Yutaro Nishi

Rotational stability of a single-piece toric acrylic intraocular lens

PURPOSE: To assess the rotational stability of a single‐piece toric hydrophobic acrylic intraocular lens (IOL) during the first 6 postoperative months. SETTING: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. DESIGN: Prospective case series. METHOD: Eyes with age‐related cataract and corneal astigmatism (1.00 to 3.00 D diopter [D]) were measured by partial coherence interferometry (IOLMaster). Preoperatively, the horizontal axis was marked. Surgical technique included a standardized temporal clear corneal incision, phacoemulsification, and in‐the‐bag implantation of a toric IOL (AcrySof SN60TT). Rotational stability of the IOL was assessed using retroillumination photographs postoperatively at 1 hour and at 1 and 6 months. Uncorrected (UDVA) and corrected distance visual acuities, residual refractive error, and keratometric and refractive cylinders were measured. RESULTS: The study enrolled 30 eyes (30 patients). The mean absolute IOL rotation was 2.44 degrees ± 1.84 (SD) at 1 month and 2.66 ± 1.99 degrees at 6 months. The photographic technique had high reproducibility of axis measurement, with consecutive measurements varying by less than 2.0 degrees. The mean UDVA was 0.16 logMAR (range 0.42 to −0.18 logMAR) at 1 month and 0.20 logMAR (range 0.60 to −0.20 logMAR) at 6 months. The residual refractive cylinder by autorefraction was −0.84 D (range −2.00 to 0.00 D) and −0.80 D (range −1.75 to 0.00 D), respectively. CONCLUSIONS: The acrylic toric IOL was rotationally stable within the first 6 months postoperatively. The photographic and axis analysis method to evaluate stability had high reproducibility and detected small changes in rotation. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Contact inhibition of migrating lens epithelial cells at the capsular bend created by a sharp-edged intraocular lens after cataract surgery

PURPOSE: To investigate whether the lens epithelial cells (LECs) at the capsular bend created by a sharp‐edged intraocular lens (IOL) are in the G0 phase of the cell cycle. SETTING: Nishi Eye Hospital, Osaka, Japan. METHOD: A CeeOn Edge silicone IOL (AMO) with sharp edges was implanted in 1 eye and a PhacoFlex II silicone IOL (AMO) with rounded edges in the contralateral eye after standard cataract surgery in 6 rabbits. Immunohistochemical staining for the Ki‐67 antibody was performed 1 day, 3, 4, and 7 weeks after surgery. RESULTS: In eyes with the sharp‐edged IOL, LECs with thin, elongated nuclei accumulated at, but did not extend beyond, the capsular bend and stained negative for the Ki‐67 antibody, indicating that they were in the G0 phase of the cell cycle. In contrast, in the eye with the round‐edged IOL, continuous migration of a predominantly monolayer of LECs over the IOL and onto the posterior capsule occurred. These cells were Ki‐67 positive, indicating that they were proliferating. CONCLUSIONS: Lens epithelial cells at the capsular bend of sharp‐edged IOLs were in the G0 phase of the cell cycle, indicating that they were contact inhibited. These findings support the theory the sharp posterior optic edge of the IOL inhibits LEC migration, reducing formation of posterior capsule opacification. Whether these LECs can reactivate when the capsular bend is eliminated by later formation of a Soemmerrings ring requires further studies.

Influence of 360-degree enhanced optic edge design of a hydrophilic acrylic intraocular lens on posterior capsule opacification

PURPOSE: To compare the rate of posterior capsule opacification (PCO) with the single‐piece hydrophilic acrylic foldable Rayner Centerflex 570H intraocular lens (IOL), which has a sharp optic edge design excluding the optic–haptic junction, and the Rayner C‐flex 570C IOL, which has an improved 360‐degree sharp edge. SETTING: Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: As part of a multicenter U.S. Food and Drug Administration (FDA) study, 42 patients who had implantation of a C‐flex IOL in 1 eye after uneventful phacoemulsification were enrolled. Six and 12 months postoperatively, PCO was evaluated by retroillumination photographs using Evaluation of Posterior Capsule Opacification (EPCO) 2000 image‐analysis software. The data were then compared with those in a matched group of patients with a Centerflex IOL who participated in a previous FDA study. RESULTS: The mean age of the patients with the C‐flex IOL was 71.5 years ± 8.2 (SD) There was a statistically significant difference in EPCO scores between the C‐flex group and Centerflex group. Six months after surgery, the mean EPCO value (total IOL optic) was 0.07 ± 0.17 in the C‐flex group (n = 37) and 0.20 ± 0.20 in the Centerflex group (n = 36) (P<.01, Wilcoxon test). By 12 months, the mean had increased to 0.16 ± 0.20 in the C‐flex group (n = 37) and 0.35 ± 0.22 in the Centerflex group (n = 31) (P<.01, Wilcoxon test). CONCLUSIONS: The C‐flex IOLs showed good functional results and significantly lower PCO formation than the earlier model Centerflex IOL. The enhanced edge of the C‐flex IOL seemed to improve PCO prevention clinically.

