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Miki Sawa

Publications and source records attributed to Miki Sawa.

17 recordsLinked to original sources
PubMed2007

Residual indocyanine green fluorescence pattern after vitrectomy for idiopathic macular hole with internal limiting membrane peeling.

BACKGROUND: Internal limiting membrane (ILM) peeling with indocyanine green (ICG) staining is a commonly used procedure to treat idiopathic macular holes (MH). AIM: To report changes in the patterns of residual ICG fluorescence over time after vitrectomy using the Heidelberg Retina Angiograph 2 (HRA2, Heidelberg Engineering, Heidelberg, Germany). METHODS: 10 patients (10 eyes) who had undergone vitrectomy for MH with ILM peeling were included. 9 (90%) patients underwent ILM peeling with ICG, and 1 (10%) patient had it with triamcinolone acetonide (TA). We observed residual ICG using HRA2, postoperatively. Autofluorescence, optical coherence tomography images and best-corrected visual acuity (BCVA) measurements were also obtained. The minimal follow-up was 3 months. RESULTS: The MHs were closed postoperatively in all patients (100%). In eyes that underwent ILM peeling with ICG, the BCVA improved significantly (p<0.001) in 8 (89%) eyes and was unchanged in 1 (11%) eye. HRA2 showed the ICG fluorescence patterns but not TA postoperatively. The ICG hyperfluorescent signal was typically diffuse at the posterior retina and was hypofluorescent around the fovea. The hyperfluorescence then migrated towards the optic nerve disc presumably along the nerve fibre, and the area of ILM peeling was clearly identified. A large number of hyperfluorescent dots were observed instead of diffuse hyperfluorescence that was observed just after surgery. CONCLUSIONS: Patterns of residual ICG fluorescence were sequentially observed with HRA2 after vitrectomy for MH with ICG-assisted ILM peeling.

Aged↗
PubMed2006

Fundus autofluorescence in patients with pseudoxanthoma elasticum.

PURPOSE: To evaluate the autofluorescence findings of patients with pseudoxanthoma elasticum, a disease resulting from a defect in a reputed transport protein encoded by the gene adenosine triphosphate-binding cassette subtype C number 6. DESIGN: Observational case series. METHODS: Color, red-free monochromatic, and autofluorescence photography and fluorescein angiography of patients with pseudoxanthoma elasticum seen in a referral practice were evaluated. MAIN OUTCOME MEASURES: Cataloging of the abnormalities as detected by autofluorescence photography. RESULTS: The 8 subjects ranged in age from 26 to 60 years (mean, 55+/-12), and their best-corrected visual acuity ranged from 20/20 to 5/400 (mean, 20/50). Of the 16 eyes of the 8 patients, all had abnormalities typical of pseudoxanthoma elasticum, including angioid streaks in 14, peau d'orange in 4, and choroidal neovascularization in 11. Angioid streaks appeared as hypoautofluorescent fissures, sometimes showing expansion of the hypoautofluorescence suggestive of retinal pigment epithelium (RPE) absence or atrophy. Peau d'orange had a stippled appearance of autofluorescence, and drusen of the optic nerve appeared as hyperautofluorescent bodies. In addition to the expansion of RPE atrophy around angioid streaks, 3 additional configurations of RPE atrophy were recognized as RPE rips in 6 eyes, multilobular areas of atrophy in 9 eyes, and broad areas of poorly demarcated atrophy in 5 eyes. Some eyes had more than one manifestation of RPE atrophy, but the latter 3 types of atrophy occurred in eyes with, but not necessary contiguous to, concurrent choroidal neovascularization. CONCLUSIONS: Autofluorescence photography demonstrated that patients with pseudoxanthoma elasticum have more widespread areas of RPE disturbance, particularly atrophy, than what is detectable by other means of ocular imaging, which suggests that the RPE disturbance may play a role in the pathogenesis of visual loss in patients with pseudoxanthoma elasticum.

Adult↗
PubMed2005

New micro vertical scissors for the surgical ablation of retinal angiomatous proliferation.

