Vanita Pathak-Ray

Is utility-based quality of life in adults affected by glaucoma?

PURPOSE We evaluated the utility values (UVs), using the time trade off (TTO) technique, associated with primary glaucoma and varying degrees of visual field (VF) loss. METHODS In this cross-sectional study, 198 adults (mean age, 59.8 years) with primary glaucoma were recruited from the glaucoma clinic of a tertiary center in Hyderabad, South India. Each patient underwent comprehensive glaucoma evaluation, and completed the utility (TTO) and Glaucoma Quality of Life-15 questionnaires (Rasch version, Glaucoma Activity Limitation [GAL]-10). Better mean deviation (MD, using Humphrey Field Analyzer program 24-2) between two eyes was used to classify participants into mild, moderate, and severe VF loss groups. Utilities (range, 0.0-1.0) derived by TTO technique (lifetime traded against perfect vision) and interval level Rasch scores of GAL-10 were used for analyses. RESULTS Mean UV was 0.81 (95% confidence interval [CI], 0.78-0.84); that is, a decrease in quality of life (QoL) of 19%. Of the subjects, 59% were willing to trade lifetime in return of perfect vision; those willing to trade were significantly younger with poorer acuity in the worse-seeing eye. In univariate and multivariate analysis, severe VF loss in the worse eye was associated with lower UV (β = -0.108; 95% CI, -0.201 to -0.014; P = 0.02). CONCLUSIONS Our results show that primary glaucoma in adults causes substantial decrease in UVs (and QoL thereof), and is highly dependent on the severity of VF loss in the worse eye.

Glaucoma symptom scale: is it a reliable measure of symptoms in glaucoma patients?

Glaucoma is the leading cause of irreversible blindness worldwide after cataract and accounts for 10% of the worlds blind.1 Although patients with acute angle closure glaucoma are symptomatic, those with other forms of glaucoma (at least in the early stages) usually do not experience many symptoms, thereby, resulting in the disease often going unnoticed with possible progression. In some cases, patients with fluctuating levels of intraocular pressure may experience blurred vision and see haloes around lights. The Glaucoma Symptom Scale (GSS) was developed to assess ophthalmic symptoms experienced by patients with glaucoma.2 The GSS comprises 10 ocular symptoms, of which six are non-visual and four are visual. The non-visual symptoms include ‘burning/smarting/stinging’, ‘tearing’, ‘dryness’, ‘itching’, ‘soreness/tiredness’, and ‘feeling of something in the eye’. The visual symptoms include ‘blurry/dim vision’, ‘hard to see in daylight’, ‘hard to see in darkness’, and ‘halos around lights’. The GSS is unique in that it assesses symptoms as compared with visual functioning by other glaucoma-specific questionnaires. Like most questionnaires in ophthalmology, the GSS was also developed using traditional psychometric methods, that is, the classical test theory (CTT).3 The limitations of CTT have been well acknowledged. A major shortcoming of CTT pertains to its scoring assumptions: Likert or summary scoring in which the scores are calculated from …

Increased Iris Stiffness in Patients With a History of Angle-Closure Glaucoma: An Image-Based Inverse Modeling Analysis

Purpose Previous studies have shown that iris mechanical properties may play a role in the pathophysiology of primary angle-closure glaucoma (PACG). Such studies, however, were not conducted in vivo and as such were limited in application and scope, especially for the development of diagnostic methods or new treatment options. The purpose of this study was to quantify in vivo iris mechanical properties both in patients with a history of angle-closure glaucoma and in healthy volunteers. Methods We acquired optical coherence tomography scans of anterior segments under standard and dim light conditions. Using a combination of finite element simulation and an inverse fitting algorithm, we quantified the stiffness of the iris. Results The irides in the eyes of patients with a history of PACG were significantly stiffer when compared with healthy control irides, a result consistent with ex vivo studies. This result was independent of the compressibility assumption (incompressible: 0.97 ± 0.14 vs. 2.72 ± 0.71, P = 0.02; compressible: 0.89 ± 0.13 vs. 2.57 ± 0.69, P = 0.02) when comparing the normalized elastic modulus of the iris between patients with PACG and healthy controls. Conclusions Our noninvasive, in vivo quantification is free of numerous ethical issues and potential limitations involved with ex vivo examinations. If further studies confirm that the iris stiffness is an omnipresent PACG risk factor and a mechanistic role between increased iris stiffness and angle-closure glaucoma does exist, treatment methods such as lowering the iris stiffness can be developed.

Prevalent practice patterns in glaucoma: Poll of Indian ophthalmologists at a national conference

Purpose: The aim of this study is to explore and compare the prevailing practice patterns in the diagnosis and management of glaucoma among subspecialists and general ophthalmologists in India. Materials and Methods: This is an interactive audience response system (ARS) based poll of ophthalmologists attending the annual conference of the Glaucoma Society of India in 2013. Results: The information was obtained from 379 ophthalmologists (146 glaucoma specialists, 54 nonglaucoma subspecialists, and 179 general ophthalmologists). The majority of polled ophthalmologists (236; 62%) had 10 or more years of experience in ophthalmology. The glaucoma specialists differed from nonglaucomatologists in their preference for Goldmann applanation tonometer (P < 0.01), four-mirror gonioscope (P < 0.01), Humphrey perimeter (P < 0.01), laser peripheral iridotomy in primary angle closure disease (P = 0.03), postiridotomy gonioscopy (P < 0.01), and usage of antifibrotic agents during filtering surgery (P < 0.01). Optical coherence tomography was the most preferred imaging modality and was utilized more often by the subspecialists than general ophthalmologists. The ophthalmologists also differed in their choice of antiglaucoma medications. More glaucoma specialists were performing surgery on children with congenital glaucoma (P < 0.01), implanting glaucoma drainage devices (P < 0.01), and using scientific journals to upgrade knowledge (P = 0.03) than the other ophthalmologists. Conclusions: This poll is the first of its kind in India, in its usage of the ARS, and in comparing the practice patterns of care for glaucoma among subspecialists and general ophthalmologists. It has revealed substantial diversity in a few areas among those who did and did not receive specialty training in glaucoma.