Efficiency, Precision, Validity, and Reliability of GlauCAT-Asian Computerized Adaptive Tests in Measuring Glaucoma-Related Quality of Life.

Purpose: To determine the efficiency, precision, and agreement of GlauCAT-Asian and its corresponding validity and reliability. Methods: In this cross-sectional study, 219 participants (mean ± standard deviation age, 66.59 ± 8.61 years; 34% female) across the spectrum of glaucoma severity and 50 glaucoma suspects were recruited from glaucoma clinics in Singapore. Participants answered seven computerized adaptive testing (CAT) evaluations (Ocular Comfort, Activity Limitation, Lighting, Mobility, Concerns, Psychosocial, Glaucoma Management) and underwent eye examinations. Efficiency (mean number of items required for each CAT and time taken for CAT versus full item banks [IBs]), agreement (concordance between CATs and full IB person measures, henceforth referred to as scores), and precision (standard error of measurement [SE]) were evaluated. Other validity and reliability metrics were also assessed. Results: The mean number of items administered ranged from 9 (Mobility/Glaucoma Management) to 12 (Ocular Comfort). Compared to answering the full IBs, CATs provided an average time saving of 38.3% (range, 10% to 70.6% for Lighting and Activity Limitation, respectively). Agreement between scores obtained by CAT versus full IB was high (intracorrelation coefficient ≥0.75), as was precision of score estimates (mean SE range: 0.35 for Psychosocial to 0.29 for Mobility). Scores from Activity Limitation, Mobility, Lighting, and Concerns decreased significantly as glaucoma severity increased (criterion validity; P-trend <0.05). All tests displayed good convergent/divergent validity and test-retest reliability. Conclusions: GlauCAT-Asian provides efficient, precise, accurate, valid, and reliable measurement of the patient-centered impact of glaucoma. Translational Relevance: GlauCAT-Asian may provide a valuable clinical tool for ophthalmologists to monitor impact of disease progression and the effectiveness of therapies.

Measuring glaucoma quality of life in an Asian population using item banking: psychometric evaluation and computerized adaptive testing simulations.

PURPOSE: To assess the psychometric properties of glaucoma-specific health-related quality of life (HRQoL) item banks (IBs), and explore their efficiency using computerized adaptive testing (CAT) simulations. METHODS: In this cross-sectional, clinical study, 300 Asian glaucoma patients answered 221 items within seven IBs: Ocular Comfort Symptoms (OS); Activity Limitation (AL); Lighting (LT); Mobility (MB); Glaucoma Management (GM); Psychosocial (PSY); and Work (WK). Rasch analysis was conducted to assess each IB's psychometric properties (e.g., item "fit" to the construct; unidimensionality) and a set of analytic performance criteria guiding decision making relating to retaining or dropping domains and items was employed. CAT simulations determined the mean number of items for 'high' and 'moderate' measurement precision (stopping rule: SEM 0.3 and 0.387, respectively). RESULTS: Participants' mean age was 67.2 ± 9.2 years (62% male; 87% Chinese). LT, MB, and GM displayed good psychometric properties overall. To optimize AL's psychometric properties, 16 items were deleted due to poor "fit", high missing data, item bias, low discrimination and/or a low clinical/patient importance rating. To resolve multidimensionality in PSY, we rehomed 16 items into a "Concern (CN)" domain. PSY and CN required further amendment, including collapsing of response categories, and removal of poorly functioning items (N = 7). Due to poor measurement precision, low applicability and high ceiling effect, low test information indices, and low item separation index the WK IB was not considered further. In CAT simulations on the final seven IBs (n = 182 items total), an average of 12.1 and 15.7 items per IB were required for moderate and high precision measurement, respectively. CONCLUSIONS: After reengineering our seven IBs, they displayed robust psychometric properties and good efficiency in CAT simulations. Once finalized, GlauCAT™-Asian may enable comprehensive assessment of the HRQoL impact of glaucoma and associated treatments.

Oral Ibuprofen is Associated With Reduced Likelihood of Early Bleb Failure After Trabeculectomy in High-Risk Glaucoma Patients.

