Clinical study of the 1CU accommodating intraocular lens

Five Years Follow-Up of Acrysof Cachet® Angle-Supported Phakic Intraocular Lens Implantation for Myopia Correction

Purpose

The Acrysof Cachet® angle-supported phakic intraocular lens (pIOL) (Alcon Laboratories, Inc., Fort Worth, TX) is designed to correct high refractive errors in human eyes. The aim of this study was to evaluate the outcome of AcrySof Cachet® angle-supported pIOL implantation with particular regard to efficacy and safety of the implant over a 60-month follow-up period.

Design

Retrospective consecutive clinical case study.

Methods

Prior to pIOL implantation, patients had a complete ophthalmologic examination including objective and subjective refraction, uncorrected visual acuity (UCVA) and corrected distance visual acuity (CDVA), endothelial cells density (ECD), slit lamp photography, optical coherence tomography (OCT), Scheimpflug digital videokeratoscopy, optical biometry, slit lamp examination, intraocular pressure (IOP) measurement, and pupillometry. Postoperatively, patients received yearly a complete eye examination.

Results

Thirty-one eyes of 16 patients were included in this study. The mean age was 36.2 ± 8.1 years. UCVA (logMAR) improved from 1.33 ± 0.20 before surgery to 0.08 ± 0.14 one year after surgery and was 0.20 ± 0.20 five years after surgery. CDVA (logMAR) improved from 0.10 ± 0.10 before surgery to 0.05 ± 0.13 one year after surgery and was 0.04 ± 0.14 five years postoperatively. The mean percentage of endothelial cells loss (ECL) was 11.51% over the first year and 15.95% five years after surgery. There were no intraoperative complications in any of the eyes.

Conclusions

Our results up to five years after implantation of the AcrySof Cachet® angle-supported pIOL demonstrated very good outcomes in all above shown measurements, including CDVA, UCVA, and ECD. However, since major endothelial cell loss may occur in some patients with this type of pIOL, regular follow-up visits are required.

Lens exchange for management of accommodative intraocular lens tilting

Accommodative intraocular lens (IOL) tilting, the so-called Z syndrome, is a rare complication of Crystalens (Bausch and Lomb) implantation. We report a significant IOL tilting and subsequent high lenticular astigmatism due to posterior capsular fibrosis 2 months after uncomplicated cataract surgery and Crystalens (AT50AO) implantation. The attempt to correct IOL position with neodymium-yttrium-aluminum garnet laser was unsuccessful, and Crystalens exchange with in-the-sulcus, three-piece monofocal IOL was performed. Accommodative IOL tilting could occur early after the surgery. Laser capsulotomy may be the first intervention to restore IOL position, but patients with a higher amount of lenticular astigmatism may require surgical intervention and IOL exchange.

The efficacy of accommodative versus monofocal intraocular lenses for cataract patients: A systematic review and meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis to evaluate whether accommodative intraocular lenses (AC-IOLs) are superior for cataract patients compared with monofocal IOLs (MF-IOLs).

METHODS

Pubmed, Embase, Cochrane library, CNKI, and Wanfang databases were searched through in August 2018 for AC-IOLs versus MF-IOLs in cataract patients. Studies were pooled under either fixed-effects model or random-effects model to calculate the relative risk (RR), weighted mean difference (WMD), or standard mean difference (SMD) and their corresponding 95% confidence interval (CI). Distance-corrected near visual acuity (DCNVA) was chosen as the primary outcome. The secondary outcomes were corrected distant visual acuity (CDVA), pilocarpine-induced IOL shift, contrast sensitivity, and spectacle independence.

RESULTS

Seventeen studies, involving a total of 1764 eyes, were included. Our results revealed that AC-IOLs improved DCNVA (SMD = -1.84, 95% CI = -2.56 to -1.11) and were associated with significantly greater anterior lens shift than MF-IOLs (WMD = -0.30, 95% CI = -0.37 to -0.23). Furthermore, spectacle independence was significantly better with AC-IOLs than with MF-IOLs (RR = 3.07, 95% CI = 1.06-8.89). However, there was no significant difference in CDVA and contrast sensitivity between the 2 groups.

CONCLUSION

Our study confirmed that AC-IOLs can provide cataract patients with DCNVA and result in more high levels of spectacle independence than MF-IOLs. Further studies with larger data set and well-designed models are required to validate our findings.

Visual Acuity and Contrast Sensitivity Function after Accommodative and Multifocal Intraocular Lens Implantation

Purpose

To evaluate visual acuities and contrast sensitivities (CS) after accommodative, refractive, and diffractive multifocal intraocular lens (IOL) implantations.

Methods

After cataract extractions, in 20 eyes accommodative IOL (group 1), in 30 eyes refractive IOL (group 2), and in 20 eyes diffractive multifocal IOL (group 3) implantations were performed. CS were measured with the stereo optical functional acuity contrast test. Uncorrected distance (UCDVA) and distance corrected near visual acuities (DCNVA) and refractive values were determined.

