucoma was 35% (22-48%). CONCLUSIONS: iPad perimetry using the visualFields Easy application had inadequate diagnostic accuracy to be used as a screening tool for glaucoma in this South Indian population.

Risk of acute angle closure and changes in intraocular pressure after pupillary dilation in Asian subjects with narrow angles.

OBJECTIVE: To evaluate the risk of primary acute angle closure (AAC), changes in intraocular pressure (IOP), and associated risk factors after pupil dilation in Asian subjects with narrow angles (primary angle-closure suspects [PACS]). DESIGN: Prospective clinical study. PARTICIPANTS: A total of 471 subjects aged more than 50 years with narrow angles in Singapore. METHODS: This study was part of a prospective trial of PACS. Subjects underwent a detailed ophthalmic evaluation including gonioscopy, biometry, pachymetry, and ultrasound biomicroscopy. All subjects underwent pupil dilation with 1% tropicamide eye drops at the baseline visit, before any laser or medical intervention. Intraocular pressure was measured using Goldmann applanation tonometry by the same observer before and 1 hour after pupil dilation. A dose of oral acetazolamide was given before the patient left the clinic. MAIN OUTCOME MEASURES: Intraocular pressure before and after dilation, and an AAC event. RESULTS: The mean age of the 471 subjects was 63.0 ± 6.9 years (mean ± standard deviation); 75.4% were women, and 92.8% were Chinese. Of the 471 participants, 3 (0.64%; 95% confidence interval [CI], 0.13-1.85) developed AAC within 6 hours of dilation despite pretreatment with oral acetazolamide. Twenty-two subjects (4.67%; 95% CI, 2.95-6.99) showed a postdilation increase in IOP of ≥ 5 mmHg in either eye, 6 subjects (1.27%; 95% CI, 0.47-2.75) had an IOP increase of ≥ 8 mmHg in either eye, and 4 subjects (0.85%; 95% CI, 0.23-2.16) had a postdilation IOP of >25 mmHg in either eye. Narrower gonioscopic angle width, that is, having a lower mean gonioscopic modified Shaffer grading (coefficient ß -0.51; standard error 0.19; P=0.01), and predilation IOP level (coefficient ß -0.17; standard error 0.04; P < 0.001) were significant risk factors for IOP increase after dilation in multivariate linear regression analysis. CONCLUSIONS: The risk of AAC among Asian subjects with narrow angles was low after pupillary dilation with tropicamide and oral acetazolamide prophylaxis. The presence of narrower angle width by gonioscopy was the only clinical parameter identified for a significant IOP increase after pupil dilation.

Changes in anterior segment morphology after laser peripheral iridotomy: an anterior segment optical coherence tomography study.

PURPOSE: Novel anterior segment optical coherence tomography (ASOCT) parameters associated with angle closure include anterior chamber area (ACA), anterior chamber volume (ACV), anterior chamber width (ACW), lens vault (LV), iris thickness (IT), iris area (I-area), and iris curvature (I-curv). We aimed to investigate changes in these parameters after laser peripheral iridotomy (LPI) in a cohort of primary angle-closure suspects (PACS). DESIGN: Prospective observational study. PARTICIPANTS AND CONTROLS: A total of 176 PACS aged ≥ 50 years who underwent LPI in 1 eye. METHODS: We analyzed ASOCT images (Visante, Carl Zeiss Meditec, Dublin, CA) from all subjects using customized software before and 1 week after LPI. Multivariate linear regression analysis was performed for predictors of percentage change in mean angle opening distance (AOD750). MAIN OUTCOME MEASURES: Change in ASOCT parameters after LPI. RESULTS: The mean age of participants was 63 ± 7.3 years. The majority of subjects were Chinese (95.5%) and women (76.7%). Mean angle width (modified Shaffer grade) changed from 0.68 ± 0.54 at baseline to 1.76±0.69 after LPI (P<0.001) with a corresponding increase in mean AOD500 (0.12 vs. 0.19 mm, P<0.001), trabecular iris surface area (TISA500, 0.06 vs. 0.08 mm(2), P<0.001), and angle recess area (ARA, 0.13 vs. 0.17 mm(2), P<0.001). Mean ACA (15.0 vs. 16.0 mm(2), P<0.001) and ACV (91.6 vs. 103.0 mm(3), P<0.001) increased significantly after LPI, but there was no change in ACW, anterior chamber depth (ACD), or LV. Mean I-curv was reduced (0.375 vs. 0.18 mm, P<0.001) after LPI, but there was no significant change in IT or I-area. After multivariate analysis, mean LV (ß = 0.286, P = 0.001), mean IT at 2000 µm (IT2000, ß = 0.172, P = 0.034), and intraocular pressure (ß = 0.159, P = 0.042) at baseline were found to be associated with ΔAOD750. CONCLUSIONS: This study confirms that LPI results in a significant increase in the angle width in PACS. The ACA and ACV increased after LPI, but there was no change in ACD, ACW, LV, IT, or I-area. The increase in ACA/ACV was mainly due to decreased I-curv after LPI.

