1-piece Hydrophobic Acrylic Intraocular Lens Research Articles

Multifocal IOL explantation in patients with opaque lentis after refractive lens exchange.

We describe the outcomes of intraocular lens (IOL) explantation in a cluster of opaque multifocal Lentis LS-313 following refractive lens exchange (RLE). Single-centre, single-surgeon, retrospective case series. The study enrolled 10 eyes of 10 patients, 6 male and 4 female. All patients had uneventful RLE with multifocal IOL implantation. The mean patient age at the time of RLE was 53years ± 2.52 (SD). Two eyes had YAG laser capsulotomy prior to explantation. The mean interval between the initial RLE and IOL explantation was 5.4years ± 1.4 (SD). IOL exchange was performed in all eyes in one procedure. Five eyes had in the bag hydrophobic acrylic IOL (3 multifocal and 2 monofocal), three eyes had 3-piece hydrophobic acrylic IOL in the ciliary sulcus and two had an anterior chamber IOL. Intraoperatively one patient had weak zonules and two patients had zonular dehiscence and required anterior vitrectomy. The mean preoperative CDVA was 0.25 ± 0.15 (SD) logMAR and at the final follow-up, improved to 0.00 ± 0.07 (SD) logMAR (p < 0.01). Light microscopy with von Kossa stain confirmed IOL calcification. No postoperative complications were recorded. IOL exchange appears to be a feasible and safe surgical option for multifocal IOL opacification. However, patients must be warned of additional intraoperative risks including zonular dialysis, vitreous loss, retinal detachment and need for potential scleral or iris fixated IOL or anterior chamber IOL (ACIOL) with its associated sequel of complications. Moreover, YAG laser capsulotomy should be considered carefully as it increases the chances of intraoperative complications and restricts the surgical options of secondary IOL insertion such as in-the-bag IOL exchange with MFIOL.

Surface light scattering from 1-piece hydrophobic acrylic intraocular lenses with hydroxyethyl methacrylate: contralateral observation for 7 years.

To quantitatively and intraindividually compare surface light scattering for 7 years after implantation of Clareon and AcrySof intraocular lenses (IOLs). Miyata Eye Hospital, Miyazaki, Japan. Retrospective comparative case series. Clinical records of eyes that had contralateral implantation of SN60WF and SY60WF IOLs were reviewed. Light scattering on the anterior surface of IOLs, corrected distance visual acuity (CDVA), and mesopic and photopic contrast sensitivities were examined at 1 year, 3 years, and 7 years postoperatively, and they were intraindividually compared. 34, 19, and 16 patients visited at 1 year, 3 years, and 7 years postoperatively, respectively. Surface light scattering in eyes with SY60WF IOL was significantly reduced, and the rate of increase was 2.74 computer compatible tapes per year. Although there were prominent increases in eyes with SN60WF IOL, no statistically significant difference was found in their CDVA and contrast sensitivities. In eyes with Clareon IOLs, the development of surface light scattering was suppressed up to 7 years. The increase rate demonstrated that the visual acuity would be least deteriorated up to 12 years postoperatively, whereas the influence of straylight induced should be investigated.

Uveal and capsular biocompatibility of a new hydrophobic acrylic microincision intraocular lens

To evaluate uveal biocompatibility and capsular bag opacification of a new hydrophobic acrylic microincision intraocular lens (IOL) in comparison with a commercially available 1-piece hydrophobic acrylic IOL. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Eight New Zealand rabbits underwent bilateral phacoemulsification and implantation of the preloaded Nanex multiSert IOL in one eye and a commercially available preloaded lens (AcrySof IQ in UltraSert, model AU00T0) in the contralateral eye. A slitlamp examination was performed weekly for 4 weeks. The rabbits were then killed humanely and their globes enucleated. Capsular bag opacification was assessed from the Miyake-Apple view, and the eyes were subjected to histopathologic evaluation. Postoperative inflammatory reactions were similar between the test and control eyes in the 8 New Zealand rabbits. The mean postmortem central posterior capsule opacification (PCO) was 0.93 ± 0.73 in the test group and 1.19 ± 0.53 in the control group. The mean postmortem peripheral PCO was 1.75 ± 0.92 in the test group and 2.06 ± 0.77 in the control group. Central and peripheral PCO scores were not statistically different between the test and control groups (P = .41 and P = .35, respectively, 2-tailed t test: paired 2-sample for means). A new 1-piece hydrophobic acrylic microincision IOL incorporating an ultraviolet-ozone treatment on the posterior surface performed similarly to a commercially available 1-piece hydrophobic acrylic IOL in terms of uveal and capsular biocompatibility in the rabbit model. To our knowledge, this is the first hydrophobic acrylic microincision IOL to demonstrate similar PCO performance when compared with a conventional, commercially available IOL.