PRCIS: Individuals prescribed ibuprofen after trabeculectomy have better postoperative intraocular pressure (IOP) control and a higher chance of bleb survival despite being at a higher risk of scarring. PURPOSE: To investigate the effects of early adjunctive oral ibuprofen treatment on IOP and bleb failure in eyes at high risk of scarring. METHODS: In these retrospective analyses, 288 eyes of 273 patients (mean ± SD age: 68.56 ± 10.47 y; 32.60% females) with primary glaucoma who underwent trabeculectomy/phacotrabeculectomy at the Singapore National Eye Centre between April 2020 and April 2021 with a follow-up duration ≥1 year were included. Of these, 77 (26.7%) eyes deemed to be at high risk of scarring were administered oral ibuprofen ≥3 months postoperatively (mean ± SD ibuprofen administration duration: 4.08 ± 2.28 wk). Participant's IOPs at baseline and at postoperative weeks 1, 2-3; and months 1, 2, 3, 6, and 12 were recorded. Bleb failure was defined as 2 consecutive IOP readings of >21, >18, and >15 mm Hg, and/or requiring remedial postoperative laser or surgery. RESULTS: The ibuprofen group experienced significantly greater postoperative IOP reductions at week 1 [mean difference, 95%CI: -2.89 (-5.22, -0.56) mm Hg] and month 1 [-2.29 (-4.53, -0.05) mm Hg]; and substantially lower odds of bleb failure at the >18 mm Hg [odds ratio, 95% CI: 0.39 (0.20-0.79)] and >15 mm Hg [0.52 (0.29-0.94)] thresholds, compared with the non-ibuprofen group. No differences in adverse ocular hypotony events were observed. CONCLUSION: Early adjunctive oral ibuprofen administered to individuals at high risk of posttrabeculectomy scarring is associated with greater IOP reductions and reduced likelihood of bleb failure. Our results suggest that oral nonsteroidal anti-inflammatory drugs may be a safe way of improving trabeculectomy survival in high-risk eyes.

The development of a glaucoma-specific health-related quality of life item bank supporting a novel computerized adaptive testing system in Asia.

BACKGROUND: A glaucoma-specific health-related quality of life (HRQoL) item bank (IB) and computerized adaptive testing (CAT) system relevant to Asian populations is not currently available. We aimed to develop content for an IB focusing on HRQoL domains important to Asian people with glaucoma; and to compare the content coverage of our new instrument with established glaucoma-specific instruments. METHODS: In this qualitative study of glaucoma patients recruited from the Singapore National Eye Centre (November 2018-November 2019), items/domains were generated from: (1) glaucoma-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with glaucoma patients (n = 27); and (4) feedback from glaucoma experts. Data were analyzed using the constant comparative method. Items were systematically refined to a concise set, and pre-tested using cognitive interviews with 27 additional glaucoma patients. RESULTS: Of the 54 patients (mean ± standard deviation [SD] age 66.9 ± 9.8; 53.7% male), 67 (62.0%), 30 (27.8%), and 11 (10.2%) eyes had primary open angle glaucoma, angle closure glaucoma, and no glaucoma respectively. Eighteen (33.3%), 11 (20.4%), 8 (14.8%), 12 (22.2%), and 5 (9.3%) patients had no, mild, moderate, severe, or advanced/end-stage glaucoma (better eye), respectively. Initially, 311 items within nine HRQoL domains were identified: Visual Symptoms, Ocular Comfort Symptoms, Activity Limitation, Driving, Lighting, Mobility, Psychosocial, Glaucoma management, and Work; however, Driving and Visual Symptoms were subsequently removed during the refinement process. During cognitive interviews, 12, 23 and 10 items were added, dropped and modified, respectively. CONCLUSION: Following a rigorous process, we developed a 221-item, 7-domain Asian glaucoma-specific IB. Once operationalised using CAT, this new instrument will enable precise, rapid, and comprehensive assessment of the HRQoL impact of glaucoma and associated treatment efficacy.

Role of socio-economic factors in visual impairment and progression of diabetic retinopathy.

