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Clinical relevance: Electronic displays, including laptops, tablets, and smartphones, have dramatically altered the way information is accessed and become significant factors in human daily life. They interfere with the blink rate and increase dry eye symptoms, which lead to more discomfort compared to hard copy while reading. Background: Digital eye strain occurs when an individual suffers from symptoms, or they are exacerbated, while performing a task requiring digital screen viewing. This study assessed the tear film status immediately following reading on a laptop computer screen versus an identical hard copy. Methods: Thirty young adults with normal ocular health and reporting no significant symptoms of dry eye (ocular surface disease index (OSDI) score < 13 and non-invasive tear break-up time (NITBUT) > 10 seconds) read a text as hard copy and on a laptop computer screen for 30 min on separate days in a random sequence in a controlled reading experimental condition. The texts were matched in size and contrast and presented at a viewing distance of 40 cm. The NITBUT and strip meniscometry tube tests were administered at baseline and after reading in both conditions. Results: The median baseline NITBUT decreased from 13.0 s to 10.0 s (P < 0.001) after hardcopy reading and to 7.0 (P < 0.001) after reading from a laptop computer screen, with a significant difference between the task medium (P = 0.001). The baseline strip meniscometry tube results decreased from 6.7 mm to 5.0 mm (P < 0.001) after hardcopy reading and to 5.0 mm (P < 0.001) after reading from a laptop computer screen, but there was no significant difference with the task medium (P = 0.085). Conclusion: Reading in both conditions led to tear film instability in terms of the tear film quality and quantity. Additionally, the computer screen has a greater impact on the TBUT compared to hardcopy reading, while these two reading mediums had a similar effect on the tear volume.

Objective: Low-vision quality-of-life (LVQOL) questionnaire was recently translated to Persian. Its model fit and construct validity were assessed by exploratory and confirmatory analysis for adults with visual impairment, before. In this study, we aimed to test the reliability of the Persian LVQOL questionnaire based on Rasch analysis. Methods: Overall, 100 low-vision patients and 100 demographic statue-matched control subjects were participated for evaluating reliability aspects. All the participants were asked to complete the Persian LVQOL questionnaire. The low-vision group was asked to fill out the LVQOL 3 months after rehabilitation to determine how rehabilitation changed the quality of life. Rasch analyses of the survey items were conducted using WINSTEPS. Results: All items fitted the Rasch model. Point-measure correlations values varied from .13 to .70, providing a preliminary indication of adequate construct validity. All factor loadings found more than .4. infit values for all other participants were in the acceptable range. All items obtained infit and outfit MSQ values of < 2.0. Patients’ abilities relative to the item difficulty were analyzed. Item difficulty was estimated and item characteristic curves were included. Sufficient unidimensionality, hierarchical order, and equal interval scaring were obtained. Conclusion: The Persian LVQOL questionnaire was reliable enough and it will be valuable in both clinical practice and research.

Objectives To compare changes in corneal biomechanical parameters one year after corneal cross-linking (CXL) in keratoconus (KCN) eyes of different severities. Methods Seventy-five eyes with mild, moderate, and severe grades of KCN (n = 24, 31, and 20 eyes, respectively) that were treated with CXL, based upon the standard Dresden protocol, were included. The corneal biomechanical assessment was performed using Corvis ST and Ocular Response Analyzer (ORA). Changes in Corvis's dynamic corneal response (DCR) parameters and ORA's derived parameters (corneal hysteresis (CH), and corneal resistance factor (CRF)) were assessed whilst the corneal thickness and intraocular pressure were considered as covariates. Results There was no statistically significant difference in the corneal biomechanical parameters obtained using both devices after surgery separately in different KCN grades, except for the deformation amplitude (DA) in the severe KCN group (P = 0.017). Changes in the classic parameters of the highest concavity phase of Corvis ST (peak distance, radius, and DA) were more positive and in the newer parameters (integrated inverse radius (IIR), deformation amplitude ratio (DAR)) more negative in the severe group compared to the other groups. Also, the mean change in CH (P = 0.710), and CRF (P = 0.565), showed a negative shift in higher grades of KCN; however, there was no significant difference in the mean changes of all parameters between different groups. (P > 0.05) Conclusions Similar changes in the Corvis ST and ORA parameters in mild, moderate, and severe KCN indicate biomechanical stability and the effective role of CXL in stopping the progressive nature of keratoconus in eyes of varying severities one year after CXL.

Most of the vision quality assessment questionnaires are in English. None of the low-vision-related quality-of-life questionnaires have been translated or developed in Persian. It will help Persian optometrists and ophthalmologists to assess improvement of visual function and quality of life during their low-vision rehabilitation programs. In this study, we aimed to translate the low-vision quality-of-life (LVQOL) questionnaire in Persian language and apply exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to assess the construct validity and fit model. Translation and cultural adjustment of the English language LVQOL questionnaire to Persian was undertaken. Overall, 100 low-vision patients were participated to validate and model the assessment questionnaire by both EFA and CFA methods. Complementary EFA and CFA results provide detailed information about item and scale performance of the Persian LVQOL. EFA showed Items 15, 16, and 21 which had factor loadings lower than 0.3. The modified model had the comparative fit index (CFI) and root mean square error of approximation (RMSEA) of 0.89 and 0.06, respectively. The translation, adjustment, and fit analysis of the LVQOL questionnaire into Persian were successful and it will be valuable in both clinical practice and research.

Purpose. To present the youngest age ever reported for acute corneal hydrops with total corneal edema in a child with advanced bilateral keratoconus. Methods. Patient presentation in ophthalmic clinic. The patient underwent various clinical tests and examinations including anterior segment optical coherence tomography (AS-OCT) and Scheimpflug corneal tomography. Results. A 5-year-old girl presented with uncorrected distance visual acuity (UDVA) of 0.4 in the right eye and nonmeasurable UDVA associated with severe photophobia in her left eye of a 3-day duration. Intraocular pressure using the iCare tonometer was 14 and 5 mmHg in the right and left eyes, respectively. An old corneal hydrops scar and posterior subcapsular cataract (PSC) in the right eye and a total limbus to limbus corneal hydrops in the left eye were observed on slit-lamp examinations. Scheimpflug corneal tomography was possible in the right eye but, due to excessive irregularity and scaring, was not possible in the left eye. Corneal thinning and scarring were evident in the anterior segment optical coherence tomography in the right eye and very edematous cornea associated with stromal cleft and epithelial bullae in the left eye. A management plan consisting of topical hypertonic solution and ointment was started to reduce her symptoms. Conclusion. Acute corneal hydrops may be the presenting sign of keratoconus; however, extensive hydrops involving the total cornea area at a very young age is very rare and has not been previously reported in the literature.