Biomedical subjects

F Nakao

Publications and source records attributed to F Nakao.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Anesthetic management for carotid and coronary artery surgery--concomitant versus two stage operation].

We reviewed the anesthetic management of 16 patients with concomitant severe coronary and carotid artery diseases. Eight patients underwent concomitant operations of coronary artery bypass graft and carotid endarterectomy, while the other 8 patients underwent two stage operation. Candidates for concomitant operations had unstable angina or serious coronary disease such as three vessel disease or severe stenosis of LMT. In comparison, most of patients undergoing two stage operation had symptomatic or occlusive carotid disease. In all cases, anesthesia was maintained with fentanyl and midazolam and the perfusion pressure during cardiopulmonary bypass was maintained above 70 mmHg. Some patients received thiopental or propofol for brain protection. The concomitant operations required much more transfusion and longer operation time than two stage operation. In addition, several cases of the concomitant operation needed intra-aortic balloon pumping or high dose of catecholamines. Indications for concomitant operation or two stage operation have to be determined through discussion among anesthesiologist, neurovascular as well as cardiovascular surgeons.

Aged↗

PubMed1999

Echoendoscopic evaluation of botulinum toxin intrasphincteric injections in Chagas' disease achalasia.

Botulinum toxin (BT) has recently been indicated as an alternative treatment of idiopathic achalasia with a success rate of 60-70%. One-third of BT-treated cases either fail to respond or fail to sustain the response beyond 6 months. An explanation for BT therapeutic failure would be that the lower esophageal sphincter muscular layer (LES) may be missed as injection is delivered 'blindly'. We aimed to evaluate the percentage of exact endoscopically 'blind' LES punctures using echoendoscopy after the injection of BT for the treatment of Chagas' achalasia (CA). Five patients with CA (mean age 53 years) were randomized to receive 1.2 ml of BT or the same amount of saline injected endoscopically. Echoendoscopy was performed immediately after puncture. Patients were evaluated by the clinical score of dysphagia, radiological examination, upper endoscopy and esophageal manometry and followed up for 6 months. All puncture sites were identified: 17 out of 20 (85%) in the muscle layer and 3 out of 20 (15%) in the submucosa. The three patients in the treatment group showed clinical improvement (average clinical score fell from 14 to 2 after 7 days, and remained at 4 after 6 months of follow-up). The mean pressure of the LES dropped by 29%. Neither patient in the placebo group showed clinical improvement, and the mean pressure of the LES increased by 35%. Endoscopic 'blind' injection of BT into the LES through endoscopy for the management of achalasia is a safe and reproducible technique and has a high percentage of exactness.

Botulinum Toxins↗

PubMed1998

Quantitative comparison of posterior capsule opacification after polymethylmethacrylate, silicone, and soft acrylic intraocular lens implantation.

OBJECTIVE: To quantitatively compare the extent of posterior capsule opacification (PCO) after polymethylmethacrylate (PMMA), silicone, and soft acrylic intraocular lens implantation. PATIENTS AND METHODS: A total of 240 eyes from 240 patients undergoing implant surgery were randomized into 3 groups based on the type of lens implanted: PMMA, silicone, and soft acrylic. The density value of PCO in 185 eyes was quantitated approximately 2 years after surgery by a new measurement method using the Scheimpflug videophotography system. RESULTS: Twenty-one eyes (30.4%) in the PMMA group, 4 (5.7%) in the silicone group, and 2 (2.7%) in the acrylic group had already undergone Nd:YAG laser posterior capsulotomy. The mean +/- SD PCO values were 26.3 +/- 12.2 computer-compatible tape steps (CCT) in the PMMA group, 12.0 +/- 8.3 CCT in the silicone group, and 16.0 +/- 10.3 CCT in the acrylic group. The PCO value in the PMMA group was significantly greater than that in the silicone or acrylic group (P < .001). The visual acuity loss in the PMMA group was also greater than that in the silicone or acrylic group (P < .001). CONCLUSION: Based on the PCO value and capsulotomy rate, the PCO was more extensive with the PMMA lens than with either the silicone or soft acrylic lens, which led to visual acuity loss.

