Shigeki Yamanishi

Two-year follow-up study comparing primary vitrectomy with scleral buckling for macula-off rhegmatogenous retinal detachment.

PURPOSE To compare the anatomic and visual outcomes achieved by scleral buckling and primary vitrectomy for the repair of macula-off rhegmatogenous retinal detachment. METHODS The records were reviewed for a consecutive series of 167 patients (167 eyes) who were initially treated with scleral buckling or pars plana vitrectomy for primary macula-off retinal detachment. Patients were treated between January 1993 and December 1996. After adjustments for preoperative characteristics, data from 102 cases (55 scleral buckle cases and 47 primary vitrectomy cases) were used for the final comparison. There had been a minimum follow-up period of 24 months. RESULTS No significant differences in single-procedure reattachment incidence (91%), final success incidence (100%) and incidence of postoperative proliferative vitreoretinopathy development (4%) were observed between the two treatment groups. Preoperative visual acuity, preoperative intraocular pressure, and duration of macular detachment were the three best predictors of postoperative visual recovery in both groups. Favorable overall visual recovery was obtained postoperatively, with no significant differences between the two groups throughout the follow-up period. However, in the eyes with poor preoperative visual acuity (<0.1), ocular hypotony (intraocular pressure <7 mm Hg), or prolonged macular detachment (more than 7 days), visual recovery in the primary vitrectomy group was significantly better (P <.05) than in the scleral buckle group from the first postoperative month. CONCLUSION Both procedures achieved favorable anatomic and visual outcomes in the majority of patients with primary macula-off retinal detachment. Primary vitrectomy may be more effective than scleral buckling for achieving early visual rehabilitation in cases complicated by poor preoperative vision, ocular hypotony, and prolonged macular detachment.

Quantitative assessment of macular thickness in normal subjects and patients with diabetic retinopathy by scanning retinal thickness analyser

AIMS To evaluate the scanning retinal thickness analyser (RTA), a novel non-invasive imaging instrument, in diagnosing and quantitatively characterising diabetic macular oedema, and to investigate the relation between central macula thickness measured by RTA and other clinical examinations. METHODS Central macular thickness was measured using the RTA in 40 normal subjects and 60 patients with diabetic retinopathy. The reproducibility of the retinal thickness measurements was evaluated by calculating the mean of the inter- and intrasession variations. Central macular thickness was correlated with the results of visual acuity measurements, biomicroscopy, and fluorescein angiography. RESULTS Intra- and intersession reproducibility of the RTA in normal subjects was plus or minus 5.2% (16 μm) and plus or minus 6.1% (19 μm), respectively. The mean central macular thickness was 182 (SD 16) μm in normal subjects, 283 (116) μm in diabetic eyes without clinically significant macular oedema (CSMO), and 564 (168) μm in diabetic eyes with CSMO. Central macular thickness was significantly greater (p<0.001) in eyes with diabetic retinopathy than in normal subjects, even when macular thickening did not meet the standard for CSMO (p=0.019) measured by biomicroscopy. Although greater fluorescein leakage at the macula results in greater central macular thickness, only eyes with diffuse leakage had statistically significant macular thickening compared with normal subjects (p=0.022). Central macular thickness measured with the RTA was significantly correlated with the logarithmic converted visual acuity (r2 = 0.76) in diabetic eyes. CONCLUSION Scanning RTA, which has good reproducibility, might be useful to quantitatively detect and monitor macular thickening in diabetic retinopathy. Central macular thickness was highly correlated with logarithmic converted visual acuity in diabetic macular oedema.

Survey of surgical indications and results of primary pars plana vitrectomy for rhegmatogenous retinal detachments

BACKGROUND Several surgical techniques to repair rhegmatogenous retinal detachment have been developed. Recently, both the method of reattaching the retina and of obtaining an early visual recovery are considered important factors when determining which surgical techniques to perform to treat retinal detachment. CASES The surgical outcome in a series of 63 consecutive patients, who were treated at Osaka Rosai Hospital between 1993 and 1996, was reviewed retrospectively to evaluate the efficacy of primary vitrectomy to treat uncomplicated rhegmatogenous retinal detachment associated with posterior hyaloid separation. The criteria for vitrectomy included the presence of not only posterior retinal breaks, but also of multiple peripheral retinal breaks. OBSERVATIONS The reattachment rate after the first surgery was 92.1% (58 eyes), and by the final examination it increased to 100%. Of the 46 eyes with macular detachment, good visual rehabilitation and a visual acuity improvement of 5 or more lines was obtained in 33 eyes (71.7%) by 1 month postoperatively. No statistically significant difference in the reattachment rate was found when eyes that underwent an encircling procedure were compared with those that did not. In eyes with lens opacity, cataract surgery was also performed and intraocular lenses were implanted uneventfully in all but one case with myopia. There was a high incidence (53.8%) of cataract progression in phakic eyes. However, no other serious complications, such as proliferative vitreoretinopathy, were found throughout the follow-up period. CONCLUSIONS The results indicate that vitrectomy performed to alleviate peripheral vitreoretinal traction is an effective surgical technique to treat primary rhegmatogenous retinal detachment. Vitrectomy combined with cataract surgery may also be a valuable surgical option in selected cases to maintain long-standing visual rehabilitation.

