Biomedical subjects

T Oshika

Publications and source records attributed to T Oshika.

At least 55 records · Page 3Linked to original sources

PubMed2000

Effects of pterygium on corneal spherical power and astigmatism.

OBJECTIVE: To evaluate prospectively the corneal refractive status before and after pterygium surgery and its relationship with preoperative pterygium size. DESIGN: Prospective, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: One hundred thirty-six eyes undergoing primary pterygium removal surgery. MAIN OUTCOME MEASURES: Corneal spherical power, astigmatism, surface regularity index (SRI), and surface asymmetry index (SAI) before and after surgery, and the preoperative pterygium size. RESULTS: Before surgery, pterygium size significantly correlated with spherical power (Pearson's correlation coefficient, r = -0.370, P < 0.001), astigmatism (r = 0.600, P < 0.001), SRI (r = 0.367, P < 0.001), and SAI (r = 0.387, P < 0.001). The surgery significantly increased spherical power of the cornea, whereas astigmatism, SRI, and SAI were significantly decreased by the surgery (P < 0.01, paired t test with Bonferroni's correction of P value for multiple comparison). Surgically induced changes in spherical power (r = 0.598, P < 0.001) and astigmatism (r = 0.653, P < 0.001) significantly correlated with the preoperative pterygium size. Precise prediction of the magnitude of refractive changes based on the preoperative pterygium size was difficult. CONCLUSIONS: The presence of pterygium and its removal significantly influence the corneal refraction including spherical power, astigmatism, asymmetry, and irregularity, with the larger pterygium exerting the greater influence.

Adult↗

PubMed2000

Regular and irregular astigmatism after superior versus temporal scleral incision cataract surgery.

OBJECTIVE: To evaluate the effect of superior and temporal scleral incisions on regular and irregular astigmatism in small incision cataract surgery. DESIGN: Prospective, randomized, comparative clinical trial. PARTICIPANTS: One hundred seventy-four eyes of 87 patients with bilateral cataracts scheduled to undergo routine cataract surgery. METHODS: One eye of each patient was randomly assigned to the superior incision group, and the contralateral eye was allocated to the temporal incision group. Phacoemulsification and intraocular lens implantation were performed through an unsutured 4.1-mm scleral incision. Patients were examined 1 day and 1, 3, and 6 months after surgery. MAIN OUTCOME MEASURES: Surgically-induced regular astigmatism calculated with vector analysis method, irregular astigmatism obtained by Fourier analysis of videokeratography data, and uncorrected and corrected visual acuity. RESULTS: Postoperatively, the superior incision group showed slight against-the-rule astigmatic changes, whereas slight with-the-rule astigmatism was seen in the temporal incision group. The amount of against-the-wound astigmatism and absolute value of length of the induced vector did not differ significantly between groups (P > 0.05, paired t test). In both groups, irregular astigmatism 1 day after surgery was significantly greater than the preoperative levels (P < 0.001), but not thereafter. No significant intergroup difference was observed in the amount of irregular astigmatism at any postoperative visits (P > 0.05). There was no significant difference in uncorrected and corrected visual acuity between groups postoperatively (P > 0.05, chi-square test). CONCLUSIONS: In small scleral incision cataract surgery, superior and temporal approaches are comparable in terms of visual rehabilitation and induction of regular and irregular astigmatism.

Aged↗

PubMed2000

Influence of excimer laser photorefractive keratectomy on the posterior corneal surface.

