Spectacle compliance postcataract surgery significantly improved vision function-related quality of life of adult patients in India: Evidence from a multicenter longitudinal cohort study.

BACKGROUND: Cataract is the leading cause of avoidable blindness globally. This study aims to measure the changes in Vision function-related quality of life (VFQoL) before and after cataract surgery and identify the predictors of an improvement in these outcomes. METHODS: A multicenter, longitudinal cohort study was conducted. Patients with first eye cataracts were interviewed before and 6 months after cataract surgery. Multiple classification analysis (MCA) was performed to assess variation in the intensities of mean change scores for general function, psychosocial impact, and visual function with select factors. RESULTS: A total of 747 participated in the baseline assessment. The 6-month follow-up rate was 86.5%. The mean general function, psychosocial impact, and visual function scores were 35.3 (±8.6), 12.5 (±3.4), and 8.3 (±3) in the baseline and 17 (±5.3), 6 (±2.2) and 3.8 (±1.3) in the follow-up assessments, respectively. In MCA, patients using spectacles postsurgery (ß 0.111) and those having a very good postoperative visual acuity (ß 0.098) had the most impact on general function. Patients reporting no ocular complaints postsurgery had a relatively higher effect on the psychosocial impact, (ß 0.168) and similarly, patients using spectacles postsurgery and those aged 70 and older had the most impact on the visual function scores (ß 0.146 and 0.126), respectively. CONCLUSION: Cataract surgery is associated with meaningful improvements in vision and VFQoL in general. The determinants of better VFQoL include the usage of spectacles postsurgery. Strategies to further improve patient participation in postoperative review visits are needed for spectacle provision and patient education regarding spectacle use and compliance is imparted during such visits.

Implications of Diagnostic Drops on Scheimpflug Tomography: The Proper Order for Clinical Testing.

PURPOSE: The purpose of this article was to study the impact of instillation of 1% fluorescein and mydriatics on measurements made by Scheimpflug imaging. METHODS: This was a cross-sectional study of patients who had measurements of corneal shape (maximum keratometry and best fit sphere of anterior and posterior corneal surfaces), pachymetry (at the pupil center, corneal apex, and thinnest location), and anterior chamber parameters (depth, volume, and angle of anterior chamber and corneal volume) using the Pentacam HR before and after the instillation of fluorescein and mydriatics. Group A had baseline measurements that were repeated 1.5 hours after the instillation of 1% fluorescein and 0.8% tropicamide+ 5% phenylephrine eye drops. Group B had baseline measurements that were repeated 10 minutes after the instillation of 1% fluorescein, and group C had baseline measurements that were repeated 1.5 hours after the instillation of mydriatics. RESULTS: Overall, 131 eyes of 131 patients were studied: 87 in group A, 28 in group B, and 16 in group C. Significant differences and wide variations were noted in corneal pachymetry and anterior chamber parameters in all 3 groups. The highest magnitude and range of difference was observed in pachymetry at the pupil center (17 ± 53.5 µm) and in anterior chamber volume (26.7 ± 69.8 mm 3 ). Corneal shape measurements of anterior and posterior corneal surfaces were not significantly affected by either fluorescein or mydriatics. Pupillary dilation also affected the ability of the Pentacam to accurately trace the pupil margin in 19.5% of cases. CONCLUSIONS: For consistent and accurate measurements, it is important that Scheimpflug imaging be performed before other tests which may need the instillation of fluorescein or mydriatics.

Automated Image Segmentation of the Corneal Endothelium in Patients With Fuchs Dystrophy.