Mid-term and long-term clinical assessments of a new 1-piece hydrophobic acrylic IOL with hydroxyethyl methacrylate.

To investigate the clinical outcomes after implantation of a new hydrophobic acrylic intraocular lens (IOL) with hydroxyethyl methacrylate (HEMA) at 1 year and 9 years postoperatively. Three surgical sites in Japan. Prospective case series and retrospective review. In 110 eyes of 110 patients who underwent phacoemulsification and implantation of a new hydrophobic acrylic IOL (Clareon CNA0T0), clinical data were collected preoperatively and at 1 day, 1 week, 1 month, 6 months, and 12 months postoperatively. Of these eyes, 20 eyes of 20 patients were examined at 9 years postoperatively, and corrected distance visual acuity (CDVA) and clarity of the IOL were evaluated. All 110 patients (110 eyes) completed every follow-up examination up to 12 months postoperatively. At 12 months, a CDVA of 20/30 and 20/20 was obtained in 110 (100%) and 101 (91.8%) of 110 eyes, respectively. The contrast sensitivity function was better than or similar to the age-matched normal controls, and there was no case of posterior capsule opacification requiring a laser treatment. Glistenings and surface light scattering were not seen in any of these cases. At 9 years postoperatively, a CDVA of 20/40, 20/30, and 20/20 was attained in 20 (100%), 19 (95%), and 14 (70%) of 20 eyes, respectively. One eye (5%) was treated with laser capsulotomy for posterior capsule opacification. There was no case of glistenings and surface light scattering. This mid-term and long-term study indicated that the new hydrophobic acrylic IOL with HEMA was safe and effective with excellent postoperative vision. Glistenings and surface light scattering did not develop with this IOL in contrast to its predecessor.

Posterior capsule opacification prevention by an intraocular lens incorporating a micropatterned membrane on the posterior surface.

To evaluate posterior capsule opacification (PCO) with a new hydrophobic acrylic intraocular lens (IOL) featuring a new micropatterned membrane, in comparison with a commercially available 1-piece hydrophobic acrylic IOL. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Twelve New Zealand rabbits had bilateral phacoemulsification and implantation of a ClearSight unpatterned IOL (Group 1), a ClearSight Sharklet-patterned IOL (Group 2), or a control, commercially available IOL (Group 3) (8 IOLs in each group). Slit-lamp examination was performed weekly for 4 weeks. The rabbits were then killed humanely, and their globes enucleated. Capsular bag opacification was assessed from the Miyake-Apple view, and the eyes underwent histopathology. The mean postmortem central PCO was 1.87 ± 1.35 in Group 1, 1.06 ± 1.23 in Group 2, and 3.14 ± 0.89 in Group 3. Peripheral PCO was 2.18 ± 1.36 in Group 1, 1.5 ± 1.03 in Group 2, and 3.57 ± 0.53 in Group 3. When comparing central and peripheral PCO between Groups 1 and 3, the difference was not statistically significant, but it was statistically significant between Groups 2 and 3 (P = .003 and P = .0003, t test with Bonferroni correction). Unique discontinuous features comprising the micropattern allow for focal adhesions to be precisely guided and therefore controlling cell migration. The patterned membrane incorporated on the posterior surface of the IOL significantly reduced capsular bag opacification compared with a commercially available control IOL.