PURPOSE: To investigate the influence of excimer laser photorefractive keratectomy on the refraction and geometry of the posterior corneal surface. SETTING: Miyata Eye Hospital, Miyazaki, Japan. METHODS: Thirty-seven eyes of 21 patients with refractive errors of -2.00 to -9.75 diopters (D) were treated with the VISX Twenty-Twenty excimer laser system. The refractive and anteroposterior changes in the posterior corneal surface were measured using scanning-slit corneal topography (Orbscan, Orbtek, Inc.) preoperatively and 1 week and 1 and 3 months postoperatively. RESULTS: Mean posterior corneal refraction was -6.51 D +/- 0. 29 (SD) preoperatively; it decreased to -7.00 +/- 0.49 D, -7.00 +/- 0.55 D, and -6.92 +/- 0.42 D at 1 week, 1 month, and 3 months, respectively (P <.001, Tukey multiple comparison). Mean forward shift of the posterior corneal surface was 29.5 +/- 1.9 microm, 34.4 +/- 3.4 microm, and 54.3 +/- 4.0 microm at 1 week, 1 month, and 3 months, respectively. The amount of posterior corneal refractive change correlated with the degree of forward shift (r= -0.691, P <. 001). The residual corneal thickness correlated with the refractive change (r = 0.524, P <.001) and the forward shift (r = -0.851, P <. 001) of the posterior corneal surface. CONCLUSION: Photorefractive keratectomy induced significant refractive changes in the posterior corneal surface and forward shift of the cornea, both of which correlated with the thinness of the residual cornea.

Adult↗

PubMed2000

Fourier analysis of irregular astigmatism after implantation of 3 types of intraocular lenses.

PURPOSE: To evaluate irregular astigmatism after silicone, acrylic, and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation using Fourier analysis of videokeratography data. METHODS: Two hundred forty eyes having phacoemulsification and IOL implantation were randomly assigned to 1 of 3 groups: 3.5 mm incision and silicone IOL, 4.1 mm incision and acrylic IOL, or 6.5 mm incision and PMMA IOL. All eyes had videokeratographic examinations preoperatively and 2, 4, and 10 days and 1 and 3 months postoperatively. The dioptric data of the central cornea were decomposed into spherical equivalent, regular astigmatism, and irregular astigmatism (decentration and higher-order irregularity) components using Fourier analysis. RESULTS: Regular astigmatism in the PMMA group was greater than in the silicone and acrylic groups. Decentration in all 3 groups increased significantly postoperatively but virtually returned to preoperative levels by 10 days. No significant difference was observed among the 3 groups. Higher-order irregularity significantly increased after surgery in all 3 groups. The higher-order irregularity in the PMMA group persisted for up to 1 month, while that in the silicone and acrylic groups returned to preoperative levels by 4 days, resulting in significant differences between these groups 10 days and 1 month after IOL implantation. CONCLUSION: Irregular astigmatism, both the decentration and higher-order irregularity components, increased significantly after 3 types of scleral tunnel incisions for silicone, acrylic, or PMMA IOL implantation but returned to preoperative levels soon after surgery except for the higher order irregularity after PMMA IOL implantation.

Acrylic Resins↗

PubMed2000

Effect of anti-inflammatory agents on corneal wound-healing process after surface excimer laser keratectomy.

PURPOSE: To investigate the effect of anti-inflammatory agents on conjunctival inflammation and corneal haze formation after excimer laser keratectomy. SETTING: Department of Ophthalmology, University of Tokyo Faculty of Medicine, Tokyo, Japan. METHODS: After excimer laser keratectomy was performed in 21 rabbits (42 eyes), saline, betamethasone 0.1%, or diclofenac 0.1% was topically applied 6 times a day for 4 weeks and then 3 times a day for 8 weeks. The degree of conjunctival inflammation was determined 1, 2, 3, and 7 days after the keratectomy. The degree of corneal haze was quantitatively measured using a digital analyzer before and once a week after the keratectomy. The expression of type IV collagen in the corneas at baseline and 4 and 12 weeks after the keratectomy was examined immunohistochemically. RESULTS: Compared with saline, betamethasone and diclofenac significantly decreased early-phase conjunctival inflammation. Betamethasone significantly inhibited corneal haze formation compared with saline at 3 to 5 and 8 to 12 weeks. Diclofenac did not inhibit corneal haze formation significantly. Although betamethasone tended to be more effective in inhibiting corneal haze formation and deposition of type IV collagen than diclofenac, there was no statistical difference between the 2 anti-inflammatory agents. CONCLUSION: Topically applied betamethasone effectively suppressed corneal haze formation after excimer laser keratectomy. Diclofenac was not statistically effective in inhibiting corneal haze formation.

