Genome-Wide Association Study in Asians Identifies Novel Loci for High Myopia and Highlights a Nervous System Role in Its Pathogenesis.

PURPOSE: To identify novel susceptibility loci for high myopia. DESIGN: Genome-wide association study (GWAS) followed by replication and meta-analysis. PARTICIPANTS: A total of 14 096 samples from East and Southeast Asian populations (2549 patients with high myopia and 11 547 healthy controls). METHODS: We performed a GWAS in 3269 Japanese individuals (1668 with high myopia and 1601 control participants), followed by replication analysis in a total of 10 827 additional samples (881 with high myopia and 9946 control participants) from Japan, Singapore, and Taiwan. To confirm the biological role of the identified loci in the pathogenesis of high myopia, we performed functional annotation and Gene Ontology (GO) analyses. MAIN OUTCOME MEASURES: We evaluated the association of single nucleotide polymorphisms with high myopia and GO terms enriched among genes identified in the current study. RESULTS: We identified 9 loci with genome-wide significance (P < 5.0 × 10-8). Three loci were previously reported myopia-related loci (ZC3H11B on 1q41, GJD2 on 15q14, and RASGRF1 on 15q25.1), and the other 6 were novel (HIVEP3 on 1p34.2, NFASC/CNTN2 on 1q32.1, CNTN4/CNTN6 on 3p26.3, FRMD4B on 3p14.1, LINC02418 on 12q24.33, and AKAP13 on 15q25.3). The GO analysis revealed a significant role of the nervous system related to synaptic signaling, neuronal development, and Ras/Rho signaling in the pathogenesis of high myopia. CONCLUSIONS: The current study identified 6 novel loci associated with high myopia and demonstrated an important role of the nervous system in the disease pathogenesis. Our findings give new insight into the genetic factors underlying myopia, including high myopia, by connecting previous findings and allowing for a clarified interpretation of the cause and pathophysiologic features of myopia at the molecular level.

Pars plana vitrectomy combined with penetrating keratoplasty and transscleral-sutured intraocular lens implantation in complex eyes: a case series.

BACKGROUND: The aim of this study was to evaluate the clinical outcomes of pars plana vitrectomy (PPV) combined with penetrating keratoplasty (PKP) and transscleral-sutured intraocular lens (IOL) implantation (IOL-suture) in complex eyes. METHODS: In this prospective, consecutive interventional case series, patients who underwent PKP combined with PPV and IOL implantation from July 2014 to March 2018 at Yokohama Minami Kyosai Hospital were enrolled. The postoperative best corrected visual acuity (BCVA) (converted to logarithm of the minimal angle of resolution [logMAR] units), intraocular pressure (IOP, mmHg), endothelial cell density (ECD, cells/mm2), graft survival, complications, astigmatism, and spherical equivalent (dioptres [D]) were evaluated. RESULTS: This study included 11 eyes of 11 patients (three females and eight males; mean age, 61.8 ± 13.9 years) with an injury (n = 6) or bullous keratopathy (n = 5). The BCVA significantly improved from 1.50 ± 0.66 logMAR preoperatively to 0.78 ± 0.59 logMAR (p < 0.001) postoperatively. The baseline ECD significantly decreased from 2396 ± 238 cells/mm2 preoperatively to 1132 ± 323 cells/mm2 (p < 0.001) postoperatively. Despite two rejection episodes, graft survival rates were 100%. The mean follow-up period was 38.0 ± 20.5 months. Two patients required combined glaucoma surgery, and three patients underwent subsequent glaucoma surgery. Postoperative astigmatism and spherical equivalent were 3.9 ± 3.2 D and 0.29 ± 2.18 D, respectively. CONCLUSION: The combination of PKP, PPV, and IOL-suture implantation could be a safe and effective approach for eyes requiring anterior segment surgery; however, these eyes are associated with a higher incidence of glaucoma surgery.

Investigation of the association between Toll-like receptor 2 gene polymorphisms and Behçet's disease in Japanese patients.

Behçet's disease (BD) is a chronic systemic inflammatory disorder characterized by recurrent ocular symptoms, oral and genital ulcers, and skin lesions. The etiology of BD is still uncertain, but genetic and environmental factors likely both play an important role in BD development. In the present study, we investigated whether polymorphisms of Toll-like receptor 2 (TLR2), previously reported to recognize BD candidate antigens, are associated with BD. Two hundred Japanese patients with BD and 128 Japanese healthy controls were recruited. We genotyped five single-nucleotide polymorphisms (SNPs) in the TLR2 gene and assessed the allele/genotype diversity between cases and controls for all SNPs. No significant differences in the frequency of TLR2 alleles, genotypes, and haplotypes in the BD cases were detected compared with the controls. These data indicate that TLR2 polymorphisms do not play an important role in the development of BD.

[A case of Leber's hereditary optic neuropathy in a female patient with the recrudescence of hyperthyroidism].