BACKGROUND: To investigate the longitudinal associations between person-level and area-level socioeconomic status (PLSES and ALSES, respectively) with diabetic retinopathy (DR) and visual impairment (VI) in Asians with diabetes mellitus (DM). METHODS: In this population-based cohort study, we included 468 (39.4%) Malays and 721 (60.6%) Indians with DM, with a mean age (SD) of 58.9 (9.1) years; 50.6% were female and the mean follow-up duration was 6.2 (0.9) years. Individual PLSES parameters (education, monthly income and housing type) were quantified using questionnaires. ALSES was assessed using the Socioeconomic Disadvantage Index derived from Singapore's 2010 areal census (higher scores indicate greater disadvantage). Incident DR and VI were defined as absent at baseline but present at follow-up, while DR and VI progression were defined as a ≥1 step increase in severity category at follow-up. Modified Poisson regression analysis was used to determine the associations of PLSES and ALSES with incidence and progression of DR and VI, adjusting for relevant confounders. RESULTS: In multivariable models, per SD increase in ALSES score was associated with greater DR incidence (risk ratio (95% CI) 1.27 (1.13 to 1.44)), DR progression (1.10 (1.00 to 1.20)) and VI incidence (1.10 (1.04 to 1.16)), while lower PLSES variables were associated with increased DR (low income: 1.68 (1.21 to 2.34)) and VI (low income: 1.44 (1.13 to 1.83); ≤4 room housing: 2.00 (1.57 to 2.54)) incidence. CONCLUSIONS: We found that both PLSES and ALSES variables were independently associated with DR incidence, progression and associated vision loss in Asians. Novel intervention strategies targeted at low socioeconomic status communities to decrease rates of DR and VI are warranted.

Evaluation of Intraocular Pressure After Water Drinking Test in Patients with Unilateral Hemifacial Spasm.

PURPOSE: The aim of the study is to examine the baseline intraocular pressure (IOP) and its changes after performing a water drinking test (WDT) in patients with unilateral hemifacial spasm (HFS). PATIENTS AND METHODS: In this prospective observational study, patients aged 21 years and above diagnosed with unilateral HFS were recruited from the Singapore National Eye Centre between January 2015 and August 2016. The unaffected eye of each patient served as a matched control. An interviewer-administered standardized questionnaire on HFS symptoms and ophthalmic examination was performed. Automated perimetry, optical coherence tomography (OCT) of the optic nerve head, color disc stereophotography and water drinking test (WDT) were done. The primary outcome measure was the difference in IOP between eyes affected by HFS and fellow eyes at baseline and at 15, 30 and 45 minutes of the WDT. RESULTS: Fifty-four patients with unilateral HFS were included. Mean age was 59.8±9.9 years (range, 37.0-84.0). Of these, 54% were female and 94% were Chinese. Mean baseline IOP was significantly higher in eyes with HFS (13.9±3.1mmHg) compared to fellow eyes (13.3±2.8mmHg) (p=0.008). There was no significant difference in absolute or percentage change in IOP from baseline between the 2 groups at 15, 30 and 45 minutes of the WDT. Mean vertical cup-disc ratio (VCDR) on clinical examination was significantly higher in eyes with HFS (0.5±0.2) compared to fellow eyes (0.4±0.2) (p=0.02). There was no significant difference between the groups for visual field parameters and mean retinal nerve fiber layer thickness on OCT. CONCLUSION: Hemifacial spasm is associated with a small but significant difference in mean baseline IOP and VCDR between affected and fellow eyes. However, when eyes affected by HFS and fellow eyes were challenged with the WDT, both responded in similar ways.

Simultaneous Accelerated Corneal Crosslinking and Laser In situ Keratomileusis for the Treatment of High Myopia in Asian Eyes.

BACKGROUND: LASIK Xtra is a recently described technique which combines LASIK and accelerated corneal cross-linking(CXL) in the same setting. Its long-term outcome in Asians with high myopia is not well described. OBJECTIVES: To compare the efficacy, predictability and safety of LASIK Xtra with LASIK in patients with high myopia. METHOD: This is a retrospective study comparing 50 consecutive eyes undergoing LASIK Xtra for the correction of high myopia and/or myopic astigmatism (-6.63 to -15.50 D manifest spherical equivalent) with a matched control group of 50 eyes undergoing LASIK alone for correction of high myopia (-6.00 to -12.25 D manifest spherical equivalent). Mean follow-up was 5.7 months (range, 1.5-13.3 months) for LASIK Xtra and 3.6 months (range, 1.7-4.2 months) for LASIK only. Outcome measures included Uncorrected Distance Visual Acuity (UDVA), Corrected Distance Visual Acuity (CDVA), refraction and intraoperative and postoperative complications. RESULTS: At post-operative 3 months, all eyes achieved UDVA of 20/40 or better, and 80.0% of LASIK Xtra eyes achieved UDVA of 20/20 or better, compared to 66.0% of LASIK only eyes (p = 0.115). Efficacy indices were 0.99±0.17 for LASIK Xtra and 0.94±0.17 for LASIK only (p = 0.164). The proportion of eyes within ±0.50 D of attempted correction was 84% in the LASIK only group and 72% in the LASIK Xtra group at post-operative 3 months (p = 0.148). Safety indices were 1.11±0.19 and 1.11±0.18 in the LASIK Xtra and LASIK only groups, respectively (p = 0.735). CONCLUSION: LASIK Xtra achieved comparable safety, predictability and efficacy as LASIK in patients with high myopia. Good refractive stability was attained at 6-12 months. Further long term studies are required to determine whether simultaneous CXL is able to reduce postoperative LASIK keratectasia in high-risk individuals.