Animals↗

PubMed2000

Histocompatibility Y antigen compatibility and allograft rejection in corneal transplantation.

PURPOSE: To assess the effects of histocompatibility Y (H-Y) antigen matching on the rate of corneal allograft rejection after penetrating keratoplasty (PKP). METHODS: We retrospectively investigated the graft survival rate and rejection-free graft survival rate after PKP in 396 eyes. The compatible combinations of H-Y antigen included male donors and male recipients (n = 135), female donors and male recipients (n = 107), and female donors and female recipients (n = 60). Incompatible combination was from male donors and female recipients (n = 94). The eyes were classified into two groups--high-risk (168 eyes) and low-risk (228 eyes)--depending on the degree of vascularisation in the recipient corneas or a history of previous allograft rejection. Data were analysed using the Kaplan-Meier life table method, the log-rank test and the Cox proportional hazards model. RESULTS: In both the high-risk and low-risk groups, the graft survival and rejection-free graft survival rates were not affected by the H-Y compatibility. The graft survival (p < 0.001) and rejection-free graft survival (p < 0.001) rates were higher in the low-risk group than in the high-risk group. High-risk PKP was associated with greater risk of graft failure (risk ratio, 2.33) and rejection (risk ratio, 2.05) than low-risk PKP. CONCLUSION: H-Y antigen matching does not influence the rate of allograft rejection after PKP.

Corneal Diseases↗

PubMed2000

Comparative study of intraoperative mitomycin C and beta irradiation in pterygium surgery.

AIMS: To compare the rate of recurrence and complication after surgery for primary pterygium performed by one surgeon using either intraoperative mitomycin C or beta irradiation. METHODS: A retrospective study was performed of 164 eyes in 164 patients who had undergone primary pterygium surgery. After the pterygium was excised, the bare sclera was covered by sliding adjacent superior conjunctiva. 103 eyes received intraoperative mitomycin C (0.04%, 150 seconds) and 61 eyes beta irradiation (total dose 21.6 Gy). The mean follow up period was 20.2 (SD 17.9) months (range 1-66 months). Recurrence was defined as the postoperative regrowth of fibrovascular tissue crossing the corneoscleral limbus. RESULTS: The recurrence rate after mitomycin C and beta irradiation was 8.74% and 23.0% of eyes, respectively, after mean follow up of 17.9 and 31.2 months, respectively. The Kaplan-Meier survival analysis revealed a significantly better outcome for those who had intraoperative mitomycin C (Mantel-Cox log rank analysis, p=0.031). The mean interval to recurrence was not significantly different between the two groups. During the follow up, none of the patients showed side effects or reactions related to mitomycin C or beta irradiation. CONCLUSIONS: The intraoperative administration of 0.04% mitomycin C is more effective than beta irradiation as an adjunctive treatment for pterygium surgery in the patient population examined in this study.

Adult↗

PubMed2000

Advanced glycation end products in diabetic corneas.