Refractive predictability of a 3-piece intraocular lens platform versus its 1-piece counterpart

ObjectiveTo compare the refractive outcomes of a 3-piece acrylic intraocular lens (IOL) with its 1-piece counterpart after phacoemulsification with in-the-bag implantation. DesignRetrospective chart review. ParticipantsOne-hundred twenty-six eyes of 95 patients were analyzed in the study, including 60 eyes of 43 patients receiving a 3-piece IOL and 66 eyes of 52 patients receiving a 1-piece IOL. MethodsRandomized chart review of all patients who underwent uncomplicated phacoemulsification with in-the-bag IOL implantation with either a 3-piece hydrophobic acrylic IOL (Tecnis ZA9003) or a 1-piece hydrophobic acrylic IOL (Tecnis ZCB00) between 2006 and 2014 in a tertiary ophthalmology care centre in Mississauga, Ontario. Preoperative visual acuity and refraction, anterior chamber depth, axial length, IOL design and power, predicted refraction, postoperative visual acuity, and refraction were recorded. ResultsMean absolute error was 0.40 ± 0.27 in the ZA9003 group and 0.39 ± 0.35 in the ZCB00 group, with no statistically significant difference between the 2 IOLs (p = 0.86). Mean arithmetic error was 0.11 ± 0.47 D in the ZA9003 group and 0.01 ± 0.47 D in the ZCB00 group (p = 0.019). In the ZA9003 group, 23 (38%), 42 (70%), and 52 (87%) of 60 eyes were within 0.25, 0.50, and 0.75 D, respectively, of predicted postoperative refraction. In the ZCB00 group, 32 (48%), 46 (70%), and 56 (85%) of 66 eyes were within 0.25, 0.50, and 0.75 D, respectively, of predicted postoperative refraction (p = 0.2836, p = 1.00, p = 0.8044). ConclusionsThe ZA9003 and the ZCB00 have similar mean absolute error and thus appear to have similar refractive predictability.

Long-term longitudinal assessment of postoperative outcomes after congenital cataract surgery in children with congenital rubella syndrome

To assess the intraoperative and long-term longitudinal postoperative outcomes of cataract surgery in children with congenital rubella syndrome. Iladevi Cataract & IOL Research Centre, Ahmedabad, India. Prospective observational clinical study. Children with congenital rubella syndrome who had cataract surgery were enrolled. All microphthalmic eyes were left aphakic. A 1-piece hydrophobic acrylic intraocular lens was implanted in the capsular bag in eyes without microphthalmos. The postoperative observations included complications and visual assessments up to 5 years. The mean age of the 21 children (37 eyes) was 3.97 months ± 2.1 (SD). Intraocular lens implantation was performed in 12 eyes (32.4%), while 25 eyes (67.6%) were left aphakic. Postoperatively, the median follow-up was 60.79 months. Posterior synechiae were observed in 22 eyes (59.5%) and visual axis opacification in 9 eyes (24.3%). Secondary glaucoma was observed in 16 eyes (43.2%), of which 14 were aphakic and 1 was pseudophakic. Nine eyes required trabeculectomy. Age at surgery and ocular comorbidities were statistically significantly associated with secondary glaucoma (P<.05, χ(2) test and Kendall τB criteria P<.05). The mean corrected distance visual acuity at the final follow-up was 0.72 ± 0.56 logMAR. The long-term results suggest good visual outcomes can be obtained with congenital cataract associated with congenital rubella syndrome after early surgical intervention. The rate of serious postoperative complications was acceptable.

Light transmittance of 1-piece hydrophobic acrylic intraocular lenses with surface light scattering removed from cadaver eyes

To assess the potential effect of surface light scattering on light transmittance of 1-piece hydrophobic acrylic intraocular lenses (IOLs) with or without a blue-light filter. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Intraocular lenses were obtained from human cadavers (49 IOLs total; 36 with blue-light filter) and from finished-goods inventory (controls). The IOLs were removed from cadaver eyes and the power and model matched to unused controls. After surface proteins were removed, the IOLs were hydrated for 24 hours at room temperature. Surface light scattering was measured with a Scheimpflug camera (EAS-1000 Anterior Segment Analysis System). Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration; RSA-PE-20 integrating sphere). Hydrated scatter values ranged from 4.8 to 202.5 computer-compatible tape (CCT) units for explanted IOLs with blue-light filter and 1.5 to 11.8 CCT units for controls; values ranged from 6.0 to 137.5 CCT units for explanted IOLs without a blue-light filter and 3.5 to 9.6 CCT units for controls. In both groups, there was a tendency toward increasing scatter values with increasing postoperative time. No differences in light transmittance were observed between explanted IOLs and controls in both groups (IOLs with blue-light filter: P=.407; IOL with no blue-light filter: P=.487; both paired t test). Although surface light scattering of explanted IOLs was significantly higher than that of controls and appeared to increase with time, no effect was observed on light transmittance of 1-piece hydrophobic acrylic IOLs with or without a blue-light filter.