In vivo imaging of riboflavin penetration during collagen cross-linking with hand-held spectral domain optical coherence tomography.

PURPOSE: To compare the effect of complete versus grid-like epithelial removal on riboflavin penetration during collagen cross-linking (CXL) in vivo using hand-held spectral domain optical coherence tomography (OCT, Bioptigen Inc). METHODS: In this prospective, observational, comparative case series, patients with progressive keratoconus undergoing CXL with riboflavin and ultraviolet A (UVA) light were enrolled. Twenty eyes (20 patients) undergoing CXL using 0.1% riboflavin and UVA light (365 nm) were imaged intraoperatively at 30 and 60 minutes after starting the procedure, using hand-held spectral domain OCT. In 10 eyes, the epithelium was removed completely in the central 7-mm zone (complete removal group) whereas in the remaining 10 eyes, the epithelium was removed in a grid pattern, leaving behind intact islands of epithelium (grid-like removal group). The depth of hyperreflective band (representing penetration of riboflavin) in the anterior corneal stroma was measured. RESULTS: In the complete removal group, the hyper-reflective band was homogenous, extending to a mean depth of 54.2±5.2 µm and 72.4±7.1 µm at 30 and 60 minutes, respectively (P<.001). In the grid-like removal group, the mean depth of the hyperreflective band was uneven, being significantly more in the "epithelium off" areas (56.90±4.66 µm and 74.2±6.7 µm at 30 and 60 minutes, respectively) (P<.001) compared to the "epithelium on" areas (18.9±2.3 µm and 24.7±2.3 µm at 30 and 60 minutes, respectively) (P<.001). CONCLUSIONS: Epithelial removal appears to be an essential step prior to performing CXL, as an intact epithelium appears to block penetration of riboflavin in the anterior corneal stroma.

Comparison of Structural, Functional, Tonometric, and Visual Acuity Testing for Glaucoma: A Prospective Diagnostic Accuracy Study.

PURPOSE: To determine the diagnostic accuracy of potential screening tests for moderate to advanced glaucoma. DESIGN: Prospective diagnostic test accuracy study. PARTICIPANTS: The study enrolled a consecutive series of patients aged ≥50 years who presented to a glaucoma clinic in South India without ever having received automated visual field testing. METHODS: All participants underwent 8 index tests: OCT of the peripapillary retinal nerve fiber layer, optic disc photography, Moorfield's Motion Displacement Test (MDT), frequency doubling technique perimetry, noncontact tonometry, pneumatonometry, presenting visual acuity, and best-corrected visual acuity. Participants also underwent stereoscopic photographs and Humphrey visual fields, which were used by 2 ophthalmologists to arrive at the reference standard diagnosis of moderate to advanced glaucoma. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. RESULTS: A total of 217 people were enrolled; 321 eyes from 180 participants had all tests performed. Of these, 127 eyes (40%) were classified as having moderate to advanced glaucoma. Among the 8 tests, OCT best optimized sensitivity (84%, 95% confidence interval [CI], 76-90) and specificity (75%, 95% CI, 68-81). Moorfield's Motion Displacement Test was the best perimetric test, with a sensitivity of 91% (95% CI, 85-96) and specificity of 53% (95% CI, 44-61). Pressure and vision tests were not sensitive (e.g., sensitivity of 16%, 95% CI, 9-23 for noncontact tonometry and 23%, 95% CI, 15-31 for best-corrected visual acuity). Moorfield's Motion Displacement Test identified 16 of 127 eyes (13%) with glaucoma that were not captured by OCT, but also had false-positive results in 65 of 194 eyes (34%) without glaucoma that OCT correctly classified as negative. CONCLUSIONS: OCT had moderate sensitivity and fair specificity for diagnosing moderate to advanced glaucoma and should be prioritized during an initial assessment for glaucoma.

Evaluation of anterior chamber angle by van Herick grading and ultrasound biomicroscopy in light and dark conditions for finding appositional angle closure and plateau iris configuration.