Purpose: To perform segmentation of specular microscopy (SM) images of the corneal endothelium for comparing average perimeter length (APL) between Fuchs endothelial corneal dystrophy (FECD) patients and healthy subjects. Methods: A retrospective review of clinical records of FECD patients and those with healthy endothelium was carried out to collect images of the endothelium. The images were segmented by modified U-Net, a deep learning architecture, followed by the Watershed algorithm to resolve merged cell borders (<5%). The segmented images were analyzed for endothelial cell density (ECDUW) and APL. Results: The combination of the U-Net and Watershed algorithm, referred to as the UW approach, enabled a complete segmentation of the endothelium. In healthy, ECDUW was close to estimates by SM and manual segmentation (31 subjects; P > 0.1). However, in FECD, ECDUW was closer to estimates by manual segmentation but not by SM (27 patients; P < 0.001). ECDUW in FECD (2547 ± 499 cells/mm2; 60 patients) was smaller compared to that in the healthy (2713 ± 401 cells/mm2; 70 subjects) (P < 0.001). APL in the healthy was 66.87 ± 7.68 µm/cell (70 subjects), but it increased with %Guttae in FECD (56.60-195.30 µm/cell; 60 patients) (P < 0.0001). Conclusions: The UW approach is precise for the segmentation of SM images from the healthy and FECD. Our analysis has revealed that APL increases with %Guttae. Translational Relevance: The average perimeter length of the corneal endothelium, which represents the length of the paracellular pathway for fluid flux into the stroma, is increased in Fuchs dystrophy.

Clinical Outcomes After Bilateral Implantation of a Trifocal Presbyopia-Correcting Intraocular Lens in an Indian Population.

PURPOSE: To evaluate the effectiveness and safety of a presbyopia-correcting trifocal intraocular lens (IOL), AcrySof® IQ PanOptix® (TFNT00), in an Indian population. PATIENTS AND METHODS: This prospective, multicenter, observational, single-arm, post-marketing study included 67 patients undergoing cataract surgery with bilateral implantation of TFNT00 across five Indian sites. Postoperative outcomes were assessed at 3 months after second eye surgery. Effectiveness outcomes included: mean binocular and monocular visual acuity (VA) at distance (4 m), intermediate (60 cm), and near (40 cm); binocular defocus curve; manifest refraction; and subjective symptom questionnaire evaluation. Safety outcomes included the rate of ocular adverse events and mesopic contrast sensitivity. RESULTS: Mean binocular and monocular distance-corrected and uncorrected VAs of 0.1 logMAR or better (approximately 20/25 Snellen) were achieved at distance, intermediate, and near. Overall, ≥70% of patients achieved binocular 0.1 logMAR vision or better across all distances. TFNT00 maintained a mean VA of 0.1 logMAR or better at the defocus range of +0.5 diopters (D) to -2.5 D (200 cm to 40 cm). The subjective symptom questionnaire-assessed frequency of halo visual disturbances was low at Month 3; halos were reported "none of the time" to "only some of the time" in 86.6% of patients. The large majority of patients (98.5%) were "satisfied" or "very satisfied" with their near, intermediate, and distance vision at Month 3, and ≥94.0% of patients reported spectacle independence for tasks at all distances. The adverse event rate was low; no patients discontinued due to an adverse event. CONCLUSION: TFNT00 provided a continuous range of vision of 20/25 or better for distance to near and performed effectively at an intermediate functional distance of 60 cm, resulting in high levels of spectacle independence and patient satisfaction. TFNT00 demonstrated a good safety profile and a low post-operative frequency of halo visual disturbances.

Extreme corneal flattening following collagen crosslinking for progressive keratoconus.

