Shigeo Yaguchi

Two year clinical study of a soft acrylic intraocular lens

Purpose: To assess the efficacy and safety of a soft acrylic intraocular lens (IOL) in small incision cataract surgery. Methods: Sixty‐four eyes of 64 patients (mean age 71.0 ± 7.7 [SD] years) who had phacoemulsification and implantation of a soft acrylic IOL were followed for 2 years. Results: At day 1, 96.9% of patients had corrected visual acuity of 20/40 or better, and 50.0% had 20/20 or better. At 2 years postoperatively, 100% had 20/40 or better, and 86.3% had 20/20. Surgically induced keratometric cylinder remained quite stable throughout the 2 year follow‐up period, with axis‐based astigmatism of ±0.3 diopters. Flare intensity measured with the laser flare‐cell meter was less than that with other type of IOLs measured, including poly(methyl methacrylate) and silicone. Neodymium:YAG laser capsulotomy was performed in seven cases (11.1 %) without causing damage to the optic. No other postoperative complications were encountered. Conclusion: Soft acrylic IOLs have clinically apparent advantages in small incision cataract surgery.

Comparative Study of Intraocular Lens Implantation Through 3.2- and 5.5-mm Incisions

PURPOSE To prospectively and comprehensively compare the clinical results of two small-incision cataract surgery procedures, silicone intraocular lens (refractive index of 1.46) implantation through a 3.2-mm incision and polymethylmethacrylate intraocular lens implantation through a 5.5-mm incision. METHODS Two hundred eyes with cataract randomly were assigned to either procedure. Except for incision size, identical surgical methods were used in every case. Data on uncorrected and corrected visual acuity, keratometry, corneal topography, flare-cell measurement, fluorophotometry, specular microscopy, glare disability measurement, and photographic examination of intraocular lens decentration were analyzed up to 6 months after surgery. RESULTS Eyes in the 3.2-mm incision group displayed significantly better uncorrected and corrected visual acuity in the early postoperative period, lower aqueous flare intensity and cell counts immediately after surgery, less operatively induced astigmatism throughout the study period, and less corneal topographic changes taken 3 months after surgery. No significant between-group differences were noted for other parameters. Complications in the two groups were few and comparable. CONCLUSION Both procedures of small-incision cataract surgery offered satisfactory clinical results, but 3.2-mm incision cataract surgery allowed significantly earlier recovery of visual function and better preservation of corneal shape.

Cytotoxicity of ophthalmic solutions with and without preservatives to human corneal endothelial cells, epithelial cells and conjunctival epithelial cells

Purpose:  The cytotoxicity of a range of commercial ophthalmic solutions in the presence and absence of preservatives was assessed in human corneal endothelial cells (HCECs), corneal epithelia and conjunctival epithelia using in vitro techniques.

Long-term study of children with implanted intraocular lenses

ABSTRACT We studied children between five and 15 years of age who were implanted with intraocular lenses (IOLs). The subjects comprised eight cases of traumatic cataract, 11 of congenital cataract, and six of steroid cataract. The follow‐up ranged from four months to nine and one half years. Twenty of the eyes studied achieved a postoperative visual acuity of equal to or better than 20/40. Binocular function was retained in most cases. Postoperative complications included seven cases of posterior iris synechia, three of iris capture, one of transitory elevated intraocular pressure, and one of cystoid macular edema. Corneal endothelial studies were normal in the eyes in which posterior chamber IOLs were implanted.

Surface scattering in implanted hydrophobic intraocular lenses

Purpose: To describe surface scattering, a new phenomenon in polyacrylic intraocular lenses (IOLs), and discuss the possible cause of this finding. Setting: Showa University, Fujigaoka Hospital, Yokohama, Kanagawa, Japan. Methods: This observational case series involved 40 patients who received the AcrySof® IOL (Alcon Laboratories, Inc.) as part of a clinical trial in 1991. Four patients (5 eyes) were evaluated. Thirty‐three patients had the same surgery in 1999, and the findings in these patients were compared with those in the earlier patients. Lens surface scattering was evaluated by area densitometry using Scheimpflug photography. No statistical analysis was done because of the small sample size. Results: The 5 IOLs implanted in 1991 showed various degrees of surface scattering. The degree of scattering was greater than that in the 1999 group. There was no degradation in visual performance and no manifestation of intraocular inflammation or other adverse effect from the IOLs in either group. Attempts to remove foreign material on the IOL using the neodymium:YAG (Nd:YAG) laser were unsuccessful. Conclusions: The surface scattering did not appear to be due to deposition of foreign material on the IOL surface. Densitometry and the results of Nd:YAG laser treatment suggest that the changes occurred in the near‐surface layer. Phase separation of water near the IOL surface in the inherently hydrophobic material may explain the phenomenon. Newer AcrySof IOLs appear to have less surface scattering.

Results of vitrectomy performed at the time of phacoemulsification complicated by intravitreal lens fragments

AIM To evaluate outcome of vitrectomy performed at the time of phacoemulsification complicated by intravitreal lens material. METHODS Clinical records associated with consecutive 8536 phacoemulsification procedures were reviewed retrospectively. RESULTS 17 (0.20%) eyes had a posterior capsule rupture with retained lens material in the vitreous cavity that required vitrectomy. Final visual acuity was 0.5 or better in 14 eyes (82%) and 0.4 to 0.1 in three eyes (18%). Retinal detachment occurred in one eye during vitrectomy and two after the surgery. Cystoid macular oedema was observed in two eyes and none developed glaucoma. The corneal endothelial cell loss was 5.7% (SD 6.8 %) (n=15) at 3–6 months postoperatively. CONCLUSIONS Combined vitrectomy and intraocular lens implantation at the time of phacoemulsification complicated by intravitreal lens material is an option to be considered to reduce the risk of postoperative complications including secondary glaucoma and corneal endothelial cell damage.

