Structural validity of the impact of vision impairment questionnaire among patients with visual impairment in Thailand.

Background: The Impact of Vision Impairment (IVI) questionnaire is used to assess vision-related quality of life (VRQOL) among patients with visual impairment. This study aims to evaluate the factor structure of the IVI in the context of Thai culture to assess psychometric properties. Methods: This cross-sectional study was conducted between February and July 2022. Purposive sampling was used to include 502 patients with visual impairment who received treatment at a tertiary eye center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand. The data were collected using the interviewer-administered questionnaire. The participants were randomly divided into two groups: one employed for exploratory factor analysis (EFA; n = 251) and the other for confirmatory factor analysis (CFA; n = 251). Results: EFA yielded 28 items that supported a four-factor structure: behaviors related to mobility and independence (8 items), reading (3 items), self-dependence (7 items), and emotional impact of vision loss (10 items), with a total variance of 64.9 %. The model fit was good: χ2/df = 1.66, CFI = 0.949, TLI = 0.940, RMSEA = 0.052, and SRMR = 0.041. The AIC and BIC for the bifactor four-factor model (17,484.86 and 17,879.41, respectively) were lower than those for the bifactor three-factor model (17,566.44 and 17,961.29, respectively), indicating that the former showed the best fit. Conclusions: Given its good reliability and validity, the IVI scale has been extensively used to explore the impact of visual impairment on the VRQOL of patients in the clinical setting, thus greatly benefitting researchers, healthcare providers, and ophthalmologists.

Health Utility Values Among Patients With Diabetic Retinopathy, Wet Age-Related Macular Degeneration, and Cataract in Thailand: A Multicenter Survey Using Time Trade-Off, EQ-5D-5L, and Health Utility Index 3.

OBJECTIVES: This study aimed to establish normative health utility data in Thai patients with diabetic retinopathy, wet age-related macular degeneration, and cataract; evaluate the sensitivity of different utility instruments to visual impairment; explore the relationship among these health utility values with the vision-specific quality of life (QoL); and assess the association of baseline characteristics and visual acuity level with health utility values and vision-specific QoL. METHODS: This multicenter cross-sectional survey included 309 patients from tertiary eye centers. We used health utility instruments (time trade-off [TTO], EuroQol five-dimension [EQ-5D-5L], and Health Utility Index 3 [HUI3]) and vision-specific QoL instrument (National Eye Institute Visual Function Questionnaire) for face-to-face interviews. Demographic data and Early Treatment Diabetic Retinopathy Study visual acuity were recorded during the participants ophthalmic visits. Univariable and multivariable mixed-effect models were used to evaluate factors associated with the utility scores. Health utility scores among each type of eye disease were compared. RESULTS: The overall mean utility values from the TTO, EQ-5D-5L, and HUI3 were 0.84 ± 0.25, 0.70 ± 0.19, and 0.68 ± 0.26, respectively. The health utility scores obtained from TTO and HUI3 showed a significant response to severe visual impairment or worse. Health utility scores from HUI3 (r = 0.54; P < .01) and EQ-5D-5L (r = 0.43; P < .01) displayed a moderate correlation with the National Eye Institute Visual Function Questionnaire score. There were no significant differences in health utility value among the 3 diseases upon adjusting for the visual acuity level and demographics. CONCLUSIONS: Visual acuity level has a greater impact on a patient's QoL than the type of eye disease. HUI3 and EQ-5D-5L and TTO are suitable for measuring health utility in leading causes of blindness.

Optical Coherence Tomography Angiography Biomarkers in Thai Patients With Diabetic Nephropathy: A Diabetic Eye and Kidney Diseases (DEK-D) Study.