PURPOSE: To study the clinical, tomographic and densitometric features of eyes that showed >5 D of corneal flattening following collagen crosslinking (CXL) for progressive keratoconus and to identify preoperative predictive factors for such a response. METHODS: This was a retrospective case control study of 548 eyes with progressive keratoconus which had undergone epithelium-off CXL (Dresden protocol) with a follow-up of 1 to 10 years. Eyes that showed ⩾5 D corneal flattening in maximum keratometry (Kmax) following CXL (group A) were compared with one eye of the remaining patients in the same cohort (group B). Changes in refraction and visual acuity, Kmax and thinnest pachymetry were compared between both groups. Univariate and multivariate regression analysis identified preoperative risk factors for unusual corneal flattening. RESULTS: Forty three eyes in group A were compared with 502 eyes in group B. At the time of maximum flattening, group A showed more flattening (-7.6 ± 3.2 D) and thinning (-53.7 ± 45.2 µ) than group B (-1.69 ± 2.9 D and -26.6 ± 36.7 µ, respectively). Multivariate analysis based on parameters suggested by a univariate regression analysis identified pre-op Kmax to be the most significant predictor of intense corneal flattening. A subgroup analysis of K-matched eyes revealed that the duration of time following CXL was a significant risk factor for extreme corneal flattening following CXL. CONCLUSION: An intense corneal flattening >5 D in Kmax was documented in 7.85% of a cohort of keratoconus patients who underwent CXL. High preoperative Kmax and the duration of time following CXL were significant predictors of this response which was accompanied by significant corneal thinning.

Tube Obstruction of a Nonvalved Glaucoma Drainage Device by a Dislocated Soemmering's Ring.

The authors report a case of tube obstruction of a nonvalved glaucoma drainage device (Aurolab aqueous drainage implant; AADI) with a dislocated Soemmering's ring (SR) leading to a postoperative intraocular pressure (IOP) spike after an initial IOP reduction. A 24-year-old man with bilateral aphakia, bilateral secondary glaucoma developed corneal decompensation in the left eye. The IOP in the left eye was 22 mm Hg with 3 topical IOP-lowering medications (timolol 0.5%, brimonidine 0.2%, and latanoprost 0.005%). To control the IOP before performing a penetrating keratoplasty, AADI was implanted. A good bleb and an IOP of 10 mm Hg were noted at 6.5 weeks postoperatively. The following day the patient developed an acute rise in IOP (42 mm Hg) because of tube obstruction of the AADI by a SR. The IOP spike was initially controlled with oral acetazolamide and topical IOP-lowering medications (fixed combination of timolol 0.5% and brimonidine 0.2%). Six days later, pars plana vitrectomy, SR removal, penetrating keratoplasty, and tube trimming were performed. Following this, the patient had good IOP control and a clear corneal graft at 1-year follow-up. In aphakic eyes undergoing nonvalved glaucoma drainage device implantation, a complete pars plana vitrectomy combined with any lens remnant removal may be considered. It helps to avoid tube obstruction because of these lens remnants, which can migrate anteriorly along with the aqueous currents.

The effect of refractive surgery on blur thresholds.

PURPOSE: The aim of this study was to measure blur thresholds before and after refractive surgery. METHODS: In this prospective cohort study conducted in a tertiary eye hospital in South India. Blur thresholds were measured for 30 young adult myopic patients 1 month prior to and after refractive surgery. Patients were asked to report three stages of blur, namely Detectable Blur (DB), Bothersome Blur (BB), and Non-resolvable Blur (NB). Blur was created by adding plus lenses (in steps of 0.12D) over their optimal subjective refraction. The blur judgments were made both monocularly and binocularly when looking through a 3 mm artificial pupil at one line above the best-corrected visual acuity. RESULTS: A total of 30 participants were included in this study (mean age = 25.5 ± 3.8 (20-36) years; 77% female). The mean binocular preoperative blur of this group was: DB = 0.39 ± 0.26D, BB = 0.74 ± 0.28D and NB = 1.04 ± 0.42D. The corresponding mean binocular blur one-month post-operatively was DB = 0.46 ± 0.28D, BB = 0.83 ± 0.35D, and NB = 1.21 ± 0.44D. Although there was a marginal increase in the blur thresholds postoperatively, the difference was not statistically significant (DB: P = 0.320; BB: P = 0.229; NB: P = 0.054). CONCLUSION: All three blur thresholds showed an insignificant minimal increase at 1 month post-operatively suggesting that patients adapt to the induced blur following refractive surgery. A longer follow up would reveal how the adaptation to blur would change with time.