Posterior Capsule Opacification with the iMics1 NY-60 and AcrySof SN60WF 1-Piece Hydrophobic Acrylic Intraocular Lenses: 3-Year Results of a Randomized Trial

To compare the intensity of posterior capsule opacification (PCO) 3 years after implantation of 2 different 1-piece foldable hydrophobic acrylic intraocular lenses (IOLs). Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison. One hundred patients with bilateral age-related cataract (200 eyes) had standard cataract surgery with implantation of an iMics1 NY-60 IOL (Hoya Corp) in one eye and an AcrySof SN60WF IOL (Alcon Laboratories) in the other eye. Follow-up examinations were performed at 1 week and 3 years. Digital retroillumination images were obtained of each eye. The main outcome measure was PCO score (scale, 0 to 10) assessed subjectively at the slit lamp and objectively using automated image analysis software (Automated Quantification of After-Cataract) 3 years after surgery. The objective PCO score (mean ± standard deviation) was 3.0 ± 2.0 for the iMics1 NY-60 IOL and 1.9 ± 1.4 for the AcrySof SN60WF IOL (P < .001). Three years after surgery, 35.6% of patients underwent a neodymium:yttrium-aluminum-garnet capsulotomy in the iMics1 NY-60 eye and 13.7% underwent a capsulotomy in the AcrySof SN60WF eye (P = .001). There was no statistically significant difference in best-corrected visual acuity, rhexis-IOL overlap, capsular folds, or anterior capsule opacification. Glistening formations were found in no iMics1 NY-60 IOLs, but in 97% of the AcrySof SN60WF IOLs. Comparison of 2 sharp-edged single-piece IOLs of similar design and hydrophobic acrylic material indicated a statistically significant difference in PCO and neodymium:yttrium-aluminum-garnet capsulotomy rate 3 years after surgery.

Pathologic Comparison of Asymmetric or Sulcus Fixation of 3-Piece Intraocular Lenses with Square Versus Round Anterior Optic Edges

To evaluate the pathologic findings of 3-piece intraocular lenses (IOLs) with asymmetric or sulcus fixation in pseudophakic cadaver eyes, comparing IOLs with square or round edges on the anterior optic surface. Comparative case series with pathology. A total of 661 pseudophakic cadaver eyes, obtained from eye banks within the United States, implanted with different IOLs. Anterior segment scanning of whole eyes with a high-frequency ultrasound system or high-resolution anterior segment magnetic resonance imaging followed by gross examination. Selected eyes were processed for complete histopathologic analysis. Findings from imaging, gross, and histopathologic evaluation that could be related to out-of-the-bag fixation of the lenses. Of 661 pseudophakic cadaver eyes obtained, 13 had 3-piece hydrophobic acrylic IOLs with anterior and posterior square optic edges, and 14 had 3-piece lenses with anterior round edges (13 silicone lenses and 1 hydrophobic acrylic lens) without symmetric in-the-bag fixation. These 27 selected eyes were processed for complete histopathologic analysis. Gross findings in both groups were composed of IOL decentration and tilt, pigmentary dispersion within the anterior segment and on the IOL surface, and iris transillumination defects. Histopathology of the 14 eyes with 3-piece IOLs with round anterior optic edges showed mild focal disruption of the iris pigmented layer and loop protrusion/erosion in the ciliary sulcus. Additional changes observed in the 13 eyes with square anterior optic edge IOLs included iris changes, such as vacuolization, disruption and loss of the pigmented epithelial layers, iris thinning and atrophy, synechiae, and pigmentary dispersion within the trabecular meshwork. One eye also exhibited initial signs of optic nerve disc cupping. In this series, pathologic findings were more severe in eyes implanted with 3-piece IOLs with square anterior optic edges, suggesting that IOLs with round anterior edges are more suitable for sulcus fixation. Proprietary or commercial disclosure may be found after the references.

