Medical hypothesis discovery and innovation in ophthalmology

Background: Clear vision is crucial for effective learning among preschool children. Hence, early detection of vision impairment and prompt treatment are required to improve prognosis. Currently, limited information is available, and no program exists to screen for vision impairment among preschoolers in Bangladesh. This study aimed to validate the KieVision™ Preschool Vision Screening Kit, translated into the Bengali language, to improve vision impairment detection among preschool children.
Methods: In this prospective case–control study, 60 preschool teachers from Chittagong were randomly selected. The study group was trained to conduct vision screening among preschool children using the translated kit, whereas the control group was trained using the Chittagong Eye Infirmary and Training Complex (CEITC) School Teachers’ Training Module. Fifteen preschool children aged 4–6 years were screened by each preschool teacher and again by the optometrist.
Results: Sixty preschool teachers screened 900 children. The results showed a higher validity of vision screening findings by the preschool teachers in the study group (sensitivity, 68.00%; specificity, 92.75%) than in the control group (sensitivity 47.37%, specificity 70.39%). The level of agreement between the preschool teachers and optometrists was high for all tests (first-order agreement coefficient [AC1] ? 0.80 in the study group). The sensitivity and specificity of the visual acuity test for the study group were 59.65% and 94.15%, respectively, while in the control group it was 13.33% and 62.54%, respectively. A similar trend was noted in the general observation component and Hirschberg’s test.
Conclusions: The Bengali Language KieVision™ Preschool Vision Screening Kit can be used effectively by preschool teachers in vision screening programs to improve the identification of vision impairment among preschool children in Bangladesh.

Background: The coronavirus disease 2019 (COVID-19) pandemic has been the most challenging health problem in the last 2 years. Post-COVID-19 multisystem inflammatory syndrome of children (MIS-C) is a severe post-COVID-19 complication in pediatric patients. Ocular manifestations may be the first presentation of MIS-C, wherein prompt treatment may improve outcomes. In this systematic review, we aimed to summarize the acute and sub-acute ocular manifestations in pediatric patients with laboratory-confirmed COVID-19.
Methods: We included all online primary studies, with no language restriction and published between January 1, 2019 and November 18, 2020, reporting any acute or sub-acute ocular manifestations in children with laboratory-confirmed COVID-19. PubMed/MEDLINE was searched using the following MeSH and Emtree terms: “eye,” “ophthalmologic,” “ocular,” “vision,” “conjunctivitis,” “severe acute respiratory syndrome coronavirus 2,” “SARS-CoV-2,” “corona,” “2019-nCoV,” “COVID19,” and “COVID.” The eligibility and quality of the selected records were assessed by two independent reviewers as per the Cochrane Handbook for Systematic Review.
Results: A total of 1,192 records were identified electronically. Seven papers were extracted from the reference lists of the eligible records. Thirty-six papers met the inclusion criteria and were categorized into two subgroups according to acute or sub-acute presentation of ocular manifestations. Among 463 pediatric patients with COVID-19, 72 (15.5%) had acute ocular manifestations. There was one patient with central retinal vein occlusion and another with photophobia and diplopia associated with meningoencephalitis. Among 895 pediatric patients with post-COVID-19 MIS-C, 469 (52.4%) had ocular manifestations, which only included non-purulent conjunctivitis.
Conclusions: Ocular manifestations have been reported in less than one-fifth of pediatric patients with acute COVID-19. Furthermore, conjunctivitis was the only ocular manifestation reported in half of the patients with MIS-C, and it may be missed easily due to its non-purulent nature. During the COVID-19 pandemic, pediatricians and health workers must remain vigilant for early detection of signs of this potentially fatal post-COVID-19 inflammatory syndrome.

Background: Cystoid macular edema (CME) is the leading cause of permanent visual impairment in patients with uveitis, particularly in patients with intermediate uveitis (IU). This study was aimed at comparing the changes in the macular microvasculature in patients with IU with uveitic non-responsive CME and without macular edema.
Methods: In this case-control study, 55 eyes of patients with IU were assessed for macular microvascular structures, including vascular density, foveal avascular zone (FAZ) measurement, and vascular morphological changes, using spectral-domain optical coherence tomography angiography (OCT-A) with the AngioVue OCT-A system. We divided patients into the following two groups: the case group, including 30 eyes with IU-related non-responsive CME, and the control group, including 25 eyes with IU without macular edema.
Results: Participants in the case and control groups had comparable age (P = 0.753) and sex (P = 0.124) distributions. Superficial capillary plexus vessel density in the case group was significantly decreased in the whole image (P = 0.027) and the parafoveal area (P  = 0.001) compared to the control group. However, there were no statistically significant differences between the two groups in terms of foveal superficial vessel density, deep capillary plexus vessel density, FAZ area, FAZ perimeter, FAZ acircularity index, or foveal vessel density in a 300-µm-wide annulus around the FAZ (all P > 0.05). Vascular morphological changes, such as the capillary tuft, telangiectatic vessels, or micro-aneurism, were not different in the overview images of the OCT-A printout between the two groups.
Conclusions: The mean superficial capillary plexus vessel density was lower in eyes with IU-related nonresponsive CME than in those without macular edema. We observed more cystoid spaces in SCP than in DCP. Microcystic changes in the inner retina and ischemia may be the underlying cause in eyes with nonresponsive CME. Future prospective longitudinal studies with healthy, matched controls are warranted to confirm our findings.