AcrySof IQ PanOptix Intraocular Lens Versus Extended Depth of Focus Intraocular Lens and Trifocal Intraocular Lens: A Clinical Overview.

AcrySof IQ PanOptix Model TFNT00 (Alcon Laboratories, Fort Worth, TX) is a 1-piece aspheric hydrophobic presbyopia-correcting intraocular lens (IOL) launched in 2015. Unlike traditional trifocal IOLs that usually have an intermediate focal point of 80 cm, the PanOptix IOL is designed to have an intermediate focal point of 60 cm (arms-length), a more natural and comfortable working distance to perform functional tasks on computers, laptops, mobiles, among others. The non-apodized PanOptix IOL uses the ENhanced LIGHT ENergy (ENLIGHTEN; Alcon Laboratories, Fort Worth, TX) optical technology that provides high (88%) utilization of light energy, low dependence on pupil size in all lighting conditions, and a more comfortable near-to-intermediate range of vision than traditional trifocal IOLs. This review provides an overview of the clinical performance of the PanOptix IOL and discusses it in the context of other commercially available trifocal IOLs, FineVision Micro F (PhysIOL, Liege, Belgium), the AT LISA tri 839MP (Carl Zeiss Meditec AG, Jena, Germany) and the extended depth of focus IOL, TECNIS Symfony (Abbott Medical Optics, Santa Ana, CA). A literature search was performed in the PubMed database to identify studies that have assessed the visual and other clinical outcomes with the PanOptix IOL. In total, 12 studies were included in this review article. Overall, the clinical evidence suggests that in general good visual outcomes, along with a high degree of spectacle independence, are achieved in patients implanted with the PanOptix, FineVision, AT LISA and Symfony IOLs. However, every MIOL has its benefits and limitations, which along with patient's needs and clinical conditions are important factors to consider while selecting an IOL to achieve best possible post-operative outcomes.

Environmental factors in school classrooms: How they influence visual task demand on children.

BACKGROUND: The key visual factors in a classroom environment include the legibility, angle subtended at the eye, illumination, contrast, and colour of the visual task. The study evaluated the visual environmental factors in the school classrooms. MATERIALS AND METHODS: The distance Visual Acuity (VA) demand was evaluated based on the size of visual task i.e. the smallest size of chalkboard writing and its viewing distance. The environmental factors which can have an effect on the visibility in classrooms such as illuminance on the chalkboard and at student's desk, chalkboard contrast, light sources and the student's perception of their classroom visual environment were measured. To quantify the distance VA demand and to compare with a standard high contrast VA chart measure, a validation of the measurements was performed by chalkboard simulation experiment. The "acuity reserve" to be included to the measured distance VA demand was evaluated. RESULTS: We included twenty-nine classrooms of eight schools. The median distance VA threshold demand was 0.28 logMAR(0.25,0.45). The median illuminance on front desk position and chalkboard contrast was 130 lux(92,208) and 40(36,50) respectively with 62% classrooms having low illumination (<150lux). The acuity reserve evaluated to be included to the distance VA demand was 0.13logMAR and 0.29 logMAR in classrooms with optimal and low chalkboard illumination respectively which was based on the results of the simulation experiment. The median distance VA demand including the acuity reserve was 0.09 logMAR(-0.03,0.23) [Snellen Equivalent: 20/25(20/19,20/34)]. CONCLUSION: The study findings highlight the increased visual task demand in school classrooms and the need for appropriate seating arrangements in classrooms based on the visual acuity of children. The study emphasises regular audit of the classroom environment along with the school eye screening.

Corneal epithelial permeability to fluorescein in humans by a multi-drop method.

