The impact of the first peak of the COVID-19 pandemic on childhood myopia control practice patterns among ophthalmologists-an international pediatric ophthalmology and strabismus council global perspective.

BACKGROUND: The prevalence of myopia keeps increasing during the COVID-19 pandemic. We aimed to map the worldwide treatment preferences of ophthalmologists managing myopia control during the first wave of the pandemic. METHODS: An online questionnaire inquiring about pharmacological and optical treatment patterns during the first half of 2020 was sent to pediatric ophthalmology as well as general ophthalmology memberships worldwide. The results among pediatric ophthalmologists were compared to a previous study we performed before the pandemic. RESULTS: A total of 2269 respondents from 94 countries were included. Most respondents were pediatric ophthalmologists (64.6%), followed by ophthalmologists from other subspecialties (32.3%). The preferred modality for all geographical regions was a combination therapy of pharmacological and optical treatments. When evaluated independently, the pharmacological treatment was more popular than the optical treatment in most regions other than East Asia (P < 0.001). Compared to a pre-pandemic questionnaire, the participation of pediatric ophthalmologists affiliated with non-university hospitals increased. Additionally, the prevalence of respondents utilizing either any type of pharmacological treatment and those that using only evidence-based treatments increased globally. Although a decline in the use of optical treatment was evident worldwide, the use of evidence-based optical treatments increased. CONCLUSION: Ophthalmologists around the world preferred a combination therapy of pharmacological and optical treatments. More pediatric ophthalmologists treated myopia progression and preferred a better evidence-based approach to control myopia. These trends reflect a positive response and more awareness of the rising prevalence of myopia due to the increased burden of myopia imposed by the COVID-19 pandemic.

Evaluation of the Ultrastructural and In Vitro Flow Properties of the PRESERFLO MicroShunt.

Purpose: To measure the in vitro flow properties of the PRESERFLO implant for comparison with the theoretical resistance to flow. Methods: The PRESERFLO was designed to control the flow of aqueous humor according to the Hagen-Poiseuille (HP) equation. Scanning electron microscopy (SEM) was performed to analyze the ultrastructure, and flow measurements were carried out using a gravity-flow setup. Results: SEM images of the PRESERFLO showed luminal diameters of 67.73 × 65.95 µm and 63.66 × 70.54 µm. The total diameter was 337.2 µm, and the wall was 154 µm wide. The theoretical calculation of the resistance to flow (R) for an aqueous humor (AH) viscosity of 0.7185 centipoises (cP) was 1.3 mm Hg/(µL/min). Hence, assuming a constant AH flow of 2 µL/min, the pressure differential across the device (ΔP) was estimated to be 2.6 mm Hg. The gravity-flow experiment allowed us to measure the experimental resistance to flow, which was RE = 1.301 mm Hg/(µL/min), in agreement with the theoretical resistance to flow R given by the HP equation. Conclusions: The experimental and theoretical flow testing showed that the pressure drop across this device would not be large enough to avoid hypotony unless the resistance to outflow of the sub-Tenon space was sufficient to control the intraocular pressure in the early postoperative period. Translational Relevance: The fluid properties of glaucoma subconjunctival drainage devices determine their specific bleb-forming capacity and ability to avoid hypotony and therefore their safety and efficacy profile.

Botulinum toxin treatment in patients up to 3 years of age who have esotropic Duane retraction syndrome.

PURPOSE: To report the results of botulinum toxin (BOTOX®, Allergan) type A (BTA) bilateral injection in the treatment of Duane retraction syndrome (DRS) type 1 in patients aged up to 3 years. METHODS: We studied the results of BTA bilateral injection in eight consecutive patients with DRS type 1 and esotropia in primary gaze. Average follow-up was 74 ± 71 months. The main variables analyzed were horizontal and vertical deviation and face turn. Patients were anesthetized with nitrous oxide (N2O). A mean dosage of 5.6 ± 1.8 IU (range 2.5-7.5 IU) of botulinum toxin diluted in 0.9% saline solution was injected under electromyography control in each medial rectus muscle. RESULTS: Seven patients had one affected eye and one patient had bilateral involvement. The mean preoperative esotropia was 32 ± 10 prism diopters (PD). Three patients (37.5%) had also a vertical deviation. All patients had face turn ranging between 15° and 45° before BTA injection. In the last follow-up, 4 patients were orthotropic (50%), 1 (12.5%) had 3 PD exotropia and 3 (37.5%) had esotropia averaging 25 PD mean. The 3 esotropic patients needed surgical correction. Vertical strabismus improved in 3 patients achieving complete resolution in one of these patients. Two patients, without vertical strabismus before the BTA injection, developed a 5-PD vertical deviation, one of them required surgery. Face turn improved in all patients. CONCLUSION: Botulinum toxin injection is an alternative treatment for patients with DRS type 1 presents esotropia and face turn in children up to 3 years of age.