Clinical performance of a smartphone-based low vision aid.

Real-time digital image processing to optimally enhance low vision is now realizable with recent advances in personal computers. This study aimed to evaluate the efficacy of a wearable smartphone-based low vision aid (LVA) with customizable vision enhancement in patients with visual impairment. We recruited 35 subjects with visual impairment and who were literate and cognitively capable. The subjects completed a training session and were provided a smartphone-based LVA for a 4-week use. Visual functions including binocular best-corrected distance, intermediate, and near visual acuities; reading performance (reading speed and accuracy); and facial recognition performance were measured at baseline and after 4-weeks use. All subjects also completed the Low Vision Quality of Life (LVQOL) Questionnaire. Thirty-four subjects (mean age, 43.82 ± 15.06 years) completed the study. Significant improvements in binocular best-corrected distance, intermediate, and near visual acuities were observed after smartphone-based LVA use (all p < 0.001). Reading accuracy and facial recognition performance also improved significantly (p = 0.009 and p < 0.001, respectively), but reading speed did not. LVQOL scores significantly improved after 4 weeks of use in subjects aged < 40 years (p = 0.024), but not in subjects aged ≥ 40 years (p = 0.653). Ocular and non-ocular adverse events were infrequent and resolved when the device was removed. The smartphone-based LVA with customizable vision enhancement could provide clinically significant improvements in the visual function of patients with visual impairment and was generally well tolerated. This study suggests that the smartphone-based LVA would be beneficial for visual rehabilitation.

Assessment of reliability and validity of the 5-scale grading system of the point-of-care immunoassay for tear matrix metalloproteinase-9.

We evaluated the reliability and validity of the 5-scale grading system to interpret the point-of-care immunoassay for tear matrix metalloproteinase (MMP)-9. Six observers graded red bands of photographs of the readout window in MMP-9 immunoassay kit (InflammaDry) two times with 2-week interval based on the 5-scale grading system (i.e. grade 0-4). Interobserver and intraobserver reliability were evaluated using intraclass correlation coefficients. The interobserver agreements were analyzed according to the severity of tear MMP-9 expression. To validate the system, a concentration calibration curve was made using MMP-9 solutions with reference concentrations, then the distribution of MMP-9 concentrations was analyzed according to the 5-scale grading system. Both intraobserver and interobserver reliability was excellent. The readout grades were significantly correlated with the quantified colorimetric densities. The interobserver variance of readout grades had no correlation with the severity of the measured densities. The band density continued to increase up to a maximal concentration (i.e. 5000 ng/mL) according to the calibration curve. The difference of grades reflected the change of MMP-9 concentrations sensitively, especially between grade 2 and 4. Together, our data indicate that the subjective 5-scale grading system in the point-of-care MMP-9 immunoassay is an easy and reliable method with acceptable accuracy.

Comparison of digital subtraction dacryocystography and dacryoendoscopy in patients with epiphora.

OBJECTIVE: To assess the diagnostic information provided by digital subtraction dacryocystography (DCG) and dacryoendoscopy in patients with epiphora. METHODS: Sixty-eight lacrimal systems of 34 patients with epiphora were prospectively studied. Patients were initially examined with syringing, followed by digital subtraction DCG and dacryoendoscopy to confirm the diagnosis. Obstructions in lacrimal pathways were evaluated by degree, location, and cause. The weighted kappa coefficient was used to compare the agreement between the tests. RESULTS: Of the 68 lacrimal pathways, partial or complete obstructions were identified in 56 cases (82.3%) with syringing, in 38 cases (55.9%) with DCG, and in 60 cases (88.2%) with dacryoendoscopy. DCG and dacryoendoscopy showed the same result in 42 of the 68 (61.8%) lacrimal pathways. The weighted kappa value for DCG and dacryoendoscopy was 0.60 (95% CI: 0.40-0.81). The most common sites of obstruction were the common canaliculus (36.7%) and the nasolacrimal duct (28.3%) in dacryoendoscopy. Thirty-three lacrimal pathways (48.5%) were identified to have obstructions on the same level between DCG and dacryoendoscopy. Among the 30 lacrimal pathways (44.1%) that were normal by DCG, obstruction was revealed in 22 cases by dacryoendoscopy, with 11 cases in the common canaliculus. Additional useful information on the cause of obstruction and identification of multiple obstructed sites was provided by dacryoendoscopy. CONCLUSIONS: DCG and dacryoendoscopy showed moderate agreement in detecting lacrimal pathway obstruction. Dacryoendoscopy allowed for comprehensive investigations of the lacrimal pathway and can help explain unidentified factors associated with lacrimal pathway obstruction in patients with epiphora.