Pathologic Assessment of Complications with Asymmetric or Sulcus Fixation of Square-Edged Hydrophobic Acrylic Intraocular Lenses

One-piece hydrophobic acrylic intraocular lenses (IOLs) are not indicated for sulcus fixation because of complications, such as uveitis-glaucoma-hyphema syndrome. Similar complications may also be observed with 3-piece lenses that have a square optic edge on the anterior surface. The objective of this study was to provide pathologic evidence of complications related to out-of-the-bag fixation of 1- or 3-piece hydrophobic acrylic IOLs with anterior and posterior square optic edges. Comparative case series with pathology. A total of 661 pseudophakic cadaver eyes obtained from eye banks within the United States, implanted with different IOLs. Anterior segment scanning of whole eyes with a high-frequency ultrasound system or high-resolution anterior segment magnetic resonance imaging, followed by gross examination. Selected eyes were processed for complete histopathologic analysis; some of them were explanted before histopathology to allow for direct light microscopic evaluation of the lenses. Findings from imaging, gross, and histopathologic evaluation that could be related to out-of-the-bag fixation of the lenses. A total of 256 eyes were implanted with hydrophobic acrylic IOLs with anterior and posterior square optic edges; 18 of them exhibiting asymmetric or sulcus IOL fixation (six 1-piece and twelve 3-piece IOLs) underwent complete histopathologic evaluation and were compared with the contralateral eyes with symmetric in-the-bag IOL implantation. Pathologic findings were composed of IOL decentration and tilt, pigmentary dispersion within the anterior segment and on the IOL surface, iris transillumination defects, iris changes including vacuolization/disruption/loss of the pigmented layer, iris thinning, and iris atrophy, as well as synechiae and loop erosion in the case of 3-piece lenses. Findings were more significant in comparison with the control contralateral eyes and were particularly evident in relation to the sulcus-fixated haptic in the case of 1-piece lenses. The majority of the eyes with 3-piece lenses showed signs of complicated surgery. This study provides pathologic correlation of complications that were clinically reported in the peer-reviewed literature in relation to sulcus fixation of 1-piece hydrophobic acrylic IOLs. The eyes with 3-piece lenses generally exhibited evidence of complicated surgery; therefore, all pathologic findings in those cases may not be strictly attributed to the out-of-the-bag fixation.

Incidence and influence of posterior capsule striae on the development of posterior capsule opacification after 1-piece hydrophobic acrylic intraocular lens implantation

To determine the incidence of intraoperative posterior capsule striae after implantation of a 1-piece hydrophobic acrylic intraocular lens (IOL), study the clinical impact on the patients' vision, and assess whether the presence of posterior capsule striae increases the risk for posterior capsule opacification (PCO). Iladevi Cataract & IOL Research Centre, Ahmedabad, India. Case-control study. Part 1 of this study evaluated consecutive adult eyes having cataract surgery performed using standardized techniques with in-the-bag 1-piece hydrophobic acrylic IOL implantation. Posterior capsule striae details were noted at the end of surgery. Part 2 was a case-control study comprising all patients with intraoperative striae and an age- and biometry-matched control group without striae, which was selected on a 1:1 ratio. Intraoperative posterior capsule striae were observed in 68 (13.6%) of 500 eyes. A single stria was seen in 43 eyes [63.2%], and multiple striae were seen in 25 eyes [36.7%]). There was no significant difference in logMAR corrected distance visual acuity at baseline (P=.881) or at 3 years (P=.191) between cases and controls. At 3 years, there was no statistically significant between-group difference in the median Evaluation of Posterior Capsule Opacification score or area values in the capsulorhexis margin (P=.36 and P=.39, respectively) or in the central 3.0 mm optic area (P=.40 and P=.42, respectively). The incidence of posterior capsule striae was 13.6%. Intraoperative striae did not influence visual acuity or the development of PCO at the 3-year follow-up.