Impact of intraocular lens haptic design and orientation on decentration and tilt

PURPOSE: To assess the effect of intraocular lens (IOL) orientation (vertical versus horizontal) and haptic design (1‐piece versus 3‐piece) on centration and tilt using a Purkinje meter. SETTING: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. DESIGN: Randomized pilot study with intrapatient comparison. METHODS: In part 1 of this study, patients received plate‐haptic IOLs (Akreos Adapt) in both eyes that were positioned vertically in 1 eye and horizontally in the other eye. In part 2, patients received a 1‐piece IOL (Acrysof SA60AT) in 1 eye and a 3‐piece IOL (Acrysof MA60AC) in the contralateral eye. Decentration and tilt were measured 1 month and 3 months postoperatively with a new Purkinje meter. RESULTS: In part 1 (n = 15), the mean decentration of plate‐haptic IOLs was 0.4 mm ± 0.2 (SD) with vertical orientation and 0.4 ± 0.2 mm with horizontal orientation and the mean tilt, 1.5 ± 1.1 degrees and 2.9 ± 0.9 degrees, respectively. In part 2 (n = 15), the mean decentration was 0.4 ± 0.3 mm with 1‐piece IOLs and 0.6 ± 0.8 mm with 3‐piece IOLs and the mean tilt, 2.2 ± 7.2 degrees and 5.3 ± 2.4 degrees, respectively. CONCLUSIONS: Three‐piece IOLs had a greater tendency toward more decentration than 1‐piece IOLs, perhaps because of slight deformation of 1 or both haptics during implantation or inaccuracies in production when the haptics are manually placed into the optic. The IOL orientation for plate‐haptic IOLs appeared to have no effect on IOL position. The Purkinje meter was useful in assessing the capsule bag performance of the IOLs. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Capsular bag refilling using a new accommodating intraocular lens.

PURPOSE: To describe a capsular bag refilling procedure using an accommodating intraocular lens (IOL). SETTING: Jinshikai Medical Foundation Nishi Eye Hospital, Osaka, Japan. METHODS: A disk‐shaped anterior foldable silicone accommodating IOL that serves as an optical device and as a mechanical device to prevent leakage of the injected silicone polymers was developed. The IOL optic is 6.0 mm and the overall diameter, 9.0 mm. After a 3.5 to 4.0 mm continuous curvilinear capsulorhexis (PCCC) is created, phacoemulsification and aspiration are performed in the usual manner. Then, a posteriorly placed accommodating IOL with sharp edges is implanted in the capsular bag to prevent posterior capsule opacification (PCO) and leakage of the injected silicone polymer. A PCCC is an option at this point. Then, an anterior accommodating IOL is piggybacked over the existing IOL and silicone polymers are injected between the 2 IOLs. RESULTS: Experiments in numerous pig cadaver eyes and in 10 rabbit eyes showed minimal to no silicone leakage. In cases in which a PCCC was not created, 2 eyes had no PCO and 3 showed slight to moderate PCO. None of the 5 eyes with a PCCC had no PCO 5 to 8 weeks after surgery within the PCCC. CONCLUSION: The procedure in rabbit eyes overcame 2 problems of lens‐refilling techniques: leakage of the injectable silicone polymer and capsule opacification.

Reproducibility of intraocular lens decentration and tilt measurement using a clinical Purkinje meter.

PURPOSE: To determine the reproducibility of intraocular lens (IOL) decentration and tilt measurements with a new Purkinje meter instrument. SETTING: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. METHODS: After pupil dilation, images of pseudophakic eyes with a plate‐style IOL (Akreos Adapt) were obtained using a recently developed Purkinje meter. Intraocular lens decentration and tilt were evaluated by analyzing the captured images using a semiobjective method by marking the reflexes in the images and automatic calculation using a dedicated software program. In study 1, examiner 1 examined the eyes first followed by examiner 2. Ten minutes later, examiner 1 performed a second measurement, after which the intraexaminer and interexaminer reproducibility were determined. In study 2, a Purkinje meter was used to measure pseudophakic eyes with slitlamp finding of clinical IOL decentration, IOL tilt, or both. The results were compared with retroillumination photographs and slitlamp findings. RESULTS: In study 1, there was high intraexaminer reproducibility for decentration (r = 0.95) and tilt (r = 0.85) and high interexaminer reproducibility for decentration (r = 0.84) and tilt (r = 0.75). In study 2, even in extreme cases of decentration and/or tilt, the Purkinje meter measurements were possible and appeared to correlate well with slitlamp findings. CONCLUSIONS: Acquisition of images in pseudophakic eyes with the Purkinje meter was simple and rapid. The method was highly reliable for 1 examiner and between 2 examiners. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Fluctuations in corneal curvature limit predictability of intraocular lens power calculations

