Medical hypothesis, discovery & innovation in optometry

Background: Valsalva retinopathy is a specific type of retinopathy that appears following an acute rise in intrathoracic or intra-abdominal pressure. This review focuses on current literature and future directions for the diagnosis and management of Valsalva retinopathy.
Methods: In this brief review, the literature was searched to provide an extensive general and updated description of Valsalva retinopathy, focusing on its management and prognosis. Selected articles are summarized to present the etiology, general pathology, pathophysiology, symptoms, signs, diagnosis, differential diagnosis, treatment, and prognosis of Valsalva retinopathy.
Results: The main symptom of Valsalva retinopathy is loss of visual acuity following exertion. This is caused by the rupture of small superficial vessels in the macula and perimacular areas, leading to extravasation of blood. No link between age, sex, or race has been found, although fundus vessel abnormalities pose some predisposition to the disease. During fundoscopy, Valsalva retinopathy appears most frequently as well-defined preretinal hemorrhages confined to the sub-internal limiting membrane (ILM) or subhyaloid space. If ILM rupture occurs, hyaloid hemorrhage can appear. Diagnosis is based on the patient’s medical history and a standard examination. Usually, only observation of the patient is required, with the hemorrhage resolving within weeks to months. In cases of large premacular hemorrhage or large sub-ILM/subhyaloid hemorrhage, vitrectomy or Nd:YAG krypton laser membranotomy can be performed.
Conclusions: Of all the aspects of Valsalva retinopathy that might trouble the physician, the most challenging features are differential diagnosis and the choice of optimal treatment. Therapeutic strategies for Valsalva retinopathy can be either conservative or based on Nd:YAG laser membranotomy and/or vitrectomy. All methods seem to have good outcomes. However, physicians should not be afraid of advancing beyond conservative therapy, especially in the event of persistent premacular hemorrhage, which could lead to permanent retinal damage if valuable time is lost, even after vitrectomy.

Background: Uncorrected myopia represents a major cause of visual disability in children, especially in low-income and middle-income countries. However, there is still debate about the effect of e-learning and “stay-at-home” guidelines on the refractive status of school children, especially in the absence of long-term follow-up data. This study aimed to assess the impact of stay-at-home enforcement during the COVID-19 pandemic on myopia progression in students in the Suez Canal Area, Egypt.
Methods: This longitudinal observational study included 1650 students. All students aged 8–15 years with visual complaints, who had attended routine annual vision checks since 2018, were enrolled and assessed annually for myopia progression until 2021. Cycloplegic and noncycloplegic refraction, axial length (AL), corneal curvature, and uncorrected and best-corrected distance visual acuity were measured. The participants were administered a questionnaire that focused mainly on collecting information on their visual habits.
Results: Our study included 3300 eyes of 1650 school students with myopia during the 4-year study period from 2018 to 2021. The mean cycloplegic spherical equivalents (CSE) were - 1.02, - 1.52, - 2.00, and - 3.50 diopters (D) in 2018, 2019, 2020, and 2021, respectively. This myopic shift in CSE over time was significant (P < 0.001). The average keratometric reading (Avg K) increased significantly during the follow-up period (P < 0.001). The Avg K measurements were 42.32, 42.62, 43.02, and 44.19 D in 2018, 2019, 2020, and 2021, respectively. The changes in Avg K were significant (P < 0.001). The mean AL measurements were 22.53, 22.59, 22.69, and 22.71 mm in 2018, 2019, 2020, and 2021, respectively. Although statistically significant (P < 0.001), changes in AL were clinically insignificant throughout the study period. The mean durations spent on electronic devices at home were 2.12, 2.46, 3.10, and 6.00 hours in 2018, 2019, 2020, and 2021, respectively. The changes over time were significant (P < 0.001).
Conclusions: During the COVID-19 pandemic, studying at home accelerated the degree of refraction toward myopia in school children in Egypt. Further studies are needed to assess the academic performance of students with progressive myopia.