Equilibrium water content and glistenings in acrylic intraocular lenses.

Purpose: To investigate the possible relationship between temperature and water absorption in acrylic intraocular lenses (IOLs). Setting: Laboratory setting, Miyata Eye Clinic, Hiroshima, Japan. Methods: The equilibrium water content (amount of water absorbed per weight of the resin × 100) in 2 hydrophobic acrylic IOLs (AcrySof® MA60BM [Alcon] and Sensar® AR40 [AMO]) was calculated at 30°C, 40°C, and 50°C. The 2 IOLs were also subjected to 3 changes in temperature: from 37°C to 35°C, 39°C to 35°C, and 41°C to 35°C. They were incubated in physiological saline at the higher temperature for 2 hours and at the lower temperature for 30 days before being examined for glistening formation. Results: The water content was higher in the AR40 IOL than in the MA60BM IOL at all temperatures. A temperature‐dependent increase in water content was seen in both IOLs, greater in the MA60BM. With a temperature change from 37°C to 35°C, glistening formation was not observed in either IOL. With a temperature change from 39°C to 35°C, glistenings were observed in the MA60BM IOL, and with a temperature change from 41°C to 35°C, they were observed in both IOLs. Conclusion: The change in the equilibrium water content caused by temperature changes between 30°C and 40°C is an important factor in glistening formation, and thus an IOL featuring less temperature‐dependent water absorption is less likely to form glistenings.

Three year prospective, randomized evaluation of intraocular lens implantation through 3.2 and 5.5 mm incisions

Purpose: To compare the long‐term clinical results of two small incision cataract surgery procedures. Setting: Seven centers in Japan. Methods: Two hundred eyes were randomly assigned to receive a silicone intraocular lens (IOL) through a 3.2 mm incision or a poly(methyl methacrylate) (PMMA) IOL through a 5.5 mm incision. Except for incision size and implantation technique, the surgical methods were identical. Uncorrected and corrected visual acuity, keratometry, flare‐cell intensity, specular microscopy, and neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate were analyzed up to 3 years after surgery. Results: Eyes in the 3.2 mm incision group had significantly better uncorrected and corrected visual acuity in the early postoperative period and lower aqueous flare intensity immediately after surgery, but these differences disappeared after the first postoperative month. However, surgically induced astigmatism was significantly less in the 3.2 mm incision group than in the 5.5 incision group throughout the study. The Nd:YAG laser capsulotomy rate was higher in the silicone IOL group (23.5% at 3 years postoperatively) than in the PMMA IOL group (18.4%), but the difference was not statistically significant. Conclusion: Smaller incision cataract surgery led to earlier recovery of visual function in the short term and less induced astigmatism in the long term.

Effect of decentration on the optical performance in multifocal intraocular lenses.

Aims: To evaluate the influence of decentration on optical performance in multifocal intraocular lenses (IOLs) using eye models. Methods: This study evaluated 4 types of multifocal IOLs (ReSTOR SA60D3, Alcon; TECNIS Multifocal ZM900, AMO; ReZoom, AMO; SFX-MV1, Hoya). The evaluations were based on measurements of the near and far modulation transfer function (MTF) and visualized actual near images (newspaper) using eye models with the IOL horizontally displaced 0, 0.25, 0.5, 0.75 and 1.0 mm from the center. Results: For the diffractive ReSTOR the near MTF decreased with increasing decentration. The near images (newspaper characters) became difficult to distinguish at a decentration of 1.0 mm. For the diffractive ZM900, the near and far MTFs gradually decreased with increasing decentration. For the refractive ReZoom and SFX-MV1, we observed almost no change in the near MTF from a decentration of 0–1.0 mm. However, the far MTF clearly decreased starting at a decentration of 1.0 mm for ReZoom and 0.75 mm for SFX-MV1. Conclusion: The MTFs and near images are affected to a different extent depending on the design of multifocal IOLs; clinically relevant effects are not to be expected up to a decentration of 0.75 mm.

Capsular stabilization device to preserve lens capsule integrity during phacoemulsification with a weak zonule

&NA; We describe a new capsular stabilization device for suspending a lens with weak zonular support. It is flexible, 10.0 mm in length, and fashioned from 5‐0 nylon. The contact portion is bent at 1.25 mm with an end bifurcating to form a T‐shape to minimize stress on the capsular equator. After a continuous curvilinear capsulorhexis is created, the capsular stabilization devices to hook the capsulotomy margin are inserted. The T‐shaped end is passed around the anterior capsular flap to fit the curvature of the equator. Phacoemulsification and aspiration using this device was performed in 12 eyes of 9 patients, and the usefulness and complications were analyzed. The capsular stabilization devices suspended the capsule and facilitated safe phacoemulsification in all eyes. Posterior capsule rupture occurred in 2 eyes. None of the cases had notable postoperative complications. This device ensures a stable capsule‐iris complex and reduces surgical risks.