Evaluation of retinal microvasculature in exotropia with abnormal binocular vision by optical coherence tomography angiography.

BACKGROUND: To explore the retinal microvasculature in large-angle concomitant exotropia patients with abnormal binocular vision using optical coherence tomography angiography (OCTA) analysis. METHODS: OCTA images of 52 healthy and 100 strabismic eyes were analyzed to quantify the retinal thickness (RT), superficial capillary plexus (SCP), deep capillary plexus (DCP), and foveal avascular zone (FAZ). Paired t-tests were performed to compare differences between the two groups, the dominant eye and the deviated eye in the exotropia group, respectively. A p-value < 0.01 was considered significant. RESULTS: The mean angle of deviation was 79.38 [± 25.64] (prism diopters, PD). There were significant differences in the DCP in deviated eyes between the exotropia group and the control group (fovea: p = 0.007; temporal: p = 0.014; nasal: p = 0.028; inferior: p = 0.013). The temporal SCP in the exotropia group was significantly higher than in the control group in deviated eyes (p = 0.020). No significant difference was found between dominant eyes and strabismic eyes (p > 0.01). CONCLUSIONS: The study showed that OCTA revealed subnormal DCP in patients with large-angle exotropia and abnormal binocularity which may be related to retinal suppression. Changes in the macular microvasculature may provide valuable insights into the development of strabismus. Further studies are needed to determine the clinical relevance of this finding. TRIAL REGISTRATION: This trial is registered as ChiCTR2100052577 at www.Chictr.org.cn .

Kearns-Sayre syndrome with a novel large-scale deletion: a case report.

BACKGROUND: Kearns-Sayre syndrome (KSS) is a rare, multisystem mitochondrial encephalomyopathy. We report a case of KSS with a novel 7.6-kb deletion as assessed through a long-range polymerase chain reaction (PCR) study in the blood. In addition, optical coherence tomography angiography (OCTA) confirmed deep retinal capillary atrophy for the first time. CASE PRESENTATION: A 13-year-old patient presented with progressive vision loss and difficulty with eye opening and was diagnosed with progressive external ophthalmoplegia and retinitis pigmentosa (RP). The patient also experienced heart block, vestibular dysfunction, growth retardation and multiple demyelinating lesions. A long-range PCR study in the blood revealed a large-scale Chrm: 6341-13,993 deletion, which was first reported and broadened the genetic spectrum of this disease. The patient underwent complete ophthalmic examination, medical history review and gene detection, resulting in a confirmation of the diagnosis of KSS. The patient was given a pair of applicable glasses to wear and was followed up every 3 months. An implantable pacemaker was also installed based on the advice of the physician. CONCLUSIONS: We reported a novel large-scale deletion in the mitochondrial DNA of KSS, and OCTA was used for the first time to confirm deep retinal capillary atrophy. Furthermore, because ophthalmic symptoms are often the primary manifestation of KSS, the relationship between ophthalmology and mitochondrial diseases should be emphasised.

Effect of bilateral inferior oblique partial myectomy on V pattern exotropia with inferior oblique overaction.