PURPOSE: To develop new micro vertical scissors for the ablation of retinal angiomatous proliferation (RAP) to minimize possible retinal damage. DESIGN: Interventional case report. METHODS: New micro vertical scissors were developed and used for the ablation of RAP vessels. RESULTS: The length of the inner side of the tip is 180 microm, which is approximately one seventh that of regular vertical scissors. The scissors handled easily and the RAP vessels were ablated with less retinal damage compared with that associated with use of standard vertical scissors. Postoperatively, intraretinal hemorrhage was reduced and hyperfluorescence seen on indocyanine green angiography resolved. CONCLUSIONS: The new micro vertical scissors developed for the ablation of RAP vessels can be used safely and effectively during this surgical procedure.

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PubMed2005

Nonvitrectomizing vitreous surgery for epiretinal membrane long-term follow-up.

PURPOSE: To report the long-term follow-up results of nonvitrectomizing vitreous surgery for idiopathic epiretinal membrane (ERM). DESIGN: Nonrandomized comparative case series. PARTICIPANTS: Thirty patients were followed up for at least 5 years after nonvitrectomizing vitreous surgery. INTERVENTION: Epiretinal membranes were peeled without infusion of balanced salt solution and removal of the vitreous. The data from the fellow eye was the control data. MAIN OUTCOME MEASURES: We examined the visual acuities (VAs), objective refractions, and slit-lamp and Scheimpflug photographs from the preoperative and the final examinations of both eyes. Quantitative assessment of the progression of nuclear sclerosis was performed by densitometry analysis using Scheimpflug photography. The recurrence rate of ERM was determined. RESULTS: The follow-up periods ranged from 60 to 102 months (mean+/-standard deviation, 72.2+/-11.0 months). The patient ages ranged from 52 to 76 years (68.8+/-6.3 years). The final VA improved or stabilized within 2 lines in 29 of 30 eyes (96.7%). No unilateral progression of nuclear sclerosis occurred in any cases. The mean preoperative and postoperative refractions without additional surgery were -0.4+/-2.9 diopters (D) and -0.2+/-3.0 D in the operated eyes, respectively, and -0.2+/-2.5 D and 0.1+/-2.4 D, respectively, in the unoperated fellow eyes. The mean differences in the refractive error between both eyes (operated eye data minus fellow eye data) were -0.2+/-0.7 D before surgery and -0.3+/-0.8 D after surgery (P = 0.319, paired t test). The mean preoperative and postoperative nuclear densities in 16 patients were 69+/-14 nuclear density units (NDUs) and 76+/-12 NDUs in the operated eyes and 71+/-14 NDUs and 78+/-14 NDUs in the fellow eyes, respectively. The mean preoperative and postoperative differences in nuclear densities in both eyes were -2+/-2 NDUs and -2+/-5 NDUs, respectively (P = 0.836, paired t test). The ERM recurred in 10 eyes (33%), and 3 eyes underwent conventional vitrectomy combined with cataract surgery. CONCLUSIONS: Unilateral nuclear sclerosis did not progress for at least 5 years after nonvitrectomizing vitreous surgery. The recurrence rate of ERM appeared to be higher than that after conventional vitreous surgery.

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PubMed2004

Macular translocation surgery and retinal circulation times.

PURPOSE: To quantify and compare the retinal circulation times before and after macular translocation surgery. METHODS: In nine patients undergoing macular translocation with 360-degree retinotomy, arm-retina and arteriovenous passage times were quantified from preoperative and postoperative scanning laser fluorescein angiograms. A control group of eight patients who had not undergone any intraocular surgery was also evaluated. The time that between injection into the antecubital vein and the appearance of fluorescein at two selected points on superotemporal and inferotemporal arteries near the disk provided the arm-retina time. For the arteriovenous passage time, 50% of the maximal fluorescence time difference was assessed from the intensity curves of arteries and corresponding veins at the same points for the arm-retina time. Postoperative measurements were obtained an average of 10.6 months after surgery. RESULTS: No significant difference was noted between preoperative and postoperative values of the arm-retina time (mean +/- SD: 14.41 +/- 2.73 seconds versus 14.67 +/- 3.85 seconds, respectively; P = 0.84) or that of the arteriovenous passage time (2.66 +/- 0.74 seconds versus 2.47 +/- 0.68 seconds, respectively; P = 0.37) in the study group. The arm-retina time (14.96 +/- 2.01 seconds) and arteriovenous passage time (2.44 +/- 0.68 seconds) in the control group did not differ from preoperative and postoperative arm-retina times (P = 0.65 and P = 0.85) and arteriovenous passage times (P = 0.54 and P = 0.93) in the study group. The arteriovenous passage time correlated with the degree of retinal rotation around the optic disk in the study group (r = -0.70; P = 0.04). CONCLUSION: Macular translocation surgery does not alter retinal macrocirculation in the long term.

