Biomedical subjects

Mitsuko Yuzawa

Publications and source records attributed to Mitsuko Yuzawa.

29 records · Page 2Linked to original sources

PubMed2003

[Preferred retinal locus in patients with age-related macular degeneration].

PURPOSE: To evaluate the status and location of the preferred retinal locus(PRL) and visual function in age-related macular degeneration(AMD). SUBJECTS AND METHODS: Thirty-five patients were examined. They were diagnosed as having bilateral AMD in the disciform stage. Scanning laser ophthalmoscopic microperimetry was performed to detect the PRL. The retinal conditions of the PRL were classified using color fundus photographs and fluorescein angiography. The eccentricities of PRL from the fovea were measured. The relationships among visual acuity, retinal sensitivity, and the eccentricities of the PRL were evaluated. RESULTS: In 34 of 35 eyes, PRLs had shifted from an extrafoveal site and were located at the nearest foveal site on the healthy retina or on an atrophic lesion of the retinal pigment epithelium. When it was possible that other lesions were located where the PRL had shifted to, the PRL moved to the upper or temporal retina. The eccentricities of PRLs were 0.5-11 degrees. Visual acuities differed among the same retinal eccentricities. CONCLUSIONS: PRLs shift to the lesion nearest the fovea. These results suggest that visual acuity and retinal sensitivity are determined by the status of the PRL.

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PubMed2003

[Surgical removal of juxtafoveal and extrafoveal choroidal neovascularization in age-related macular degeneration].

PURPOSE: In the treatment of age-related macular degeneration (AMD), the effect on the fovea of photocoagulation of juxtafoveal choroidal neovascularization(CNV) and extrafoveal CNV near the fovea has been of concern, and so usefulness of surgical excision of CNV was evaluated. SUBJECTS AND METHODS: Fifteen eyes with AMD that underwent removal of juxtafoveal CNV and extrafoveal CNV near the fovea and had been followed for over one year were included in this study. Eligibility criteria were preoperative visual acuity of 0.3 or less and evidence of CNV activity by fundus angiography. RESULTS: Visual acuity of 0.4 or more was obtained in 60% of the eyes with best visual acuity and 47% with final visual acuity. The mean best visual acuity was 0.51 in cases with Gass type 2, 0.51 in type 1 + 2 CNV, and 0.21 in type 1 CNV. Good post-operative visual acuity was obtained in type 2 and 1 + 2 cases with type 2 CNV at the foveal side accompanied by preoperative foveal retinal sensitivity of 25 dB or more. There was little improvement of visual acuity in type 1 CNV because the retinal pigmented epithelium defect occurred at the fovea. CONCLUSION: For juxtafoveal CNV and extrafoveal CNV near the fovea in AMD, type 2 and 1 + 2 cases with type 2 CNV at the foveal side are thought to be candidates for surgery. Especially, relatively good postoperative visual acuity was obtained in cases with preoperative foveal retinal sensitivity of 25 dB or above. Active surgical removal is thought to be indicated for these cases.

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PubMed2002

[Preoperative factors influencing visual acuity following vitrectomy for exudative age-related macular degeneration].

PURPOSE: We investigated the relations between ingrowth site and visual results in patients undergoing surgical removal of subfoveal choroidal neovascular membranes (CNV) caused by age-related macular degeneration (AMD). MATERIALS AND METHODS: The subjects were 70 eyes(69 patients), which underwent surgical removal of CNV for AMD and were followed up for 6 months or more. The eligibility criteria were active subfoveal choroidal neovascular membrane 3 disc diameters (DD) or less in size located above the retinal pigment epithelium, and visual acuity of 0.3 or worse. We analyzed the relationships between postoperative best-corrected visual acuity and preoperative factors: ingrowth site of CNV, distance between the fovea and the CNV edge, CNV size, and fluorescence pattern in indocyanine green angiography (IA). RESULTS: Patients 1) with feeder vessels located outside the foveal avascular zone (FAZ) rather than inside the FAZ and/or unknown feeder vessels, 2) with a distance between the fovea and the CNV edge 0.2 DD or less than 0.2 DD versus larger, than 0.2 DD 3) with a 1 DD or smaller CNV versus 1.5 DD or larger, and 4) type I, II, or III findings in IA rather than type IV had good postoperative best-corrected visual acuity. CONCLUSIONS: To achieve better postoperative visual acuity after surgical removal of CNV associated with AMD, it is important to select CNV with ingrowth sites outside the FAZ, small and large CNV with a relatively short distance between the fovea and the CNV edge closest to the fovea, and type I, II, and III findings in IA.

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PubMed2002

[Clinical dose finding study of indocyanine green to detect choroidal neovascularization in patients with exudative age-related macular degeneration].

