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

Characteristics and factors associated with intraocular lens tilt and decentration after cataract surgery

PURPOSE

To analyze the characteristics and factors associated with intraocular lens (IOL) tilt and decentration after uneventful phacoemulsification with IOL implantation.

SETTING

Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

DESIGN

Cross-sectional study.

METHODS

All patients underwent a general ophthalmologic examination and anterior segment photography. IOL tilt and decentration were measured with a second-generation anterior segment optical coherence tomography (Casia2). Univariate and multivariate regression analyses were performed to assess the association between IOL tilt and decentration with ocular biometric and systemic parameters, and the visual acuity.

RESULTS

A total of 196 eyes of 196 patients were enrolled in this study. IOLs showed a mean tilt of 4.8 degrees toward the inferotemporal direction, and the mean decentration was 0.21 mm. Both eyes presented a mirror symmetry relationship. Twenty-two eyes (11.22%) had a tilt greater than 7 degrees, and 21 eyes (10.72%) had a decentration more than 0.4 mm. Multivariate regression analysis showed previous pars plana vitrectomy (PPV) and short axial length (AL) were associated with greater IOL tilt (P = .014 and P < .001). In addition, long AL, thicker lens, and less capsulorhexis-IOL overlap were positively correlated with decentration (P < .001, P = .029, and P = .026). Corrected distance visual acuity did not directly correlate with IOL tilt and decentration (P = .417 and P = .550).

CONCLUSIONS

PPV history and short AL were associated with greater IOL tilt, whereas longer AL, thicker lens, and overlarge capsulorhexis contribute to greater decentration. Implantation of toric and multifocal IOLs in these patients should be cautious.

A Review of Complicated Cataract in Retinitis Pigmentosa: Pathogenesis and Cataract Surgery

Retinitis pigmentosa (RP) is a set of inherited retinal degenerative diseases that affect photoreceptor and retinal pigment epithelial cells (RPEs), possibly associated with some ocular complications, including cataract. The complicated cataract formation is most likely the result of RP-related inflammation response, and the most common morphology category is posterior subcapsular cataract (PSC). Despite the absence of curative pharmacologic treatment, phacoemulsification with intraocular lens implantation to deal with opacification in the lens is preferred due to the considerable visual outcomes. However, the incidence of intraocular and postoperative complications is higher in RP patients than those without, including intraoperative phototoxic retinal damage, posterior capsular opacification (PCO), capsular contraction syndrome (CCS), pseudophakic cystoid macular edema (PCME), increased postoperative intraocular pressure (IOP), and intraocular lens (IOL) dislocation. Hence, it needs much attention to surgery progress and close follow-up. In this review, we discuss the current understanding of RP patients with complicated cataracts from morphology to potential pathogenesis to cataract surgical procedure and provide a concise description and the recommended management of related surgery complications to broaden the knowledge and lower the latent risks to yield better clinical outcomes.

Dynamic tracking of Purkinje images for the comparison of pseudophakodonesis between in-the-bag and secondary fixated intraocular lenses

PURPOSE

To compare the pseudophakodonesis of in-the-bag intraocular lens (IOL) and a secondary fixated IOL by tracking the Purkinje image IV.

SETTING

Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, India.

DESIGN

Prospective case series.

METHODS

The IOL movement was recorded via slitlamp videography (DC3), streamed in video editor (Pinnacle), and evaluated by ImageJ analysis. The positional difference of Purkinje IV in relation to the stationary image Purkinje I at 3 random timeframes was measured. Pseudophakodonesis was quantified, compared, and correlated clinically.

RESULTS

The study comprised 127 eyes that had posterior chamber IOLs (PC IOLs) (n = 50), anterior chamber IOLs (AC IOLs) (n = 20), iris-claw IOLs (n = 20), glued IOLs (n = 30), and sutured scleral-fixated IOLs (n = 7). The iris-claw IOL showed significant difference in Purkinje IV at various timeframes (P = .0418) whereas others showed no significant change. On comparison of the Purkinje IV difference, there was a significant difference between the PC IOL and the iris-claw IOL (P = .0001), the glued IOL and the iris-claw IOL (P = .0020), and the AC IOL and the iris-claw IOL (P = .0302). The iris-claw IOL showed significant exaggeration of the position of Purkinje IV (P = .0395) after saccade. Pseudophakodonesis seemed mild (difference < 0.5 mm) in the PC IOL (68%), glued IOL (53.3%), and AC IOL (50%); moderate in the scleral-fixated IOL (71.4%); and severe (≥ 1.0 mm) in the iris-claw IOL (55%).