BACKGROUND: Thyroid hormone increases oxygen consumption and regulates mitochondrial biogenesis. On the other hand, in Leber's hereditary optic neuropathy(LHON), retinal ganglion cells are exposed to the oxidative stress generated during the process of adenosine 5'-triphosphate (ATP) synthesis, eventually leading to a loss of vision. Although there is a possibility that the thyroid hormone may have a role in the development or the course of LHON, no case has been reported indicating a relation between them. We report a female case with LHON who also presented exacerbation of hyperthyroidism during the course of the disease. CASE: The patient was a thirty-nine-year-old woman who complained of bilateral loss of vision. Her corrected visual acuity was 0.2 in the right eye, and 0.1 in the left. Fundus examination showed characteristic findings of LHON in both eyes. The blood free thyroxin(FT4) level at that time was abnormally high. The diagnosis of LHON was confirmed by the presence of mitochondrial DNA mutation at the nucleotide position 11778. Her visual acuity improved after one month of FT4 normalization. A year later, her corrected visual acuity recovered to 0.9 in the right eye and 1.0 in the left. CONCLUSION: Hyperthyroidism may be a trigger in the development of LHON.

Analysis of the association between the LUM rs3759223 variant and high myopia in a Japanese population.

PURPOSE: Many studies have investigated the relationship of the lumican gene (LUM) rs3759223 variant with the risk of high myopia, but the results have been inconsistent and inconclusive. In this study, we investigated whether LUM rs3759223 is associated with high myopia in a Japanese population. METHODS: We recruited 1,585 Japanese patients with high myopia (spherical equivalent [SE] <-9.00 diopters [D]) and 1,011 Japanese healthy controls (SE ≥-1.00 D). The rs3759223 variant was genotyped using the TaqMan assay, and the allelic and genotypic diversity among cases and controls was analyzed according to the SE level. RESULTS: In the allelic tests, the odds ratio (OR) for the T allele of rs3759223 tended to increase with the progression of SE, and the highest OR (1.56) was found in patients with SE <-15 D in both eyes. The OR of the T allele tended to increase with the progression of SE in the additive, dominant, and recessive inheritance models. However, we found no significant associations for any of the alleles or genotype models. CONCLUSION: These data support the possibility that the LUM rs3759223 T allele accelerates the progression of SE in the Japanese population, although no significant associations were observed in this study. Additional genetic studies with larger samples that take into account the degree of SE are needed to clarify the contribution of rs3759223 to the risk of high myopia.

Flomoxef sodium and levofloxacin concentrations in aqueous humor.

AIMS: We intravenously administered flomoxef sodium (FMOX) 120 minutes before cataract surgery, topically administered levofloxacin (LVFX) into the eyes four times at 30-minute intervals before surgery, and measured the aqueous humor concentrations of these agents to investigate their penetration into the aqueous humor and their efficacy in the prevention of postoperative endophthalmitis. METHODS: Sixty-eight patients who underwent cataract surgery at the Department of Ophthalmology, Yokohama City University School of Medicine, or its affiliate, Kanazawa Hospital, Yokohama, were enrolled in this study. They received one or both of the following: 1.0 g FMOX via a 20-minute intravenous drip and LVFX ophthalmic solution applied four times at 30-minute intervals, both beginning two hours before the operation. Aqueous humor was aspirated from the anterior chamber and assayed for FMOX and LVFX concentrations using high-performance liquid chromatography (HPLC). RESULTS: The mean intraoperative FMOX and LVFX concentrations in the patients' aqueous humor were 1.21 +/- 0.63 microg/ml and 0.69 +/- 0.47 microg/ml, respectively. These concentrations sufficiently exceeded the MIC90 values against Staphylococcus epidermidis, S. aureus, and Propionibacterium acnes. CONCLUSIONS: The FMOX and LVFX concentrations in the aqueous humor sampling were adequate to kill bacteria in vitro. These drugs may have efficacy in the prevention of postoperative endophthalmitis in patients undergoing cataract surgery.

Study of association of PAX6 polymorphisms with susceptibility to high myopia in a Japanese population.