PURPOSE: The permeability of the corneal epithelium to fluorescein Pdc is an indicator of the health of the ocular surface. It can be measured in a clinical setting by determining the accumulation of fluorescein in the stroma following administration of the dye on the ocular surface. Here we demonstrate a new multi-drop method for the measurement of Pdc by a spot fluorometer. METHODS: Twenty-nine healthy participants were recruited for this study. First, a probe-drop of fluorescein (0.35%, 2 µL) was instilled on the conjunctiva. The clearance of the dye from the tears was immediately measured using the fluorometer. Following this, two loading drops (2%; 6 µL each) were administered 10 min apart. Fifteen minutes later, the ocular surface was washed and fluorescence from the stroma Fs was measured. Permeability was calculated using Pdc = (Q x Fs)/ (2 x AUC), where Q is the stromal thickness and AUC is the area under the fluorescence vs. time curve for the loading drops. RESULTS: After the probe drop, the tear fluorescence followed an exponential decay (elimination rate constant; kd = 0.41 ± 0.28 per min; 49 eyes of 29 subjects), but the increase in Fs was negligible. However, after the loading drops, the measured Fs was ~ 20-fold higher than the autofluorescence and could be recorded at a high signal to noise ratio (SNR > 40). The intra-subject variability of kd was insignificant. Since fluorescein undergoes concentration quenching at > 0.5%, the value of AUC for the loading drops was estimated by scaling the AUC of the probe drop. The calculated Pdc was 0.54 ± 0.54 nm/sec (n = 49). A Monte Carlo simulation of the model for the multi-drop protocol confirmed the robustness of the estimated Pdc. CONCLUSIONS: The new multi-drop method can be used in place of the single-drop approach. It can overcome a lack of sensitivity in fluorometers of high axial resolution. The Pdc estimated by the multi-drop method is ~ 11-fold higher than previously reported but closer to the value reported for other drugs with equivalent octanol/water partition coefficient.

Are children with low vision adapted to the visual environment in classrooms of mainstream schools?

PURPOSE: The study aimed to evaluate the classroom environment of children with low vision and provide recommendations to reduce visual stress, with focus on mainstream schooling. METHODS: The medical records of 110 children (5-17 years) seen in low vision clinic during 1 year period (2015) at a tertiary care center in south India were extracted. The visual function levels of children were compared to the details of their classroom environment. The study evaluated and recommended the chalkboard visual task size and viewing distance required for children with mild, moderate, and severe visual impairment (VI). RESULTS: The major causes of low vision based on the site of abnormality and etiology were retinal (80%) and hereditary (67%) conditions, respectively, in children with mild (n = 18), moderate (n = 72), and severe (n = 20) VI. Many of the children (72%) had difficulty in viewing chalkboard and common strategies used for better visibility included copying from friends (47%) and going closer to chalkboard (42%). To view the chalkboard with reduced visual stress, a child with mild VI can be seated at a maximum distance of 4.3 m from the chalkboard, with the minimum size of visual task (height of lowercase letter writing on chalkboard) recommended to be 3 cm. For 3/60-6/60 range, the maximum viewing distance with the visual task size of 4 cm is recommended to be 85 cm to 1.7 m. CONCLUSION: Simple modifications of the visual task size and seating arrangements can aid children with low vision with better visibility of chalkboard and reduced visual stress to manage in mainstream schools.

Ocular Spot Fluorometer Equipped With a Lock-In Amplifier for Measurement of Aqueous Flare.

PURPOSE: To evaluate a custom-made ocular fluorometer for detection of intensity of light scatter (ILS) from the anterior chamber (A/C) as an objective measure of aqueous flare. METHODS: The fluorometer, equipped with a lock-in amplifier, was employed in the scatter mode to detect ILS from A/C. Measurements were performed with two illumination slit widths of 0.5 and 0.25 mm. The axial resolution at these slit widths were 80 and 200 µm, respectively. Healthy and pseudophakic eyes, with grade 0 Standardization of Uveitis Nomenclature (SUN) score, were employed as control subjects. ILS was also recorded in a cohort of patients who had undergone phacoemulsification and showed grades 1+ or 2+ on postoperative days 1 and 4. RESULTS: The inter- and intraobserver variabilities in the measurement of ILS were not significant. In cataract patients, ILS was significantly higher on postoperative day 1 relative to healthy eyes. By day 4, ILS decreased significantly and was only marginally different from ILS in quiet pseudophakic eyes or healthy eyes. Eyes with higher SUN scores showed proportionately increased ILS. The receiver-operator characteristic analysis indicated no advantage in using the smaller slit width in discriminating ILS at different SUN scores although it provided higher axial resolution. CONCLUSIONS: The lock-in-based spot fluorometer is reliable for measurement of ILS with high precision and accuracy.The measured ILS correlates linearly with SUN scores and can be used to provide a higher granularity for recording aqueous flare. TRANSLATIONAL RELEVANCE: The instrument can be used in the clinical management of uveitis and drug development toward uveitis.