Results

The mean UCDVA (0.99±0.03) and DCNVA (0.98±0.04) of group 3 were significantly better than the other IOL groups. The mean DCNVA of group 2 (0.71±0.14) was significantly better than group 1 (0.5±0.08). One month after the operations CS, values of group 2 were significantly lower than the 2 other IOL groups. Photopic CS values of group 1 at 12 and 18 cycles per degree (cpd) were significantly higher than group 3. Three months after the operations, CS values of group 1 and 3 were significantly higher than that of group 2 at 3, 6, 12, and 18 cpd and in all spatial frequencies respectively. There was no difference between groups 1 and 3 with respect to photopic CS values. Mesopic CS values of group 3 were significantly higher than that of group 1 at 1.5, 3, and 6 cpd. At the 6th and 12th month, CS values of group 3 were similar or better compared to the values of the 3rd month.

Conclusions

The diffractive multifocal IOL resulted in more favorable visual acuities and higher CS values than accommodative and refractive multifocal IOL.

Accommodative Intraocular Lenses: Short-Term Visual Results of Two Different Lens Types

Purpose

To compare the ability of two types of accommodative intraocular lenses (IOLs) to provide uncorrected near and distance visual acuity (VA) after cataract surgery.

Methods

A total of 108 eyes of 75 patients underwent cataract surgery by phacoemulsification and IOL implantation either bilaterally or monocularly with one of two types of accommodative IOLs: the AT-45 lens (69 eyes) or the 1-CU lens (39 eyes). Patients were followed for up to 1 year after cataract surgery. Near VA was measured through the distance correction to obtain the true near vision effect of the accommodating IOL.

Results

Uncorrected distance VA of 20/30 or better was achieved by 84.6% of the bilaterally implanted 1-CU patients and 73.6% of the bilaterally implanted AT-45 IOL patients 1 year following surgery. Uncorrected near VA of J1 or better was achieved by 42% of the patients with the bilateral 1-CU implant and 36.8% of the patients with the bilateral AT-45 implant. For J3 or better near acuity, the values were 92.3% for the bilateral 1-CU patients and 84.2% for the bilateral AT-45 patients at 1 year. A total of 54% of the eyes with 1-CU implants underwent a mild myopic shift (<1.0 D), 21% had a mild hyperopic shift, and 45% of the eyes were emmetropic at 1 year.

Conclusions

Both accommodative IOLs provided good near and distance vision postoperatively. The 1-CU IOL appears clinically to provide slightly better uncorrected distance and distance-corrected near VA than the AT-45 lens.

Positional accommodative intraocular lens power error induced by the estimation of the corneal power and the effective lens position

Purpose:

To evaluate the predictability of the refractive correction achieved with a positional accommodating intraocular lenses (IOL) and to develop a potential optimization of it by minimizing the error associated with the keratometric estimation of the corneal power and by developing a predictive formula for the effective lens position (ELP).

Materials and Methods:

Clinical data from 25 eyes of 14 patients (age range, 52–77 years) and undergoing cataract surgery with implantation of the accommodating IOL Crystalens HD (Bausch and Lomb) were retrospectively reviewed. In all cases, the calculation of an adjusted IOL power (P_IOLadj) based on Gaussian optics considering the residual refractive error was done using a variable keratometric index value (n_kadj) for corneal power estimation with and without using an estimation algorithm for ELP obtained by multiple regression analysis (ELP_adj). P_IOLadj was compared to the real IOL power implanted (P_IOLReal, calculated with the SRK-T formula) and also to the values estimated by the Haigis, HofferQ, and Holladay I formulas.

Results:

No statistically significant differences were found between P_IOLReal and P_IOLadj when ELP_adj was used (P = 0.10), with a range of agreement between calculations of 1.23 D. In contrast, P_IOLReal was significantly higher when compared to P_IOLadj without using ELP_adj and also compared to the values estimated by the other formulas.

Conclusions:

Predictable refractive outcomes can be obtained with the accommodating IOL Crystalens HD using a variable keratometric index for corneal power estimation and by estimating ELP with an algorithm dependent on anatomical factors and age.

Physiological constraints for an intraocular inductive distance sensor

In this paper the design restrictions of an inductive sensor for an intraocular lens with focus control on the basis of a marker implanted in the ciliary muscle of the eye are discussed in the framework of anatomical and physiological influences and constraints: limitations on the marker size, influences of tissue conduction and effects of off-axis implantation of the marker with respect to the coil.

Clinical and quality of life data correlation with a single-optic accommodating intraocular lens

Purpose

To examine a single-optic accommodating intraocular lens (IOL) visual performance by correlating IOL implanted eyes’ defocus curve with the intraocular aberrometric profile and the impact on the quality of life (QOL).

Methods

Prospective consecutive case series study including a total of 25 eyes of 14 patients with ages ranging between 52 and 79 years old. All cases underwent cataract surgery with implantation of the single-optic accommodating IOL Crystalens HD (Bausch & Lomb). Distance and near visual acuity outcomes, intraocular aberrations, the defocus curve and QOL (NEI VFQ-25) were evaluated 3 months after surgery.