Pathology of 219 human cadaver eyes with 1-piece or 3-piece hydrophobic acrylic intraocular lenses: Capsular bag opacification and sites of square-edged barrier breach

To assess capsular bag opacification and sites of initial posterior capsule opacification (PCO) in human cadaver eyes with square-edged 1-piece or 3-piece hydrophobic acrylic intraocular lenses (IOLs). John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Eyes were immersed in 10% formalin after enucleation and had anterior segment scanning with very-high-frequency ultrasound (Artemis). After the eyes were sectioned at the equator, gross examination of the anterior segment was performed from the posterior aspect to assess capsular bag opacification, anterior capsule coverage of the IOL edge, and IOL fixation. Selected eyes had histopathologic examination. One hundred nineteen eyes with 1-piece IOLs and 100 with 3-piece IOLs were included in the analyses of capsular bag opacification. There was no difference in central (P=.29) or peripheral (P=.76) PCO. In 63 of 84 eyes with a 1-piece IOL and peripheral PCO, the optic-haptic junction was the site of initiation. In eyes with a 3-piece IOL, initial peripheral PCO was observed at nearly the same rate whether there was full 360-degree anterior capsulorhexis overlap of the optic or no overlap (P=.13). In the latter, the site of PCO initiation was in areas lacking capsulorhexis coverage in 46% of eyes. There was no difference in central or peripheral PCO between 1-piece and 3-piece hydrophobic acrylic IOLs. With 1-piece IOLs, PCO tended to start at the optic-haptic junctions. With 3-piece IOLs, full anterior capsule coverage did not produce a statistically significant benefit with respect to PCO prevention.

Unusual pattern of glistening formation on a 3-piece hydrophobic acrylic intraocular lens

A 3-piece hydrophobic acrylic intraocular lens (IOL) was explanted from the left eye of a 68-year-old patient 26 days after implantation because of glistenings that impaired fundus visualization. The effect of the glistenings on the patient's visual function was unknown because of retinal issues. The fluid-filled vacuoles within the IOL optic were different from those described in clinical and experimental studies. They were initially observed 4 days after surgery and were very large. The glistening formation was reproduced experimentally by immersing the explanted IOL in balanced salt solution at 37 degrees C and analyzing the IOL at room temperature for up to 2 weeks. An IOL of the same design was used as a control. Although both IOLs were subjected to the same laboratory conditions, gross and light microscopic analyses confirmed that the pattern of the glistening formation differed between them. Analyses of the explanted IOL and the control IOL under differential scanning calorimetry, as well as by attenuated total reflection Fourier transform infrared spectroscopy, revealed slight differences between the IOLs.

Long-term Effect of 1-Piece and 3-Piece Hydrophobic Acrylic Intraocular Lens on Posterior Capsule Opacification: A Randomized Trial

To compare the intensity of posterior capsule opacification (PCO) between the 1-piece and 3-piece haptic designs of the foldable hydrophobic acrylic AcrySof intraocular lens (IOL) over a 5-year period. Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison. Fifty-two patients with bilateral age-related cataract (104 eyes). Each study patient had cataract surgery in both eyes and received a 1-piece AcrySof IOL in 1 eye and a 3-piece AcrySof IOL in the other eye. Follow-up examinations were performed at 1 week, 1 month, 6 months, and 1, 2, and 5 years. Digital retroillumination images were obtained of each eye. The amount of posterior capsule opacification (score range, 0-10) was assessed subjectively at the slit lamp and objectively using automated image analysis software 1, 2, and 5 years after surgery. Posterior capsule opacification score (scale, 0-10). There was no significant difference between the 1-piece and 3-piece AcrySof IOL in best-corrected visual acuity, overlap of rhexis and IOL, capsular folds, anterior capsule opacification, and posterior capsule opacification (1-piece AcrySof PCO score, 1.7+/-1.7; 3-piece AcrySof PCO score, 1.3+/-1.4; P = 0.30). Modification of the IOL haptic design of the sharp optic edged AcrySof IOL from a 3-piece to a 1-piece haptic design caused no significant change in PCO intensity and neodymium:yttrium-aluminium-garnet laser treatment rate 5 years after surgery.