CONCLUSION

Positional difference in Purkinje IV was highest in iris-claw IOLs and lowest in PC IOLs.

Multifocal Intraocular Lenses Implantation in Presbyopia Correction. Literature Review

Reduced dependence on glasses is an increasingly common expectation among those who want to take advantage of new surgical opportunities, especially for patients who lead an active lifestyle. Currently, due to the increase in the duration of active life in people over 40, there is a need for effective correction of presbyopia. Multifocal intraocular lenses are increasingly used in the treatment of presbyopia. After implantation of multifocal intraocular lenses most patients have no need for spectacle or contact vision. However, complications can affect the patient’s quality of life and level of satisfaction. The most common complications of multifocal correction are blurred vision and the presence of optical phenomena (“halo” and “glare”), associated with residual ametropia, clouding of the posterior capsule, large pupil size, anomalies of the wave front, dry eye and lens decentration. The main reasons for this are the failure to attempt to neuroadapt a patient, the dislocation of the lens, the residual refractive error and the clouding of the lens. The review presents the main features of various models of multifocal intraocular lenses, their implantation techniques, associated complications and methods for their correction. The development of multifocal correction of presbyopia and ametropia seems to be a promising direction in ophthalmic surgery.

Evaluation of crystalline lens and intraocular lens tilt using a swept-source optical coherence tomography biometer

PURPOSE

To evaluate crystalline lens and intraocular lens (IOL) tilt using a swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700).

SETTING

Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.

DESIGN

Retrospective case series.

METHODS

The study patients were evaluated for 1) repeatability of the crystalline lens tilt measurement, 2) preoperative crystalline lens and postoperative IOL tilt in right eyes, 3) mirror symmetry between right eyes and left eyes, 4) the correlation between preoperative crystalline lens and postoperative IOL tilt, and 5) the correlation between the magnitude of lens tilt and ocular parameters.

RESULTS

The study comprised 333 patients. The repeatability was 0.1 degrees for tilt magnitude and 3.0 degrees for tilt direction. Both the crystalline lens and IOL had anterior tilt of the nasal portion with mean tilt magnitudes of 3.7 degrees ± 1.1 (SD) (range 0.4 to 6.9 degrees) for the crystalline lens and 4.9 ± 1.8 degrees (range 1.6 to 10.7 degrees) for the IOL. There was mirror symmetry between right eyes and left eyes. The mean IOL tilt magnitude exceeded crystalline lens tilt by 1.2 ± 1.1 degrees (range -3.2 to 4.0 degrees), and the 2 values were significantly correlated (all P < .01). The magnitude of crystalline lens tilt significantly increased with decreasing axial length and with increasing angle α (all P < .05).

CONCLUSIONS

The repeatability of crystalline lens tilt measurements using the SS-OCT biometer was excellent. There was mirror symmetry between the right eyes and left eyes. Preoperative crystalline lens tilt could be used to predict the postoperative IOL tilt. The lens tilt magnitude was greater in short eyes and in eyes with larger angle α.

INTRAOCULAR LENS POSITION IN COMBINED PHACOEMULSIFICATION AND VITREORETINAL SURGERY

PURPOSE

To assess the decentration and angle of tilt of the intraocular lens (IOL) according to the intravitreal tamponade types used in combined phacoemulsification and vitreoretinal surgery.

METHODS

This prospective and randomized clinical study involved 73 eyes of 69 patients who underwent combined vitreoretinal surgery. Eyes with intravitreal tamponades formed the study group and eyes without intravitreal tamponades formed the control group. The study group was further divided into silicone oil and gas tamponade subgroups. Cross-sectional IOL images were captured using a Pentacam HR (Oculus, Germany) and tilt and decentration were calculated with Adobe Photoshop software (Adobe, San Jose, CA).

RESULTS

The mean angle of tilt and decentration at the vertical meridian were significantly higher in both tamponade groups than in the control group (P < 0.05 for all). No significant difference was observed among the groups regarding IOL position parameters at the horizontal meridian (P > 0.05). When comparing the silicone oil and gas tamponade subgroups, no significant differences were noted on the position of IOL at both meridians (P > 0.05 for all).