PURPOSE: To evaluate the proper clinical dosage of indocyanine green(ICG) in angiography for detecting choroidal neovascularization(CNV) of exudative age-related macular degeneration(AMD). SUBJECTS AND METHODS: Indocyanine green angiography (IA) was performed using a randomized crossover method with two different doses on two occasions. Ease of detection, side effects and clinical serum data were also evaluated. RESULTS: Among the 39 eyes, detection of CNV using 12.5 mg and 25 mg was most effective in 21 and 31 eyes respectively, showing a statistically significant difference. Slight vomiting was observed temporarily in one patient who had taken 25 mg. CONCLUSION: A dose of 25 mg is appropriate for detection of CNV of exudative AMD and this dosage raises no safety concerns.

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PubMed2002

[Utility of indocyanine green angiography guided laser photocoagulation of choroidal neovascularization in age-related macular degeneration].

PURPOSE: The efficacy of photocoagulating choroidal neovascularization (CNV) of age-related macular degeneration with indocyanine green angiography(ICG) was evaluated. 1. The utility of ICG-guided laser photocoagulation for juxtafoveal and extrafoveal CNV, 2. The utility of photocoagulating feeder vessels of subfoveal CNV. METHODS: 1. We compared 139 eyes undergoing ICG-guided laser photocoagulation (IA group), with 85 eyes treated with fluorescein angiography (FAG)-guided laser photocoagulation(FA group), of juxtafoveal and extrafoveal CNV. 2. We treated 35 eyes of 35 patients in which feeder vessels detected by ICG served as targets of photocoagulation. RESULTS: 1. The success rate of laser photocoagulation was 81% in the IA group and 82% in the FA group. There was no statically significant difference between the IA and FA groups in terms of distance from the fovea, CNV size, or lesion type. The rates of maintained or improved visual acuity in groups of IA and FA at the final follow-up as compared with those before treatment, were 71% (61/86 eyes) and 65% (36/55 eyes), respectively. 2. The feeder vessels were obliterated in 66%. The percentage of eyes with maintained or improved visual acuity at six months and at final follow-up as compared to visual acuity before treatment was 64% and 58%, respectively. Thirteen(81%) of 16 eyes which had shown extrafoveal feeder vessel ingrowth sites and small CNV of 1-disc area or less showed feeder vessel closure. CONCLUSION: 1. ICG-guided laser photocoagulation of juxtafoveal and extrafoveal CNV should be performed actively in the same way as FAG-guided laser photocoagulation. 2. It is best to attempt to coagulate feeder vessels when they are extrafoveal and when the CNV is small.

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PubMedDate not supplied

Correlation between indocyanine green angiographic findings and histopathology of polypoidal choroidal vasculopathy.

PURPOSE: To analyze the histopathology of polypoidal choroidal vasculopathy (PCV) and choroidal neovascularization (CNV) developing from PCV, the authors evaluated correlations between pathological findings and the findings of preoperative indocyanine green angiography (IA). METHODS: Two specimens were obtained during CNV excision associated with PCV. PCV tissue was excised with the CNV. The specimens were examined by light microscopy. RESULTS: In one case, IA revealed polypoidal lesions exhibiting hyperfluorescence in both the early and the late phase, and in the affected area, abnormally dilated vessels were identified histologically underneath relatively healthy retinal pigment epithelium (RPE). In the other case, the polypoidal lesions seen on IA showed early hyperfluorescence and late isofluorescence, and dilated vessels were observed under the RPE; perivascular amorphous material was present. The RPE adhered to the side of the choroid, and there was CNV under the neurosensory retina in both cases. The CNV had numerous vascular lumens, was not surrounded by the RPE, and exhibited few fibrous components. CONCLUSIONS: IA findings vary depending on the condition of the RPE located above the PCV and the extent of amorphous material around the PCV.

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PubMedDate not supplied

Correlation between angiographic and pathological findings in experimental choroidal neovascular membranes after transpupillary thermotherapy.

PURPOSE: To evaluate the correlation between angiographic and pathological findings in experimental choroidal neovascular membranes after transpupillary thermotherapy (TTT). METHODS: Experimental subretinal choroidal neovascular membranes were produced in the monkey eye macula by intense photocoagulation. TTT was delivered, targeting the choroidal neovascular membranes, using a diode laser at 810 nm. One week and 4 weeks after TTT, indocyanine green angiography (IA), fluorescein angiography (FA), optical coherence tomography (OCT), and histological examinations were performed. RESULTS: One week after TTT, indocyanine green dye leakage from choroidal neovascular membranes was reduced on IA, and FA showed staining in the late phase. Light microscopic examination showed numerous small-caliber blood vessels and persistent subretinal exudation. Four weeks after TTT, there was no indocyanine green dye leakage on IA, and FA showed staining. OCT showed a decrease in retinal detachment. Light microscopic examination showed fewer blood vessels and subretinal exudation had disappeared. Choroidal neovascular membranes were composed of fibrous tissue. CONCLUSIONS: Changes in angiographic and OCT findings observed after TTT were inferred to be the result of accelerated fibrosis due to TTT and the disappearance of exudation.