PURPOSE: To evaluate association of the van Herick (VH) grades with the ultrasound biomicroscopic (UBM) parameters, appositional irido-trabecular contact (A-ITC) and plateau iris (PI) in a randomly sampled population. METHODS: A 10% random sample of all residents aged 40 or older of the Kumejima study underwent UBM under dark and light conditions in the four quadrants of right eyes. RESULTS: Of 301 right eyes with eligible UBM images, 101 (33.6%) and 200 (66.4%) were classified as VH ≤ 2 and VH ≥ 3, respectively. The UBM parameters on angle width and ciliary body configuration were significantly different between VH ≤ 2 and VH ≥ 3 eyes (p < 0.001). A-ITC was found in at least one quadrant in 54.5% and 75.2% of VH ≤ 2 eyes under light and dark conditions, respectively; and 20.5% and 45.5% of VH ≥ 3 eyes. When 'VH ≤ 2' was used to screen eyes with A-ITC in three or more quadrants, the sensitivity and specificity were 74.1% and 75.3%, respectively. A-ITC was significantly associated with shallower anterior chamber (p = 0.018) and higher intraocular pressure (p = 0.044) in VH ≥ 3 eyes. Plateau iris (PI) was found in 15.8% and 6.0% of VH ≤ 2 and VH ≥ 3 eyes, respectively. Plateau iris (PI) was significantly associated with the UBM parameters on angle width and ciliary body configuration. When 'VH ≤ 2' was used to screen eyes with PI, the sensitivity and specificity were 57.1% and 68.9%, respectively. CONCLUSIONS: The VH grade of ≤2 and ≥3 showed significant association with UBM angle width and ciliary body configuration parameters. The VH ≤ 2 criterion should be useful for screening of A-ITC and PI.

Accuracy of autorefraction in an adult Indian population.

PURPOSE: Autorefractors allow non-specialists to quickly assess refractive error, and thus could be a useful component of large-scale vision screening programs. In order to better characterize the role of autorefraction for public health outreach programs in resource-limited settings, the diagnostic accuracy of two autorefractors was assessed relative to subjective refraction in an adult Indian population. METHODS: An optometrist refracted a series of patients aged ≥50 years at an eye clinic in Bangalore, India using the Nidek ARK-900 autorefractor first, followed by the 3nethra Royal autorefractor, and then subjective refraction. The diagnostic accuracy of each autorefractor for myopia, hyperopia, and astigmatism was assessed using subjective refraction as the reference standard, and measures of agreement between refractions were calculated. RESULTS: A total of 197 eyes in 104 individuals (mean age 63 ± 8 years, 52% female) were evaluated. Both autorefractors produced spherical equivalent estimates that were on average more hyperopic than subjective refraction, with a measurement bias of +0.16 D (95%CI +0.09 to +0.23D) for Nidek and +0.42 D (95%CI +0.28 to +0.54D) for 3nethra. When comparing pairs of measurements from autorefraction and subjective refraction, the limits of agreement were approximately ±1D for the Nidek autorefractor and ±1.75D for the 3Nethra autorefractor. The sensitivity and specificity of detecting ≥1 diopter of myopia were 94.6% (95%CI 86.8-100%) and 92.5% (95%CI 88.9-97.5%) for the Nidek, and 89.2% (95%CI 66.7-97.4) and 77.5% (95%CI 71.2-99.4%) for the 3Nethra. The accuracy of each autorefractor increased at greater levels of refractive error. CONCLUSIONS: The sensitivity and specificity of the Nidek autorefractor for diagnosing refractive error among adults ≥50 years in an urban Indian clinic was sufficient for screening for visually significant refractive errors, although the relatively wide limits of agreement suggest that subjective refinement of the eyeglasses prescription would still be necessary.

Diurnal intraocular pressure fluctuation and associated risk factors in eyes with angle closure.