Purpose: To identify optical coherence tomography angiography (OCTA) biomarkers to predict the diabetic nephropathy (DN) and their associations with 24-hour urine albumin levels in diabetic patients. Methods: This cross-sectional, observational study examined 186 eyes from 93 individuals subdivided into three groups according to 24-hour urine albumin levels: no DN, early DN, and late DN. Vessel density (VD), fractal dimension, foveal avascular zone area, intercapillary area, central retinal thickness, and subfoveal choroidal thickness were measured from OCTA images to determine their association with the DN stages. Results: VD values of the superficial capillary plexus, deep capillary plexus, and whole retina were significantly lower in the early DN group compared to the no DN group (adjusted P = 0.042, 0.016, and 0.008, respectively). VD values for the deep capillary plexus and whole retina were significantly decreased in the late DN group compared to the no DN group (adjusted P = 0.025 and 0.021, respectively). Mean fractal dimension, intercapillary area, foveal avascular zone area, central retinal thickness, and subfoveal choroidal thickness were not statistically different among the three groups. Conclusions: VD may be a useful parameter for the early non-invasive screening of DN. Further studies in larger populations are needed to establish a cutoff value for detection. Translational Relevance: This study investigated the association of each retinal vasculature measurement by OCTA and diabetic nephropathy status which could serve as an alternative way to screen for albuminuria.

Prevalence and Factors Associated with Suicidal Ideation Among Older People with Visual Impairments Attending an Eye Center During the COVID-19 Pandemic: A Hospital-Based Cross-Sectional Study.

Purpose: To evaluate the prevalence of suicidal ideation and associated factors among older people with visual impairments attending an eye center during the COVID-19 pandemic. Patients and Methods: A total of 314 older people aged 60 and above with visual impairments who attended an eye center were included in this study. This was a hospital-based cross-sectional study conducted from February to July, 2022. Data were collected in person. Suicidal ideation was measured using the Columbia-Suicide Severity Rating Scale (C-SSRS). Multivariable logistic regression analysis was used to explore associations between related factors and suicidal ideation. Results: Of 314 older people with visual impairments, the prevalence of suicidal ideation was 32.5%. Suicidal ideation was independently associated with diabetic retinopathy (adjusted odds ratio (AOR)=2.4, 95% confidence interval (CI): 1.0-5.8; p=0.038) and depression (AOR=6.3, 95% CI: 3.5-11.2; p<0.001). Conclusion: This study found a relatively high prevalence of suicidal ideation among older people with visual impairments. There was also a significant association between depression and suicidal ideation among these individuals. Visual impairments can lead to negative émotions. This underscores the importance of addressing the mental health needs of older individuals with visual impairments, including suicide prevention efforts tailored to their needs. Ophthalmologists should be equipped with the skills necessary to identify the early signs of suicidal ideation and refer patients to mental healthcare specialists for appropriate treatment.

Impact of COVID-19 on Depressive Symptoms Among Patients with Low Vision and Blindness.

Background: Disability is globally recognized as a key cause of depression. Likewise, the COVID-19 pandemic has significantly increased the vulnerability of patients with low vision to health and health-related issues, especially mental health. This study aimed to examine the association between the impact of COVID-19 and depressive symptoms in patients with low vision and blindness. Methods: This cross-sectional study was conducted between February and July 2022 and involved face-to-face interviews. Patients with low vision and blindness diagnosed with depression were excluded. The following items were included in the questionnaire: sociodemographic information, Multi-Dimensional Scale of Perceived Social Support (MSPSS), the impact of COVID-19, and The Center for Epidemiological Studies-Depression (CES-D). Hierarchical linear regression analysis was used to examine the association between the impact of COVID-19 and depression. Results: The prevalence of depression among patients with low vision and blindness was 43.0%. Three factors were associated with depressive symptoms: compliance with COVID-19 prevention strategies (ß = 0.16, p<0.01), anxiety during COVID-19 (ß = 0.24, p<0.001), and social support (ß = -0.16, p<0.01). Conclusion: The findings indicated that COVID-19 significantly increased depressive symptoms among patients with low vision and blindness. The psychological effects of the COVID-19 pandemic have been considered critical and emergent public health issues. Stakeholders, particularly public health organizations, need to urgently implement preventive and protective measures to help patients with physical and mental disabilities.