Aged↗
PubMed2004

Evaluation of choroidal perfusion of the new central macular area by dilution analysis of indocyanine green angiography after macular translocation.

PURPOSE: To evaluate the possible long-term alterations of choroidal perfusion parameters in the new central macular area after macular translocation surgery. METHODS: Eleven subjects with subfoveal neovascular membrane secondary to age-related macular degeneration or degenerative myopia underwent indocyanine green angiography by using a scanning laser ophthalmoscope before and after macular translocation (mean, 10 months after surgery). Fluorescence intensity of the new central macular area over time was evaluated. Parameters derived from the intensity curves included 10% filling time, ascending slope, and maximal intensity of brightness. The 10% filling time reflects the rapidity of the early choroidal filling phase, whereas the slope of the filling of the curve shows the speed of blood entrance into the choroid. Maximal intensity of brightness indicates vascular density of the area. RESULTS: No statistical difference was encountered before or after macular translocation in 10% filling time (14.25 +/- 2.09 seconds versus 16.20 +/- 2.95 seconds), slope of the ascending portion of the curve (0.12 +/- 0.04 versus 0.11 +/- 0.04), and maximal intensity of brightness (0.89 +/- 0.09 versus 0.88 +/- 0.07) in the new central macular area. The rotational degree of the retina against the retinal pigment epithelium did not show any significant correlation with 10% filling time, slope, or maximal intensity of brightness. CONCLUSION: Choroidal perfusion parameters in the new foveal region do not change after macular translocation surgery.

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PubMed2004

Nonaxoplasmic transfer of indocyanine green into the optic nerve after intravitreal application.

PURPOSE: To investigate whether indocyanine green (ICG) migrates into the optic nerve after intravitreal application in the rabbit eye. METHODS: Gas vitrectomy was performed in one eye of adult Dutch belted rabbits by pars plana injection of 0.4 ml of 100% C3F8 (n = 10). One week later, vitrectomy was performed and 0.2 ml of 0.25% ICG was instilled into the vitreous cavity of these vitrectomized eyes. After 30 seconds of ICG application, the vitreous cavity was rinsed with balanced salt solution plus. Unoperated rabbits served as controls (n = 2). Globes, optic nerves, and the entire brain were removed, and ICG fluorescence of the specimens was examined with a digital fundus camera starting from the first day to the fourth postoperative week. Other rabbit eyes (n = 2) were injected with ICG directly into the vitreous without vitrectomy, and assessed for ICG signal after 1 day of ICG application. In the second part of the experiment, four rabbit eyes were gas vitrectomized and ICG was instilled onto retina after blockage of axonal flow by vinblastine. They were evaluated on the first (n = 2) and seventh postoperative days (n = 2). RESULTS: No fluorescein was detected in the visual pathways and the brains of the control group of rabbits. The optic nerves of the ICG-instilled eyes were stained diffusely with ICG starting from the first day after surgery. ICG injected nonvitrectomized eyes showed similar ICG staining patterns when compared with vitrectomized eyes. ICG staining pattern of the optic nerve did not differ in vinblastine-pretreated eyes. Fluorescence extended along the intraorbital portion of the optic nerve but did not transport more posteriorly in all animals. At the fourth week after vitrectomy, ICG signal was still detectable, but staining was less intense. CONCLUSION: Intravitreal ICG injection results in nonaxoplasmic extension into the optic nerve in the rabbit.

Animals↗
PubMed2004

Involvement of rho-kinase pathway in contractile activity of rabbit RPE cells in vivo and in vitro.