Do school classrooms meet the visual requirements of children and recommended vision standards?

BACKGROUND: Visual demands of school children tend to vary with diverse classroom environments. The study aimed to evaluate the distance and near Visual Acuity (VA) demand in Indian school classrooms and their comparison with the recommended vision standards. MATERIALS AND METHODS: The distance and near VA demands were assessed in 33 classrooms (grades 4 to 12) of eight schools. The VA threshold demand relied on the smallest size of distance and near visual task material and viewing distance. The logMAR equivalents of minimum VA demand at specific seating positions (desk) and among different grades were evaluated. The near threshold was converted into actual near VA demand by including the acuity reserve. The existing dimensions of chalkboard and classroom, gross area in a classroom per student and class size in all the measured classrooms were compared to the government recommended standards. RESULTS: In 33 classrooms assessed (35±10 students per room), the average distance and near logMAR VA threshold demand was 0.31±0.17 and 0.44±0.14 respectively. The mean distance VA demand (minimum) in front desk position was 0.56±0.18 logMAR. Increased distance threshold demand (logMAR range -0.06, 0.19) was noted in 7 classrooms (21%). The mean VA demand in grades 4 to 8 and grades 9 to 12 was 0.35±0.16 and 0.24±0.16 logMAR respectively and the difference was not statistically significant (p = 0.055). The distance from board to front desk was greater than the recommended standard of 2.2m in 27 classrooms (82%). The other measured parameters were noted to be different from the proposed standards in majority of the classrooms. CONCLUSION: The study suggests the inclusion of task demand assessment in school vision screening protocol to provide relevant guidance to school authorities. These findings can serve as evidence to accommodate children with mild to moderate visual impairment in the regular classrooms.

Comparison of documentation time between an electronic and a paper-based record system by optometrists at an eye hospital in south India: a time-motion study.

PURPOSE: The adoption of electronic medical record (EMR) system is gradually increasing. However, various time-motion studies reveal conflicting data regarding time effectiveness on workflow due to computerization. One of the major issues for physicians is their uncertainty with EMRs' potential impact of time on workflow. A tertiary eye hospital in south India was in the process of implementing an EMR system in their ambulatory care unit. Many of the staff did not have previous computing experience and there were conflicting views on the time effectiveness of the computerized system after implementation. The management was thus interested to know the real time effectiveness of EMR in their hospital. The study compliments existing studies of this type by comparing the time efficiency of documentation time using EMR system with paper documentation in a hospital in a developing country where a transition between paper and EMR documentation was currently in progress. METHODS: Ten randomly selected optometrists documented the time they spent during consultation with both paper and EMR documentation. The time spent was documented for a total of 200 records (100 EMR and 100 paper records). The independent-samples t-test and analysis of variance were used to compare the means of the consultation time and calculated documentation time spent between the electronic and paper records. RESULTS: There was no statistically significant difference in the time spent for documentation between electronic and paper records. The mean time spent in documenting electronic records was 0.92min (95% CI -3.06 to 1.14) longer than in paper records. CONCLUSION: EMR systems can be adopted in eye hospitals without having significant negative impact on duration of consultation and documentation for optometrists. More time-motion studies that include ophthalmologists are however needed in order to get a more complete picture of time impact of the EMR system on clinical workflow in eye hospitals.