Medical hypothesis discovery and innovation in ophthalmology

Background: Vernal keratoconjunctivitis (VKC) is a bilateral, recurrent, chronic conjunctival inflammatory disease with seasonal exacerbations. This study aimed to assess the efficacy and safety of tacrolimus 0.03% eye ointment in the management of chronic VKC.
Methods: This was an open-label, prospective, non-randomized, comparative interventional study that enrolled 50 patients with chronic VKC, who were allocated to one of two groups. The first group was treated with tacrolimus 0.03% eye ointment twice daily for 2 months then once daily for 2 months, followed by once every other day for another 2 months. The control group was treated with standard anti-allergic drugs, topical fluorometholone 0.1% eye drops three times daily for 2 weeks and gradually tapered for another 2 weeks, with topical olopatadine 0.1% administered twice daily during the follow-up period. Disease severity was assessed using a four-point scale for symptoms and signs. Treatment efficacy was assessed by analyzing changes in symptoms and signs, and by clinical photography.
Results: Fifty patients with bilateral chronic VKC completed the follow-up. The mean (standard deviation) ages of the tacrolimus and control groups were comparable (16.20 [5.10] years versus 16.48 [4.19] years, P > 0.05). The most commonly reported symptom was itching, and the most common signs were papillary hypertrophy and conjunctival hyperemia. All symptoms and signs were significantly reduced after treatment in both groups. The tacrolimus group showed a more significant improvement at 3 and 6 months in the mean composite symptom score (both P < 0.05) and in the mean composite sign score (both P < 0.05). Regarding complications, one case of increased intraocular pressure occurred in the control group (4%) after 2 weeks of steroid treatment, while there were no complications in the tacrolimus group, except for some reports of stinging sensation, which was well tolerated.
Conclusions: Treatment of chronic bilateral VKC with tacrolimus 0.03% eye ointment is effective and safe. It could be considered an alternative treatment to reduce steroid-associated complications in patients with chronic VKC. Future double-blinded clinical trials with a longer follow-up period are necessary to confirm our findings and to determine the long-term safety of topical tacrolimus 0.03% ointment in VKC.

Background: Magnetic resonance imaging (MRI) has been used to investigate eye shapes; however, reports involving children are scarce. This study aimed to determine ocular dimensions, and their correlations with refractive error, using three-dimensional MRI in emmetropic versus myopic children.
Methods: Healthy school children aged < 10 years were invited to take part in this cross-sectional study. Refraction and best-corrected distance visual acuity (BCDVA) were determined using cycloplegic refraction and a logarithm of the minimum angle of resolution (logMAR) chart, respectively. All children underwent MRI using a 3-Tesla whole-body scanner. Quantitative eyeball measurements included the longitudinal axial length (LAL), horizontal width (HW), and vertical height (VH) along the cardinal axes. Correlation analysis was used to determine the association between the level of refractive error and the eyeball dimensions.
Results: A total of 70 eyes from 70 children (35 male, 35 female) with a mean (standard deviation [SD]) age of 8.38 (0.49) years were included and analyzed. Mean (SD) refraction (spherical equivalent, SEQ) and BCDVA were -2.55 (1.45) D and -0.01 (0.06) logMAR, respectively. Ocular dimensions were greater in myopes than in emmetropes (all P < 0.05), with no significant differences according to sex. Mean (SD) ocular dimensions were LAL 24.07 (0.91) mm, HW 23.41 (0.82) mm, and VH 23.70 (0.88) mm for myopes, and LAL 22.69 (0.55) mm, HW 22.65 (0.63) mm, and VH 22.94 (0.69) mm for emmetropes. Significant correlations were noted between SEQ and ocular dimensions, with a greater change in LAL (0.46 mm/D, P < 0.001) than in VH (0.27 mm/D, P < 0.001) and HW (0.22 mm/D, P = 0.001).
Conclusions: Myopic eyeballs are larger than those with emmetropia. The eyeball elongates as myopia increases, with the greatest change in LAL, the least in HW, and an intermediate change in VH. These changes manifest in both sexes at a young age and low level of myopia. These data may serve as a reference for monitoring the development of refractive error in young Malaysian children of Chinese origin.