Acceptance and Perception of Artificial Intelligence Usability in Eye Care (APPRAISE) for Ophthalmologists: A Multinational Perspective.

Background: Many artificial intelligence (AI) studies have focused on development of AI models, novel techniques, and reporting guidelines. However, little is understood about clinicians' perspectives of AI applications in medical fields including ophthalmology, particularly in light of recent regulatory guidelines. The aim for this study was to evaluate the perspectives of ophthalmologists regarding AI in 4 major eye conditions: diabetic retinopathy (DR), glaucoma, age-related macular degeneration (AMD) and cataract. Methods: This was a multi-national survey of ophthalmologists between March 1st, 2020 to February 29th, 2021 disseminated via the major global ophthalmology societies. The survey was designed based on microsystem, mesosystem and macrosystem questions, and the software as a medical device (SaMD) regulatory framework chaired by the Food and Drug Administration (FDA). Factors associated with AI adoption for ophthalmology analyzed with multivariable logistic regression random forest machine learning. Results: One thousand one hundred seventy-six ophthalmologists from 70 countries participated with a response rate ranging from 78.8 to 85.8% per question. Ophthalmologists were more willing to use AI as clinical assistive tools (88.1%, n = 890/1,010) especially those with over 20 years' experience (OR 3.70, 95% CI: 1.10-12.5, p = 0.035), as compared to clinical decision support tools (78.8%, n = 796/1,010) or diagnostic tools (64.5%, n = 651). A majority of Ophthalmologists felt that AI is most relevant to DR (78.2%), followed by glaucoma (70.7%), AMD (66.8%), and cataract (51.4%) detection. Many participants were confident their roles will not be replaced (68.2%, n = 632/927), and felt COVID-19 catalyzed willingness to adopt AI (80.9%, n = 750/927). Common barriers to implementation include medical liability from errors (72.5%, n = 672/927) whereas enablers include improving access (94.5%, n = 876/927). Machine learning modeling predicted acceptance from participant demographics with moderate to high accuracy, and area under the receiver operating curves of 0.63-0.83. Conclusion: Ophthalmologists are receptive to adopting AI as assistive tools for DR, glaucoma, and AMD. Furthermore, ML is a useful method that can be applied to evaluate predictive factors on clinical qualitative questionnaires. This study outlines actionable insights for future research and facilitation interventions to drive adoption and operationalization of AI tools for Ophthalmology.

Psychometric properties of the general self-efficacy scale among Thais with type 2 diabetes: a multicenter study.

Background: Type 2 diabetes (T2D) is one of the most common chronic diseases in the world. In recent decades the prevalence of this disease has increased alarmingly in lower to middle income countries, where their resource-limited health care systems have struggled to meet this increased burden. Improving patient self-care by improving diabetes knowledge and diabetes management self-efficacy represents a feasible way of ameliorating the impact of T2D on the patient, and the health care system. Unfortunately, the relationships between self-efficacy, diabetes self-management, and thereafter, patient outcomes, are still far from well understood. Although a domain-specific measure of diabetes management self-efficacy, the Diabetes Management Self-Efficacy Scale (DMSES), has been validated in the Thai T2D population, more general measures of self-efficacy, such as the General Self-Efficacy scale (GSE) have not been validated in this population. In this paper we translate and examine the psychometric properties of the GSE in Thais living with T2D. Methods: In this nation-wide study we examined the psychometric properties of the GSE in 749 Thais diagnosed with T2D within the last five years, and evaluated its relationship with the DMSES along with other patient characteristics. Reliability of GSE was assessed using Cronbach's alpha, and the construct validity was examined using confirmatory factor analysis, along with GSE's convergence and discrimination from DMSES. Results: The Thai version of the GSE was shown to have good psychometric properties in Thais living with T2D. Cronbach's alpha was shown to be 0.87 (95% CI [0.86, 0.88]). We also demonstrated the structural validity of the GSE (Tucker-Lewis Index = 0.994, Cumulative Fit Index = 0.995, Adjusted Goodness of Fit Index = 0.998, Root Mean Square Error of Approximations = 0.025, 95% CI [0.06-0.039]), and that this instrument has a similar structure in Thais as in other populations. GSE was also shown to have some overlap with the DMSES with correlations among GSE and the DMSES domains ranging from 0.18 to 0.26, but also the GSE has substantial discrimination from DMSES (Disattenuated correlation coefficient = 0.283, 95% CI [0.214-0.352], p < 0.001). This suggests that while general and diabetes management self-efficacy are somewhat associated, there are aspects of diabetes management self-efficacy not captured by the more stable general self-efficacy. Conclusions: We demonstrate that the Thai GSE is a reliable and valid measure. We believe the GSE may represent a useful tool to examine the efficacy of proposed and existing diabetes self-management, and management self-efficacy interventions.

