Fuminori Nakao

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.

Changes in anterior chamber angle width and depth after intraocular lens implantation in eyes with glaucoma

OBJECTIVE To examine the changes in anterior chamber angle width and depth induced by intraocular lens (IOL) implantation in eyes with angle-closure glaucoma (ACG), in eyes with open-angle glaucoma (OAG), and in eyes with no evidence of glaucoma or ocular hypertension. DESIGN A comparative, nonrandomized, interventional study. PARTICIPANTS Seventy-seven eyes with ACG, 73 eyes with OAG, and 74 control eyes undergoing cataract extraction and IOL implantation. INTERVENTION All eyes underwent phacoemulsification and soft acrylic IOL implantation. MAIN OUTCOME MEASURES The angle width and depth of the anterior chamber were measured using a Scheimpflug videophotography system before surgery, and at 1 week and at 1, 3, 6, 9, and 12 months after surgery. RESULTS Before surgery, the mean anterior chamber angle width and depth in the ACG group was less than that in either the OAG or control groups by approximately 10 degrees in angle width and 1.0 mm in depth (P < 0.0001). After cataract extraction and IOL implantation, the angle width and depth increased significantly in all three groups (P < 0.0001). Although the width and depth in the ACG group were still smaller than that in the other groups, the differences decreased to 2 degrees for angle width and 0.3 mm for depth. In addition, no significant differences were found in these values between the OAG and control groups before or after surgery. Furthermore, no significant changes were observed in the angle width or depth in any of the three groups throughout the postoperative observation period. As expected, the mean preoperative intraocular pressure (IOP) in the ACG and OAG groups was higher than that in the control group. After cataract surgery, however, the mean IOP decreased significantly and was almost the same in all three groups at 1, 6, and 12 months after surgery. CONCLUSIONS The width and depth of the anterior chamber angle in eyes with ACG increased significantly after cataract extraction and IOL implantation and became similar to that in eyes with OAG and that in normal eyes, which may lead to the decrease in IOP seen in the postoperative period. No significant changes were observed in angle width and depth in any of the three groups after surgery.

Effect of cataract surgery on intraocular pressure control in glaucoma patients

Purpose: To examine the effect of cataract surgery on intraocular pressure (IOP) control in eyes with angle‐closure glaucoma (ACG) and open‐angle glaucoma (OAG). Setting: Hayashi Eye Hospital, Fukuoka, Japan. Methods: This study included 74 eyes with ACG and 68 eyes with OAG having cataract surgery. The IOP was measured and the number of glaucoma medications recorded preoperatively, 1 month postoperatively, and then every 3 months. The IOP control in the 2 groups was compared using survival analysis, with failure criteria being an IOP greater than 21 mm Hg, addition of medications, or the need for additional glaucoma surgery. Results: The mean IOP and number of medications decreased significantly after surgery in both groups (P < .0001). However, the mean decrease in IOP and percentage of IOP reduction in the ACG group were greater than in the OAG group, and fewer medications were required in the ACG group. The cumulative survival probability of IOP control at 24 months was 91.9% in the ACG group and 72.1% in the OAG group. The survival curve in the ACG group was significantly better than in the OAG group (P = .0012). The IOP was controlled without medication in 30 eyes (40.5%) in the ACG group and 13 (19.1%) in the OAG group; the difference between groups was significant (P = .0055). Conclusions: Cataract surgery substantially reduced IOP and the number of medications required for IOP control in glaucomatous eyes. Specifically, cataract extraction normalized the IOP in most eyes with ACG.

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.

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.

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.

Correlation between pupillary size and intraocular lens decentration and visual acuity of a zonal-progressive multifocal lens and a monofocal lens