Background: Neovascular age-related macular degeneration (nAMD) is one of the main causes of blindness in developed countries. Complement factor H (CFH) is one of the genes involved in the pathogenesis of nAMD. This study investigated the rs10737680 polymorphism in CFH and its conferred susceptibility to nAMD in Yogyakarta, Indonesia.
Methods: This case-control hospital-based study recruited participants consisting of 96 patients with nAMD and 101 controls without nAMD from the Eye Polyclinic of Sardjito Hospital, YAP Eye Hospital, and Hardjolukito Hospital Yogyakarta. nAMD was diagnosed when fundus examination, fundus photographs, and optical coherence tomography revealed hard or soft drusen in the macular area measuring > 63 µm that appeared below the retinal pigment epithelium, with or without macular hypo- or hyperpigmentation, and was accompanied by choroidal neovascularization. Genomic DNA was extracted using a commercial DNA isolation kit. The restriction fragment length polymorphism technique was used to identify the rs10737680 polymorphism in CFH.
Results: The mean (standard deviation [SD]) age of the nAMD group was not homogeneous with that of the control group (P < 0.05); 65.41 (9.74) years versus 68.24 (7.82) years. The number of patients with hypertension in the nAMD group was significantly higher than in the control group (P < 0.05). In the nAMD group, the genotype distribution indicated homozygous risk allele in 34.38%, heterozygous risk allele in 57.29%, and homozygous non-risk allele in 8.33%. In the control group, the genotype distribution indicated homozygous risk allele in 21.78%, heterozygous risk allele in 36.63%, and homozygous non-risk allele in 41.58%. Statistical analysis between the two study groups according to homozygous risk allele genotype (odds ratio [OR], 7.87; 95% confidence interval [CI], 2.88–22.79) and heterozygous genotype (OR, 7.80; 95% CI, 3.11–21.19) showed a significant difference (both P < 0.01).
Conclusions: Homozygous risk allele was less frequent than heterogeneous risk allele in patients with nAMD; however, both increased the risk for nAMD. Although the homozygous or heterozygous risk-alleles were detected in most patients, yet other important genetic or environmental factors could be involved in the pathogenesis of nAMD. Overall, we found a significant association between rs10737680 polymorphism in CFH and the susceptibility to nAMD in Yogyakarta, Indonesia; however, future studies are needed to fully delineate the mechanism.

Background: Retinopathy of prematurity (ROP) is a leading cause of irreversible blindness in infants. The Postnatal Growth and ROP (G-ROP) study proposed new screening criteria for ROP. This study aimed to validate the G-ROP screening criteria in a group of Iranian premature infants who were treated in the neonatal intensive care unit (NICU) for at least 40 days.
Methods: In this retrospective study, we extracted the data pertaining to infants admitted to the NICU from January 2020 to December 2021. We screened all the included infants for ROP based on the Iranian national screening criteria. We applied the G-ROP criteria to our study population, and if no criterion was met, the infant was exempted from ROP screening. We determined the sensitivity and specificity of the G-ROP guidelines for ROP detection, along with its capacity for predicting the requirement for ROP treatment. Moreover, we compared the G-ROP guidelines with the Iranian and North American guidelines for ROP screening.
Results: A total of 166 premature infants with complete datasets were included: 130 had ROP, of whom 61 were treated. There were 109 female infants (65.7%). The mean (standard deviation [SD]) birth weight and gestational age were 1080 (256) g and 28.28 (1.97) weeks, respectively. Applying the G-ROP criteria, 127 of 130 infants with ROP were identified (sensitivity, 97.69%; 95% confidence interval [CI], 95.11% – 100%), and of 36 infants without ROP, three were correctly excluded (specificity, 8.33%; 95% CI, 0% – 17.36%). The G-ROP criteria did not fail to identify infants who required treatment for ROP (sensitivity, 100%; 95% CI, 98.29 – 100) and had a specificity of 8.69% (95% CI, 2.04% – 15.34%). Although the Iranian and North American criteria had 100% sensitivity for infants with any stage of ROP, they could not detect infants without ROP (0% specificity).
Conclusions: The G-ROP screening criteria had a sensitivity of 100% in identifying infants requiring treatment for ROP in our high-risk group; however, specificity was not sufficiently high. Further studies with larger numbers of referred infants could confirm a decrease in the burden of retinal examinations using these criteria.

Background: Corneal endothelial cell (CEC) loss in glaucoma can be attributed to the direct compressive effect of elevated intraocular pressure. Herein, we aimed to evaluate specular microscopic changes in CEC count and morphology in correlation to retinal nerve fiber layer (RNFL) changes detected by spectral-domain optical coherence tomography (SD-OCT) in early and advanced primary open-angle glaucoma (POAG).
Methods: This descriptive-analytical study involved patients with medically controlled POAG versus non-glaucomatous patients of the same age group. Specular microscopy, visual field testing, and SD-OCT of the RNFL and macular ganglion cell complex (GCC) were performed. Eyes with POAG were further subcategorized into early and advanced stages.
Results: The study included 130 eyes of 130 participants; 70 were eyes with POAG (40 eyes with early-stage POAG, 30 eyes with advanced-stage POAG), and 60 were healthy eyes. The groups were comparable regarding mean age and sex. No significant difference was found in corneal parameters between healthy eyes, eyes with early POAG, and eyes with advanced POAG (all P > 0.05). In eyes with early-stage POAG, a significant negative correlation was found between the coefficient of variation (CV) and superior RNFL thickness (r = - 0.5; P = 0.018), and between the percentage of hexagonal cells (hexagonality) and vertical cup-to-disc ratio (r = - 0.43; P = 0.035). A significant positive correlation was found between hexagonality and superior as well as inferior RNFL thickness (r = + 0.53; P = 0.008 and r = + 0.50; P = 0.015, respectively). However, in the advanced glaucomatous eyes, no significant correlation was found between RNFL thickness and CEC parameters.
Conclusions: CEC parameters were not affected in eyes with early or advanced POAG compared with healthy eyes, despite a significant thinning of RNFL and macular GCC. In eyes with early-stage POAG, a significant correlation was found between morphological characteristics of CECs, such as CV and hexagonality, with superior and inferior RNFL thickness in the optic nerve head on SD-OCT images. Future longitudinal studies with larger sample sizes are needed to verify our results.

Letter to the editor
KEYWORDS: monkey pox, vaccinations, transmission, communicable disease, primary healthcare, conjunctivitides, blepharitides