Acrylic Resins↗

PubMed1998

In vivo quantitative measurement of posterior capsule opacification after extracapsular cataract surgery.

PURPOSE: To introduce a new in vivo quantitative measurement of posterior capsule opacification (PCO) after extracapsular cataract surgery and also to analyze the correlation between opacification density and the patient's visual acuity. METHODS: Prospectively, the opacification density value in the central 3-mm portion of the posterior capsule was quantitated by means of an area densitometry with the Scheimpflug photography system (EAS-1000). The EAS-1000 examination was performed on 40 eyes with clinically significant PCO both before and after undergoing Nd:YAG laser posterior capsulotomy, and on 10 eyes without PCO. The correlation between the opacification density value and the visual acuity was analyzed with a linear regression analysis. RESULTS: The mean opacification density values +/- SD were 48.8 +/- 29.5 computer-compatible tapes (CCT) steps in the PCO group before capsulotomy, 15.5 +/- 7.8 CCT steps in the PCO group after capsulotomy, and 12.9 +/- 4.9 CCT steps in the non-PCO group. The mean opacification density value in the PCO group before capsulotomy was significantly greater than that in the PCO group after capsulotomy or than that of the non-PCO group. A linear regression analysis determined that the opacification density value also correlated well with the visual acuity (R2 = .808). CONCLUSIONS: We have established a new in vivo quantitative measurement of PCO. Because the opacification density value obtained by this measurement correlated well with the patient's visual acuity, we consider this measurement to be useful in both the research and clinical management of PCO.

Aged↗

PubMed1998

Anterior capsule contraction and intraocular lens dislocation after implant surgery in eyes with retinitis pigmentosa.

OBJECTIVE: The purpose of the study was to investigate the extent of anterior capsule contraction, intraocular lens (IOL) decentration, and tilt after implant surgery in eyes with retinitis pigmentosa (RP). DESIGN: A case-control study. PARTICIPANTS: Forty-seven eyes from 47 patients with typical RP and 47 control eyes from 47 age-matched healthy patients were studied. INTERVENTION: Phacoemulsification surgery with polymethylmethacrylate IOL implantation with continuous curvilinear capsulorrhexis was performed. MAIN OUTCOME MEASURES: The area of the anterior capsule opening obtained with capsulorrhexis and the amount of the decentration and tilt of the IOL were measured using a Scheimpflug photography system at 1 week and 1, 3, 6, 9, and 12 months after surgery. RESULTS: The mean area in the RP group was found to be significantly smaller than that in the control group at 1 month after surgery and later (P < 0.0001). The percent area reduction in the RP group at 6 months was 45.2 +/- 25.8% and 4.6 +/- 13.5% in the control group. Both the decentration length and tilt angle were also greater in the RP group than in the control group. Fourteen (29.8%) of the 47 RP eyes had undergone a neodymium:YAG (Nd:YAG) laser anterior capsulotomy at 12 months after surgery, whereas none of the control eyes had undergone an Nd:YAG. CONCLUSIONS: Anterior capsule contraction in the RP eyes was more extensive than in the control eyes, leading to a high Nd:YAG laser anterior capsulotomy rate. Both lens decentration and tilt also were greater in the RP eyes than in the control eyes.

Anterior Chamber↗

PubMed1998

Area reduction in the anterior capsule opening in eyes of diabetes mellitus patients.