PURPOSE: Corneal complications are often associated with diabetes mellitus and can be vision threatening. Corneas in diabetic patients are exposed to increased glucose concentration despite cornea's avascular property, and this condition may contribute to the accumulation of advanced glycation end products (AGEs). The focus of this study was to examine the role of AGEs in the pathogenesis of diabetic keratopathy. METHODS: An anti-AGE monoclonal antibody (6D12), which recognizes a N(epsilon)-carboxymethyl lysine (CML)-protein adduct as an epitope, was prepared. Immunohistochemical localization of CML was examined in human age-matched diabetic and nondiabetic corneas (8 of each). In vitro, type I collagen-, type IV collagen-, or laminin-coated 96-well plates were glycated by glucose-phosphate. In some experiments, aminoguanidine was present in the incubation mixture. The amounts of CML-protein adducts in the extracellular matrix (ECM) were determined by enzyme-linked immunosorbent assay using 6D12. SV40-immortalized human corneal epithelial cells were seeded onto modified or unmodified ECM in 96-well plates and allowed to attach for 3 hours. Attached cells were fixed, and the areas of attached cells in each condition were measured. Attached cells without fixation were removed, and cell number was counted. RESULTS: In all of the 8 diabetic corneas, CML immunoreactivity was observed in the epithelial basement membrane, whereas CML immunoreactivity was not found in the corresponding area in 7 of 8 nondiabetic corneas. In vitro, nonenzymatic glycation of laminin on the culture dish attenuated adhesion and spreading of corneal epithelial cells. The presence of amninoguanidine in the incubation mixture during glycation inhibited CML formation and promoted the adhesion and spreading of corneal epithelial cells in a dose-dependent manner. CONCLUSIONS: The accumulation of AGEs on the basement membrane, particularly on laminin, may play a causative role in the corneal epithelial disorders of diabetic patients.

Aged↗

PubMed2000

Expression regulation of hyaluronan synthase in corneal endothelial cells.

PURPOSE: Our previous study showed that hyaluronan synthase (HAS), the enzyme protein of hyaluronan (HA) biosynthesis, is expressed in ocular tissues including the corneal endothelium. In the current study, the mechanism that regulates HAS expression in bovine corneal endothelial cells (BCECs) was investigated. METHODS: Cultured BCECs were used. HAS expression in BCECs at the mRNA level was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis. The effects of transforming growth factor (TGF)-beta and platelet-derived growth factor (PDGF)-BB on HAS expression were examined by quantitative RT-PCR. The involvement of the Smad family (intracellular signal transducer of TGF-beta) was also investigated. The expression of HAS in BCECs at the protein level was confirmed by immunocytochemistry and Western blot analysis. RESULTS: Three HAS isoforms in BCECs were expressed at the mRNA level. The transcriptional sizes of each HAS in BCECs were 4.9 kb for HAS1, 2.8 kb for HAS2, and 1.6 kb for HAS3. The expression of HAS2 at the mRNA level was stimulated by TGF-beta1 and/or PDGF-BB treatment. In contrast, HAS1 and HAS3 expression was not affected by these growth factors. The additive effects of TGF-beta1 and PDGF-BB were observed in the stimulation of the expression levels of HAS2. HAS2 upregulation by these growth factors was also detected by Western blot analysis. The stimulation of the expression of HAS2 at the mRNA level by TGF-beta was accelerated by the overexpression of Smad2, Smad3, and Smad4 and inhibited by that of Smad7, all of which were confirmed to be involved in the signal transduction from TGF-beta through HAS expression. CONCLUSIONS: Although three HAS isoforms were expressed in the corneal endothelial cells, the expression of HAS2 was upregulated by TGF-beta1 and/or PDGF-BB. HAS2 expression was regulated by TGF-beta through Smad family members.

Amino Acid Sequence↗

PubMed1999

Effects of endothelin receptor antagonists on anterior chamber inflammation induced by intravitreal injection of endothelin-1.