The sterility, stability and efficacy of repackaged ziv-aflibercept for intravitreal administration.

To evaluate the sterility, stability, and efficacy of repackaged ziv-aflibercept in 1-mL plastic tuberculin syringes for intravitreal injection after storage for up to 90 days at controlled (4 °C) and ambient (25.8 °C) temperature. A total of 168 tuberculin-type 1-mL syringes were prepared containing ziv-aflibercept (100 mg/4 mL). Samples were stored at 4 °C and 25.8 °C for 0, 3, 7, 14, 21, 28, 60, and 90 days. At each time point, four samples were evaluated for the stability and binding affinity of anti-VEGF to VEGF (efficacy) using enzyme-linked immunosorbent assays (ELISAs). All samples were analyzed for microbial growth. No microbial growth was obtained from any of the ziv-aflibercept samples during each time point, indicating that the repackaged ziv-aflibercept stored at 4 °C and 25.8 °C remained sterile. ELISA analysis revealed no significant decrease in concentration, and binding affinity was observed, indicating that the stability and efficacy were preserved. However, the concentration of ziv-aflibercept decreased less than the minimum expected concentration of 8 ng/mL after 60 days at 4 °C and after 30 days at 25.8 °C. The repackaged anti-VEGF drug ziv-aflibercept does not lose stability or efficacy and remains uncontaminated if prepared under sterile conditions and stored at 4 °C for up to 60 days or stored at 25.8 °C for up to 30 days.

Factors associated with the development of blepharoptosis after pars plana vitrectomy surgery.

PURPOSE: To determine the incidence and risk factors for developing blepharoptosis after vitrectomy surgery. METHODS: This prospective observational study conducted in patients who had vitrectomy surgery at the University of California, San Francisco. The patients' eyelids were photographed before, surgery and follow-up visits at 1 day, 1 week, 1 month, 3 months, and 6 months after surgery. Levator excursion (LE), palpebral fissure (PF) height and marginal reflex distance 1 (MRD1) changes from baseline were evaluated. Operative parameters associated with lid parameter changes were analyzed. RESULTS: Thirty-eight eyes were enrolled in the study. Multivariate analysis performed for PF changes from pre-operative were -0.47 mm, 0.33 mm, and 0.09 mm at 1 week, 1 month and 6 months after surgery, respectively (p-value 0.1, 0.2, and 0.8). The mean change of LE from preoperative was -0.44 mm, -0.15 mm, and 0.35 mm at 1 week, 1 month and 6 months after surgery, respectively (p-value 0.3, 0.7 and 0.4). The reduction of MRD1 at 1 week, 1 month and 6 months after surgery were -0.08 mm, -0.13 mm and -0.01 mm, respectively (p = .003, p = .6 and 0.9). Triamcinolone usage was associated with reduction of MRD1 and LE. CONCLUSION: Blepharoptosis presents most during the first week after surgery. The possibility of developing transient changes in eyelid position after vitrectomy surgery should be discussed with patients.