OBJECTIVE: To investigate diurnal intraocular pressure (IOP) fluctuation in eyes with angle closure in comparison with normal subjects and to look for associated risk factors for IOP fluctuation. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Ninety-eight eyes of 98 Asian subjects with angle closure (consisting of 32 primary angle-closure suspects [PACS], 34 subjects with primary angle closure [PAC], and 32 subjects with primary angle-closure glaucoma [PACG]) and 21 eyes of 21 normal control subjects. METHODS: All angle-closure subjects were enrolled after laser peripheral iridotomy but before commencement of any medical or surgical treatment. Ophthalmic examination, including dynamic gonioscopy and automated perimetry, were performed, and diurnal IOP measurements were obtained using noncontact air-puff tonometry at hourly intervals between 8:00 am and 5:00 pm. Mean diurnal IOP, peak diurnal IOP, trough IOP, and IOP fluctuation (peak IOP-trough IOP) were compared between groups. Multiple linear regression analysis was performed to study the association of IOP fluctuation with clinical variables such as age, extent of peripheral anterior synechiae (PAS), central corneal thickness, vertical cup-to-disc ratio, and pattern standard deviation (PSD) on automated perimetry. MAIN OUTCOME MEASURES: Mean diurnal IOP, peak IOP, and IOP fluctuation. RESULTS: Most subjects were Chinese (89.1%) and female (61.3%). Intraocular pressure fluctuation was significantly higher in PACG (5.4+/-2.4 mmHg) and PAC (4.5+/-2.3 mmHg) subjects compared with PACS subjects (3.7+/-1.2 mmHg) and normal controls (3.8+/-1.1 mmHg; P = 0.005), with highest IOP found in the early morning. The combined PACG and PAC group had more than twice the risk (odds ratio, 2.38; 95% confidence interval, 1.1-5.1; P = 0.025) of having IOP fluctuation of more than 3 mmHg compared with the combined PACS and normal group. Extent of PAS (Pearson's correlation coefficient, r = 0.37; P = 0.0001) and visual field PSD (r = 0.34; P = 0.0002) were found to be associated with greater IOP fluctuation. CONCLUSIONS: The PACG and PAC eyes showed diurnal IOP fluctuation of 4 to 5 mmHg, and this fluctuation was higher than in PACS subjects and normal controls. The degree of PAS and visual field loss were associated with IOP fluctuation in PAC and PACG eyes.

Reproducibility of 5 Methods of Ocular Tonometry.

PURPOSE: To evaluate the agreement between Goldmann applanation tonometry (GAT; Haag-Streit, Bern, Switzerland) and several portable tonometers that could be used for glaucoma screening programs. DESIGN: Evaluation of a diagnostic test. PARTICIPANTS: Three hundred twenty-one eyes of 168 participants seeking treatment at the glaucoma clinic of a tertiary eye hospital in India. METHODS: Participants underwent intraocular pressure (IOP) measurement with GAT and 4 index tests: the Icare TA01i rebound tonometer (Icare USA, Raleigh, NC), a noncontact tonometer (NCT; Topcon CT-80; Topcon; Tokyo, Japan), a pneumatonometer (Model 30; Reichert Technologies; Depew, NY), and the Tono-Pen AVIA (Reichert Technologies). MAIN OUTCOME MEASURES: Estimates of reproducibility of IOP measurements between each index test and GAT, including the intraclass correlation coefficient (ICC) and the Bland-Altman 95% limits of agreement. RESULTS: The Icare showed the greatest agreement with GAT (ICC, 0.69; 95% confidence interval, 0.61-0.74), followed by the NCT (ICC, 0.65; 95% confidence interval, 0.58-0.71), the Tono-Pen (ICC, 0.51; 95% confidence interval, 0.43-0.59), and the pneumatonometer (ICC, 0.36; 95% confidence interval, 0.27-0.44). The pneumatonometer and Tono-Pen tended to overestimate IOP relative to GAT, with a mean difference of 3.4 mmHg (95% limits of agreement [LOA], -7.3 to 14.1 mmHg) for the pneumatonometer and 3.2 mmHg (95% LOA, -6.1 to 12.6 mmHg) for the Tono-Pen. In contrast, measurements from the Icare and NCT were on average within 1 point of those for GAT (mean difference, -0.4 mmHg [95% LOA, -8.4 to 7.6 mmHg] and -0.5 mmHg [95% LOA, -8.7 to 7.6 mmHg], respectively). CONCLUSIONS: The Icare and NCT both demonstrated good agreement with GAT across a wide range of IOPs and could be considered for glaucoma screening programs.

Diagnostic capability of scanning laser polarimetry with variable cornea compensator in Indian patients with early primary open-angle glaucoma.

PURPOSE: To evaluate the diagnostic ability of scanning laser polarimetry (GDx variable corneal compensator [VCC]) for early glaucoma in Asian Indian eyes. DESIGN: Cross-sectional observational study. PARTICIPANTS: Two groups of patients (early glaucoma and normal) who satisfied the inclusion and exclusion criteria were included. Early glaucoma was diagnosed in presence of open angles, characteristic glaucomatous optic disc changes correlating with the visual field (VF) on automated perimetry (VF defect fulfilling at least 2 of 3 Anderson and Patella's criteria with mean deviation >or= -6 decibels). Normal subjects had visual acuity >or= 20/30 and intraocular pressure < 22 mmHg, with a normal optic disc and fields and no ocular abnormality. METHODS: All patients underwent complete ophthalmic evaluation, including VF examination (24-2/30-2 Swedish interactive threshold algorithm standard program) and imaging with GDx VCC. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value and negative predictive value, area under the receiving operating characteristic curve, and likelihood ratios (LRs) were calculated for various GDx VCC parameters. RESULTS: Seventy-four eyes (74 patients) with early glaucoma and 104 eyes (104 normal subjects) were enrolled. TSNIT Std Dev (temporal-superior-nasal-inferior-temporal standard deviation) had the best combination of sensitivity and specificity-61.3 and 95.2, respectively-followed by nerve fiber index score > 50 (sensitivity, 52.7%; specificity, 99%). Nerve fiber index score > 50 had positive and negative predictive values of 74.3% and 97.6%, respectively, for an assumed glaucoma prevalence of 5%. Nerve fiber index score > 50 had a positive LR (+LR) of 54.8 for early glaucoma. CONCLUSIONS: GDx VCC has moderate sensitivity, with high specificity, in the diagnosis of early glaucoma. The high +LR for the nerve fiber index score can provide valuable diagnostic information for individual patients.