Molecular Characterization in the VP7, VP4 and NSP4 Genes of Human Rotavirus Serotype 4 (G4) Isolated in Japan and Kenya

The VP7, VP4 and NSP4 genes of human rotavirus serotype 4 (G4) were analyzed to investigate intraserotypic variations. The techniques used included reverse transcription polymerase chain reaction with subtype specific primers, restriction fragment length polymorphism analysis and sequence analysis. Twelve isolates (nine from Japan and three from Kenya) and two standard strains (Hochi, Odelia) were G4A P[8] Wa group NSP4. A standard strain (ST3) was G4A P[6] Wa group NSP4 and a strain (VA70) was G4B P[8] Wa group NSP4. These results show G4 rotaviruses can be divided into three combinations at the moment.

Sequence analysis of SRSV in fecal specimens from an epidemic of infantile gastroenteritis, October to December 1995, Japan

From October to December in 1995, an epidemic of infantile gastroenteritis occurred all over Japan except in Hokkaido and Okinawa prefectures. The number of infected infants and young children was estimated to be over 5 million cases [Editorial, IASR 1996]. The stool specimens from patients were examined for the presence of small round structured viruses (SRSVs) by reverse transcription‐polymerase chain reaction (RT‐PCR) and nucleotide sequencing of parts of the RNA‐dependent RNA polymerase region. Thirty‐five of 87 stool specimens examined gave positive results. Genomic variation was investigated by sequence analysis of a 327 bp cDNA region. The nucleotide and deduced amino acid sequences of the ten strains segregated into two distinct groups; one showed 96.0–100% nucleotide and 99.1–100% amino acid identity, the others showed 91.4–99.7% nucleotide and 93.5–100% identity. The main mechanism of transmission remains unknown. However, these data suggest the possibility of person‐to‐person spread by two or more kinds of SRSV. J. Med. Virol. 52:377–380, 1997.

Optical cross-sectional evaluation of successfully repaired idiopathic macular holes by retinal thickness analyzer.

Purpose: To describe optical cross‐sectional images of successfully repaired idiopathic macular holes and to determine the influences of epiretinal membranes and retinal pigment epithelial (RPE) changes on foveal reconstruction and the correlation between retinal thickness and postoperative visual acuity. Methods: In a prospective study, optical cross‐sectional imaging and retinal thickness measurement of the macula using a retinal thickness analyzer were performed on 63 eyes of 63 patients who underwent successful macular hole surgery. Results: Cross‐sectional images of foveal reconstruction were morphologically categorized into four patterns: normal fovea (23 eyes [37%]), cavernous fovea (19 eyes [30%]), flat fovea (11 eyes [17%]), and irregular fovea (10 eyes [16%]). Epiretinal membranes were observed in the last two groups (55% and 40%) and RPE changes were observed only in the irregular fovea group (16%). The mean retinal thickness of the fovea in all eyes was 213 ± 92 μm (mean ± SD; range, 93‐570 μxm), which varied significantly (P < 0.001) among the four groups. Linear regression analysis showed a significant correlation between retinal thickness at the fovea and logarithmic converted visual acuity (R2 = 0.42, P< 0.001). Conclusions: Structural features of foveal reconstruction following successful macular hole surgery involved four patters: normal fovea, cavernous fovea, flat fovea, and irregular fovea. Retinal thickness of the fovea, which varied among the groups, correlated with postoperative visual acuity. Postoperative epiretinal membrane formation and RPE damage may disturb normal foveal reconstruction and visual recovery.

Rheological Evaluation of X‐Ray Irradiated Blood

CPD blood, in glass containers and polyvinyl chloride (PVC) bags, was X‐irradiated with 50 Gy (n = 4), and then stored for up to 4 weeks. Rheological, hematological and biochemical changes of the red cells during storage were examined. Changes in blood viscosity and various properties of red cells (deformability, shape, hematological indices and concentrations of 2,3‐diphosphoglycerate and nucleotides) during storage at 4°C were not altered by the irradiation. The rheological, biochemical and morphological properties of red cells were as well preserved in PVC bags as in glass containers. No abnormal and/or cross‐linked proteins in red‐cell membranes were induced by the irradiation. Irradiation of PVC bags did not affect the above properties of red cells through any changes in the bag constituents. In conclusion, X‐ray irradiation with 50 Gy to CPD blood in PVC bags does not affect the rheological functions of red cells.