OBJECTIVE To see whether there is a correlation between pupillary area or intraocular lens (IOL) decentration and tilt and the visual acuity (VA) at all distances for eyes with a zonal-progressive multifocal IOL or a monofocal IOL. DESIGN Comparative, nonrandomized, interventional study. PARTICIPANTS Fifty-five eyes of 55 patients undergoing five-zone refractive multifocal IOL implantation and 55 eyes of 55 age-matched patients undergoing monofocal IOL implantation. INTERVENTION All eyes underwent phacoemulsification and IOL implantation. MAIN OUTCOME MEASURES The VAs from far to near distances were examined using an all-distance vision tester at 1 month after surgery. The pupillary area was also measured using an infrared pupillometer, and the degrees of IOL decentration and tilt were measured using a Scheimpflug videophotography system. Univariate associations between VA and the pupillary area and IOL decentration or tilt were evaluated statistically. RESULTS The mean intermediate VAs and contrast sensitivities at all spatial frequencies in the multifocal IOL group were worse than those in the monofocal IOL group, whereas near VA was better in the multifocal group. In the multifocal group, smaller pupillary area was associated significantly with worse near logarithm of the minimum angle of resolution (LogMAR) VA (r = 0.636), but not with far or intermediate VAs. When pupil diameter was 4.5 mm or greater, near mean VA reached 20/63. A greater degree of IOL decentration was associated significantly with worse far and intermediate LogMAR VAs (r = 0.460 at 5.0 m and 0.527 at 1.0 m) but not with near VA. When decentration was 0.9 mm or greater, distance mean VA did not reach 20/32. However, the correlation between tilt and VA was not statistically significant. In the monofocal group, no significant correlation was found between pupillary area, IOL decentration, or tilt and the VA. CONCLUSIONS Smaller pupil size is correlated significantly with worse near VA, whereas greater decentration is correlated with worse distance and intermediate VA in eyes with refractive multifocal IOLs. Specifically, a pupil diameter of less than 4.5 mm cannot provide useful near VA, and decentration of 0.9 mm is the maximum allowable limit for adequate distance VA. However, pupil size and IOL decentration do not influence VA in eyes with monofocal IOLs.

Changes in posterior capsule opacification after poly(methyl methacrylate), silicone, and acrylic intraocular lens implantation.

Purpose: To prospectively evaluate the progression of posterior capsule opacification (PCO) after poly(methyl methacrylate) (PMMA), silicone, and acrylic intraocular lens (IOL) implantation. Setting: Hayashi Eye Hospital, Fukuoka, Japan. Methods: Three hundred eyes of 300 patients scheduled to have IOL implantation were initially randomized into 3 groups based on IOL type: PMMA, silicone, or acrylic. Of the 300 eyes, 269 completed the follow‐up. The PCO density in these eyes was measured 1 week and 3, 6, 12, 18, and 24 months postoperatively using special computer software developed for the Scheimpflug videophotography system. Visual acuity and the incidence of neodymium:YAG (Nd:YAG) laser capsulotomy were also examined. Results: Three months postoperatively and later, the mean PCO value in the PMMA group increased significantly (P < .0001); the increase in the silicone and acrylic groups was not significant. The PCO value in the PMMA group was significantly greater than in the silicone or acrylic group (P < .0001). The PCO value in the acrylic group was slightly less than in the silicone group at 18 and 24 months, but the difference was marginal. The survival rate not requiring Nd:YAG capsulotomy was least in the PMMA group, followed by the silicone and acrylic groups in that order (P < .0001). The mean logMAR visual acuity in the PMMA group increased postoperatively and was worse than in the silicone or acrylic group. Conclusions: The degree of PCO after PMMA IOL implantation progressed significantly with time, while the progression after silicone and acrylic IOL implantation was slight. Therefore, PCO in eyes with a PMMA IOL was significantly more extensive than in those with a silicone or acrylic IOL and resulted in marked impairment of visual acuity.

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.

Intraocular lens tilt and decentration, anterior chamber depth, and refractive error after trans-scleral suture fixation surgery.

OBJECTIVES To compare the extent of intraocular lens (IOL) tilt and decentration, as well as the anterior chamber depth after trans-scleral suture IOL fixation after either secondary out-of-the-bag or primary in-the-bag IOL implantation. DESIGN Retrospective, comparative, nonrandomized, interventional study. PARTICIPANTS Fifty-two eyes that underwent scleral suture fixation were compared with 51 eyes that underwent secondary out-of-the-bag implantation and 50 eyes that underwent in-the-bag implantation. INTERVENTION One-piece polymethyl methacrylate IOL implantation by three different techniques. MAIN OUTCOME MEASURES The tilt angle and decentration length of the IOL, as well as the anterior chamber depth, were measured by the Scheimpflug videophotography system. The spherical equivalent error from the predicted value was also examined. RESULTS The mean tilt angle in the scleral suture fixation group was significantly greater than that in either the out-of-the-bag or the in-the-bag implantation group (P<0.0001). The mean decentration length was also largest in the suture group, followed by the out-of-the-bag group and the in-the-bag group (P<0.0001). The anterior chamber depth in the suture group and the out-of-the-bag group was significantly smaller than that in the in-the-bag group (P<0.0001). The spherical equivalent error in the suture group and the out-of-the-bag group was also greater than that in the in-the-bag group (P<0.0001). CONCLUSIONS The extent of both tilt and decentration after scleral suture fixation was greater than that observed after either out-of-the-bag or in-the-bag implantation. The anterior chamber depth with the sutured or out-of-the-bag fixated IOL was shallower than that with the in-the-bag fixated IOL, which resulted in a significant myopic shift.