Factors Associated with Visual Outcome after Primary Repair of Open-Globe Injury by Ophthalmology Residents in Training in a Tertiary Eye Center.

PURPOSE: To assess factors associated with visual outcome after open-globe injury (OGI) repair by trainees. METHODS: In this observational study, charts of OGIs repaired by trainees at King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok were retrospectively reviewed. Preoperative, intraoperative, and postoperative outcomes (day 1, month 1, and month 6 postoperation) were analyzed. RESULTS: A total of 78 OGIs presented in a 10-year period. A biphasic pattern was found among the young and the elderly. Approximately 73.6% of the cases had had surgical repair outside office hours. A majority of cases had been caused by machinery and hammers, and had visual acuity (VA) <20/200. Three cases were reported as having been unsuccessful intraoperatively for globe repair. A fifth of the cases required evisceration/enucleation within 2 weeks of presentation. Presenting VA worse than hand motion was associated with the risk of evisceration/enucleation (OR 14.5, P=0.013). VA improved at 6 months postoperation to the range of counting fingers and 20/200 (OR 15.6, P<0.01). High ocular trauma scores (OTSs) was associated with lower risk of evisceration/enucleation, and 12% retinal detachment (RD) was discovered, of which 90% occurred within 1 month after OGI repair. CONCLUSION: Most OGIs were efficiently managed by the trainees, seldomly requiring assistance from subspecialists. Poor initial VA was associated with high risk of visual loss, whereas higher OTSs were inversely related to lower risk of evisceration or enucleation. There was a higher percentage of participants with final VA of 20/100-20/20 than the preoperative period. Precaution and careful evaluation of RD in the early postoperative period is recommended.

The Effect of Anti-Vascular Endothelial Growth Factor on Retinal Microvascular Changes in Diabetic Macular Edema Using Swept-Source Optical Coherence Tomography Angiography.

PURPOSE: This study evaluates the effect of anti-vascular endothelial growth factor (anti-VEGF) therapy on microaneurysm changes and foveal avascular zone (FAZ) using optical coherence tomography angiography (OCTA) in patients with diabetic macular edema (DME). DESIGN: Prospective observational study. MATERIALS AND METHODS: This study involved patients with DME undergoing anti-VEGF treatment (aflibercept, ranibizumab, and bevacizumab). Macula OCTA images were obtained before (visit 0) and 1 month after (visit 1) anti-VEGF injection. Microaneurysm counts were performed, and the FAZ was evaluated in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The differences in microaneurysms, FAZ, and clinical correlations were analyzed. RESULTS: A total of 152 eyes were analyzed. The patients' mean age was 59 years. Bevacizumab was used in 69.7%, ranibizumab in 15.1%, and aflibercept in 15.1%. There was a significant reduction in the FAZ in the SCP and DCP between visits 0 and 1. All anti-VEGF medications reduced the number of microaneurysms (p<0.01). After treatment, changes in the FAZ in SCP and DCP corresponded with changes in visual acuity (p<0.01). CONCLUSION: Microaneurysms as detected by OCTA might serve as a biomarker for a clinical response to anti-VEGF treatment in the short term. The FAZ might also predict visual acuity improvement after anti-VEGF injection. TRIAL REGISTRATION: Thai Clinical Trials Registry (TCTR20161010005).

Literature Review of Surgical Treatment in Idiopathic Full-Thickness Macular Hole.

