Mitsuru Nakazawa

Apparent Accommodation in Pseudophakic Eyes after Implantation of Posterior Chamber Intraocular Lenses

We measured apparent accommodation in 42 pseudophakic eyes (34 patients) after implantation of posterior chamber intraocular lenses. The mean apparent accommodation was 2.03 +/- 1.03 diopters. The mean accommodative power of 16 phakic eyes used as controls was 2.91 +/- 1.29 diopters. The diameter of the pupil appeared to be the most important factor in apparent accommodation--the smaller the pupil, the greater the apparent accommodation. Apparent accommodation was inversely proportional to the pupillary diameter. There was no correlation, however, between apparent accommodation and corrected visual acuity, refractive error, corneal astigmatism, or axial length. There was a negative correlation between apparent accommodation and anterior chamber depth.

Expression profiles of cytokines and chemokines in vitreous fluid in diabetic retinopathy and central retinal vein occlusion

PurposeThe involvement of cytokines and chemokines in vitreous fluid is important in the development and progression of diabetic retinopathy (DR) and central retinal vein occlusion (CRVO). In this study, the concentrations of cytokines and chemokines in the vitreous fluid of eyes with DR and CRVO were measured and compared.MethodsWe studied 76 eyes with proliferative DR and diabetic macular edema (DR group), 10 eyes with CRVO (CRVO group), and 23 eyes with an epiretinal membrane and macular hole (control group), among a series of 160 eyes from which vitreous fluid samples were collected during vitrectomy. The vitreous fluid samples were collected by suction with a vitreous cutter at the initial stage of vitrectomy. Twenty-seven different cytokines and chemokines were measured simultaneously using an array system (Bio-Plex®) with beads combined with antibodies (Bio-Rad), as follows: interleukin (IL)-1β, IL-1 receptor agonist, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, eotaxin, basic fibroblast growth factor, granulocyte colony-stimulating factor (G-CSF), granulocyte/macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-γ, interferon-inducible 10-kDa protein (IP-10), monocytochemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1α), MIP-1β, platelet-derived growth factor (PDGF)-BB, regulated upon activation, normal T cell expressed and secreted, tumor necrosis factor alpha (TNF-α), and vascular endothelial growth factor (VEGF).ResultsCompared to the control group, the levels of IL-6, IL-8, IL-10, IL-13, IP-10, MCP-1, MIP-1β, PDGF and VEGF in the vitreous fluid were significantly higher in the DR group, while the levels of IL-1β, IL-2, IL-5, IL-8, IL-9, IL-10, IL-12, IL-13, eotaxin, G-CSF, IFN-γ, IP-10, MCP-1, MIP-1β, TNF-α and VEGF were significantly higher in the CRVO group. Compared to the DR group, IL-2, IL-9, IL-12, MCP-1 and IFN-γ were significantly elevated in the CRVO group. Multivariate regression analysis revealed that among 6 factors correlated to VEGF in the DR group, IL-10 and IL-13 were more positively correlated and PDGF was most inversely correlated to VEGF.ConclusionIn addition to inflammatory cytokines and neurotrophic factors such as VEGF, anti-inflammatory cytokines such as IL-10 and IL-13 may be involved more in the pathogenesis of DR and CRVO than in other diseases; cytokines and chemokines may also be correlated to VEGF in the vitreous fluid. It is also suggested that the inflammatory reaction may be more activate in CRVO than in DR.

Postoperative refractive error after simultaneous vitrectomy and cataract surgery.

PURPOSE To evaluate the effect of vitrectomy on postoperative refraction after simultaneous vitrectomy and cataract surgery. METHODS We compared the spread between predicted and actual refractions in 206 eyes after a simultaneous vitrectomy, phacoemulsification, aspiration and acrylic lens insertion (combined surgery group), and in 67 eyes after cataract surgery only (cataract surgery group) as control. A vitrectomy was performed for diabetic retinopathy in 127 eyes, macular hole in 32 eyes, rhegmatogenous retinal detachment in 16 eyes, branch retinal vein occlusion in 15 eyes, and other conditions in 26 eyes. In the combined surgery group, 79 eyes had a gas tamponade after insertion of the intraocular lens. RESULTS The spread between predicted and actual refractions was - 0.05 +/- 1.18 diopters (average +/- SD) in the combined surgery group and +0.55 +/- 1.32 D in the cataract surgery group. The actual refractive errors in the combined surgery group were found to shift toward myopia when compared with the controls. Among the combined surgery group, 127 eyes without a gas tamponade showed a postoperative refractive error of +0.14 +/- 1.11 D, while 79 eyes with a gas tamponade demonstrated an error of -0.36 +/- 1.22 D. CONCLUSIONS Use of a gas tamponade in the combined surgery group increased the myopic change and was thought to have pressed the intraocular lens forward.