Impact of financial background and student debt on postgraduate residency choices of medical students in Singapore.

INTRODUCTION: Medical school fees are rising globally. Student debt and financial background may affect residency choices, but few studies have been conducted in Asia. This study aimed to explore the relationship between financial background, student debt and postgraduate residency choices among medical students in Singapore. METHODS: An anonymised survey of all medical students in Singapore was conducted and had a response rate of 67.9%. RESULTS: 40.5% of our study population would graduate with debt. Medical students with monthly per capita household income < SGD 1,000 were more likely to graduate with debt (unadjusted odds ratio [OR] 2.0, 95% confidence interval [CI] 1.6-2.7; p < 0.001) and feel burdened by the cost of medical education (unadjusted OR 2.8, 95% CI 2.0-3.9; p < 0.001). Students with monthly per capita household income < SGD 1,000 (unadjusted OR 1.818, 95% CI 1.338-2.470, p < 0.001; adjusted OR 1.692, 95% CI 1.202-2.381, p = 0.003) and those with debt (unadjusted OR 1.623, 95% CI 1.261-2.090, p < 0.001; adjusted OR 1.393, 95% CI 1.048-1.851, p = 0.022) were more likely to rank at least one economic factor as 'very significant' in influencing their postgraduate training choices. CONCLUSION: It is concerning that despite financial aid schemes, the cost of medical education remains a burden to students from lower-income households in Singapore. Student debt and financial background may distort postgraduate career choices, creating an undue push towards high-paying specialties.

A Protocol to Reduce Interobserver Variability in the Computed Tomography Measurement of Orbital Floor Fractures.

Orbital fracture detection and size determination from computed tomography (CT) scans affect the decision to operate, the type of surgical implant used, and postoperative outcomes. However, the lack of standardization of radiological signs often leads to the false-positive detection of orbital fractures, while nonstandardized landmarks lead to inaccurate defect measurements. We aim to design a novel protocol for CT measurement of orbital floor fractures and evaluate the interobserver variability on CT scan images. Qualitative aspects of this protocol include identifying direct and indirect signs of orbital fractures on CT scan images. Quantitative aspects of this protocol include measuring the surface area of pure orbital floor fractures using computer software. In this study, 15 independent observers without clinical experience in orbital fracture detection and measurement measured the orbital floor fractures of three randomly selected patients following the protocol. The time required for each measurement was recorded. The intraclass correlation coefficient of the surface area measurements is 0.999 (0.997-1.000) with p-value < 0.001. This suggests that any observer measuring the surface area will obtain a similar estimation of the fractured surface area. The maximum error limit was 0.901 cm(2) which is less than the margin of error of 1 cm(2) in mesh trimming for orbital reconstruction. The average duration required for each measurement was 3 minutes 19 seconds (ranging from 1 minute 35 seconds to 5 minutes). Measurements performed with our novel protocol resulted in minimal interobserver variability. This protocol is effective and generated reproducible results, is easy to teach and utilize, and its findings can be interpreted easily.

The outcomes of primary pediatric keratoplasty in Singapore.