Comparison of gonioscopy and anterior segment ocular coherence tomography in detecting angle closure in different quadrants of the anterior chamber angle.

PURPOSE: To compare the performance of gonioscopy and anterior segment (AS) optical coherence tomography (OCT) in detecting angle closure in the different quadrants of the anterior chamber angle (ACA). DESIGN: Cross-sectional observational study. PARTICIPANTS: Five hundred two consecutive subjects more than 50 years of age with no previous ophthalmic problems recruited from a community clinic in Singapore. METHODS: All subjects underwent gonioscopy and AS OCT imaging in the dark. Using gonioscopy, the ACA was graded using the Scheie system by a single examiner masked to AS OCT findings. MAIN OUTCOME MEASURES: The ACA in a particular quadrant was classified as closed if the posterior trabecular meshwork could not be seen on gonioscopy. A closed ACA on AS OCT imaging was defined by the presence of any contact between the iris and angle wall anterior to the scleral spur. RESULTS: After excluding eyes with poor image quality, a total of 423 right eyes were included in the analysis. A closed angle in at least 1 quadrant was observed in 59% of the eyes by AS OCT and in 33% of the eyes by gonioscopy (P<0.001), with fair agreement between the two methods (kappa = 0.40). The frequency of closed angles by AS OCT and gonioscopy were 48% versus 29% superiorly, 43% versus 22% inferiorly, 18% versus 14% nasally, and 12% versus 20% temporally, respectively. Of the 119 of 1692 quadrants that were closed on gonioscopy but open on AS OCT, a steep iris profile was present in 61 (51%) of 119 quadrants on AS OCT, and of the 276 of 1692 quadrants that were open on gonioscopy but closed on AS OCT, 196 (71%) of 276 quadrants showed short iridoangle contact on AS OCT. CONCLUSIONS: The highest rates of closed angles on gonioscopy and AS OCT images were observed in the superior quadrant. Anterior segment OCT tended to detect more closed ACAs than gonioscopy, particularly in the superior and inferior quadrants. Variations in the iris profile and level of iridoangle contact also may explain some of the differences seen between gonioscopy and AS OCT.

Prevalence of plateau iris in primary angle closure suspects an ultrasound biomicroscopy study.

PURPOSE: To determine the prevalence of plateau iris in a cohort of primary angle closure suspects (PACSs) using ultrasound biomicroscopy (UBM). DESIGN: Cross-sectional observational study. PARTICIPANTS: Subjects over the age of 50 years diagnosed as PACSs. INTERVENTION: Subjects were randomized to undergo laser peripheral iridotomy (LPI) in one eye. Ultrasound biomicroscopy was performed before and a week after LPI. MAIN OUTCOME MEASURES: Ultrasound biomicroscopy images were qualitatively assessed using standardized criteria. Plateau iris was defined in a quadrant by the presence of an anteriorly directed ciliary body, an absent ciliary sulcus, a steep iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, presence of a central flat iris plane, and irido-angle contact. At least 2 quadrants had to fulfil the above criteria for an eye to be defined as plateau iris. RESULTS: Two hundred five subjects were enrolled; UBM images of 167 subjects were available for analysis. Plateau iris was found in 54 of 167 (32.3%) PACS eyes after LPI. Quadrantwise analysis showed that 44 of 167 (26.3%) eyes had plateau iris in 1 quadrant, 36 (21.5%) in 2 quadrants, 16 (9.5%) in 3 quadrants, and 2 (1.2%) in all 4 quadrants. Plateau iris was most commonly observed in the superior and inferior quadrants. CONCLUSIONS: Using standardized UBM criteria, plateau iris was found in about a third of PACS eyes after LPI. Prospective longitudinal studies are required to determine the clinical significance of this finding for the management of PACSs.