PURPOSE: Many studies have investigated the relationship of paired box 6 (PAX6) gene polymorphisms with the risk of high myopia, but the results across studies remain inconsistent and ambiguous. In the present work, we investigated whether PAX6 polymorphisms are associated with high myopia in a Japanese population. METHODS: A total of 1,585 Japanese patients with high myopia (spherical equivalent [SE] <-9.00 diopters [D]) and 1,011 Japanese healthy controls (SE≥-1.00 D) were recruited. To compare genotype frequencies between cases and controls, we genotyped five single nucleotide polymorphisms in the PAX6 gene that are reportedly associated with high/extreme myopia: rs662702, rs3026393, rs644242, rs3026390, and rs667773. RESULTS: For rs662702, rs644242, and rs667773, odds ratios (ORs) for their risk alleles tended to increase with the progression of SE and axial length in the additive and recessive models. Of these, rs644242 had the highest OR (2.56) in patients with SE<-15 D in both eyes in the recessive model. On the other hand, for rs3026393 and rs3026390, the ORs for their risk alleles tended to increase according to the progression of SE and axial length in the dominant model. Of the two, rs3026393 had the highest OR (2.32) in patients with SE<-15 D in both eyes in the dominant model. However, no significant associations were identified in this study. CONCLUSION: We found that these PAX6 single nucleotide polymorphisms were associated with an increased risk of extreme myopia. Although the results, which are in agreement with some previous studies, did not reach statistical significance, PAX6 single nucleotide polymorphisms may be important risk factors for the development of extreme myopia. Further genetic studies with larger sample sizes and taking into account the degree of myopia are needed to clarify the contribution of PAX6 variants in myopia development.

Common variants in the COL4A4 gene confer susceptibility to lattice degeneration of the retina.

Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS) using a dense panel of 23,465 microsatellite markers covering the entire human genome. This GWAS in a Japanese cohort (294 patients with lattice degeneration and 294 controls) led to the identification of one microsatellite locus, D2S0276i, in the collagen type IV alpha 4 (COL4A4) gene on chromosome 2q36.3. To validate the significance of this observation, we evaluated the D2S0276i region in the GWAS cohort and in an independent Japanese cohort (280 patients and 314 controls) using D2S0276i and 47 single nucleotide polymorphisms covering the region. The strong associations were observed in D2S0276i and rs7558081 in the COL4A4 gene (Pc = 5.8 × 10(-6), OR = 0.63 and Pc = 1.0 × 10(-5), OR = 0.69 in a total of 574 patients and 608 controls, respectively). Our findings suggest that variants in the COL4A4 gene may contribute to the development of lattice degeneration of the retina.

Treatment effects and sequelae of radiation therapy for orbital mucosa-associated lymphoid tissue lymphoma.

PURPOSE: Among extranodal lymphomas, orbital mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively rare presentation. We performed a review to ascertain treatment efficacy and toxicity of radiation therapy for orbital MALT lymphoma. We also evaluated changes in visual acuity after irradiation. METHODS AND MATERIALS: Thirty patients with orbital MALT lymphoma underwent radiation therapy with curative intent. Clinical stages at diagnosis were stage IEA in 29 patients and stage IIEA in 1 patient. Total doses of 28.8 to 45.8 Gy (median, 30 Gy) in 15 to 26 fractions (median, 16 fractions) were delivered to the tumors. RESULTS: All irradiated tumors were controlled during the follow-up period of 2 to 157 months (median, 35 months) after treatment. Two patients had relapses that arose in the cervical lymph node and the ipsilateral palpebral conjunctiva outside the radiation field at 15 and 67 months after treatment, respectively. The 5-year local progression-free and relapse-free rates were 100% and 96%, respectively. All 30 patients are presently alive; the overall and relapse-free survival rates at 5 years were 100% and 96%, respectively. Although 5 patients developed cataracts of grade 2 at 8 to 45 months after irradiation, they underwent intraocular lens implantation, and their eyesight recovered. Additionally, there was no marked deterioration in the visual acuity of patients due to irradiation, with the exception of cataracts. No therapy-related toxicity of grade 3 or greater was observed. CONCLUSIONS: Radiation therapy was effective and safe for patients with orbital MALT lymphoma. Although some patients developed cataracts after irradiation, visual acuity was well preserved.

Brain-derived neurotrophic factor enhances neurite regeneration from retinal ganglion cells in aged human retina in vitro.

To investigate the capability of neurite regeneration from retinal ganglion cells (RGCs) in an adult human retina and to evaluate the effect of neurotrophin on the neurite regeneration, an in vitro model for retinal explants was developed. A human retina was obtained from a 70 year old patient with retrobulbar carcinoma. The retina was excised and the retinal explants were cultured in serum-free medium with or without brain-derived neurotrophic factor. The capability of neurite regeneration was evaluated by counting the numbers of outgrowing neurites outside the retinal explants. In culture without brain-derived neurotrophic factor (control), there was no neurite outgrowth from the retinal explants after 2 days. And at 3 days in culture, a small number of outgrowing neurites were first observed outside the retinal explants. In contrast, within 24 hr in culture with brain-derived neurotrophic factor, there were a considerable number of elongating neurites with spread growth cones from the retinal explants. Immunohistochemical analysis revealed that these neurites were derived from RGCs. The addition of brain-derived neurotrophic factor increased the number of outgrowing neurites approximately 10-fold compared to that of the control at 3 days in culture. The enhancement of neurite regeneration induced by brain-derived neurotrophic factor continued for longer than 1 week in culture. In conclusion, an aged human retina can regenerate neurites from RGCs in vitro and brain-derived neurotrophic factor significantly promotes the regeneration.