PURPOSE: To evaluate the long-term corneal graft survival and risk factors for graft failure in pediatric eyes. DESIGN: Retrospective, interventional consecutive case series. METHODS: Unilateral eyes of 105 patients aged 16 years and below were included from the Singapore Corneal Transplant Study between April 4, 1991 and April 4, 2011. Corneal graft survival was calculated using Kaplan-Meier survival analysis, and survival distributions were compared using log-rank test. RESULTS: Mean recipient age was 8.38 ± 5.63 years (range 0.18-15.92 years). Mean follow-up time was 34.16 ± 39.10 months. Main diagnoses were corneal scar (22.9%), limbal dermoid (21.9%), anterior segment dysgenesis (15.2%), and keratoconus (14.3%). Forty-four eyes (41.9%) underwent penetrating keratoplasty (PK), 37 (35.2%) underwent anterior lamellar keratoplasty (ALK), 22 (21.0%) underwent lamellar corneal patch graft, and 2 (1.9%) underwent Descemet stripping automated endothelial keratoplasty (DSAEK). Kaplan-Meier survival rates for PK were 92.8% at 1 year, 88.9% at 2-4 years, and 80.9% at 5-16 years; survival rates for ALK were 88.0% at 1 year and 84.3% at 2-7 years; survival rates for corneal patch graft were 100% at 1-3 years and 90% at 4-10 years; these were not statistically significant (P = .362). Deep corneal vascularization (P = .012), preexisting active inflammation (P = .023), preexisting glaucoma drainage device (P = .023), and preexisting ocular surface disease (P = .037) were associated with reduced graft survival in a univariate analysis. CONCLUSIONS: We report good long-term graft survival following pediatric keratoplasty for various indications. Lamellar keratoplasty, when indicated, should be the procedure of choice in high-risk keratoplasties.

Computer-assisted navigational surgery improves outcomes in orbital reconstructive surgery.

Orbital reconstruction is a difficult procedure, success of which is dependent on the surgeon's experience. The lack of objective methods requires a fair amount of estimation is its execution. This study evaluates the efficacy of Kolibri (BrainLab, Munich, Germany), an intraoperative navigation device, in improving outcomes. From 2004 to 2009, 58 patients with orbital trauma who underwent surgery at the National University Hospital, Singapore, were included in this prospective matched control trial. Twenty-nine consecutive patients underwent surgery with Kolibri. The control group underwent surgery without the device. Both groups were matched for age, sex, orbital wall fracture, preoperative ophthalmologic features, etiology and severity of trauma, surgical approach, and types of implant used. The postoperative follow-up was at 1, 3, 6, and 12 months. For subjective assessment, the postoperative ophthalmologic features, including diplopia, infraorbital hypoesthesia, ophthalmoplegia, and enophthalmos, were compared. At 1, 3, 6, and 12 months, respectively, there were fewer patients with postoperative ophthalmologic complications in the study group (italicized; n = 29) compared with the control group (n = 29; P < 0.05): 12/29 (41%) versus 21/29 (72%), 8/29 (28%) versus 19/29 (66%), 5/29 (17%) versus 15/29 (52%), and 2/29 (7%) versus 12/29 (41%). For objective assessment, using the Kolibri workstation, operative plans were created and fused with postoperative computed tomographic scans. Vertical distances between the actual reconstructed and planned orbital floors were measured. On average, the vertical distance measured from the boundaries of floor defects for patients in the study group was 3.24 mm (95% confidence interval, 1.56-4.91) lower than the control group (P = 0.001). In conclusion, navigation minimizes postoperative complications, reduces the need for repeat procedures, and helps surgeons with planning, execution, and postoperative assessment.

Undifferentiated carcinoma of the lacrimal sac: case report and review of literature.

A 55-year-old man presented with a 2-year history of right-sided epiphora and was referred to the Oculoplastic services for dacryocystorhinostomy. A 3-month progressive growth of a right medial canthal mass was found. MRI revealed an extraconal, lobulated, homogeneously enhancing mass in the lacrimal sac fossa with globe indentation and displacement supero-temporally. Following a transcanalicular needle biopsy which was suggestive of a carcinoma, he underwent medial orbitectomy and maxillectomy, through a lateral rhinotomy, with removal of puncta and canaliculi after ensuring no regional or systemic spread. The lacrimal sac tumor was encapsulated, extending superiorly above the medial canthal tendon and involving the nasolacrimal duct, and posteriorly along the medial orbital wall. After ensuring surgical margins were cleared of tumor infiltration, orbital reconstruction was performed with titanium plate and nasolabial flap. He has completed adjuvant radiotherapy with no evidence of tumor recurrence at 15 months of follow-up.