PURPOSE: To summarize current surgical techniques for treating primary macular holes (MHs). METHODS: We reviewed publications detailing surgical approaches to primary MHs, briefly described their protocols, and outlined their results. RESULTS: Currently, the technique for primary MH repair is pars plana vitrectomy, removing the posterior cortical vitreous, stripping the epiretinal membranes, and ending with intraocular gas tamponade. The evident benefit of peeling off the internal limiting membrane (ILM) was clearly shown for MHs at stages 2 to 4 by achieving an anatomical closure rate of >90%, even in large MH up to 650 µm. Newer MH surgical techniques include modification of ILM flap techniques, placing an autologous scaffolding of tissue within the hole, and cell therapy has shown to increase the closure rate of large and chronic macular holes, resulting in modest functional improvement in complicated MHs. CONCLUSION: Since the turn of the century, the success rate of modern macular surgery has increased, even for large and chronic MHs. There seems to be no limit to novel concepts in MH surgery, which range from anatomical closure to those proposing natural restoration of visual function via stem cell therapy.

The Role of Head Elevation in Treatment of Vitreous Haemorrhage.

OBJECTIVE: To investigate the effect of head elevation on macular clearance of acute vitreous haemorrhage. DESIGN: Crossover, prospective, randomized clinical study. SETTING: University, tertiary care hospital. PARTICIPANTS: 24 vitreous haemorrhage patients, average age 55 years. METHODS: Patients with acute vitreous haemorrhage who were randomly separated into 2 groups. In group A, the patients were assigned normal head position for the first week of sleep, then switched to head elevation for the second week (n=12). In group B, the patients were assigned the head position in reverse order (n=12). A washout period of 24 hrs was used between treatments. The carryover, sequence, and treatment effects were analysed by using various mixed models. OUTCOMES: Best-corrected visual acuity (BCVA), vitreous haemorrhage grading, fundus photo colour intensity, and self-assessment scores. RESULTS: Although the mean BCVA (LogMAR) change following head elevation was higher than following normal head position, the difference was not statistically significant (-0.053 and 0.065 LogMAR, respectively, p = 0.2). Vitreous haemorrhage grading in the central region showed no statistical improvement in either group. Fundus photo colour intensity comparison in all fundus areas also showed no statistically significant differences in either group. CONCLUSION: Although head elevation is recommended to patients with acute vitreous haemorrhage, this study showed no statistically significant improvement in BCVA, vitreous haemorrhage grading, or fundus photo colour intensity between head elevation and normal head position in the early observation period.Trial registration: TCTR20150314001.

Foveal and parafoveal choroidal thickness pattern measuring by swept source optical coherence tomography.

OBJECTIVE: To evaluate the choroidal thickness (CT) in foveal and parafoveal regions in Thai adults using swept-source optical coherence tomography (SS-OCT). METHODS: We enrolled healthy volunteers ≥18 years of age from King Chulalongkorn Memorial Hospital, Thailand, during September 2015 to March 2016. Optical coherence tomography (OCT) of the macula was performed, and subfoveal CT was measured manually using a line scan. Average thicknesses of retinal and choroidal layers in regions of the Early Treatment Diabetic Retinopathy Study grid were measured automatically. A multivariate analysis was conducted to determine correlations between CTs in the foveal and parafoveal regions and retinal layers. RESULTS: Altogether, 144 eyes from 144 subjects (29 men, 115 women; mean age 41 years) were studied. The mean foveal CT was 282.4 ± 13.8 µm. It was thicker in the temporal fovea than in the nasal fovea (p < 0.001) and thicker in men than in women. Multivariate analysis showed that age and sex were significantly negatively correlated with the thickness of the retina, ganglion cell layer, outer retinal layer, and choroid but not of the nerve fiber layer. Regression analysis revealed that the CT decreased approximately 1.5 µm per year. CONCLUSIONS: Age and sex significantly influence choroidal thickness. Macular CT in a healthy eye thins with age. CT decreases with age faster at distances away from the foveal center than at the center. Subfoveal CT was greater than the mean CT. Parafoveal CT should be evaluated to identify specific retinal-choroidal disease.

Neovascular age-related macular degeneration: intraocular inflammatory cytokines in the poor responder to ranibizumab treatment.