Letter to the Editor

Background: Focusing the gaze for prolonged periods on a fixed distance demands high visual efficiency in handloom silk weavers and might result in various accommodative and vergence dysfunctions. The aim of the present study was to assess accommodative and vergence parameters and determine the frequency of non-strabismic binocular vision anomalies (NSBVAs) among handloom silk weavers.
Methods: In this cross-sectional study, we recruited voluntary handloom silk weavers from the Government-aided Society of Arignar Anna Silk Co-op Society K.H.-1, Kanchipuram, aged 20–39 years. All participants underwent preliminary visual examinations and comprehensive binocular vision testing of accommodative and vergence parameters. Sensory evaluation was performed using stereopsis testing and the Worth 4 Dot test. Motor evaluation included the ocular motility assessment, heterophoria checks for distance and near, near point of convergence, negative and positive fusional vergences for distance and near, vergence facility, negative and positive relative accommodations, both monocular and binocular near points of accommodation, and accommodative facility. The monocular estimate method was used to determine the accommodative response. Quantitative data are expressed as mean (standard deviation [SD]), and qualitative data are expressed as frequency (percentage).
Results: We recruited a total of 72 weavers, including 41 (56.9%) men and, 31 (43.1%) women with mean (SD) age, working hours, and work experience of 34.15 (4.12) years, 9 (2.5) h/day, and 17.5 (6.9) years, respectively. Of the 29 (40.3%) weavers with a refractive error, 18 (25%) had astigmatism; seven (9.7%) had myopia; and four (5.6%) had hyperopia. Of the 72 weavers, 38 (52.8%) presented with NSBVAs, including 13 (18.1%) with accommodative dysfunctions, 11 (15.3%) with vergence dysfunctions, and 14 (19.4%) with combined accommodative and vergence dysfunctions. Accommodative insufficiency was the most prevalent dysfunction among all NSBVAs. Overall, 57 (79.2%) handloom silk weavers reported vision-related symptoms during their weaving hours, all with NSBVAs (n = 38), 19 with normal parameters in the binocular vision test, and 15 with no symptoms.
Conclusions: The frequency of NSBVAs was high among handloom silk weavers compared to the literature. This implies a need for comprehensive binocular vision examination for people in this occupation to rule out NSBVAs for improving their quality of life and occupational productivity. Future large-scale studies are required to determine the exact NSBVAs prevalence among workers of this near vision-related occupation.

Background: Visual fatigue is categorized as a complex phenomenon that decreases visual performance. The aim of the present study was to assess changes in accommodation at different levels of visual fatigue among students of a Malaysian private university using digital devices.
Methods: In this cross-sectional study, students regardless of sex and ethnicity were included. A comprehensive eye examination was performed. After estimating the level of visual fatigue, the amplitude of accommodation (AA), accommodation facility (AF), and monocular estimation method (MEM) were measured. The visual fatigue questionnaire was filled out by the participants. Participants were categorized based on the visual fatigue scores into low, moderate, and high visual fatigue groups. Moderate and severe visual fatigue groups were combined, as the distribution of participants was uneven across the groups. Accommodation parameters were measured for each group and compared between the two groups, i.e., the low visual fatigue group and the combined moderate to severe visual fatigue group.
Results: We enrolled a total of 86 students, including 29 (33.72%) men and 57 (66.28%) women, with a mean (standard deviation [SD]) age of 22.02 (1.51) years and age ranging from 19 to 26 years. By ethnicity, there were 69 (80.23%) Chinese, five (5.81%) Indian, four (4.65%) Malay, and eight (9.30%) participants from other ethnicities. Most participants were in the low visual fatigue group (54.65%), followed by the severe (25.58%) and moderate (19.77%) visual fatigue groups. AA for both eyes and AF for the right eye differed significantly between the two groups of visual fatigue: low (Group 1) and moderate-to-severe (Group 2) (both P < 0.05). None of the accommodative parameters correlated with visual fatigue (P > 0.05).
Conclusions: Binocular AA and monocular AF significantly differed between the visual fatigue groups, but MEM was comparable. However, none of the accommodative parameters correlated with visual fatigue. These perceived vision dysfunctions could affect the visual skills of students. Therefore, future studies on the relationship between the observed dysfunctions and students’ reading performance are necessary.

Background: Optic disc edema is a pathological condition with various causes. Cases of optic disc swelling should be dealt with a multidisciplinary approach to rule out those causes. Unilateral optic disc edema is seen in papillitis, non-arteritic anterior ischemic optic neuropathy, retinal vein occlusion, and infection or inflammation of the contiguous sinus or orbit. Here, we report a rare case of unilateral asymptomatic optic disc edema due to posterior ethmoid sinusitis.  
Case Presentation: A 53-year-old man presented for a routine 3-monthly follow-up after an uneventful cataract surgery of the right eye. All examinations were unremarkable, except for the right eye optic disc edema on fundus examination, consistent with an enlarged blind spot in the visual field test. Contrast-enhanced magnetic resonance imaging revealed mucosal thickening with muco-inflammatory exudates of the posterior ethmoidal sinus overriding the optic disc on the right side, leading to optic disc edema of the right eye. The patient was diagnosed with unilateral asymptomatic optic disc edema in the right eye due to posterior ethmoid sinusitis and referred to an otorhinolaryngologist for the management. The otorhinolaryngologist performed functional endoscopic sinus surgery and prescribed antibiotics and anti-histamines for 6 weeks. At the final examination, his visual acuity was 6/6, and the fundus examination revealed no optic disc edema.
Conclusions: We reported a rare case of unilateral optic nerve edema and visual field loss with a treatable cause. Contemporary imaging provided the accurate diagnosis. Therefore, in cases of disc edema, sinusitis of the adjacent paranasal sinuses should be ruled out as a possible cause of compressive optic neuropathy or inflammation overriding the optic nerve.