Results

A significant improvement in distance visual acuity was found postoperatively (p = 0.02). Mean postoperative LogMAR uncorrected near visual acuity was 0.44 ± 0.23 (20/30). 60% of eyes had a postoperative addition between 0 and 1.5 diopters (D). The defocus curve showed an area of maximum visual acuity for the levels of defocus corresponding to distance and intermediate vision (−1 to +0.5 D). Postoperative intermediate visual acuity correlated significantly some QOL indices (r ≥ 0.51, p ≤ 0.03; difficulty in going down steps or seeing how people react to things that patient says) as well as with J₀ component of manifest cylinder. Postoperative distance-corrected near visual acuity correlated significantly with age (r = 0.65, p < 0.01).

Conclusions

This accommodating IOL seems to be able to restore the distance visual function as well as to provide an improvement in intermediate and near vision with a significant impact on patient's QOL, although limited by age and astigmatism. Future studies with larger sample sizes should confirm all these trends.

Real and pseudoaccommodation in accommodative lenses

In the attempt to manage presbyopia, different intraocular lens designs have been proposed such as monofocal IOLs with monovision or multifocal IOLs. Even though the lenses mentioned offer satisfactory visual results, contemporary ophthalmology has not completely answered the presbyopic dilemma by simulating the accommodative properties of the crystalline lens itself. Accommodative IOLs were designed to fill this gap and provide satisfactory vision for all distances by restoring some degree of "pseudoaccommodation." Pseudo accommodative capability can be linked to monofocal IOL's as well but the results are not satisfactory enough to fully support unaided near vision. Pseudoaccommodation is a complex phenomenon that can be attributed to several static (i.e., pupil size, against-the-rule cylindrical refractive error, multifocality of the cornea) and dynamic (i.e., anterior movement of the implant itself) factors. Objective measurement of the accommodative capability offered by the accommodative IOLs is extremely difficult to obtain, and different methods such as autorefractometers, retinoscopy, and ultrasound imaging during accommodative effort, ray tracing, or pharmacological stimulation have been developed but the results are sometimes inconsistent. Despite the difficulties in measuring accommodation, accommodative IOLs represent the future in the attempt to successfully "cure" presbyopia.

Pilot study of new focus-shift accommodating intraocular lens

PURPOSE

To determine the visual and accommodative performance of the OPAL-A focus-shift accommodating intraocular lens (IOL).

SETTING

Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom.

METHODS

In this study comprising unilateral phacoemulsification and accommodating IOL implantation, patients were followed for 6 months. Corrected distance (CDVA) and distance-corrected near (DCNVA) visual acuities were measured. Objective amplitude of accommodation was measured with an autorefractor and subjective amplitude of accommodation, using push-up tests and defocus curves. Physiological and pilocarpine-stimulated IOL movement was measured by anterior segment optical coherence tomography.

RESULTS

The mean values at 1 month, 3 months, and 6 months, respectively, were as follows: CDVA, -0.06 +/- 0.08 (SD), -0.08 +/- 0.09, and -0.05 +/- 0.09; DCNVA, 0.31 +/- 0.15, 0.31 +/- 0.15, and 0.34 +/- 0.16; objective amplitude of accommodation, 0.36 +/- 0.38 diopters (D), 0.12 +/- 0.34 D, and 0.10 +/- 0.34 D; subjective amplitude of accommodation, 2.79 +/- 0.86 D, 2.55 +/- 0.85 D, and 2.50 +/- 0.62 D with push-up test and 0.90 +/- 0.40 D, 0.78 +/- 0.23 D, and 0.93 +/- 0.35 D with defocus curves. The maximum physiologic IOL shift at 1 month (mean 45.2 +/- 63.4 microm) occurred with a 3.0 D accommodative stimulus. At 6 months, the mean pilocarpine-stimulated forward IOL shift was 306 +/- 161 microm.

CONCLUSIONS

Objective accommodation and forward axial shift were clinically insignificant with the accommodating IOL. The near visual performance was attributed to depth of focus rather than to true pseudophakic accommodation.

Biconvex posterior chamber accommodating intraocular lens implantation after cataract surgery: long-term outcomes

PURPOSE

To evaluate the long-term efficacy of a biconvex accommodating intraocular lens (IOL) to restore near visual performance.

SETTING

Department of Ophthalmology, Keio University Hospital, Tokyo, Japan.

METHODS

This 4-year study comprised eyes that had cataract surgery with implantation of a 1CU accommodating IOL. At all postoperative visits, the following were assessed: subjective spherical equivalent (SE) refraction; uncorrected (UDVA) and corrected (CDVA) distance visual acuities; uncorrected (UNVA), distance-corrected (DCNVA), and corrected (CNVA) near visual acuities; change in minimum additional (add) power (diopters) to attain CNVA; and accommodation amplitude. A questionnaire was administered at the last visit.

RESULTS

Twelve eyes of 8 cataract patients (mean age 59.0 years +/- 18.4 [SD]) were evaluated. Postoperatively, the mean SE at 1 year and 4 years was significantly more hyperopic than at 1 month (P<.05). The mean UDVA increased significantly at 4 years compared with 1 month (P<.05). There were no significant changes in CDVA, UNVA, CNVA, and DCNVA throughout the follow-up period. The change in the minimum add power to attain CNVA and in the subjective and objective accommodation amplitudes also did not change significantly over time. Eighty-three percent of patients reported being satisfied with the results.

