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Objective: We aimed to evaluate anatomical and functional outcomes and determine posterior scleral contraction (PSC) timing in treating myopic traction maculopathy (MTM)., Methods: This is a retrospective study of MTM patients undergoing PSC with genipin cross-linked strip at a single hospital site. Differences in demographic and clinical characteristics were compared among three groups defined by the MTM staging system. All patients were followed up for at least one year postoperatively. The best-corrected visual acuity (BCVA), macular hole diameter, axial length (AL), optical coherence tomography findings, and the complications were evaluated. Additionally, regression analyses were performed to account for confounders., Results: Sixty-one MTM patients (24 eyes at stage 2, 22 eyes at stage 3, and 18 eyes at stage 4) were included. The macular holes were closed in 16 eyes (66.7%), 13 eyes (59.0%), and 11 eyes (61.1%) at stage 2, stage 3, and stage 4, respectively. PSC improved the BCVA in patients at each stage (all P < 0.05). Postoperative BCVA at stage 2 was significantly better than that at stage 4 ( P = 0.0069). Preoperative BCVA was associated with postoperative BCVA ( P < 0.001). Preoperative AL (OR 0.676, 95% CI 0.480 to 0.951, P = 0.025), AL shortening amount (OR 5.129, 95% CI 1.974 to 13.327, P = 0.001) and macular hole diameter (OR 1.003, 95% CI 1.000 to 1.006, P = 0.030) were associated with macular hole closure., Conclusions: PSC is safe and effective in treating MTM at different stages. Early PSC intervention will have more significant visual benefits., Competing Interests: None., (AJTR Copyright © 2022.)

It is controversial that retina and photoreceptors are involved in amblyopic development. Lack of imaging devices for quantitative assessment of photoreceptors in vivo impedes further investigation. In this study we investigated the differences of macular thickness, outer nuclear layer (ONL) thickness and cone density among eyes with unilateral anisometropic amblyopia, amblyopic fellow eyes, and normal control eyes using high-definition spectral-domain optical coherence tomography and adaptive optics imaging system. Thicker fovea and parafovea with characteristic quantitative retinal changes in unilateral amblyopic patients indicated that the amblyopic process might involve the retina. Cones tended to be homogeneously distributed at 1.5° from the foveal center in all participants. However, we did not detect any significant differences in cone density and ONL thickness at 1.5° from the foveal center in patients with unilateral amblyopia when compared with the fellow eyes and the normal control eyes. This is the first study to explore whether photoreceptors are involved in amblyopic development in vivo that would help for understanding the underlying mechanisms of amblyopia. Whether macular changes relate to cone photoreceptors migration of the amblyopic eyes remains to be determined., Competing Interests: None.

Objective: To investigate the clinical effectiveness and safety of posterior scleral contraction (PSC) surgery in controlling high myopia in young people., Methods: Twenty patients with high myopia (30 eyes) were treated with PSC. The average age for the patients was 11.45 ± 5.17 years old (range 3-22). A genipin cross-linked sclera was implanted to the posterior sclera in PSC surgery. Axial length and myopia progression rates were measured at least two years before and after PSC surgery., Results: Prior to surgery, the mean AL progression was 0.73 ± 0.33 mm, compared to -0.08 ± 0.31 mm (P=0.00) post-surgery; the degree of myopia increased was -1.40 ± 0.95 D, compared to 0.18 ± 1.10 D post-surgery (P=0.00). The best corrected visual acuity (BCVA, in LogMAR) improved from 0.21 ± 0.16 preoperatively to 0.13 ± 0.13 two years after PSC (P=0.014)., Conclusions: PSC can restrict AL extension and safely control high myopia progression in young people., Competing Interests: None.

Objective: To study the effects of posterior chamber phakic intraocular lens (IOL) on axial length (AL) measurements and whether a correction factor for later IOL power calculation before cataract surgery is necessary., Methods: Twenty-two high myopic patients (39 eyes) with mean spherical equivalent -19.00 +/- 4.03 D received phakic refractive lens (PRL) implantation, and 24 patients (40 eyes) with mean spherical equivalent (-13.10 +/- 2.53) D received implantable Collamer lens (ICL) implantation. Pre-and postoperative AL measurements with the IOLMaster were compared. Results The pre-and postoperative ALs were (30.87 +/- 2.18) mm and (30.94 +/- 2.16) mm, respectively (t = -2.635, P = 0.012) in the PRL group, and (28.35 +/- 1.20) mm and (28.45 +/- 1.22) mm, respectively ( t = -3.97, P < 0.001) in the ICL group. Linear regression analysis showed: in the PRL group, preoperative AL = 1.01 x postoperative AL-0.24 (R2 = 0.99, P < 0.001), or postoperative AL--preoperative AL = 0.24-0.0055 x postoperative AL; in the ICL group, preoperative AL = 0.96 x postoperative AL +1.17 (R2 = 0.99, P < 0.001), or postoperative AL--preoperative AL = 0.0154 x postoperative AL -0.3763. The mean differences between pre-and postoperative ALs in the PRL and, ICL groups were 0.075 mm and 0.054 mm, respectively., Conclusions: Based on the SRK formula, a < 0.1 mm AL difference would result in a <0.25 D change in the calculated IOL power, possibly a < 0.20 D change in manifest refraction. Furthermore, for PRL, the longer the AL, the smaller the difference between pre-and postoperative ALs. These differences are so small that it is unnecessary to correct IOL power calculation.