Activation of mitochondrial calpain and release of apoptosis-inducing factor from mitochondria in RCS rat retinal degeneration.

The present study was performed to investigate changes of cytosolic and mitochondrial calpain activities, and effects of intravitreously injected calpain inhibitor on photoreceptor apoptosis in Royal College of Surgeons (RCS) rats. Time courses of activities for both cytosolic and mitochondrial calpains and amount of calpastatin in RCS rat retina were analyzed by subcellular fractionation, calpain assay and western blotting. Calpain assay was colorimetrically performed using Suc-LLVY-Glo as substrate. Effects of intravitreously injected calpain inhibitor (ALLN and PD150606) on RCS rat retinal degeneration were analyzed by TUNEL staining. Effects of mitochondrial calpain activity on activation and translocation of apoptosis-inducing factor (AIF) were analyzed by western blotting. Mitochondrial calpain started to be significantly activated at postnatal (p) 28 days in RCS rat retina, whereas cytosolic micro-calpain was activated at p 35 days, although specific activity of mitochondrial calpain was 13% compared to cytosolic micro-calpain. Intravitreously injected ALLN and PD150606 effectively inhibited photoreceptor apoptosis only when injected at p 25 days, but did not inhibit photoreceptor apoptosis when injected at p 32 days. Parts of AIF were truncated/activated by mitochondrial calpains and translocated to the nucleus. These results suggest that 1), calpain presents not only in the cytosolic fraction but also in the mitochondrial fraction in RCS rat retina; 2), mitochondrial calpain is activated earlier than cytosolic calpain during retinal degeneration in RCS rats; 3), photoreceptor apoptosis may be regulated by not only calpain systems but also other mechanisms; 4), mitochondrial calpain may activate AIF to induce apoptosis; and 5), calpain inhibitors may be partially effective to inhibit photoreceptor apoptosis in RCS rats. The present study provides new insights into the molecular basis for photoreceptor apoptosis in RCS rats and the future possibility of new pharmaceutical treatments for retinitis pigmentosa.

Mutations in the gene coding for guanylate cyclase-activating protein 2 (GUCA1B gene) in patients with autosomal dominant retinal dystrophies.

BackgroundWe investigated mutations in the gene coding for guanylate-cyclase activating protein 2 (GCAP2), also known as GUCA1B gene, in Japanese patients with retinitis pigmentosa (RP) and tried to identify phenotypic characteristics associated with mutations in the gene.Subjects and methodsGenomic DNA samples from 63 unrelated patients with autosomal dominant retinitis pigmentosa (ADRP) and 33 patients with autosomal recessive retinitis pigmentosa (ARRP) were screened by single-strand conformational polymorphism analysis followed by direct sequencing. Clinical features associated with a mutation were demonstrated by visual acuity, visual field testing, fundus photography, and electroretinography.ResultsA novel transitional mutation converting GGA to AGA at codon 157 (G157R) was identified. This mutation has been found in three index patients from three independent families. Phenotypic examination of seven members of the three families revealed that this mutation was associated with RP with or without macular involvement in five members, macular degeneration in one member, and asymptomatic normal phenotype in one member. In addition, previously unknown polymorphic changes including V29V, Y57Y, T87I, and L180L were identified.ConclusionsA racial difference exists in the spectrum of mutations and/or polymorphisms in the GCAP 2 gene between British and Japanese populations. Our findings suggest that the mutation in the GCAP 2 gene can cause one form of autosomal dominant retinal dystrophy, with variable phenotypic expression and incomplete penetrance.

Macular dystrophy associated with monogenic Arg172Trp mutation of the peripherin/RDS gene in a Japanese family.

Objective Mutations of the peripherin/RDS gene have been reported in several kinds of retinal dystrophy, and they show variation of manifestation. In some pedigrees, the same mutation can produce different phenotypic features, a factor that makes it difficult to deduce certain rules for genotype-phenotype correlations in the peripherin/RDS gene. The authors report the phenotypic features of a Japanese family with a mutation in codon 172 of the peripherin/RDS gene and compare them to previously reported ocular findings in British pedigrees with the same mutation. Patients and Methods A 45-year-old man and his 15-year-old son were screened for mutations in the peripherin/RDS gene and the ROM1 gene. Clinical features were characterized by visual acuity and visual field testing, fundus examination, fluorescein angiography, and electroretinography. Results Both patients had the same mutation in codon 172 of the peripherin/RDS gene designated as Arg172Trp. No mutation was found in the ROM1 gene in either patient. Clinical features were summarized as autosomal dominant macular dystrophy. The father had sharply demarcated chorioretinal atrophy in the macula. The son showed mild granularity in the macular area in ophthalmoscopic appearances. Conclusions The Arg172Trp mutation was confirmed to produce autosomal dominant macular dystrophy. This particular phenotype was caused by the monogenic mutation in the peripherin/RDS gene.