CONCLUSION

Four years after implantation of an accommodating IOL, most patients had good vision and were satisfied, although the accommodation amplitude for near vision was not sufficient throughout the follow-up.

Functional assessment of accommodating intraocular lenses versus monofocal intraocular lenses in cataract surgery: metaanalysis

PURPOSE

To compare accommodating intraocular lens (IOLs) and monofocal IOLs in restoring accommodation in cataract surgery.

SETTING

Dartmouth Medical School and Department of Ophthalmology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.

METHODS

In this metaanalysis, 2 researchers independently extracted data, assessed trial quality, and contacted authors for missing information. Because of measurement-scale variations, outcomes were pooled for distance-corrected near visual acuity (DCNVA) as standardized mean differences with 95% confidence intervals [CIs] and anterior displacement of the lens as weighted mean differences (95% CI).

RESULTS

The metaanalysis comprised 12 randomized controlled studies of 727 eyes. Based on 10 studies that compared DCNVA, accommodating IOLs were favored but failed the test of heterogeneity (I(2) = 94%). Pooling the 6 homogeneous trials (I(2) = 43%) showed no difference (standardized mean difference, -0.16; 95% CI, -0.56 to 0.25). Heterogeneity could not be explained by any characteristic of the study population or methodology. Based on 4 studies that evaluated pilocarpine-induced IOL shift, there was a significant anterior compared with the control (weighted mean difference, 95% CI, -0.36 - 0.47 to -0.24]), although the studies were heterogeneous (I(2) = 58%). Three of 5 studies mentioning posterior capsule opacification (PCO) reported increased rates in the accommodating IOL group postoperatively.

CONCLUSIONS

There was no clear evidence of near acuity improvement despite statistically significant pilocarpine-induced anterior lens displacement. Further randomized controlled studies with standardized methods evaluating adverse effects (eg, PCO) are needed to clarify the tradeoffs.

Femtosecond laser induced flexibility change of human donor lenses

BACKGROUND

According to the Helmholtz theory of accommodation the loss of accommodation amplitude is caused by the growing sclerosis of the crystalline lens, whereas the ciliary muscle and the lens capsule are mainly uneffected by age. A permanent treatment method for presbyopia which offers a dynamic accommodation ability is a recent field of study. The concept followed in this paper uses femtosecond laser pulses to potentially overcome the loss of deformation ability of the crystalline lens by creating gliding planes inside the lens tissue to improve its flexibility.

METHODS

The aim of the study is to show that the flexibility of human donor lenses can be increased by applying tightly focused near infrared femtosecond laser pulses into the lens tissue. Thereby the tissue is separated by the photodisruption effect. A certain pattern of gliding planes is cut inside the tissue of 41 human donor lenses and the deformation ability of the lenses are compared using the Fisher spinning test before and after laser treatment.

RESULTS

The laser treatment results in an increased deformation ability of the crystalline lens. The lens a-p thickness increases on average by 97 microm+/-14 microm after the treatment. The Fisher spinning test shows an increase of 16% in deformation ability of the lens at a rotational speed of 1620 rpm.

CONCLUSION

The creation of gliding planes with a fs laser inside the crystalline lens tissue can change the deformation ability of the lens. This might be an indication for a possible method to treat presbyopia in future.

Depth of focus in pseudophakic eyes

PURPOSE

To assess depth of field/depth of focus in pseudophakic eyes as function of visual acuity.

SETTING

Department of ophthalmology of National Medical Academy of Postgraduate Education.

METHODS

Forty-three pseudophakic eyes of 43 patients after implantation in the capsular bag of monofocal posterior chamber IOLs were examined. All patients had visual acuities at least 20/20 for distance. Visual acuity was examined by charts consisting the Landolt's rings under defined constant illumination within distance from 3 m to 20 cm from patients' eyes at various distances with difference of 10 cm (29 measurements). Depth of field was calculated in diopters.

RESULTS

The mean value of the depth of field in pseudophakic eyes with pupil diameter of 3 +/- 0.3 mm was as follows: 1.12 D for visual acuity 20/20, 0.62 D for visual acuity 20/13, and 0.47 D for visual acuity 20/10.

CONCLUSIONS

Depth of focus correlates to normal levels of visual acuity. The higher the visual acuity, the lower the depth of focus. The ability of clear vision due to depth of focus-pseudoaccommodation is passive function. Separating the pseudoaccommodation from artificial accommodation in eyes with accommodative IOLs requires strict standardization of methodology especially regarding diameter of pupil, size of test objects, and level of illumination.

Objective accommodation measurements in prepresbyopic eyes using an autorefractor and an aberrometer

PURPOSE

To test the repeatability of the iTrace wavefront aberrometer (Tracey Technologies, Inc.) and the WR-5100K autorefractor (Grand Seiko Co., Ltd.) and to measure accomodation in young and phakic prepresbyopic subjects.

SETTING

University of Houston, College of Optometry, Houston, Texas, USA.