Posterior capsule opacification in rabbit eyes implanted with 1-piece and 3-piece hydrophobic acrylic intraocular lenses

To evaluate the outcome of posterior capsule opacification (PCO) after implantation in rabbit eyes of currently available 3-piece and 1-piece hydrophobic acrylic intraocular lenses (IOLs) with square optic edges. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. The 3-piece designs evaluated were the AR40e (Advanced Medical Optics Inc.) and the MA60AC (Alcon, Inc.); the 1-piece designs were the SA60AT and the SA30AT (Alcon, Inc.). Nine lenses of each type were implanted in a randomized manner by the same surgeon in 18 Dutch Belted pigmented rabbits. After a follow-up of 3 weeks, the rabbits were killed and analyses of the enucleated eyes were performed from the posterior or Miyake-Apple view. The intensity of central PCO, peripheral PCO, and Soemmering's ring formation was scored from 0 to 4. The area of Soemmering's ring formation was also scored from 0 to 4 based on the number of quadrants involved. Other parameters analyzed were capsulorhexis coverage of the IOL anterior surface, IOL centration, fixation, and presence of striae. Results from the posterior view were complemented by histopathologic evaluation of the eyes. No statistically significant difference was found between the 4 groups of IOLs in the parameters analyzed from the posterior view. When cell ingrowth occurred with the 1-piece designs, causing peripheral and central PCO formation, it was more likely to start at the optic-haptic junctions, as observed during the clinical follow-up with slitlamp examination and confirmed by gross and histopathologic analyses of the enucleated eyes. The square, truncated optic edge is the most important IOL design feature for PCO prevention. The optic-haptic junctions of the 1-piece designs appear to be sites where the barrier effect of the truncated optic edge is less effective.

Comparison of tilt and decentration of 1-piece and 3-piece hydrophobic acrylic intraocular lenses

To determine the amount of tilt and decentration of 1-piece and 3-piece hydrophobic acrylic intraocular lenses (IOLs) in patients having cataract surgery. Department of Ophthalmology, Gulhane Military Medical Academy and Medical School, Ankara, Turkey. Eighty-eight patients having phacoemulsification with IOL implantation were divided into 2 groups. One group received a 3-piece hydrophobic acrylic IOL with 12.5 mm poly(methyl methacrylate) haptics and the other, a 1-piece hydrophobic acrylic IOL with 12.5 mm haptics. The amount of IOL decentration and tilt was quantitated using Purkinje reflections and photographic documentation at the last postoperative control. The results of the 2 groups were compared. Bag fixation of the IOL and an intact continuous curvilinear capsulorhexis (CCC) were confirmed in all cases at the last postoperative control, which was at a mean of 27.1 months +/- 5.4 (SD) and 26.7 +/- 4.4 months in the 3-piece group and 1-piece group, respectively (P = 0.659). There was no significant difference between groups in the percentage of patients with measurable tilt and decentration and of patients without measurable tilt and decentration (P = .956). The mean IOL tilt was 2.72 +/- 0.55 degrees in the 3-piece group and 2.70 +/- 0.84 degrees in the 1-piece group and the mean IOL decentration, 0.39 +/- 0.13 mm and 0.34 +/- 0.08 mm, respectively. There were no significant between-group differences in tilt or decentration (P = .897 and P = .103, respectively). There were no significant differences in tilt and decentration between 1-piece and 3-piece hydrophobic acrylic IOLs in eyes with capsular bag IOL implantation and an intact CCC.

Effect of 1-piece and 3-piece AcrySof intraocular lenses on the development of posterior capsule opacification after cataract surgery

Purpose: To evaluate the effect of 1-piece and 3-piece hydrophobic acrylic intraocular lenses (IOLs) on posterior capsule opacification (PCO) after cataract surgery. Setting: Ophthalmology departments of 3 hospitals in the United Kingdom and Germany and the Department of Physics at a United Kingdom university. Methods: A series of 131 patients having cataract surgery had implantation of an acrylic 1-piece (SA30AL) or an acrylic 3-piece (MA30BA) IOL (AcrySof ®, Alcon). Surgery was performed according to standardized protocol by a single surgeon at each hospital. Posterior capsule opacification was assessed using digital retroillumination photography. All images were analyzed at a single center according to a standard protocol. Data were analyzed 6 months and 1 year after surgery. Results: There was no statistically significant difference in the percentage area of PCO between the 1-piece (mean 16.0% ± 15.7% [SD]) and 3-piece (mean 13.6% ± 19.8%) cohorts 6 months and 1 year after surgery ( P = .0664). Conclusion: There was no evidence of a difference in the area of PCO after cataract surgery between 1-piece and 3-piece IOLs, which were otherwise matched for material and lens geometry.