PURPOSE: To compare the extent of area reduction in the anterior capsule opening after continuous curvilinear capsulorhexis in the eyes of diabetes mellitus (DM) patients with that in the eyes of patients without DM. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Ninety-one eyes of 91 DM patients and 91 age-matched eyes of patients without DM (control group) having intraocular lens (IOL) implantation were recruited for this prospective study. The DM group comprised 36 eyes with diabetic retinopathy (DR) and 55 without retinopathy (NDR). The anterior capsule opening area was quantitated using Scheimpflug photography 1 week and 1, 3, and 6 months postoperatively. RESULTS: There was no statistically significant difference in mean anterior capsule opening area between the DM and control groups at 1 week or 1 month postoperatively. The area was significantly smaller in the DM group at 3 (P = .0221) and 6 (P = .0075) months. The percentage area reduction was also greater in the DM group than in the control group. The area in the DR group was significantly smaller than in the control group at 3 (P = .0392) and 6 (P = .0080) months. The percentage reduction in the DR group was larger than in the NDR or control group. CONCLUSIONS: After IOL implantation, contraction of the anterior capsule opening area was more extensive in eyes of DM patients than in those of patients without DM, especially in the case of DR.

Aged↗

PubMed1998

Reproducibility of posterior capsule opacification measurement using Scheimpflug videophotography.

PURPOSE: To examine the intraobserver and interobserver reproducibility in measuring posterior capsule opacification (PCO) using a Scheimpflug videophotography system. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHOD: Twenty eyes with PCO and 10 without PCO had 5 independent measurements 15 minutes apart performed by 3 observers. The eyes without PCO were selected within 1 week after surgery. Intraobserver and interobserver reproducibility were evaluated using the coefficient of variation and intraclass correlation coefficient. RESULTS: The median coefficients of variation of the 3 observers were 11.6%, 11.3%, and 9.8%, respectively, which indicates an acceptably low observer variability. The intraobserver correlation coefficients of the 3 observers were all more than 0.95, and the interobserver correlation coefficient was 0.976, which indicates excellent reproducibility. CONCLUSION: The results of intraobserver and interobserver reproducibility of PCO measurement using the Scheimpflug videophotography system indicate it would be effective for use in research and clinical management of PCO.

Adult↗

PubMed1998

Anterior capsule contraction and intraocular lens dislocation in eyes with pseudoexfoliation syndrome.

AIMS: To examine the extent of anterior capsule contraction as well as intraocular lens (IOL) decentration and tilt following implant surgery in eyes with pseudoexfoliation syndrome (PE). METHODS: 53 eyes from 53 patients with PE and 53 control eyes from 53 age matched patients, undergoing phacoemulsification and implant surgery, were recruited. The anterior capsule opening area and the amounts of IOL decentration and tilt after undergoing continuous curvilinear capsulorhexis were measured using the Scheimpflug videophotography system at 1 week and 1, 3, 6, 9, and 12 months postoperatively. RESULTS: The mean area of the anterior capsule opening in the PE group was significantly smaller than that in the control group at 1 month postoperatively and later. The percentage reductions in the PE group were approximately 25%, while they were less than 10% in the control group. The degree of IOL tilt was also larger in the PE group than in the control group. Five eyes (9.4%) in the PE group underwent a neodymium: YAG laser anterior capsulotomy, but none in the control group underwent a capsulotomy. CONCLUSIONS: The contraction of the anterior capsule opening was more extensive in the PE eyes than in the control eyes, thus resulting in a high Nd:YAG laser anterior capsulotomy rate. The IOL tilt was also greater in the PE eyes than in the control eyes.

Aged↗

PubMed1998

Comparison of decentration and tilt between one piece and three piece polymethyl methacrylate intraocular lenses.

BACKGROUND: The extent of the decentration and tilt was prospectively compared between one piece polymethyl methacrylate (PMMA) and three piece PMMA intraocular lenses (IOLs) which were implanted in the capsular bag after performing continuous curvilinear capsulorhexis. METHODS: 91 patients underwent a one piece PMMA IOL implantation in one eye as well as the implantation of the three piece PMMA IOL with polyvinylidene fluoride loops in the opposite eye. The length of the lens decentration and the angle of the tilt were quantitated using the anterior eye segment analysis system (EAS-1000) at 1 week as well as 1, 3, and 6 months postoperatively. RESULTS: The mean length of the decentration in the one piece IOL was smaller than that in the three piece IOL at 1 week (p = 0.0092), 1 month (p = 0.0044), 3 months (p = 0.0069), and 6 months (p = 0.0010) postoperatively. However, no significant difference was found in the degree of the tilt between the two types of IOLs throughout the observation periods. CONCLUSION: These results clarified that the one piece PMMA IOL with rigid PMMA haptics implanted in the capsular bag provides a better centration than the three piece PMMA IOL with flexible haptics, whereas the tilt was the same between the two types of IOLs.