PURPOSE: Increased alpha-smooth muscle actin (alpha-SMA) expression in epiretinal membranes causes tractional retinal detachment (TRD) in proliferative vitreoretinopathy (PVR). The Rho-A/Rho-associated kinase signaling pathway is a principal mediator of contractile force generation in nonmuscle cells. In the current study, the relation between the Rho-kinase pathway and alpha-SMA expression and type I collagen gel contractile activity in retinal pigment epithelial (RPE) cells was investigated, using Y27632, a specific inhibitor of p160ROCK, and the involvement of the Rho-kinase pathway was evaluated in a rabbit PVR model with cultured RPE cells and platelet-rich plasma (PRP). METHODS: RPE cells were obtained from rabbits and cultured. The number of passages and the effect of Y27632 on alpha-SMA expression were studied by immunohistochemistry and immunoblot analysis. An in vitro type I collagen gel contraction assay and MTT assay evaluated the effect of Y27632 on RPE cell contractile force and proliferation. Cultured sixth-passage rabbit RPE cells were coinjected with PRP intravitreally, followed by 50 micro M of Y27632, injected weekly. The presence of TRD was assessed until 28 days to evaluate the effect of Y27632 in vivo. RESULTS: Expression of alpha-SMA was increased according to the passages. Y27632 suppressed alpha-SMA expression in cultured RPE cells and impaired contractile force. Y27632 did not affect the proliferative potential. Y27632 significantly (P < 0.01) reduced TRD development. CONCLUSIONS: Y27632 decreased alpha-SMA expression and the contractile force generated by RPE cells and attenuated PVR, indicating the involvement of the Rho-kinase pathway in cell-dependent collagen contraction in vitro and in vivo. The drug may affect the biological event by inhibiting alpha-SMA expression, and Y27632 could be useful for preventing PVR.

Actins↗
PubMed2003

Successful photodynamic therapy with verteporfin for recurrent choroidal neovascularization beneath the new fovea after macular translocation surgery with 360-degree retinotomy.

PURPOSE: To report a case of successfully treated recurrent choroidal neovascularization after macular translocation surgery with 360-degree retinotomy by photodynamic therapy with verteporfin. DESIGN: Interventional case report. METHODS: A 76-year-old man developed recurrent choroidal neovascularization at the new fovea after macular translocation surgery with 360-degree retinotomy. RESULTS: Two sessions of photodynamic therapy were applied, which resolved the choroidal neovascularization. Best-corrected visual acuity improved to 20/50 at the 6 and 12 months follow-up. CONCLUSION: Photodynamic therapy may be an option for treatment of recurrent choroidal neovascularization in the new subfoveal region after macular translocation surgery with 360-degree retinotomy.

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PubMed2002

Changes in fluorescein angiogram early after surgical removal of choroidal neovascularization in age-related macular degeneration.

BACKGROUND: Retinal pigment epithelial (RPE) defects inevitably occur in surgical removal of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). RPE can proliferate and cover the denuded area, but the healing process has not been investigated in humans. To understand the RPE wound-healing process, we estimated the changes in fluorescein angiograms early after CNV removal. METHODS: Ten consecutive patients with exudative AMD underwent CNV removal without gas tamponade. Fluorescein angiography was performed within 4 days of surgery and again 1 or 2 weeks postoperatively. Areas of leakage were measured using a computer-assisted image analyser. The decreasing rate of leakage was calculated as the change in disc areas of leakage per day (DA/day). RESULTS: The rates of decreasing leakage ranged from 0 to 0.42 DA/day (mean, 0.24 +/- 0.15 DA/day; median, 0.26 DA/day). The rate of decreasing leakage correlated with changes in visual acuity (r = 0.642, P = 0.0456). CONCLUSION: The retinal pigment epithelial wound after surgical removal of choroidal neovascularization may heal at the rate of 0.24 disc areas/day based on the blood retinal barrier function in patients with age-related macular degeneration. A faster rate of decreasing leakage may be associated with better visual prognosis.

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PubMed2002

[Ocular complications in systemic lupus erythematosus--choroidal and retinal pigment epithelial changes].