Antirecoverin antibody in the aqueous humor of a patient with cancer-associated retinopathy

PURPOSE To describe a patient with cancer-associated retinopathy (CAR) in whom antirecoverin antibody was found in the aqueous humor. DESIGN Interventional case report. METHODS A 65-year-old man underwent resection of adenocarcinoma of the lung in June 1991 and noted deterioration of vision 10 months later. Goldmann perimetry revealed a ring-like scotoma in each eye, and the electroretinogram was nonrecordable. Aqueous humor and peripheral venous blood were collected for Western blot analysis from this patient and three other patients during surgery for age-related cataract. RESULTS We found antirecoverin antibody within the aqueous humor and serum in the patient with CAR. In contrast, such imunoreactivities were not observed in specimens from the control patients. CONCLUSION These observations strongly suggest that antirecoverin antibody penetrates into the aqueous humor and vitreous cavity beyond the blood-retina barrier in CAR.

Oguchi disease: phenotypic characteristics of patients with the frequent 1147delA mutation in the arrestin gene.

OBJECTIVE To characterize clinical features of patients with Oguchi disease associated with a homozygous deletion of adenine at nucleotide 1147 (1147delA) in codon 309 in the arrestin gene. METHODS Mutation screening by single-strand conformation polymorphism analysis was done, followed by sequencing. Ophthalmologic testing included evaluation of visual acuity and color vision, fundus examination, electroretinography, fluorescein angiography, evaluation of kinetic visual field, and dark adaptometry. Nine patients with Oguchi disease from seven unrelated families and family members who were unaffected by the disease were examined. RESULTS A homozygous 1147delA mutation in the arrestin gene was identified in eight patients from six families with Oguchi disease. All patients who were examined exhibited a golden-yellow retinal reflex associated with Mizuo-Nakamura phenomenon and impairment of rod function in dark adaptation tests, although fundus examination showed slight variation in these findings. Four patients with the mutation had slightly reduced visual acuity, and the electroretinograms of three patients showed slightly reduced amplitudes during 30-Hz flicker electroretinography. CONCLUSION Patients with Oguchi disease associated with the arrestin 1147delA mutation typically demonstrate retarded rod adaptation, whereas some patients have slightly impaired cone function.

Effect of nilvadipine on central visual field in retinitis pigmentosa: a 30-month clinical trial.

Purpose: To assess the effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). Design: Prospective, randomized, nonmasked, single-center trial. Methods: Patients with RP were randomly divided into a treated group receiving oral nilvadipine at 4 mg/day for ≧30 months and a control group receiving tocopherol nicotinate at 300 mg/day, helenien at 15 mg/day or no medication for the same periods. Progression of RP was evaluated using the 10-2 SITA Fast Program of the Humphrey Visual Field Analyzer, and regression coefficients calculated from the time courses of mean deviation (MD slope) were compared between groups. Results: Nineteen patients in the treated group and 14 patients in the control group completed the follow-up for ≧30 months. The mean (±standard deviation) duration of observation was 48.8 ± 11.8 months (median 48 months, range 30–66 months) for the treated group and 49.2 ± 18.1 months (median 48 months, range 30–90 months) for the control group (p = 0.94). Mean (±standard error of the mean, SEM) regression coefficients of the averaged MD values for the initial 30 months were –0.35 ± 0.17 dB/year in the treated group and –0.75 ± 0.06 dB/year in the control group (p < 0.01). Mean (±SEM) MD slopes for total observational periods were –0.49 ± 0.17 dB/year in the treated group and –0.89 ± 0.16 dB/year in the control group (mean ± SEM, p = 0.042). Conclusion: Nilvadipine at 4 mg/day significantly retarded progression of central visual field defects in RP in this small patient series.

Longterm findings in peripapillary crescent formation in eyes with mild or moderate myopia

Purpose:  To describe early changes of optic disc deviation and peripapillary crescent formation in eyes with mild or moderate myopia.