Purpose: The adenosine A(2A) receptor (A(2A)R) modulates collagen synthesis and extracellular matrix production in ocular tissues that contribute to eye growth and the development of myopia. We aimed to determine if single nucleotide polymorphisms (SNPs) in A(2A)R exons associates with high myopia found in Chinese subjects., Methods: DNA samples were prepared from venous lymphocytes of 175 Chinese subjects with high myopia of less than -8.00 diopters (D) correction and 101 ethnically similar controls with between -1.00 D and +1.00 D correction. The coding region sequences of A(2A)R were amplified by PCR and analyzed by Sanger sequencing. The detected variations were confirmed by reverse sequencing. Allelic frequencies of all detected common SNPs were assessed for Hardy-Weinberg equilibrium., Results: Five variations in A(2A)R exons, 5675 A>G, 5765 C>T, 13325 G>A, 13448 C>T, and 14000 T>A, were detected in controls at a low frequency (<1%). However, one SNP, 13772 T>C (rs5751876), showed its polymorphism in 53.3% of the total study population. The rs5751876 is a synonymous substitution located in a tyrosine codon of exon 2. Despite no significant difference in genotype distribution between cases and controls, the frequency of heterozygotes with the rs5751876 genotype was significantly lower in subjects with high myopia., Conclusions: The reduced frequency of the heterozygote rs5751876 genotype in subjects suggests a possible association of A(2A)R with high myopia in a Chinese population.

Purpose: BH3-like motif containing, cell death inducer (BLID) and LOC399959 are two genes associated with the single nucleotide polymorphism (SNP) rs577948, which is a susceptibility locus for high myopia in Japanese subjects. The purpose of this study was to determine if BLID and LOC399959 are associated with high myopia in Chinese Han subjects., Methods: High myopia subjects (n=476) had a spherical refractive error of less than -6.00 D in at least one eye and/or an axial length greater than 26 mm. Genomic DNA was extracted and genotyped from peripheral blood leukocytes of high myopes and controls (n=275). Using a case-control association study of candidate regions, linkage disequilibrium blocks for 19 tag SNPs (tSNPs), including rs577948, harbored within and surrounding the BLID and LOC399959 genes were analyzed on a MassArray platform using iPlex chemistry. Each of the tSNPs had an r(2)>0.8 and minor allele frequency >10% in the Chinese Han population. Haplotype association analysis was performed on Haploview 4.1 using Chi-square (χ(2)) tests., Results: None of the 19 tSNPs were statistically associated with high myopia., Conclusions: While rs577948 may be associated with high myopia in Japanese subjects, it and the other tSNPs near the BLID and LOC399959 genes are not susceptibility loci for high myopia in the Chinese Han population. Thus, associations of SNPs with high myopia as determined by Genome-Wide Association Study (GWAS) may be restricted to certain ethnic or genetically distinct populations. Without systematic replication in other populations, the results of GWAS associations should be interpreted with great caution.

Purpose: High myopia or pathological myopia is a common refractive error. Individuals with high myopia are subject to increased risk of serious eye complications. Accumulating evidence has demonstrated the role for heritability in ocular growth and in the development of high myopia. Retinoic acid and retinoic acid receptors play important roles in ocular development and in experimentally induced myopia. The purpose of this study was to determine if high myopia is associated with single nucleotide polymorphism (SNP) variants in the retinoic acid receptor beta (RARbeta) gene in Chinese subjects., Methods: DNA samples were purified from venous lymphocytes of 175 unrelated Chinese patients with high myopia (less than -8.00 diopters) and 101 Chinese control subjects without high myopia (+/-1.00 diopters). Direct nucleotide sequence analysis in the RARbeta gene was performed, and the detected variations were further confirmed by reverse sequencing. Allelic frequencies of all detected SNPs were assessed for Hardy-Weinberg equilibrium., Results: Five variations in RARbeta were detected in Chinese subjects with high myopia, including 32574G>A, 32629G>A, 32645C>T, 32647T>G, and 151973C>T, of which only 32647T>G (NCBI notes as rs58244688 and rs2067964) had already been reported. The majority of SNP genotypes were heterozygous. While 32647T>G, 32629G>A, and 32645C>T were located in introns and 32574G>A and 151973C>T were located in coding regions, none of the SNPs affected the amino acid sequence. In the present study, no evidence of association was found between variations in the nucleotide sequence of RARbeta and high myopia., Conclusions: Five SNP variants in RARbeta were detected in Chinese subjects with high myopia, none of them were associated significantly with high myopia. Further studies are needed to identify which genes are responsible for high myopia.

Purpose: To evaluate the effects of angle-supported, iris-fixated and posterior chamber phakic intraocular lens (PIOL) implantation on contrast sensitivity (CS)., Methods: This prospective study included 69 eyes of 41 consecutive cases of high myopia which received an angle-supported (Phakic-6H; 26 eyes), iris-fixated (Verisyse; 23 eyes) or posterior chamber PIOL [phakic refractive lens (PRL); 20 eyes]. Photopic, mesopic and mesopic with glare CS were evaluated preoperatively and at least 6 months postoperatively., Results: In the PRL group, the mean postoperative CS at all frequencies and across all lighting conditions increased. These changes were significant for 6, 12 and 18 cycles per degree (cpd) under both photopic and mesopic conditions (p < 0.01) and for all the tested frequencies under mesopic with glare condition (p < or = 0.01). The average CS was relatively low in the PRL group. These changes were significant for 6 and 12 cpd between the Verisyse and PRL group under photopic condition (p < 0.05), for 3 and 6 cpd under mesopic condition (p < 0.01, p = 0.01) and under mesopic with glare condition (p < 0.01, p < 0.05)., Conclusions: Improvements in postoperative CS confirm that PIOL implantation is a promising alternative for correction of high myopia. In comparison to posterior chamber PIOLs, angle-supported and iris-fixated PIOLs seem to produce a better visual quality in terms of CS, which needs to be warranted by further investigations., ((c) 2007 S. Karger AG, Basel.)