Aged↗

PubMed1997

Reduction in the area of the anterior capsule opening after polymethylmethacrylate, silicone, and soft acrylic intraocular lens implantation.

PURPOSE: To report reduction in the area of anterior capsule opening at various postoperative intervals after continuous capsulorrhexis and to compare any differences in the area reduction between polymethylmethacrylate, silicone, and soft acrylic intraocular lenses. METHODS: Prospectively, 240 eyes of 240 patients undergoing phacoemulsification and intraocular lens implant surgery were randomized into three groups based on the type of intraocular lens used: polymethylmethacrylate, silicone, and soft acrylic. The area of the anterior capsule opening was quantitated, and examinations were performed at 1 week and 1, 3, and 6 months postoperatively. RESULTS: After intraocular lens implantation, the mean anterior capsule opening area 3 months postoperatively was significantly smaller than that at 1 week in all groups (polymethylmethacrylate, P = .0090; silicone, P < .0001; soft acrylic, P = .0127). Mean percentages in area reduction at both 3 and 6 months postoperatively were significantly greater than those at 1 week and 1 month (P < .0001). In comparing the three intraocular lenses at 1 week postoperatively, no statistical significance was observed regarding the anterior capsule opening area between the three groups. However, the mean anterior capsule opening areas in the polymethylmethacrylate and soft acrylic intraocular lens groups were significantly larger than those in the silicone intraocular lens group at 1 month (P = .0024), and 3 months (P = .0032), and 6 months (P = .0022) postoperatively. CONCLUSIONS: After continuous capsulorrhexis and intraocular lens implant surgery, the area of the anterior capsule opening gradually decreased for up to 3 months postoperatively. The contraction of the anterior capsule opening was greater in the silicone group than in either the polymethylmethacrylate or the soft acrylic groups.

Acrylates↗

PubMed1997

Corneal shape changes after scleral buckling surgery.

PURPOSE: A prospective study was conducted to investigate the corneal shape changes due to scleral buckling surgery. These changes were analyzed based on the type of buckling procedures performed. METHODS: A total of 89 eyes from 88 patients were stratified into four groups based on the type of buckling procedures used, including:group A, local buckling; group B, encircling; group C, encircling with vitrectomy; and group D, encircling with additional segmental buckling. These eyes underwent keratometry and videokeratography examinations before surgery as well as at 1, 3, and 6 months after surgery. RESULTS: No statistical significance was observed in the amounts of the induced corneal astigmatism and the refractive cylinder among the four groups. After local or segmental buckling (groups A and D), corneal steepening, which corresponded to the buckle, occurred at a high incidence. After encircling (groups B and C), either peripheral corneal flattening with focal central steepening or flattening on one side with coupled steepening on the opposite side was observed. Such corneal changes persisted for up to 6 months in an irregular and asymmetric configuration. CONCLUSIONS: All four types of circumferential scleral buckling surgery were found to produce prolonged irregular and asymmetric corneal shape changes, whereas the patterns of the changes differed depending on the buckling procedures used.

Adolescent↗

PubMed1997

Decentration and tilt of polymethyl methacrylate, silicone, and acrylic soft intraocular lenses.