CONCLUSION

Intravitreal tamponades have an important effect on the position of IOL in combined vitreoretinal surgery. Silicone oil and gas tamponades may induce postoperative tilt and decentration of one-piece acrylic IOLs.

Comparisons of the in-the-bag stabilities of single-piece and three-piece intraocular lenses for age-related cataract patients: a randomized controlled trial

Background

To compare the in-the-bag stability and visual function of single-piece intraocular lenses (IOLs) and three-piece IOLs.

Methods

A total of 65 patients with age-related cataracts (80 eyes) were enrolled and randomly assigned to receive in-the-bag implantation of either a single-piece IOL (40 eyes) or a three-piece IOL (40 eyes). Follow-up visits were conducted at 1 week, 1 month and 3 months postoperatively. Visual acuity, refraction and total aberration were examined. IOL position stability (including axial movement, decentration and tilt) was measured using a Scheimpflug imaging system.

Results

At the 3-month follow-up visit, single-piece IOLs did not exhibit significant axial movement (0.07 ± 0.30 mm, p = 0.13) compared with their axial position at 1 week postoperatively, whereas three-piece IOLs displayed forward axial movement of −0.22 ± 0.23 mm (p < 0.0001). The mean manifest spherical equivalence (SE) of eyes with single-piece IOL was 0.15 ± 0.18D, whereas in eyes with three-piece IOLs, the mean manifest SE was −0.34 ± 0.15D (p < 0.001). There was no statistically significant difference in IOL decentration, tilt, uncorrected visual acuity, best-corrected visual acuity or total spherical aberration between the two groups.

Conclusions

Three months after implantation, single-piece IOLs exhibit better axial stability and more stable refractive outcome than three-piece IOLs, but both IOLs perform equally well in terms of decentration, tilt, visual acuity and total aberration.

Trial registration

ClinicalTrial.gov, NCT02609997, 11/18/2015, retrospectively registered.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-016-0283-4) contains supplementary material, which is available to authorized users.

Evaluation of actual retinal images produced by misaligned aspheric intraocular lenses in a model eye

Purpose

To examine the effect of misalignment (decentration and tilt) of intraocular lenses (IOLs) on retinal image quality using a water-immersed model eye with corneal spherical aberration adjusted to the values found in normal human eyes (spherical aberration 0.25 μm; pupil diameter 6 mm).

Methods

Three types of IOL holders were prepared. The first was without decentration or tilt, the second had a decentration of 0.5 mm, and the third had a tilt of 5.0°. One spherical IOL and three aspherical IOLs, each with a power of +20 D, were set in the holders and their optical properties (wave front aberration, defocused modulation transfer function, defocused point spread function, and Landolt ring simulations) were compared.

Results

Coma aberrations generated by misaligned IOLs were related to the spherical aberration corrective power of the IOLs. Landolt ring simulations show that the depth of focus increased as spherical aberration increased and that the retinal image quality was degraded by increases in coma aberration.

Conclusion

Coma aberration was generated by IOLs with a large degree of spherical aberration correction, leading to reduced retinal image quality when the IOL was misaligned. This suggests that, in a clinical setting, the quality of vision might be improved by reducing the degree of coma aberration using IOLs that retain, or minimally correct, spherical aberration.

Prospective Comparison of One-Piece and Three-Piece Tecnis Aspheric Intraocular Lenses: 1-year Stability and its Effect on Visual Function

PURPOSE

To compare the stability and visual function of one-piece hydrophobic intraocular lens (IOL) (ZCB00, Abbot Medical Optics) and a three-piece hydrophobic IOL (ZA9003, Abbot Medical Optics) after cataract surgery.

MATERIALS AND METHODS

Eighteen eyes of 18 patients with the one-piece IOL and 20 eyes of 20 patients with the three-piece IOL who underwent cataract surgery were evaluated prospectively on best corrected distance visual acuity, postoperative refractive error, IOL decentration and tilt, anterior chamber depth (ACD), spherical aberration and contrast sensitivity. Measurements were performed 1 week and 1, 3, 6 and 12 months postoperatively. The postoperative outcomes were compared between the two groups.