METHODS

This study comprised 30 young adults and 15 prepresbyopic subjects. Accommodation was stimulated with near charts presented at various distances. Measurements were repeated 3 times for each target distance with both instruments. For test-retest reliability, the entire protocol was repeated on 3 additional days in 3 prepresbyopic subjects as well as twice on the same day in the young adults.

RESULTS

The mean age was 25.5 years +/- 3.25 (SD) (range 21 to 31 years old) in the young adult group and 41.2 +/- 2.98 years (range 38 to 49 years) in the prepresbyopic group. Bland-Altman analysis of repeated measures of the young subjects had limits of agreements (LoA) of 1.58 diopters (D) or less for each instrument and when compared between instruments. Normalized mean stimulus response functions in the prepresbyopic group were similar for the 2 instruments. Bland-Altman analysis of the accommodation measurements between the 2 instruments showed a mean difference of 0.07 D and an LoA of 0.70 D. Repeated measures of 3 prepresbyopic subjects had a range of standard deviations from 0.07 to 0.51 D.

CONCLUSION

The accommodative responses measured with the 2 instruments were not significantly different, and testing showed both instruments to be suitable for objective measurement of accommodation in a phakic prepresbyopic population with low accommodative amplitudes.

Comparing the 1CU accommodative, multifocal, and monofocal intraocular lenses: a randomized trial

OBJECTIVE

To compare the binocular near vision performance in patients implanted with the 1CU accommodating intraocular lens (IOL) with a multifocal and monofocal IOL.

DESIGN

Prospective, randomized, double-masked clinical trial.

PARTICIPANTS

Ninety patients presenting for cataract surgery to the Department of Ophthalmology, Hillingdon Hospital were randomized to receive the 1CU accommodative IOL, a multifocal IOL, or a monofocal IOL (control group).

METHODS

Patients underwent bilateral sequential phacoemulsification with implantation of 1 of the 3 IOL types and were assessed at 3 and 18 months after second-eye surgery.

MAIN OUTCOME MEASURES

Logarithm of the minimum angle of resolution distance and near visual acuities (VAs) (unaided and distance corrected), contrast sensitivity, and accommodative amplitude (near point and defocusing) were measured at 3 and 18 months. Reading speed was assessed at 18 months, and glare symptoms and spectacle independence were compared using a standardized questionnaire.

RESULTS

Mean unaided and distance-corrected binocular near VAs were similar in the 1CU and multifocal and were significantly higher than the control group's (P<0.02). There was no significant difference in reading speed between any of the groups, but critical print sizes were similar in the 1CU and multifocal groups and significantly better than the control group's (P = 0.02). The accommodative range was highest in the multifocal group and lowest in the control group, and there was no significant difference between the 1CU and control groups for defocus or near point at 18 months. Of the 1CU group and control group, 71.4% and 63.2%, respectively, experienced no glare at 18 months, compared with only 25% of the multifocal group (P = 0.01). Of the 1CU group and multifocal group, 19% and 27.3%, respectively, were completely spectacle independent at 18 months; none of the control group was (P = 0.05).

CONCLUSIONS

The 1CU accommodating IOL provides improved near vision compared with a monofocal IOL. There is a discrepancy between the near function and accommodative amplitude measured in the 1CU. The multifocal provides excellent near acuity, but photopic phenomena remain a problem inherent in the lens design.

Accommodative intraocular lenses: considerations on use, function and design

PURPOSE OF REVIEW

To review the development, design and clinical implications of the first US Food and Drugs Administration approved accommodative lens. To inform the reader of forthcoming accommodative intraocular lens technologies that are being clinically tested and other technologies that are under design.

RECENT FINDINGS

We present clinical data that are currently available or pending release on accommodative intraocular lenses. As much as the results of the technology can be appreciated, the approach toward the refractive mindset of the presbyopic intraocular lens patient must be understood and mastered.

SUMMARY

Accommodative intraocular lens design and development are at a feverish pace. The lure is the perceived holy grail for the solution of presbyopia.

Far and near visual acuity with multifocal intraocular lenses in an optomechanical eye model with imaging capability

PURPOSE

To compare the quantitative and qualitative visual performances of different multifocal intraocular lenses (IOLs) in an experimental model of the human eye.

SETTING

University Hospital San Raffaele, Milan, Italy.

METHODS

Five multifocal IOLs and 1 monofocal IOL were implanted in an optomechanical eye model with imaging capability. The comparative optical characterization of the imaging performance included aberrometry, simulated visual acuity testing at variable contrast for far and near distance, glare tests, and image records of optotype charts.

RESULTS

The maximum recorded far visual acuity for the monofocal IOL was between 20/12.5 and 20/16; the multifocal IOLs decreased visual acuity by 1 to 2 lines. The difference tended to increase at reduced contrast. Full-contrast near visual acuity with multifocal IOLs ranged between 20/63 and 20/25; the near distance performance of the monofocal IOL without an additional correcting lens was worse by 1 to 3 lines of acuity with large pupils but was comparable with small pupils. Multifocal IOLs of different designs showed marked differences as a function of contrast, which tended to balance between far and near behaviors.

CONCLUSIONS

Multifocal IOLs of different optical designs were well characterized and distinguished by simulated contrast acuity testing in an experimental eye model, allowing quantitative comparison. Their overall visual performance, averaged over contrast and distance, was not superior to the performance of a monofocal IOL without an additional correcting lens.