PURPOSE: Cotton wool patch and retinal hemorrhage are common ocular findings in systemic lupus erythematosus(SLE). Immunosuppressive treatment with corticosteroids may modify choroidal and retinal findings. We examined ocular complications, mainly choroidal and retinal pigment epithelium (RPE) changes in patients with SLE. MATERIALS AND METHODS: Fifty SLE cases[3 males, 47 females, 41 +/- 15 (mean +/- standard deviation) year-old] were examined and treated in the departments of Internal Medicine and Ophthalmology of Osaka University Medical Hospital. RESULTS: Complications included cataract in 16 cases, glaucoma or ocular hypertension in 9 cases, and choroidal and retinal changes in 15 cases. Occlusive retinal vasculitis, retinal pigment epithelial dysfunction, such as pigment epithelial detachment, choroidal neovascularization and multiple posterior pigment epitheliopathy, in 6 cases, and branch retinal vein occlusion in 2 cases were detected as fundus complications. Average time period from the first detection of SLE was 13 years in patients with RPE changes. CONCLUSION: Long term corticosteroid therapy is probably responsible for the RPE complications.

Adult↗
PubMedDate not supplied

A microperimeter that provides fixation pattern and retinal sensitivity measurement.

PURPOSE: To investigate a microperimeter (MP-1) that can independently measure fixation status and microperimetry of retinal threshold sensitivity by comparing the results obtained by the MP-1 with those obtained by scotometry using scanning laser ophthalmoscopy (SLO). METHODS: Fourteen patients (15 eyes) with a macular disorder were examined by the MP-1 fixation test, MP-1 microperimetry, and SLO scotometry. The scotoma size seen in MP-1 microperimetry was compared with that observed in SLO scotometry. The location of the preferred retinal locus (PRL) and the fixation stability, which were obtained from the fixation test in MP-1, were also compared with those obtained in SLO scotometry. RESULTS: The scotoma size, which was not seen with 0 dB in MP-1 microperimetry, was larger than that in SLO scotometry in 8 of the 15 eyes. Retinal threshold sensitivity decreases were found using MP-1 microperimetry within a sensitive area of SLO scotometry in all eyes. The PRL in the MP-1 fixation test and in SLO scotometry agreed in all eyes. Fixation stability in the MP-1 fixation test significantly correlated with that in SLO scotometry (P = 0.0192). CONCLUSIONS: The results of MP-1 microperimetry do not completely agree with those of SLO scotometry owing to the difference in stimulus intensity. The MP-1 fixation test is useful for measuring PRL and fixation stability in a short time. MP-1 might be helpful to evaluate the foveal function in patients with macular disorders without severely damaged macular function.

Aged↗
PubMedDate not supplied

Platelet-derived growth factor receptor kinase inhibitor AG1295 and inhibition of experimental proliferative vitreoretinopathy.

PURPOSE: Receptor tyrosine kinase (RTK) activation is critical for growth factor-mediated cell proliferation. The present study was designed to determine the effect of tyrphostin AG1295, a selective blocker of platelet-derived growth factor (PDGF) RTK, on proliferative vitreoretinopathy (PVR) development. METHODS: Rabbit conjunctival fibroblasts cells (1 x 10(4)) were seeded into 96-well plates and maintained in Dulbecco's modified essentialmedium (DMEM) with 0.5% fetal bovine serum. The cells were exposed to 50 ng/mL PDGF-AAor PDGF-BBor phosphate-buffered saline with or without AG1295 (1 microM, 10 microM, and 100 microM). After 3 days, the viable cells in each well were measured by 3,(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Homologous rabbit conjunctival fibroblasts were injected intravitreally, followed by injection of 100 microM of AG1295. The development of tractional retinal detachment (TRD) was assessed to evaluate the effect of AG1295 in vivo. Electroretinography and histologic studies were performed after intravitreal injection of AG1295 into untreated eyes to evaluate toxicity. RESULTS: Two concentrations of AG1295 (10 and 100 microM) significantly inhibited rabbit conjunctival fibroblast cell growth stimulated by PDGF-AA or PDGF-BB in vitro. Development of TRD was significantly attenuated (P <.01) with 100 microM of AG1295 until day 21. No significant histologic or retinal functional damage was found in the AG1295-treated group. CONCLUSIONS: PDGF receptor specific inhibitor AG1295 attenuated PVR without significant side effects in rabbits. This reagent could be a useful treatment to prevent PVR.

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