RESULTS

In the one-piece group, a hyperopic refractive error (p < 0.002) and deeper ACDs during 1-year post-operatively were observed compared with the three-piece group. There were no significant differences in BCVA, IOL tilt, spherical aberration or contrast sensitivity.

CONCLUSIONS

The stability of the one-piece IOL was greater than that of the three-piece IOL. The postoperative ACD and refractive error demonstrated that an anteriorly offset haptic in the one-piece IOL allowed incremental fixation to the posterior capsule.

Positioning of the posterior intraocular lens in the longer term following cataract surgery in eyes with and without pseudoexfoliation syndrome

PURPOSE

To assess long-term positioning of posterior chamber intraocular lenses within the capsular bag in eyes with pseudoexfoliation syndrome.

METHODS

The study includes 44 patients with pseudoexfoliation syndrome and 85 age-matched controls, who underwent cataract surgery in 2001 and 2002 at the Eye Department, Oslo University Hospital. In 2008, all patients were re-examined. A comparison of the extent of possible decentration in eyes with and without pseudoexfoliation syndrome was made by evaluating Scheimpflug images (Pentacam) of the anterior segment.

RESULTS

It was found that, 6-7 years following cataract surgery, posterior chamber intraocular lenses were positioned lower in eyes with pseudoexfoliation syndrome than in control eyes. The difference was statistically significant (p=0.01). Downward shift was associated with presence of glaucoma only in eyes with pseudoexfoliation syndrome (p=0.01). No patients had visual disturbances related to displacement of the intraocular lens. Three of the patients with pseudoexfoliation syndrome (6.8%) had observable pseudophacodonesis by slit-lamp examination, compared to one in the control group (1.2%). The study demonstrated that Pentacam is an appropriate instrument to measure decentration of intraocular lenses.

CONCLUSION

The study suggests that, 6-7 years after cataract surgery, the intraocular lenses within the capsular bag are more prone to decentration in pseudoexfoliation syndrome eyes, compared to controls.

New bi-sign aspheric IOL and its application

PURPOSE

To present a bi-sign aspheric intraocular lens (IOL) and make theoretical comparisons with spherical and one-sign aspheric IOLs for retinal image quality in mesopic conditions and intermediate image capability in photopic conditions.

METHODS

Using ray-tracing in pseudophakic eye models, retinal image quality in terms of modulation transfer function was analyzed between the bi-sign aspheric and three types of one-sign aspheric IOLs and the spherical IOL for the range of corneal asphericities and different lens misalignments at 5 mm pupil diameter; comparison is made with the spherical IOL at defocus conditions characterized by negative refractive errors at 3 mm pupil diameter.

RESULTS

Retinal image quality of the bi-sign aspheric lens was equal to or exceeded the one-sign aspheric and spherical IOLs in the majority of anterior cornea asphericities and lens misalignments within the spatial frequencies of 6 to 15 c/deg. Intermediate image capability of the bi-sign aspheric exceeded the spherical IOL.

CONCLUSIONS

A new bi-sign aspheric lens produces regions of opposite spherical aberrations in the eye model with pupil diameters above 3 mm to balance out aberrations within the lens itself in addition to compensating corneal aberration as with a one-sign aspheric lens. This allows reduction in the variability of the retinal image quality at different anterior cornea asphericities and lens misalignments, when compared with a one-sign aspheric and spherical lens. The bi-sign aspheric produces positive longitudinal spherical aberration in the eye model within 3 mm pupil diameter that improves intermediate image capability when compared with the spherical IOL.

Three-haptic intraocular lens for myopia: early results

PURPOSE

To report the intraoperative experience and early postoperative results of implantation of an intraocular lens (IOL) developed specifically for myopic eyes.

SETTING

Wolverhampton Eye Infirmary, Wolverhampton, United Kingdom.

METHODS

This retrospective study evaluated consecutive highly myopic eyes having implantation of a Bigbag IOL from November 2003 to December 2007. Before IOL placement, a 2.8 mm clear corneal incision was created and phacoemulsification performed. The IOL was implanted using the dedicated folder and injector supplied by the manufacturer.