PURPOSE: To compare the effect of bilateral inferior oblique partial myectomy on V-pattern exotropia patients with bilateral symmetric inferior oblique overaction (IOOA) and asymmetric IOOA. METHODS: This was a retrospective study including 53 V-pattern exotropia patients with bilateral IOOA of all grades who underwent bilateral inferior oblique partial myectomy. Success was defined as the elimination of the IOOA and the collapse of the V pattern at the final follow-up. The fovea-disc angle (FDA) and V-pattern exotropia were compared before and after surgery. RESULTS: This study included 53 V-pattern exotropia patients, containing 29 patients with symmetric IOOA (Group I) and 24 patients with asymmetric IOOA (Group II). The last follow-up ranged from 3 to 16 months (mean of 5 months). After myectomy, 3 eyes in Group I and 2 eyes in Group II were observed with residual grade 1 IOOA. The surgical success rates of IOOA correction in Group I and Group II were 96% and 95%, respectively. The difference was not statistically significant (P = 0.808). V-pattern exotropia collapsed with residual 2 (min. 0, max. 6) PD for Group I and 2 (min. 0, max. 10) PD for Group II, and there was a statistically significant difference between pre- and postoperative V-pattern exotropia in the two groups (P = 0.000). No inferior oblique (IO) underaction or antielevation syndrome (AES) was found in either group. The average preoperative FDA of the right eye and the left eye was (8.93 ± 4.34)° and (10.86 ± 4.27)° in Group I and (9.08 ± 4.92)° and (11.00 ± 5.69)° in Group II. There was a significant difference in preoperative FDA between the right eye and the left eye in the two groups (Group I p = 0.029; Group II p = 0.038). CONCLUSIONS: Bilateral inferior oblique partial myectomy can bring "symmetric" effectiveness in the correction of IOOA and FDA. It can potentially be used as a safe and successful treatment for V-pattern exotropia with bilateral IOOA. In addition, the FDA may be a promising index for evaluating fundus extorsion.

Most nonpathological eyes present a small area of hyperreflective Henle's fiber layer on pupil-centered optical coherence tomography.

PURPOSE: Henle's fiber layer (HFL) is hyporeflective and indistinct on pupil-centered optical coherence tomography (OCT). However, a small area of HFL is also found to be hyperreflective on pupil-centered OCT. This study characterized the hyperreflective HFL of healthy eyes on pupil-centered OCT and investigated the possible physiological and functional relationship of hyperreflective HFL. METHODS: Subjects with different degrees of ametropia underwent a complete ophthalmologic examination, including binocular function by synoptophore and Titmus test, ocular axial length, refractions, and pupil-centered OCT angiography coupled with OCT. The area of hyperreflective HFL was manually plotted and calculated using the Optovue AngioVue system technology. The possible ocular physiological and functional relationship with the area of hyperreflective HFL was investigated. RESULTS: A total of 111 subjects (222 eyes) without other ocular diseases were enrolled, of which 164 eyes (74%) presented hyperreflective HFL. The average area of hyperreflective HFL was 0.71 ± 0.07 mm2. The area of hyperreflective HFL was significantly related to spherical diopters (P = 0.032). The average binocular area of hyperreflective HFL was 1.38 ± 0.17 mm2. The binocular area of hyperreflective HFL was significantly related to the angle of superposition and far stereoacuity (P = 0.013 and 0.038, respectively). CONCLUSION: Most healthy eyes present a small area of hyperreflective HFL, which might be due to alternation of the orientation of some Henle fibers by ametropia during the development of visual function postpartum. The small area of hyperreflective HFL may serve as a marker in identifying the boundary of HFL on OCT.

RNA sequence analysis identified bone morphogenetic protein-2 (BMP2) as a biomarker underlying form deprivation myopia.

Purpose: Form deprivation myopia (FDM) is an urgent public issue characterized by pathological changes, but the underlying mechanism remained unclear. The aim was to investigate bone morphogenetic proteins (BMPs) utilizing the pathogenesis of FDM. Material and methods: Gene expression omnibus (GEO) database was used to analyze one mRNA profile (GSE89325) of FDM. Sixteen retina samples (8 FDM and 8 controls) were randomly divided into seven groups for differential gene expression analysis in R. software. The gene pathway and protein-protein interaction (PPI) analysis were performed by the DAVID and STRING databases. Cytoscape was used to draw the PPI network. The gene ontology (GO) enrichment and Kyoto encyclopedia of genes and Genomes (KEGG) analysis were determined to achieve gene annotation and visualization. Results: A total of 18420 differentially expressed genes (DEGs) were identified associated with FDM. The only non-significant gene (BEND6) was separately analyzed between two groups. Thirteen hub genes were discovered, ACVR1, ACVR2A, ACVR2B, RGMB, BMPR2, BMPR1A, BMP2, BMPR1B, CHRD, PTH, PTH1R, PTHLH, and WNT9A. The expression alteration in FDM were mainly enriched in cytokine-cytokine, and neuroactive ligand receptor interaction pathways. BMP2 was the key gene in myopia progression. Conclusions: Of clinical perspective, our findings reveal that expression of BMP2 as an underlying mechanism of FDM, providing an insight for therapeutic interventions.