Visual outcome of macular hole surgery with internal limiting membrane peeling

PURPOSE To evaluate the efficacy of the internal limiting membrane(ILM) peeling on macular hole surgery. METHODS A series of 102 patients(105 eyes) who underwent primary macular hole surgery between October 1994 and April 1999 was used for this retrospective study. The mean age was 65.6 +/- 7.1 years (mean +/- standard deviation). Of the study eyes, 34 eyes(32%) had a Stage II hole, 49 eyes(47%) had a Stage III hole, and 22 eyes(21%) had a Stage IV hole based on the Gass classification. Here we compared the surgical and visual outcome of the ILM peeling-treated group(treated group: 51 eyes) with those of ILM peeling-untreated group(untreated group: 54 eyes). RESULTS The hole closure rate after initial surgery was 98.0% in the treated group and 90.7% in the untreated group, and mean postoperative visual acuity, excluding cases where the hole was not closed by initial surgery, was 0.44 and 0.47, respectively. Visual improvement of 2 or more lines on Snellen chart was achieved in 84.3% and 57.4%(p < 0.01), and that of 4 or more lines in 54.9% and 25.9% (p < 0.01), respectively. Of the eyes with Stage II and III holes, visual outcome of the treated group was significantly better than that of the untreated group(p = 0.034, p = 0.037). In Stage IV, the initial closure rate of the treated group was significantly better than that of the untreated group(p = 0.02), but the visual outcome was not significantly different. CONCLUSION Vitreous surgery combined with ILM peeling for the management of idiopathic macular hole is effective not only on hole closure but also on visual recovery.

A Comparative Study of Visual Outcomes Following Primary Vitrectomy and Scleral Buckling Procedures to Manage Macular-off Rhegmatogenous Retinal Detachments

PURPOSE To determine the difference between two types of retinal detachment surgery in postoperative visual recovery in the management of macular-off rhegmatogenous retinal detachment. METHODS We evaluated retrospectively the postoperative visual acuity (VA) in 37 patients who underwent primary vitrectomy (group V) and 39 patients treated with conventional scleral buckling (group S). RESULTS Although the mean preoperative VA in group V (0.03) was significantly worse (p = 0.04) than that in group S (0.06), there was no statistically significant difference between the groups in postoperative VA throughout the follow-up period. However, in the cases with poor preoperative VA (VA < 0.1), ocular hypotony (IOP < 7 mmHg), or prolonged macular detachment (duration > 7 days), the visual recovery was significantly better (p < 0.05) in group V than in group S from 1 month postoperatively. There were more eyes with a final VA of more than 0.5 in group V than in group S. When considering only the eyes with lenses spared intraoperatively, postoperative cataract progression resulting in secondary visual reduction was statistically significantly greater (p < 0.01) in group V (62%) than in group S (8%). CONCLUSIONS Primary vitrectomy is effective to attain early visual rehabilitation, especially to manage macula-off retinal detachments with poor preoperative VA, ocular hypotony, and prolonged macular detachment. To prevent a secondary visual reduction, cataract surgery combined with vitrectomy is recommended in selected cases.

Macular morphologic reconstruction and visual recovery in patients following macular hole surgery

PURPOSE To examine the characteristics of retinal reconstruction at the macula following macular hole surgery and to assess the impact of postoperative macular morphological changes on the visual outcome. METHODS A prototype of the scanning retinal thickness analyzer (RTA) was used to obtain optical section images at the macula in 53 eyes of 52 patients who underwent macular hole surgery between April 1994 and July 1997. The mean age of participants was 64.7 years. At the time of RTA examination, macular hole was biomicroscopically closed in 49 eyes (91%) and unclosed in 5 eyes (9%). RESULTS There were 5 types of cross-sectional images of postoperative maculae: normal foveal depression [19 eyes (36%)], crater-like fovea formation [12 eyes (22%)], flattened fovea [8 eyes (15%)], fovea with abraded retinal pigment epithelium [9 eyes (17%)], and persistant macular hole [5 eyes (9%)]. Central macular thickness measured by RTA was 165 +/- 39 (mean +/- standard dereation) microns in the normal foveal depression group, 210 +/- 67 microns in the crater-like fovea formation group, and 300 +/- 50 microns in the flatened fovea group. There were statistically significant differences (p < 0.01) between groups. Postoperative visual acuity was significantly different (p < 0.01) between these three groups, and central macular thickness was highly correlated with postoperative visual acuity (R = 0.70). CONCLUSION Visual recovery following macular hole surgery is closely associated with the retinal reconstruction at the macula.