To investigate the role of endothelin receptors (ET(A) and ET(B)) in the inflammatory reaction induced by endothelin-1 (ET-1), the time course of changes in aqueous protein concentration (APC) after the intravitreal injection of ET-1 (10(-4), 10(-5) M) was measured using a laser flare-cell meter in pigmented rabbit eyes. The effects of pre-treatment with specific ET(A) receptor antagonist (97-139) (10(-1), 10(-2), 10(-3), 10(-4) M), specific ET(B) receptor antagonist (BQ-788) (1.6 x 10(-3) M), and vehicle solution were assessed. The influence of ET(A)receptor antagonist pre-treatment on aqueous prostaglandin E(2) and leukotriene B(4) concentrations was also evaluated. As a result, pre-treatment with ET(A) receptor antagonist blocked the APC increase induced by 10(-4) M ET-1 in a dose dependent fashion, while BQ-788 did not suppress the inflammatory reaction. The injection of ET-1 increased aqueous prostaglandin E(2) concentration, which was inhibited by pre-treatment with ET(A) receptor antagonist. Aqueous leukotriene B(4) concentration was not affected by ET-1 nor ET(A) receptor antagonist. In conclusion, ET(A) receptor mediates the increases in aqueous protein and prostaglandin E(2) concentration induced by ET-1 injection, and this inflammatory reaction occurs via the cyclooxygenase pathway of arachidonic acid cascade.

Animals↗

PubMed1999

Functional and molecular evidence for Na(+)-HCO3- cotransporter in human corneal endothelial cells.

Although bicarbonate transport in corneal endothelium has been suggested to be coupled to Na+, the underlying molecular mechanism has not been clarified. In the present study we investigated whether a recently cloned Na(+)-HCO3- cotransporter (NBC-1) is responsible for this process, and, if so, whether the endothelium expresses a separate isoform or one of the other two isoforms that have recently been identified (kNBC-1 from kidney and pNBC-1 from pancreas). Using primers designed for specific and common regions we demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) that both kNBC-1 and pNBC-1 are expressed in cultured human corneal endothelial cells. In addition functional studies with a pH-sensitive fluorescence probe were performed. In the presence of HCO3-/CO2 a pH regulatory process was demonstrated which depends on the presence of Na+ and membrane potential, but is independent of Cl- and is inhibited by the disulfonic stilbene DIDS. These results support the presence of NBC-1 as the major bicarbonate transport system in corneal endothelium.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed1999

Comparison of corneal wavefront aberrations after photorefractive keratectomy and laser in situ keratomileusis.

PURPOSE: To compare changes in the corneal wavefront aberrations after photorefractive keratectomy and laser in situ keratomileusis. METHODS: In a prospective randomized study, 22 patients with bilateral myopia received photorefractive keratectomy on one eye and laser in situ keratomileusis on the other eye. The procedure assigned to each eye and the sequence of surgery for each patient were randomized. Corneal topography measurements were performed preoperatively, 2 and 6 weeks, 3, 6, and 12 months after surgery. The data were used to calculate the wavefront aberrations of the cornea for both small (3-mm) and large (7-mm) pupils. RESULTS: Both photorefractive keratectomy and laser in situ keratomileusis significantly increased the total wavefront aberrations for 3- and 7-mm pupils, and values did not return to the preoperative level throughout the 12-month follow-up period. For a 3-mm pupil, there was no statistically significant difference between photorefractive keratectomy and laser in situ keratomileusis at any postoperative point. For a 7-mm pupil, the post-laser in situ keratomileusis eyes exhibited significantly larger total aberrations than the post-photorefractive keratectomy eyes, where a significant intergroup difference was observed for spherical-like aberration, but not for coma-like aberration. This discrepancy seemed to be attributable to the smaller transition zone of the laser ablation in the laser in situ keratomileusis procedure. Before surgery, simulated pupillary dilation from 3 to 7 mm caused a five- to six-fold increase in the total aberrations. After surgery, the same dilation resulted in a 25- to 32-fold increase in the photorefractive keratectomy group and a 28- to 46-fold increase in the laser in situ keratomileusis group. For a 3-mm pupil, the proportion of coma-like aberration increased after both photorefractive keratectomy and laser in situ keratomileusis. For a 7-mm pupil, coma-like aberration was dominant before surgery, but spherical-like aberration became dominant postoperatively. CONCLUSIONS: Both photorefractive keratectomy and laser in situ keratomileusis increase the wavefront aberrations of the cornea and change the relative contribution of coma- and spherical-like aberrations. For a large pupil, laser in situ keratomileusis induces more spherical aberrations than photorefractive keratectomy. This finding could be attributable to the smaller transition zone of the laser ablation in the laser in situ keratomileusis procedure.