Longterm results of 1 CU® accommodative intraocular lens implantation: 2-year follow-up study

PURPOSE

To evaluate the longterm efficacy of 1 CU accommodative intraocular lenses (IOLs) to restore near visual performance.

METHODS

This prospective study comprised 14 eyes previously included in a 6-month, case-control clinical trial, undergoing phacoemulsification and implantation of a 1 CU accommodative IOL. The main outcome measures were subjective refraction, uncorrected distance visual acuity (UCDVA), best corrected distance VA (BCDVA), distance-corrected near VA (DCNVA), best corrected near VA (BCNVA), and subjective amplitude of accommodation (AA). In addition, anterior and posterior capsule opacification were assessed. Patients were examined over a 2-year follow-up period.

RESULTS

Distance and near visual performance worsened after 6 months. Uncorrected DVA and BCDVA were 0.8 +/- 2.1 and 1.0 +/- 0.8 at 6 months and 0.4 +/- 0.1 and 0.6 +/- 0.1 at 1 year, respectively (p = 0.001). Distance-corrected NVA and BCNVA were 3.7 +/- 2.1 Jaeger (J) and 1.0 +/- 0.7 J at 6 months and 8.1 +/- 0.7 J and 1.5 +/- 0.5 J at 1 year, respectively (p = 0.001). Anterior and posterior capsule opacification were present, respectively, in 28% and 21% of patients at 6 months and in 100% of patients at 1 and 2 years (p < 0.001). After Nd:YAG laser capsulotomy (performed in 100% of patients), UCDVA and BCDVA increased to 0.7 +/- 0.2 (p = 0.007) and 1.0 +/- 0.1 (p = 0.001), respectively, at 2 years. Distance-corrected NVA improved to 7.3 +/- 0.5 J (p = 0.006). Mean AA was 1.9 +/- 0.8 D at 6 months, 0.3 +/- 0.2 D (p = 0.004) at 1 year and 0.3 +/- 0.2 D at 2 years.

CONCLUSIONS

Patients implanted with 1 CU IOLs lost their accommodation capacities with time because of the high incidence and degree of anterior and posterior capsule opacification. The accommodative lens material and design may have played a role in capsule fibrosis.

Meta-analysis of accommodating intraocular lenses

Accommodating intraocular lenses (IOLs) based on the concept of optic shift were introduced to restore accommodation after cataract surgery. Currently, 3 types of accommodating IOLs are commercially available: 1CU (HumanOptics), BioComFold (Morcher), and AT-45 Crystalens (eyeonics, Inc.). We present a meta-analysis of the peer-reviewed data from studies of these IOLs that use optic-shift measurements and visual acuity as the main outcome measures. In the 6 randomized controlled studies, 5 of which studied the 1CU IOL, the visual acuity results showed moderate to no improvement in near visual acuity compared with control IOLs and a statistically significant but small and inter-patient variable anterior shift of the IOL optic after pilocarpine stimulation. More clinical trials with randomized, controlled, and patient- and examiner-masked study designs that follow the guidelines of evidence-based medicine are needed to prove a benefit of accommodating focus-shift IOLs.

Potentially Accommodating 1CU Intraocular Lens: 1-year Results in 553 Eyes and Literature Review

PURPOSE

To investigate the advantages, clinical outcomes, and safety after implantation of the 1CU (HumanOptics AG) optic shift intraocular lens (IOL) in comparison with a conventional monofocal IOL.

METHODS

In a prospective non-randomized study, 553 eyes implanted with the 1CU IOL were examined. In a control group, a monofocal posterior chamber IOL (MCTE, Dr Schmidt) was implanted in 219 eyes. Follow-up was performed at 1, 6, and 12 months postoperatively. The clinical effect for near visual acuity was evaluated by subjective measurements using an accommodometer, defocusing curve, and Nieden charts.

RESULTS

No significant differences were noted in distance best spectacle-corrected visual acuity (BSCVA) between groups. Average near visual acuity with distance BSCVA for the 1CU was 0.41 and 0.35 for the control group. The difference in the accommodation response between both groups measured with the accommodometer was 11 cm (P < .01). The refraction tolerance for the 1CU was 0.25 D whereas the MCTE revealed no refraction tolerance (P < .01). Decentration and tilting of the 1CU resulted in explantation of three IOLs.

CONCLUSIONS

The 1CU indicates a minor statistical advantage of half a reading step towards monofocal IOLs measured with subjective methods in near point, defocusing curve, and near visual acuity with distance BSCVA. This could be due to pseudophakic accommodation by the optic shift mechanism or a result of additional pseudophakic pseudoaccommodation. The accommodative effect of the 1CU differed from patient to patient and was not predictable.