PURPOSE: To determine the levels of interleukin (IL)-6, vascular endothelial growth factor-A, platelet-derived growth factor, placental growth factor (PLGF), and other cytokines in the aqueous fluid of patients with neovascular age-related macular degeneration who respond poorly to ranibizumab. PATIENTS AND METHODS: This is an observational, prospective study. Thirty-two eyes from 30 patients were included in the study: 11 patients who responded poorly to ranibizumab and were switched to aflibercept (AF group), 8 patients who received ranibizumab and photodynamic therapy (PDT group), and 13 patients who responded to ranibizumab (control group). Aqueous fluid samples were collected for analysis of cytokine levels at baseline and after 1, 2, and 3 months of treatment. The effect of treatment on cytokine levels was compared between the study groups and between different time points using a linear mixed-effect regression model. RESULTS: In the AF group, there was an increase in vascular endothelial growth factor-C, IL-7, and angiopoeitin-2 levels (P=0.01) and a decrease in intercellular adhesion molecule and IL-17 levels (P=0.01) between baseline and 3 months. After adjustment for age, sex, race, and type of lesion at baseline, the PLGF level was higher (P=0.02) and the IL-7 level was lower (P=0.04) in the ranibizumab non-responder group than in the ranibizumab responder group. CONCLUSION: Switching from ranibizumab to aflibercept did not reduce intraocular levels of angiogenesis cytokines, but resulted in improvement of central subfield thickness. PLGF levels were higher in poor responders to ranibizumab. The response of lesions to medication might be related to the stage of choroidal neovascularization. TRIAL REGISTRATION: www.ClinicalTrial.gov (NCT02218177c).

Association between visual status and mental health status in Thai rural elderly: a community-based study.

AIM: To evaluate the association between visual impairment (VI) and mental health or social engagement in older adults living in rural Thailand. METHODS: Data for this cross-sectional study were drawn from a community survey conducted in 2015 in Saraburi Province, Thailand. Participants were 327 adults aged ≥50y. VI was assessed using presenting distance visual acuity. Mental health and social engagement were evaluated in face-to-face interviews using validated questionnaires. After determining the prevalence of VI and relevant sociodemographic characteristics, multivariate regression analysis was used to evaluate the impact of VI on mental health and social engagement. RESULTS: The prevalence of VI was 18.3%. Major causes were refractive error (58.3%) and cataract (35%). Factors associated with VI in the crude analysis were: older age [odds ratio (OR) 8.08], unemployment (OR 2.72), widowhood (OR 2.47), being divorced/separated (OR 3.27), smoking (OR 2.09) and disability in activities of daily living (OR 2.35). Protective factors were undergoing eye screening at least once a year (P=0.029) and obesity (P=0.005). VI was significantly associated with low social engagement (adjusted OR 4.13) but not with poor mental health (P>0.05). CONCLUSION: Although VI older adults reported less participation in social activities, there is no significant association between VI and poor mental health. Annual eye examinations may prevent VI in older adults. Information about employment and anti-smoking should be targeted to older adults with VI.

Accuracy of axial length measurements obtained by optical biometry and acoustic biometry in rhegmatogenous retinal detachment: a prospective study.

PURPOSE: We compared the accuracy of axial length (AL) measurement obtained by optical biometry with that obtained by acoustic biometry in eyes with rhegmatogenous retinal detachment (RRD). PATIENTS AND METHODS: This prospective descriptive analytic study measured the AL of eyes with RRD preoperatively and 3 months postoperatively using optical biometry (intraocular lens [IOL] master group) and acoustic biometry (immersion A-scan group). Preoperative and postoperative measurements were compared by paired t-test. The agreement between preoperative and postoperative measurements was analyzed using a Bland-Altman plot. Subgroup analysis of macular involvement status was performed. RESULTS: Twenty-seven eyes were analyzed in this study. The mean AL in the IOL master group was 23.58±0.97 mm preoperatively and 24.17±1.16 mm postoperatively; the mean difference was -0.59±0.90 mm (P = 0.007). The mean AL in the immersion A-scan group was 24.29±1.59 mm preoperatively and 24.27±1.69 mm postoperatively; the mean difference was 0.02±0.48 mm (P = 0.827). Bland-Altman analysis revealed disagreement between preoperative and postoperative AL measurements in both techniques. In subgroup analysis of macula with RRD, there were significant differences between preoperative and postoperative AL measurements in the IOL master group (P = 0.014). CONCLUSION: Significant underestimation of AL measurement was observed when using the IOL master in eyes with RRD with macular involvement, which could affect IOL power selection.