Background: Pediatric corneal transplantation can be indicated in congenital and acquired conditions. Challenges include preoperative evaluation, multiple intraoperative obstacles, and postoperative problems in follow-up and management. This study was aimed at identifying the indications and clinical outcomes of pediatric penetrating keratoplasty (PKP) in Jordan.
Methods: This retrospective cohort study was conducted in Amman, Jordan. Using the hospital’s electronic database, all medical records of patients aged < 18 years who underwent PKP between January 2004 and October 2019 were reviewed. Preoperative evaluations included best-corrected distance visual acuity (BCDVA) and anterior and posterior segment examinations. Postoperative complications, BCDVA, and graft survival were examined 1 year postoperatively.
Results: A total of 149 cases of pediatric PKP were performed on 141 eyes of 118 patients with an age mean ± standard deviation (SD) of 11.44 ± 4.97 years at the time of surgery. Acquired non-traumatic corneal pathologies accounted for 65.8% of indications for PKP. The most frequent indication was advanced keratoconus (55.7%). Preoperative and 1-year postoperative BCDVAs significantly differed (P < 0.001), with 111 (74.5%) patients showing improved BCDVA, 12 (8.05%) patients showing worsened BCDVA, and 26 (17.45%) patients showing no change in BCDVA. The overall 1-year graft survival rate was 80.54%.
Conclusions: This was the largest study in Jordan involving pediatric patients who underwent PKP for various indications, showing a significant improvement in BCDVA, with a high survival rate at 1 year. Future studies with longer follow-up periods could provide stronger evidence for surgical outcomes and graft survival. Further, the option of lamellar keratoplasty in the pediatric age group should be assessed.

Background: Macular edema (ME) is a vision-threatening condition that commonly develops as a consequence of ocular diseases, including age-related macular degeneration, retinal vaso-occlusion of the central retinal vein and its branches, diabetic retinopathy, central serous chorioretinopathy, uveitis, retinitis pigmentosa, pseudophakia, ocular trauma, and drug toxicity. The treatment of ME remains challenging, although steroids and vascular endothelial growth factor inhibitors are available. Cost-effective therapy using a noninvasive administration route is required. This study aimed at reviewing the role of carbonic anhydrase inhibitors (CAIs) in the management of ME.
Methods: A literature search was conducted using PubMed/MEDLINE and Google Scholar for studies from January 2000 to March 2022. The following keywords were used in various combinations: “macular edema”, “carbonic anhydrase”, “carbonic anhydrase inhibitors”, “acetazolamide”, “dorzolamide”, and “brinzolamide”.
Results: Articles with high or medium clinical relevance were selected for this  review. We found that multiple studies have demonstrated the relevance and efficacy rates of CAIs in the management of ME. Most published studies focused on acetazolamide and dorzolamide, with nearly all studies reporting therapeutic responses.
Conclusions: ME is the leading cause of vision loss and requires noninvasive and cost-effective pharmacotherapy. With progress in the understanding of ME, particularly the role of carbonic anhydrase as a key driver, CAIs are the focus of research. Further optimization of the choice of CAIs and retinal bioavailability, potentially with nanoparticle formulations, is required to enable the effective management of ME. Further research is warranted to address the therapeutic effects of CAIs in different formulations.

Letter to the editor

Background: Pars plana vitrectomy with implantation of an Ahmed glaucoma valve in the vitreous cavity has been reported with a success rate in the management of refractory and neovascular glaucoma. This study aimed to present the outcomes of pars plana Ahmed glaucoma valve (PPAV) surgical implantation in cases with refractory glaucoma.
Methods: In this single-center, retrospective, comparative study, 87 consecutive patients diagnosed with refractory glaucoma who underwent PPAV surgical implantation between October 2015 and October 2019 were evaluated. A successful postoperative outcome was defined as intraocular pressure (IOP) less than or equal to 21 mmHg upon examination and a reduction in the number of anti-glaucoma agents used at the last follow-up.
Results: Finally, 81 eyes of 78 patients with refractory glaucoma were included; 54 (66.66%) of the eyes had neovascular glaucoma. The mean follow-up was 20.65 ± 12.17 months (range: 2 to 52 months). The mean preoperative IOP was 40.01 ± 1.19 mmHg and reduced significantly to 16.73 ± 0.82 mmHg at the latest follow-up (P < 0.001); thus, a successful IOP outcome was achieved in 88.89% of eyes. The mean number of anti-glaucoma agents decreased significantly from 2.86 ± 0.09 preoperatively to 1.46 ± 0.11 at the latest follow-up (P < 0.001); while 61 (75.31%) of eyes had a reduction in the number of IOP lowering eye drops, and 14 (17.28%) had no need for IOP lowering eye drops.
Conclusions: PPAV surgery is a successful procedure for IOP reduction in patients with refractory glaucoma. Our study demonstrated either reduction or elimination of IOP lowering eye drops postoperatively. Large scale studies with a comparison group, a longer follow-up, and having various subtypes of glaucoma are required as future research to confirm these outcomes.