Purpose To analyze fluctuations in corneal curvature over time. Setting Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. Design Case series. Methods A 3‐piece IOL was implanted in 1 eye and a 1‐piece IOL in the other eye through a 3.2 mm clear corneal temporal incision. Keratometry was performed preoperatively and at several points in time postoperatively. Differences between measurements were analyzed by power vectors. Statistical significance was assessed by monovariate, bivariate, and trivariate paired t tests. Acute angle shifts were determined as differences between meridians at 2 points in time. Results Fifty patients were enrolled. From preoperatively to 1 year postoperatively, the changes in vector components (M, J0, J45) were, respectively, −0.02 diopter (D) ± 0.23 (SD) (P=.38), −0.07 ± 0.27 D (P=.02), and +0.04 ± 0.25 D (P=.14). Corresponding changes from 1 year to 2 years postoperatively were +0.01 ± 0.25 D (P=.73), +0.01 ± 0.23 D (P=.83), and +0.01 ± 0.16 D (P=.40). The meridian shift was −5 ± 32 degrees (P=.13) from preoperatively to postoperatively and +3 ± 22 degrees (P=.23) from 1 year to 2 years. Conclusions Surgically induced astigmatism was composed of slight flattening in the horizontal meridian and slight steepening in the oblique meridian but was insignificant in relation to random fluctuations, which were almost equally large between postoperative measurements 1 year apart. The fluctuations were not due to imprecision in measurement. Financial Disclosure Dr. Norrby is a retiree from Abbott Medical Optics, Inc., and holder of a small amount of stock. Dr. Findl is scientific advisor to Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Pain reduction after epi-LASIK with a simple surgical procedure

monstrated in this study can be expected to be even more effective in inflamed eyes; ie, in bacterial endophthalmitis and serious injuries of the eye. In one case of endophthalmitis (Bacteroides species) in the Department of Ophthalmology at our university, the human aqueous humor concentration of oral moxifloxacin (400 mg) was 3.6 mg/mL after 21 hours (unpublished data). This level is 6-fold higher than the 10-hour level in the present series of noninflamed eyes. Oral antibiotics cannot replace intravitreal application in endophthalmitis. Further studies will help define the precise role of moxifloxacin in the treatment of bacterial endophthalmitis.

Capsular bag performance of a hydrophobic acrylic 1-piece intraocular lens.

Purpose To compare parameters after 1‐piece and 3‐piece intraocular lens (IOL) implantation. Setting Moorfields West End Clinic, London, United Kingdom, and Hanusch Hospital, Vienna, Austria. Design Prospective randomized controlled trial. Methods Each eye of patients having bilateral surgery for age‐related cataract was randomized to have implantation of a 1‐piece IOL (Tecnis ZCB00) or a 3‐piece IOL (Tecnis ZA9003). Changes in visual acuity, refraction, and anterior chamber depth (ACD) were evaluated during a 2‐year follow‐up. Intraocular lens tilt and decentration were evaluated using a Purkinje meter. Regeneratory posterior capsule opacification (PCO) was analyzed using retroillumination photographs in Automated Quantification of After‐Cataract image‐analysis software. Results This study comprised 100 eyes of 50 patients. No statistically significant differences were found in IOL tilt or decentration between groups (P≥.06). Minimal but statistically significant changes were observed in the vertical tilt component 12 months postoperatively in the 3‐piece IOL group (P<.01). The tilt and decentration components did not correlate with changes in sphere or the regeneratory PCO score (r = 0.38, P≥.06). The ACD decreased significantly between 1 day and 1 month postoperatively in both groups (P<.01), with no significant changes afterward (P≥.22). The anterior chamber was significantly deeper in the 1‐piece group at all follow‐up visits (P<.01). Conclusions Both the 1‐piece IOL and the 3‐piece IOL showed excellent positional stability in the capsular bag, resulting in good clinical outcomes. Regeneratory PCO levels were low and comparable between the IOLs. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Epidemiological evaluation of YAG capsulotomy incidence for posterior capsule opacification in various intraocular lenses in Japanese eyes

Background and objective We investigated the yttrium aluminum garnet (YAG) capsulotomy rates in various intraocular lenses (IOLs). Study design/patients and methods We retrospectively analyzed 23,440 eyes implanted with either MA60BM, MA60AC, VA-60BB, CeeOnEdge, Clariflex, Technis Z9002, SI-40NB, or UV26T IOLs. We calculated the YAG capsulotomy rates at 1, 3, 5, and 10 years post lens implantation. Results YAG capsulotomy rates at 3 years postimplantation for the eight groups of IOLs were, respectively, 3.7%, 3.9%, 23.7%, 3.4%, 4.5%, 4.7%, 10.4%, and 21.0%. YAG capsulotomy rates at 10 years postimplantation for the MA60BM and SI-40NB IOLs were, respectively, 9.1% and 15% (P<0.05). The average YAG rates for all sharp-edged and round-edged IOLs at 5 years postimplantation were, respectively, 5.2%±0.7% and 25.6%±9.0% (P<0.05). Conclusion In all studied IOLs, posterior capsule opacification prevention seemed to be associated with the posterior optic sharp-edge design. Round-edged silicone IOLs may also retard posterior capsule opacification formation, though not as much as sharp-edged IOLs. As the follow-up period progressed, round-edged silicone IOLs showed significantly higher YAG rates than sharp-edged IOLs.