RESULTS

The study evaluated 67 eyes (48 patients) with a mean follow-up of 8.5 months (range 0.75 to 31 months). Intraoperative complications were IOL haptic damage from the injector system (3 eyes; 4.5%) and posterior capsule tear (1 eye; 1.5%). Postoperative complications were posterior capsule opacification (29 eyes; 43%), retinal detachment (1 eye; 1.5%), and iritis (1 eye; 1.5%). The postoperative corrected distance visual acuity was 0.10 logMAR or better in 24 eyes (35.8%) and 0.18 to 0.48 logMAR in 32 eyes (47.8%). Forty-three eyes (64.2%) were within +/-1.00 diopter of the intended refractive outcome.

CONCLUSION

Preliminary results indicate that this 3-haptic IOL is safe and appropriate for use in highly myopic patients having cataract surgery.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Intraocular lens stability and refractive outcomes after cataract surgery using primary posterior continuous curvilinear capsulorrhexis

PURPOSE

To evaluate the amount of intraocular lens (IOL) decentration and refractive changes after cataract surgery using posterior continuous curvilinear capsulorrhexis (PCCC).

DESIGN

Prospective comparative case series.

PARTICIPANTS

We included 86 eyes of 77 patients who had cataract surgery using PCCC (the PCCC group), and 79 eyes of 68 patients treated without PCCC (the control group).

METHODS

Foldable IOLs with polymethylmethacrylate haptics (VA-60BB, Hoya Corporation, Tokyo, Japan) were implanted in both groups. The best-corrected visual acuity (BCVA) was assessed. Automated refractokeratometry, Scheimpflug imaging (Pentacam; Oculus, Wetzlar, Germany), and slit-lamp photography with retroillumination were performed at each follow-up visit over 6 months. The axial shift of each IOL was measured as the distance between the corneal endothelium and the anterior surface of the IOL on Scheimpflug images. The horizontal shift was assessed as the distance between the geometric center of the IOL and the centers of the pupil and the limbus.

MAIN OUTCOME MEASURES

Best-corrected visual acuity, horizontal and axial shift of the IOL, and automated refraction.

RESULTS

There was no difference between the 2 groups in the mean BCVA before surgery and at any postoperative follow-up. The mean horizontal shift of the IOL after 6 months was 0.25 ± 0.14 mm for the pupil and 0.31 ± 0.17 mm for the limbus in the PCCC group (P = 0.315), and 0.26 ± 0.09 mm and 0.31 ± 0.13 mm, respectively, in the control group (P = 0.115). These were not different from the measurement on the postoperative day 1 (P = 0.515, P = 0.263, P = 0.421, and P = 0.875, respectively). At each follow-up visit over 6 months, there was no difference in the horizontal shift between the 2 groups (P > 0.05). The IOL shifted insignificantly in the PCCC group (-0.08 ± 0.24 mm anterior shift), but the shift was significant in the control group (-0.42 ± 0.27 mm anterior shift; P = 0.009). The mean postoperative refractive shift 6 months after surgery compared with refraction on the first day after surgery was -0.16 ± 0.67 diopter (D) in the PCCC group and -0.60 ± 0.70 D in the control group (P = 0.042).

CONCLUSIONS

During cataract surgery, PCCC is useful to stabilize and minimize postoperative refractive changes. The IOL displacement attributable to capsular contraction is less when cataract surgery involves PCCC.

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

PURPOSE

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.

DESIGN

Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison.

PARTICIPANTS

Fifty-two patients with bilateral age-related cataract (104 eyes).

METHODS

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.

MAIN OUTCOME MEASURE

Posterior capsule opacification score (scale, 0-10).

RESULTS

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).

CONCLUSIONS

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.

Intraocular lens centration and visual outcomes after bag-in-the-lens implantation

PURPOSE

To examine the centration and visual outcomes after cataract surgery using the bag-in-the-lens (BIL) implantation technique.

SETTING

University Hospital Antwerp, Department of Ophthalmology, Edegem, Belgium.

METHODS

This study comprised 180 eyes of 125 patients who had cataract surgery with implantation of the BIL intraocular lens (IOL) between March 2002 and September 2005. Postoperative data at 5 weeks, 6 months, and 1 year were evaluated. The geometric center of the IOL, measured on a red reflex slitlamp photograph, was compared with the geometric center of the pupil and the limbus.