Efficacy and Adverse Effects of Atropine for Myopia Control in Children: A Meta-Analysis of Randomised Controlled Trials.

OBJECTIVES: To explore the rebound effects and safety of atropine on accommodation amplitude in slowing myopia progression. METHODS: We conducted a meta-analysis to testify proper dosage of atropine in children with myopia. We searched in PubMed, EMBASE, Ovid, and the Cochrane Library up to March 30, 2021. We selected randomised controlled trials (RCTs) that evaluated the efficacy of atropine for controlling myopia progression in children. We performed the inverse variance random-effects model to pool the data using mean difference (MD) for continuous variables. Statistical heterogeneity was assessed using the I2 test. Additionally, we conducted subgroup analyses and sensitivity analyses. RESULTS: Seventeen RCTs involving 2955 participants were included. Myopia progression was significantly less in the atropine group than that of the control group, with MD = 0.38 D per year (95% confidence interval, 0.20 to 0.56). Less axial elongation was shown with MD = -0.19 mm per year (95% CI, -0.25 to -0.12). There was a statistically difference among various doses (p=0.00001). In addition, 1.0% atropine showed the rebound effect with MD = -0.54 D per year (95% CI, -0.81 to -0.26) and was more effective in the latter six months than in the former one. Less accommodation amplitude was shown in 0.01% atropine. CONCLUSION: The efficacy of atropine is dose dependent, and 0.01% atropine may be the optimal dose in slowing myopia progression in children with no accommodation dysfunction. A rebound effect is more prominent in high-dose atropine in the former cessation after discontinuation.

Vessel Density and Retinal Thickness from Optical Coherence Tomography Angiography as New Indexes in Adolescent Myopia.

PURPOSE: To evaluate and quantify blood perfusion and retinal thickness (RT) from the perspective of quadrants by optical coherence tomography angiography (OCTA) in adolescents with myopia and explore the relationship between axial elongation and related indexes of OCTA. METHODS: A total of 88 subjects (149 eyes) with different degrees of myopia were included in this cross-sectional study. Vessel density (VD) and RT of quadrants in macular and peripheral regions were measured through OCTA. RESULTS: The superficial VD (SVD) of the parainferior region was significantly correlated with axial length (AL) between the emmetropia (EM) group and high myopia (HI) group (P=0.012). There were significant differences in deep VD (DVD) in all quadrants, except for the foveal, perifoveal, and peri-inferior regions (P > 0.05). However, there were significant alterations in the whole, parainferior, and perinasal regions (P=0.030, 0.023, and 0.035) in the low-to-moderate myopia (L-M) group compared with those in the HI group. There were significant differences in the RT in all quadrants, except for the foveal, paratemporal, and paranasal regions (P > 0.05) between the EM and L-M groups and the foveal region (P > 0.05) between the EM and HI groups. Nevertheless, only RT in the peri-inferior region of the L-M and HI groups showed significant differences. AL was negatively correlated with SVD in the perifoveal and parainferior regions (r = -0.179, P=0.029; r = -0.227, P=0.005) and inversely correlated with DVD and RT in almost all quadrants, except for the foveal region (r = -0.020, P=0.811; r = 0.135, P=1.000). CONCLUSION: DVD and RT were closely associated with the severity of myopia and might be new indexes in assessing and detecting myopia development via OCTA.

Comparison between binocular therapy and patching for treatment of amblyopia: a meta-analysis of randomised controlled trials.