Adult↗

PubMed1999

Herpes simplex virus in the trabeculum of an eye with corneal endotheliitis.

PURPOSE: To report an eye with corneal endotheliitis and increased intraocular pressure in which the trabeculum demonstrated immunoreactivity for herpes simplex virus. METHOD: Case report. A 62-year-old man presented with increased intraocular pressure, keratic precipitates, and corneal stromal edema in his left eye. The tissue excised during trabeculectomy was immunohistochemically examined for herpetic viruses. RESULT: Immunoreactivity for herpes simplex virus was identified in the trabeculum. CONCLUSION: Herpes simplex virus may cause trabeculitis and increased intraocular pressure in patients with corneal endotheliitis.

Acyclovir↗

PubMed1999

Relationship between apparent accomodation and corneal multifocality in pseudophakic eyes.

OBJECTIVE: To investigate whether any association exists between apparent accommodation in pseudophakic eyes and multifocal corneal effects. DESIGN: A prospective observational case series. PARTICIPANTS: A total of 121 eyes of 98 patients who had undergone phacoemulsification and posterior chamber intraocular lens implantation were studied. METHODS: The amount of apparent accommodation was measured using an accommodometer. The degree of corneal multifocality was determined on the corneal topography by measuring the maximum and minimum corneal refractive powers within the pupillary area. Refractive astigmatism, keratometric astigmatism, pupillary diameter, and age were also analyzed. MAIN OUTCOME MEASURES: Apparent accommodation, corneal multifocality, refractive and keratometric astigmatism, pupillary diameter, and age. RESULTS: Multiple regression analysis revealed that corneal multifocality and pupillary diameter had significant positive correlations with apparent accommodation, whereas other explanatory variables showed no relationship with apparent accommodation. CONCLUSION: Multifocal corneal effects contribute to apparent accommodation in pseudophakic eyes.

Accommodation, Ocular↗

PubMed1999

Severe iridodialysis from phacoemulsification tip suction.

During cataract surgery, the iris of an 83-year-old woman was strongly sucked into the phacoemulsification tip twice, resulting in severe iridodialysis. The dehisced iris was sutured to the sclera using double-armed 10-0 polypropylene on a long curved needle. Intensive suction of the iris by the phacoemulsification tip can lead to severe iridodialysis. Machine setting parameters, particularly flow rate, should be lowered after the first iris suction to avoid further iris damage.

Aged↗

PubMed1999

Influence of phacoemulsification and intraocular lens implantation on the course of diabetic retinopathy.

