Purpose: To assess the variability of osmolarity measured by the point-of-care TearLab system in healthy eyes. Methods: A systematic review was performed by searching MEDLINE, Scopus, and the Web of Science Databases until November 2016 and checking reference lists of included articles and reviews. The requirements for inclusion were the availability of TearLab results in healthy subjects and a minimum study sample of 20 eyes. Two reviewers assessed articles against the inclusion criteria, extracted relevant data, and examined the methodological quality. We computed the weighted mean osmolarity using the study size as the weighting factor and calculated the rate of subjects with osmolarity values >308 mOsm/L, the Dry Eye Workshop Report 2017 (DEWS) cut-off value for dry eye disease (DED). We repeated the analysis after excluding reports with a possible conflict of interest or missing description of subject selection. Results: Searches retrieved 105 nonduplicate articles, and we included 33 studies investigating 1362 eyes of healthy participants who were asymptomatic and showed no clinical signs of DED. Sixty-three percent were female, and mean age was 37.3 years (range: 21.5–69.0 yr). Weighted mean osmolarity was 298 mOsm/L (95% confidence interval, 282–321 mOsm/L). The result of the subgroup analysis was similar. Overall, 386 of 1362 eyes (28.3%) fulfilled the DEWS's definition of DED (>308 mOsm/L). Conclusions: There is a high variability of osmolarity measurements with the TearLab system. A substantial number of healthy subjects fulfill the DEWS's definition of DED. We propose interpreting the TearLab osmolarity results cautiously and in the context of other established methods.

Purpose: The prevalence of keratoconus in the general population is reported to be up to 1 of 84. Over the past 2 decades, diagnosis and management evolved rapidly, but keratoconus screening in clinical practice is still challenging and asks for improving the accuracy of keratoconus detection. Deep learning (DL) offers considerable promise for improving the accuracy and speed of medical imaging interpretation. We establish an inventory of studies conducted with DL algorithms that have attempted to diagnose keratoconus. Methods: This systematic review was conducted according to the recommendations of the PRISMA statement. We searched (Pre-)MEDLINE, Embase, Science Citation Index, Conference Proceedings Citation Index, arXiv document server, and Google Scholar from inception to February 18, 2022. We included studies that evaluated the performance of DL algorithms in the diagnosis of keratoconus. The main outcome was diagnostic performance measured as sensitivity and specificity, and the methodological quality of the included studies was assessed using QUADAS-2. Results: Searches retrieved 4100 nonduplicate records, and we included 19 studies in the qualitative synthesis and 10 studies in the exploratory meta-analysis. The overall study quality was limited because of poor reporting of patient selection and the use of inadequate reference standards. We found a pooled sensitivity of 97.5% (95% confidence interval, 93.6%–99.0%) and a pooled specificity of 97.2% (95% confidence interval, 85.7%–99.5%) for topography images as input. Conclusions: Our systematic review found that the overall diagnostic performance of DL models to detect keratoconus was good, but the methodological quality of included studies was modest.

Purpose: The purpose of this study was to assess the diagnostic performance of measurements from a new noninvasive, automated ocular surface analyzer (IDRA) in the diagnosis of dry eye disease (DED). Methods: We prospectively identified patients with and without DED using best practice methods. Subsequently, all participants underwent IDRA analysis, consisting of 5 components: noninvasive tear film break-up time, tear meniscus height, lipid layer interferometry, eye blink quality, and infrared meibography. The manufacturer provides cutoff values for a pathologic result for each of these components. Using a stepwise augmentation multivariate logistic regression model, we identified the components with the strongest association for the presence of DED. For the 3 components with the strongest association (interferometry, tear meniscus, and infrared meibography), we calculated the probability of DED. Results: We enrolled 40 patients (80 eyes) with DED (mean age 60.5 years; women 78.3%) and 35 healthy subjects (70 eyes, mean age 31.1 years; women 21.7%). The IDRA had an area under the curve of 0.868 (95% confidence interval: 0.809–0.927) to detect DED. A normal (≥80) interferometry combined with a normal (>0.22) tear meniscus and a normal (≤40) infrared meibography was associated with an estimated probability of 18% for the presence of DED, whereas the estimated probability of DED was as high as 96% when all 3 findings were pathologic. Conclusions: The results of IDRA showed a positive concordance with routine clinical diagnostic tests. The new analyzer is an easy-to-access diagnostic tool to rule out the presence of DED in the extramural setting and to guide a timely DED treatment.

Background: To assess whether Swiss general ophthalmologists have the minimal keratoconus knowledge that corneal specialists would expect them to have. Methods: Corneal specialists defined “minimal keratoconus knowledge” (MKK) with respect to definition, risk factors, symptoms and possible treatment options of keratoconus. A telephone interview survey was conducted among one hundred ophthalmologists (mean age 51.9 years (SD 9.5), 60 % male) from the German-speaking part of Switzerland. For each participant, years of work experience, number of keratoconus patients seen per year and access to a topography device were obtained. We calculated the proportion of MKK and examined in multivariate analyses whether ophthalmologists with access to topography and with greater work experience performed better than other groups. Results: No single ophthalmologist had MKK. The mean MKK was 52.0 %, and the range was 28.6–81.0 %. Per 10 years of working in private practice, the MKK decreased by 8.1 % points (95 % CI: -14.2, -2.00; p = 0.01). Only 24 % of participants correctly recalled the definition of keratoconus, 9 % all risk factors, 5 % all symptoms and 20 % all treatment modalities. The MKK values were not associated with the number of keratoconus patients seen per year and the availability of topography to diagnose keratoconus. Conclusions: There is a substantial mismatch between corneal specialist’ expectations and general ophthalmologists’ knowledge about keratoconus. The low recall of symptoms and risk factors may explain why ophthalmologists diagnose relatively few cases of keratoconus, resulting in inefficient care delivery and delayed intervention.

Purpose: To assess agreement of measurements by 2 swept-source optical coherence tomography biometers and to evaluate the prediction error (PE) in intraocular lens power calculation with 7 formulas. Setting: Tertiary public eye hospital. Design: Consecutive observational. Methods: Axial length (AL), keratometry (K), anterior chamber depth (ACD), lens thickness (LT), and corneal diameter (CD) were measured with the IOLMaster 700 (Biometer A) and Anterion (Biometer B). Agreement was quantified by the limits of agreement and concordance correlation coefficient (CCC). The PE, the median absolute error, and the mean absolute error of the Barrett Universal II, EVO 2.0, Haigis, Hoffer Q, Holladay 1, Kane, and SRK/T formulas were investigated after constant optimization. Results: In 78 eyes from 78 patients, excellent agreement was obtained for AL (CCC >0.99), very good agreement for K, ACD, and LT (CCC >0.95), and strong agreement for CD (CCC >0.72). An additive offset of 0.07 mm was measured for ACD and LT whose mean values were higher with Biometer B (P < .001). No statistically significant difference was found between the PEs and their absolute values when comparing the results of each formula between the 2 biometers. Conclusions: Agreement of biometric measurements by the 2 biometers was high, although Biometer B provided higher mean values of ACD and LT by 0.07 mm. In cataract patients with normal eye length, measurements by the 2 biometers did not lead to different refractive outcomes with the 7 formulas investigated.