Several studies have compared binocular therapy and patching for the treatment of amblyopia. However, most of them involved a small number of cases and reported controversial results. Thus, the benefit of binocular therapy remains to be confirmed. We conducted a meta-analysis to evaluate the efficacy of binocular therapy versus patching and to testify whether binocular therapy could become supplementary method in children with amblyopia. Randomised controlled trials that evaluated the efficacy of binocular therapy for amblyopia versus patching were identified using PubMed, Embase, Cochrane Library, Ovid, Web of Science, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform. Data screening, extraction and quality assessment were performed independently by two researchers. Six trials were identified and analysed to compare binocular therapy (708 eyes) with patching (664 eyes) for change in best-corrected visual acuity and stereoacuity. Efficacy estimates were evaluated by standard mean difference (SMD) and 95% CI. The best-corrected visual acuity in binocular group was better than that of in patching group (SMD=-0.21 logarithm of the minimum angle of resolution (log MAR), 95% CI of -0.50 to 0.08 log MAR, p=0.003). The results showed statistically significant difference in the change of best-corrected visual acuity between the groups, but not in stereoacuity. Binocular therapy may be a promising treatment of conditions affecting visual acuity, and could be applied as a supplementary method to patching for amblyopia in clinical practice. The present analysis showed that some children with amblyopia may benefit from binocular therapy. Nevertheless, larger randomised controlled clinical trials are required to confirm these findings.

Effects of Cigarette Smoking on Retinal and Choroidal Thickness: A Systematic Review and Meta-Analysis.

BACKGROUND: Cigarette smoking has been regarded as a risk factor for the incidence of a wide variety of chronic illness; however, its effect on thickness of the retina or choroid is still unknown. METHODS: A consummate literature search was conducted in PubMed and Embase up to January, 2018. The quantitative synthesis was conducted by Stata 12.0. RESULTS: A total of 13 observational studies were included in this meta-analysis. In this meta-analysis of all available observational studies, no significant effect of tobacco smoking on retinal or choroidal thickness change was detected. However, advanced analyses showed that smoking would influence the thickness of RNFL (average: SMD, -0.332; 95% CI, -0.637 to -0.027; inferior: SMD, -0.632; 95% CI, -1.092 to -0.172; and superior: SMD, -0.720; 95% CI, -0.977 to -0.463) and GCL (superior: SMD, -0.549; 95% CI, -0.884 to -0.215; inferior: SMD, -0.602; 95% CI, -0.938 to -0.265). Meanwhile, subgroup analyses demonstrated that the results based on studies in some regions (America and Africa) and cross-sectional studies showed a reduced choroidal thickness in smokers. No publication bias was detected in this study. CONCLUSION: In conclusion, no significant effect of tobacco smoking on retinal or choroidal thickness change was detected. However, smoking would influence the thickness of RNFL and GCL. Future research on this field would help in the prevention and treatment of smoking-associated disorders.

Involvement of dysregulated coding and long non­coding RNAs in the pathogenesis of strabismus.

Strabismus is a common ocular disorder in children and may result in exterior abnormalities and impaired visual functions. However, the detailed pathogenesis of strabismus unclear. The present study assessed the comprehensive analyses on the roles of RNAs in the development of strabismus. The public datasets of strabismus and the corresponding control tissues were downloaded from the Gene Expression Omnibus (GEO). Reannotations of the dysregulated coding and long non­coding RNAs (lncRNAs) and functional enrichments of the differently expressed genes (DEGs) were conducted. A total of 790 DEGs were screened (648 upregulated and 142 downregulated) in the present study. Among the DEGs, a total of 32 differently expressed lncRNAs were detected (14 upregulated and 18 downregulated). When the Gene Ontology (GO) enrichment was considered, it was identified that a total of 143 GO terms (82 for biological process, 31 for cellular component and 30 for molecular function) were identified. Among all the 57 detected Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, the phagosome pathway, which was labeled as hsa004145, demonstrated the most bioinformatics importance. However, most lncRNAs, except LINC01279 and LOC643733, indicated <3 target mRNAs and were not suitable for advanced bioinformatics analyses. Bioinformatics analyses demonstrated that there was a GO term for each lncRNA (proteinaceous extracellular for LINC01279 and cell surface for LOC643733). In conclusion, a set of coding RNA as well as lncRNAs differentially expressed in strabismus EOM samples were indicated. Notably, the present findings important information for advanced pathogenesis research and biomarkers detection.