PURPOSE: To study the effect of phacoemulsification and posterior chamber intraocular lens implantation on the course of diabetic retinopathy using the nonoperated fellow eye as a control. SETTING: Departments of Ophthalmology, Diabetes Center, Tokyo Women's Medical University, and University of Tokyo School of Medicine, Tokyo, Japan. METHODS: One eye of 66 diabetic patients who preoperatively had a similar stage of retinopathy in both eyes or no retinopathy bilaterally had cataract surgery. The course of diabetic retinopathy was followed for 1 year postoperatively. Patients were placed into 1 of 2 groups: Group A, progression of retinopathy in the operated eye was attributable to the surgical invasion (i.e., there was progression of retinopathy only in the operated eye or more progression in the operated eye than in the nonoperated fellow eye); Group B, no deterioration of retinopathy bilaterally, comparable level of deterioration in both eyes, or greater progression in the nonoperated eye than in the operated eye. RESULTS: Surgery resulted in retinopathy progression in 16 patients (24.2%, Group A): 13 with unilateral deterioration and 3 with greater progression in the operated than in the nonoperated fellow eye. Of the remaining 50 patients (75.8%, Group B), 39 presented no significant progression in either eye, 8 had bilaterally comparable progression, and 3 showed progression in the nonoperated fellow eye only. Retinopathy worsened in the operated eye in 24 cases (36.3%); of these, changes in 16 patients were attributed to surgical influence. There was no significant difference between Groups A and B in age, diabetes mellitus duration, diabetes treatment method, and preoperative and postoperative hemoglobin A1c levels. The distribution of preoperative retinopathy stage significantly differed between groups, with more patients without retinopathy in Group A and more patients with advanced retinopathy in Group B. CONCLUSION: Factors such as age, diabetes mellitus duration, diabetes treatment method, and hemoglobin A1c level did not affect the progression of retinopathy; however, preoperative status of retinopathy may influence the susceptibility of the retinopathy to surgical invasion. A considerable proportion of eyes with aggravation of retinopathy would reflect the natural course of the disease, systemic factors, or both rather than the influence of cataract surgery.

Adult↗

PubMed1999

Anesthetic dose and analgesic effects of sub-Tenon's anesthesia in cataract surgery.

PURPOSE: To compare the analgesic effects of different doses of sub-Tenon's anesthesia in cataract surgery by assessing patient response to visceral stimulus. SETTING: Inouye Eye Hospital, Tokyo, Japan. METHODS: A prospective study was done of 1019 eyes of 1019 patients having phacoemulsification and posterior chamber intraocular lens implantation. They received a 1.0 mL (391 eyes), 2.0 mL (366 eyes), or 3.0 mL (262 eyes) anesthetic infiltration into the sub-Tenon's space. Pain scores were recorded when the anterior chamber was irrigated with an acetylcholine chloride solution to attain miosis after lens implantation. RESULTS: The distribution of pain scores was significantly different among the 3 groups (P < .0001, Kruskal-Wallis test). Multiple comparison revealed that the 3.0 mL anesthetic infiltration offered significantly higher analgesic effects than the 2 lower doses. The 3.0 mL sub-Tenon's anesthesia effectively blocked the visceral stimulus. CONCLUSION: For cataract surgery, 3 mL is the optimal dose of anesthetic solution in sub-Tenon's anesthesia.

Aged↗

PubMed1999

Radial keratotomy to treat myopic refractive error after cataract surgery.

PURPOSE: To assess the predictability and effectiveness of radial keratotomy in patients with myopic refractive error and unacceptable anisometropia after cataract surgery. SETTING: A prospective multicenter study. METHODS: This study comprised 40 eyes of 40 Japanese patients who had had cataract surgery. Radial keratotomy was performed, and the 6 month postoperative data were analyzed. RESULTS: Mean patient age was 71.0 years +/- 7.4 (SD) (range 51 to 84 years) and mean preoperative anisometropia -3.41 +/- 1.69 D (range -1.25 to -7.75 D). The surgery decreased mean anisometropia to -1.01 +/- 0.94 D (P < .000001, Wilcoxon signed-rank test), a mean reduction of 2.22 +/- 1.23 D (range 0.75 to 5.88 D). Postoperative anisometropia ranged from 0.81 to -3.13 D. The surgical effects were overestimated by the nomograms developed for the correction of naturally occurring myopia in the eyes of white patients. Multiple regression analysis revealed that optical zone size and number of incisions were significantly correlated with the amount of myopic correction, and the regression equation (R2 = 0.77) was expressed as follows: Effects = (-1.45 x optical zone size) + (0.24 x incision number) + 7.60. A new nomogram was derived based on this equation. CONCLUSIONS: Radial keratotomy was a safe and efficient procedure to treat myopic refractive error in pseudophakic eyes. Separate nomograms are necessary for white and Asian populations.

Aged↗