RESULTS

The mean decentration compared with the limbus was 0.304 mm+/-0.17 (SD) at a mean angle of -24.9+/-113.3 degrees. Compared with the dilated pupil, the mean deviation was 0.256+/-0.15 mm at a mean angle of -5.2+/-119.0 degrees. The amount of decentration was stable during the postoperative follow-up period. There was no correlation between the amount of decentration and the visual outcomes (pupil: r=-0.07, P=.494; limbus: r=0.11, P=.304).

CONCLUSIONS

Surgeon-controlled BIL centration was predictable 5 weeks and unchanged 6 months and 1 year postoperatively. It can therefore be concluded that capsular bag healing has no influence on BIL IOL centration over time.

Influence of tilt and decentration of scleral-sutured intraocular lens on ocular higher-order wavefront aberration

AIM

To investigate the influence of tilt and decentration of scleral-sutured intraocular lenses (IOLs) on ocular higher-order wavefront aberrations.

METHODS

In 45 eyes of 36 patients who had undergone scleral suture fixation of posterior chamber IOL, tilt and decentration of IOLs were determined by Scheimpflug videophotography, and higher-order aberration for a 4-mm pupil was measured using the Hartmann-Shack aberrometer. In another 100 eyes of 100 patients after standard cataract surgery with posterior chamber IOL implantation, ocular higher-order aberration was measured.

RESULTS

In eyes with scleral-sutured IOL, the mean (SD) tilt angle and decentration were 4.43 degrees (3.02 degrees ) and 0.279 (0.162) mm, respectively. Ocular coma-like aberration in the sutured IOL group was 0.324 (0.170) microm, which was significantly greater than that of the standard cataract surgery group (0.169 (0.061) microm, p<0.001, Student's t test). No significant difference was found in ocular spherical-like aberration between the sutured IOL group (0.142 (0.065) microm) and standard surgery group (0.126 (0.033) microm; p = 0.254). In the sutured IOL group, IOL tilt significantly correlated with ocular coma-like aberration (Pearson's correlation coefficient r = 0.628, p<0.001), but no significant correlation was found between IOL tilt and ocular spherical-like aberration (r = 0.222, p = 0.175). The IOL tilt did not correlate with corneal coma-like (r = 0.289, p = 0.171) and spherical-like (r = 0.150, p = 0.356) aberrations. The IOL decentration did not correlate with any higher-order aberrations.

CONCLUSION

In eyes with scleral-sutured posterior chamber IOL, tilting of the lens induces considerable amount of ocular coma-like aberrations.

Prospective Intrapatient Comparison of 6.0-Millimeter Optic Single-Piece and 3-Piece Hydrophobic Acrylic Foldable Intraocular Lenses

PURPOSE

To compare postoperative performance and stability of 6.0-mm optic single- and 3-piece acrylic foldable intraocular lenses (IOLs).

DESIGN

Prospective, randomized, self-controlled trial.

PARTICIPANTS

Eighty eyes of 40 patients with bilateral senile cataracts.

INTERVENTION

Phacoemulsification and IOL implantation were performed. One eye of a patient was randomly assigned to the SA60AT single-piece IOL, and the contralateral eye was allocated to the MA60AC 3-piece IOL.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA), spherical equivalent, aqueous flare intensity, anterior chamber depth, amount of IOL decentration and tilt, area of anterior capsule opening, and degree of posterior capsule opacification (PCO) were measured 2 days, 1 week, and 1, 3, 6, and 12 months after surgery. Specular microscopy was performed at 12 months postoperatively.

RESULTS

In the SA60AT group, the anterior chamber depth did not show significant changes after surgery (P>0.05; paired t test), and the refraction remained highly stable throughout the 1-year study period. The MA60AC group showed significant shallowing of the anterior chamber (P<0.05) and a myopic shift (P<0.05) up to 1 month after surgery. There were no significant differences between the 2 groups (P>0.05) in BCVA, aqueous flare intensity, the amount of IOL decentration, IOL tilt, area of anterior capsule opening, and degree of PCO throughout the 12-month follow-up period.

CONCLUSIONS

Both the SA60AT single-piece and MA60AC 3-piece lenses showed a minimum amount of decentration, tilt, anterior capsule contraction, and PCO. Although the MA60AC showed significant forward shift and myopic refractive changes after surgery, the SA60AT displayed little axial movement associated with highly stable refraction after surgery. This feature of the SA60AT should facilitate earlier spectacle prescription and quicker visual/social rehabilitation of patients after cataract surgery.