Comparison of methods for identifying causative bacterial microorganisms in presumed acute endophthalmitis: conventional culture, blood culture, and PCR.

BACKGROUND: Identification of bacterial pathogens in endophthalmitis is important to inform antibiotic selection and treatment decisions. Hemoculture bottles and polymerase chain reaction (PCR) analysis have been proposed to offer good detection sensitivity. This study compared the sensitivity and accuracy of a blood culture system, a PCR approach, and conventional culture methods for identification of causative bacteria in cases of acute endophthalmitis. METHODS: Twenty-nine patients with a diagnosis of presumed acute bacterial endophthalmitis who underwent vitreous specimen collection at King Chulalongkorn Memorial Hospital were enrolled in this study. Forty-one specimens were collected. Each specimen was divided into three parts, and each part was analyzed using one of three microbial identification techniques: conventional plate culture, blood culture, and polymerase chain reaction and sequencing. The results of the three methods were then compared. RESULTS: Bacteria were identified in 15 of the 41 specimens (36.5%). Five (12.2%) specimens were positive by conventional culture methods, 11 (26.8%) were positive by hemoculture, and 11 (26.8%) were positive by PCR. Cohen's kappa analysis revealed p-values for conventional methods vs. hemoculture, conventional methods vs. PCR, and hemoculture vs. PCR of 0.057, 0.33, and 0.009, respectively. Higher detection rates of Enterococcus faecalis were observed for hemoculture and PCR than for conventional methods. CONCLUSIONS: Blood culture bottles and PCR detection may facilitate bacterial identification in cases of presumed acute endophthalmitis. These techniques should be used in addition to conventional plate culture methods because they provide a greater degree of sensitivity than conventional plate culture alone for the detection of specific microorganisms such as E. faecalis. TRIAL REGISTRATION: Thai Clinical Trial Register No. TCTR20110000024 .

Kinematic study of ozurdex injection in balanced salt solution: modeling the behavior of an injectable drug delivery device in vitrectomized eyes.

PURPOSE: To analyze the kinematics of a dexamethasone intravitreal implant, Ozurdex, after its injection in a balanced salt solution (BSS) at different release angles to simulate its movement in BSS/aqueous-filled eyes. METHODS: Eighteen Ozurdex implants were injected into a BSS-filled box at different release angles (15°, 30°, 45°), using 6 implants/group. The movement of injected implants was recorded by a high-speed video camera. Each implant's trajectory was graphically demonstrated by plotting over time. By using a distance-time function graph, the implant's velocity and normalized energy were calculated. RESULTS: The high-speed video revealed that implants injected at 15° followed a more horizontal trajectory compared to those injected from 30° and 45°, respectively. The implant injected at 15° also achieved the highest mean initial velocity and mean initial normalized energy. The implant velocity from each injection angle decreased exponentially over time and reached nearly zero at 0.1 s. An injection of the implant at a flatter angle was also associated with higher mean retinal impact normalized energy. CONCLUSIONS: An implant injected at a flatter angle tends to travel farther in the horizontal plane and has more initial velocity, which theoretically generates higher initial normalized energy and retinal impact normalized energy. The accidental injection at a flatter angle, which results in shortening of the effective travel distance, may carry the potential risk of direct retinal injury from the injected implant. The amount of energy necessary to cause direct retinal injury, and whether this would be clinically significant, requires further study.