Dental occlusion and body posture: no detectable correlation

The present study was designed to determine if a correlation could be found between dental occlusion and body posture through posturography. Twenty-six healthy subjects (mean age 26.8+/-5.3 years) were monitored under opposing visual (eyes open/closed) and dental occlusion (mandibular rest/intercuspidation positions) conditions. The spatial (absolute displacement of centre of pressure from the theoretical point; ACOPD) and dynamic (sway area, length and velocity) posturographic parameters were recorded. Statistically significant differences were found among the experimental conditions for all of the variables except for ACOPD. Dynamic posturographic parameters were higher for eyes closed versus eyes open under both mandibular positions, although there were no differences between mandibular rest position and dental intercuspidation under the different visual conditions. This study thus shows no detectable correlation at the posturography level between dental occlusion and body posture.

Accommodating intraocular lenses: a critical review of present and future concepts

BACKGROUND

Significant efforts have been made to develop lens implants or refilling procedures that restore accommodation. Even with monofocal implants, apparent or pseudoaccommodation may provide the patient with substantial though varying spectacle independence. True pseudophakic accommodation with a change of overall refractive power of the eye may be induced either by an anterior shift or a change in curvature of the lens optic.

MATERIALS AND METHODS

Passive-shift lenses were designed to move forward under ciliary muscle contraction. This is the only accommodative lens type currently marketed (43E/S by Morcher; 1CU by HumanOptics; AT-45 by Eyeonics). The working principle relies on various hypothetical assumptions regarding the mechanism of natural accommodation. Dual-optic lenses were designed to increase the dioptric impact of optic shift. They consist of a mobile front optic and a stationary rear optic which are interconnected with spring-type haptics. With active-shift lens systems the driving force is provided by repulsing mini-magnets. Lens refilling procedures replace the lens content by an elastic material and provide accommodation by an increase of surface curvature.

RESULTS

Findings with passive-shift lenses have been contradictory. While uncorrected reading vision results were initially reported to be favorable with the 1CU, and excellent with the AT-45 lens, distant-corrected near vision did not exceed that with standard monofocal lenses in later studies. Mean axial shift from laser interferometric measurements under stimulation with pilocarpine showed a moderate anterior shift with the 1CU, while the AT-45 paradoxically exhibited a small posterior shift. With the 1CU, the shift-induced accommodative effect was calculated to be less than +0.5 D in most cases, while +1 D was achieved in a single case only. Ranges and standard deviations were very large in relation to the mean values. Under physiological near-point stimulation, however, no shift was seen at all. Prevention of capsule fibrosis by extensive capsule polishing did not enhance the functional performance. Dual optic lenses are under clinical investigation and are reported to provide a significant amount of accommodation. However, possible long-term formation of interlenticular opacifications remains to be excluded. Regarding magnet-driven active-shift lens systems, initial clinical experience has been promising. Prevention of fibrotic capsular contraction is crucial, and it has been effectively counteracted with a special capsular tension ring, or lens fixation technique, together with capsule polishing. Lens refilling has been extensively studied in the laboratory and in primates. Though it offers great potential for fully restoring accommodation, a variety of problems must be solved, such as achieving emmetropia in the relaxed state, adequate response to ciliary muscle contraction, satisfying image quality over the entire range of accommodation and sustained functioning. The key problem, however, is again after-cataract prevention.

CONCLUSIONS

As opposed to psychophysical evaluation techniques, laser interferometry measures what shift lenses are designed to provide: axial shift on accommodative effort. While under pilocarpine some movement was recorded, no movement at all was found under near-point stimulation with any of the lenses currently marketed. In contrast, magnetic-driven active-shift lens systems carry the potential of sufficiently topping up apparent accommodation to provide for clinically useful accommodation while using conventional lens designs with proven after-cataract performance. Dual optic implants significantly increase the impact of axial optic shift. The main potential problem, however, is delayed formation of interlenticular regenerates. Lens refilling procedures offer the potential of fully restoring accommodation due to the great impact of increase in surface curvature on refractive lens power. However, various problems remain to be solved before clinical use can be envisaged, above all, again, after-cataract prevention. The concept of passive single-optic shift lenses has failed. Concomitant poor capsular bag performance makes these lenses an unacceptable trade-off. Magnet-assisted systems potentially combine clinically useful accommodation with satisfactory after-cataract performance. Dual optic lenses theoretically offer substantial accommodative potential but may allow for interlenticular after-cataract formation. Lens refilling procedures have the greatest potential for fully restoring natural accommodation, but will again require years of extensive laboratory and animal investigations before they may function in the human eye.

Objective measurement of intraocular lens movement and dioptric change with a focus shift accommodating intraocular lens

PURPOSE

To objectively measure the shift and refractive change of the 1CU accommodating intraocular lens (IOL) (HumanOptics) and compare them to that of a monofocal AcrySof MA30 IOL (Alcon Laboratories) in the fellow eye.

SETTING

Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom.

METHODS

Thirty patients who had bilateral cataract surgery 18 to 24 months previously with a 1CU IOL prospectively randomly allocated to 1 eye and an AcrySof MA30 monofocal IOL to the other eye were examined. Distance correction, near vision, reading fluency, near point, and defocus to minus spheres were measured. Intraocular lens shift to an accommodative stimulus following instillation of pilocarpine 4% was measured with the ACMaster. Refractive change between distance and near was measured with the Tracey wavefront analyzer.