PURPOSE: The purpose of the study is to investigate the periodic changes regarding the decentration and tilt of the intraocular lens (IOL) and to compare any differences in the decentration and tilt among polymethyl methacrylate (PMMA), silicone, and acrylic soft IOLs. METHODS: A total of 225 cataractous eyes undergoing IOL implant surgery were randomized into 3 groups based on the type of IOL: group A, one-piece PMMA IOL; group B, three-piece silicone IOL; and group C, three-piece acrylic soft IOL. Both the length of the decentration and the degree of the tilt of the IOL were quantitated using the Anterior Eye Segment Analysis System (EAS-1000). All eyes underwent EAS-1000 examinations at 1 week as well as 1, 3, 6, 9, and 12 months after surgery. RESULTS: All IOLs were confirmed to be implanted accurately in the capsular bag after continuous curvilinear capsulorhexis was accomplished. No statistically significant differences were observed regarding the IOL decentration or tilt between the various postoperative periods in any of the three IOL groups. Furthermore, the differences regarding both the IOL decentration and the tilt between the three IOLs were not determined to be statistically significant throughout the observation period. CONCLUSIONS: As long as the IOL was placed properly in the capsular bag after the continuous capsulorhexis, neither the decentration nor the tilt of the IOL showed a significant progression up to 12 months after surgery. Furthermore, both the extent of the decentration and tilt almost were the same among the PMMA, silicone, and acrylic soft IOLs.

Acrylic Resins↗

PubMed1997

Hypogammaglobulinaemia in a patient with ring chromosome 21.

An 8 year old boy with ring chromosome 21 who was susceptible to sinorespiratory infections due to hypogammaglobulinaemia is reported. He presented with the characteristic features of monosomy 21 syndrome, such as psychomotor retardation, hypertonia, large saccular ears, prominent nasal bridge, micrognathia, thrombocytopenia, and patent ductus arteriosus. His serum IgG concentration was less than 1.5 g/l at 3 years and 6 months of age after repeated hospitalisations with pneumonia, otitis media, and convulsions. Regular replacement of intravenous gammaglobulin effectively reduced such infectious episodes. A predisposition to infection in patients with ring chromosome 21 may be explained by hypogammaglobulinaemia and merit treatment with gammaglobulin.

Agammaglobulinemia↗

PubMed1996

Capsular capture of silicone intraocular lenses.

PURPOSE: To examine the incidence of capsular capture in silicone IOL implantation and determine its effect on visual acuity. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: This study comprised 144 eyes that had phacoemulsification with three-piece silicone intraocular lens (IOL) implantation that were evaluated about 3 months after surgery. The examination included the status of the haptic and optic placement, extent of posterior capsular opacification (PCO), and the best corrected visual acuity. RESULTS: One hundred twenty-eight eyes had an in-in haptic placement, 15 had in-out placement, and 1 had out-out placement. Capsular capture occurred in 30 eyes (20.8%). The extent of PCO in eyes with capsular capture was greater than in those without capture. The best corrected visual acuity in eyes with capsular capture was worse than in those without capture. In addition, eyes with in-out and out-out haptic placement had significantly worse PCO and visual impairment than the eyes with in-in placement. CONCLUSION: There was a high incidence of capsular capture after silicone IOL implantation. This complication, along with the undesirable placement of the haptics, led to PCO and thus visual impairment.

Humans↗

PubMed1996

Risk factors for corneal endothelial injury during phacoemulsification.

PURPOSE: To determine the principal risk factors for corneal endothelial injury during phacoemulsification. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: We prospectively investigated 859 consecutive eyes of 800 patients who had had phacoemulsification surgery. The percentage of corneal endothelial cell loss at 3 months after surgery was quantitated using specular microscopy. The firmness of the nucleus was graded by Emery's classification prior to surgery. We selected nine variables that could be associated with endothelial injury. The univariate associations between the endothelial cell loss and these variables were evaluated using simple correlation coefficients. A multiple linear regression analysis was performed to identify independent predictors of endothelial cell loss. RESULTS: In the simple regression analysis, older age, small pupil diameter, high nucleus grade, large nucleus, greater infusion volume, type of IOL implanted, and a greater amount of total emitted ultrasound energy were univariately associated with endothelial cell loss. In the multiple linear regression analysis, the best final model (R2 = 0.42) identified high nucleus grade, greater infusion volume, type of IOL implanted, and large nucleus as independent predictors of endothelial cell loss. CONCLUSION: Both univariate and multivariate analyses identified the firmness of the nucleus as the most significant risk factor for endothelial cell loss. Therefore, mechanical contact with nuclear fragments is considered the principal cause of endothelial injury.