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PubMedDate not supplied

Surgical excision of type 1 + 2 choroidal neovascularization in age-related macular degeneration.

PURPOSE: To evaluate the visual acuity outcome and the various factors influencing visual outcome in patients undergoing surgical removal of type 1 + 2 choroidal neovascularization (CNV) caused by age-related macular degeneration (AMD). METHODS: We studied the records of 54 patients (54 eyes) followed for at least 1 year after surgical excision of CNV associated with AMD. RESULTS: The final visual acuity was 0.4 or better in 4%, 0.1 to 0.3 in 46%, and worse than 0.1 in 50% of the patients. Final visual acuity was improved in 39%, stable in 37%, and worse in 24%. Stepwise regression showed that the distance between the center of the foveal avascular zone and the CNV margin had the greatest effect on final visual acuity. CONCLUSIONS: Surgical excision of type1 + 2 CNV due to AMD may be indicated for preserving preoperative visual acuity. The distance between the center of the foveal avascular zone and the CNV margin is the most important factor affecting final visual acuity.

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PubMedDate not supplied

Surgical excision of type 2 choroidal neovascularization in age-related macular degeneration.

PURPOSE: To evaluate the visual acuity outcome and the influence of various factors on visual outcome in patients undergoing surgical removal of type 2 choroidal neovascular neovascularization (CNV) caused by age-related macular degeneration (AMD). METHODS: We studied the records of 92 patients (92 eyes) who were followed for at least 1 year after surgical excision of CNV associated with AMD. RESULTS: The final visual acuity was 0.4 or better in 21%, 0.1 to 0.3 in 66%, and worse than 0.1 in 13% of the patients. Final visual acuity was improved in 62%, stable in 29%, and worse in 9%. Stepwise regression identified CNV size as a significant factor influencing final visual acuity (R = 0.287, P = 0.0045). CONCLUSIONS: Surgical excision of CNV for AMD is indicated for patients with subfoveal active type 2 CNV with a visual acuity of 0.3 or worse. To achieve better postoperative visual acuity it is important to operate on AMD patients in the early stage of CNV.

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PubMedDate not supplied

How spatial orientation of Japanese text affects fixation points in patients with bilateral macular atrophy.

PURPOSE: To ascertain the retinal area used by patients with bilateral macular atrophy when reading Japanese text of different character sizes written horizontally or vertically. In addition, to determine fixation points as part of the first of a series of studies designed ultimately to enhance the quality of life of these patients through the improvement of reading acuity. METHODS: Seventeen patients (34 eyes) with bilateral macular atrophy were tested to determine the retinal area employed for reading (R fixation point). Sentences were arranged either horizontally or vertically and projected onto the retina using a scanning laser ophthalmoscope. We also determined the fixation point using microperimetry (M fixation point). The positional relationships between these two fixation points and the scotoma were examined. RESULTS: The R and M fixation points were the same in 20 of the 34 eyes. Multiple R fixation points were found in 11 eyes. The R fixation point was frequently positioned above the lesion when reading horizontally (nine eyes), while it was often positioned in the area nasal to (eight eyes) or temporal to (six eyes) the lesion when reading vertically. CONCLUSIONS: Fixation points changed frequently in these patients with bilateral macular atrophy depending on the spatial orientation of the text. These data should be used in the future to help patients learn how to use the preferred retinal locus to improve their reading skills and enhance their quality of life.

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PubMedDate not supplied

A study of laser photocoagulation for polypoidal choroidal vasculopathy.

PURPOSE: To evaluate the efficacy of laser photocoagulation for polypoidal choroidal vasculopathy (PCV) involving the macula. METHODS: The records of 38 patients (47 eyes) undergoing laser photocoagulation for PCV causing serosanguineous detachment involving the fovea were reviewed and the results were evaluated. Ten eyes underwent photocoagulation to induce a fusion scar covering whole lesions consisting of both abnormal vessels and polypoidal lesions. Thirty-seven eyes underwent photocoagulation for only polypoidal lesions. When serosanguineous detachment recurred, additional photocoagulation was performed, targeting the causative lesions. Photocoagulation was performed with an argon dye laser or multicolor krypton laser. Final visual acuity, macular changes at the final visit, and the number of photocoagulations were evaluated. Follow-up period after the first photocoagulation was at least 1 year. RESULTS: Of the 10 eyes undergoing photocoagulation of whole lesions, 9 showed absorption of exudate and/or blood after one photocoagulation, and maintained or improved visual acuity. Of the 37 eyes undergoing laser photocoagulation of only polypoidal lesions, 20 (54%) showed decreased visual acuity because of recurrent or persistent exudation and/or classic choroidal neovascularization or, alternatively, because of atrophy at the fovea; 32 of the 37 eyes had undergone photocoagulation at least twice or more. CONCLUSION: Photocoagulation is recommended only for whole lesions.

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