Adult↗

PubMed1996

[Changes in axial length after scleral buckling surgery].

The eye lengthens after scleral buckling surgery for retinal detachment. We investigated the changes in axial length and refraction after scleral buckling. A total of 89 eyes from 88 patients which were all scheduled to undergo scleral buckling were included in this study. The eyes were classified into four groups based on the type of buckling procedures:1 local buckling, 2 encircling, 3 encircling with vitrectomy, and 4 encircling with local buckling. We examined the axial length of these eyes using ultrasonography, preoperatively and at 1, 3, and 6 months postoperatively. The refractive changes were also examined. Depending on the type of scleral buckling procedure employed, the eyes in Groups 2, 3, and 4 clearly lengthened, but those of Group 1 did not. The amount of axial lengthening in Groups 2, 3, and 4 was significantly greater than in Group 1 at 3 and 6 months after surgery. In the spherical equivalent, a myopic shift occurred in the eyes in Groups 2, 3, and 4, and this shift was significantly greater than in Group 1 In addition, the correlation between the extent of axial lengthening and myopic shift was significant. In conclusion, the axial length increases with a myopic shift due to encircling, whereas local buckling changed the axial length only slightly.

Adolescent↗

PubMed1995

The correlation between incision size and corneal shape changes in sutureless cataract surgery.

PURPOSE: To examine the correlation between incision size and corneal shape changes in sutureless surgery using corneal topography. METHODS: Two hundred eyes undergoing sutureless cataract surgery were assigned randomly to three groups according to the incision size: group A, 3.2-mm incision; group B, 4.0-mm incision; and group C, 5.0-mm incision. All eyes were examined by corneal topography preoperatively as well as at 1 week and at 1, 3, and 6 months after surgery. RESULTS: In the average of difference maps of eyes in the 3.2-mm incision group, a wound-related flattening in the peripheral cornea occurred 1 week after surgery, but decreased rapidly thereafter. Subsequently, no significant changes were observed in the cornea after 1 month. In the 4.0-mm incision group, with a reduction of the wound-related peripheral flattening, an irregular steepening appeared in the lower central cornea 6 months after surgery. In the 5.0-mm incision group, a similar steepening in the lower cornea occurred just after surgery. This steepening persisted and even extended to the upper central cornea in its later postoperative periods. CONCLUSION: The 3.2-mm incision hardly produced any irreversible corneal shape changes, whereas both the 4.0- and 5.0-mm incisions caused a persistent irregular steepening in the central cornea.

Adult↗

PubMed1994

Corneal endothelial cell loss after phacoemulsification using nuclear cracking procedures.

This study assessed corneal endothelial damage in endocapsular phacoemulsification surgery using a nuclear cracking procedure in which the nucleus was divided into four quadrants and emulsified. Forty-five eyes had phacoemulsification using this technique, and 33 eyes had phacoemulsification using undivided sculpting techniques (without cracking). We examined the extent of endothelial cell loss at one and three months after surgery using specular microscopy. We also measured ultrasound time, time spent for phacoemulsification, and infusion volume during surgery. Endothelial cell loss was significantly less in the nuclear cracking group than in the undivided sculpting group. Ultrasound time in surgery with cracking was significantly shorter than that in surgery without cracking. The time for the phacoemulsification maneuvers and the infusion volume were the same for both procedures. These findings indicate that the ultrasound time was shortened using the nuclear cracking technique and resulted in less corneal injury.

Aged↗