RESULTS

Of the original 30 patients recruited, complete measurements could only be obtained for 20. There was no significant difference in near visual function with either IOL. A small anterior movement of the 1CU was seen with accommodation 0.010 mm +/- 0.028 (SD). After pilocarpine 4% instillation, a forward movement of 0.220 +/- 0.169 mm was seen with the 1CU compared to a backward movement of 0.028 +/- 0.095 with the MA30. There was no significant correlation between distance corrected near visual acuity and IOL movement. No change in spherical equivalent between distance and near was seen on wavefront analysis of either IOL.

CONCLUSIONS

Small forward movement of the 1CU IOL was seen with accommodation and increased following pilocarpine, compared to the posterior movement of the MA30 IOL. The amount of the IOL shift was not sufficient to provide useful near vision, but the difference suggests that the engineering concept behind the 1CU IOL is valid.

Subjective and objective performance of the Lenstec KH-3500 "accommodative" intraocular lens

AIM

To determine whether eyes implanted with the Lenstec KH-3500 "accommodative" intraocular lenses (IOLs) have improved subjective and objective focusing performance compared to a standard monofocal IOLs.

METHODS

28 participants were implanted monocularly with a KH-3500 "accommodative" IOL and 20 controls with a Softec1 IOL. Outcome measures of refraction, visual acuity, subjective amplitude of accommodation, objective accommodative stimulus response curve, aberrometry, and Scheimpflug imaging were taken at approximately 3 weeks and repeated after 6 months.

RESULTS

Best corrected acuity with the KH-3500 was 0.06 (SD 0.13) logMAR at distance and 0.58 (0.20) logMAR at near. Accommodation was 0.39 (0.53) D measured objectively and 3.1 (1.6) D subjectively. Higher order aberrations were 0.87 (0.85) microm and lower order were 0.24 (0.39) microm. Posterior subcapsular light scatter was 0.95% (1.37%) greater than IOL clarity. In comparison, all control group measures were similar except objective (0.17 (0.13) D; p = 0.032) and subjective (2.0 (0.9) D; p = 0.009) amplitude of accommodation. Six months following surgery, posterior subcapsular scatter had increased (p<0.01) in the KH-3500 implanted subjects and near word acuity had decreased (p<0.05).

CONCLUSIONS

The objective accommodating effects of the KH-3500 IOL appear to be limited, although the subjective and objective accommodative range is significantly increased compared to control subjects implanted with conventional IOLs. However, this "accommodative" ability of the lens appears to have decreased by 6 months post-surgery.

Pseudophakic accommodation with 2 models of foldable intraocular lenses

PURPOSE

To evaluate the amplitude of pseudophakic accommodation of 2 foldable intraocular lenses (IOLs) by measuring the anterior chamber depth (ACD) shift during a 1-year follow-up.

SETTING

Department of Ophthalmology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.

METHODS

This prospective study comprised 44 eyes of 44 cataract patients operated on with phacoemulsification and in-the-bag implantation of Akreos Disc (22 eyes) or AcrySof MA60BM (22 eyes) IOLs. The ACD was measured by A-scan during fixation at 30 cm and again after instillation of cyclopentolate 1%. The ACD shift was calculated by subtracting the ACD under cyclopentolate from the ACD during fixation at 30 cm. Follow-up measurements were performed 3, 6, and 12 months after surgery. Statistical analysis concerning the difference between the 2 groups was done by the Student unpaired t test.

RESULTS

The ACD shift was greater in the AcrySof group than in the Akreos Disc group at all 3 follow-up examinations. The difference was highly significant between the 2 groups at 6 and 12 months (both P = .004). After the operation, the ACD shift increased continuously with time in both groups. The mean ACD shift reached 0.57 mm +/- 0.25 (SD) in the AcrySof group and 0.42 +/- 0.24 mm in the Akreos group at 12 months.

CONCLUSIONS

The 3-piece AcrySof MA60BM IOL with 10-degree posterior angulation had a significantly higher capacity for pseudophakic accommodation than the 1-piece plate-haptic Akreos Disc IOL. The continuous increase in the ACD shift in the postoperative period may mean that patients learn to achieve better accommodation with an IOL as time goes on.

Phacoemulsification and Implantation of an Accommodating IOL After PRK

PURPOSE

To present a case of phacoemulsification and implantation of an accommodating intraocular lens (IOL) in a patient with cataract formation after previous refractive surgery.

METHODS

A 50-year-old man, who initially had photorefractive keratectomy to correct moderate myopia, developed a cataract in one eye. He subsequently underwent phacoemulsification and implantation of a 1CU accommodating IOL, as he wished to remain spectacle independent.

RESULTS

The patient's distance vision was fully restored. However, accommodative function, which was assessed using subjective and novice objective techniques, was only partially restored.

CONCLUSIONS

Although the accommodating IOL fully restored the patient's distance vision, accommodative function was only partially restored.

Phakic Intraocular Lenses

An analytical review of the data available in the field of phakic intraocular lens implantation was conducted. Particular attention was paid to the more critical issues of intraocular lens sizing and safety guidelines. A comprehensive, competitive analysis of different implantation sites, intraocular lens model designs, and safety guidelines has been included. Specialized biometry techniques, such as very high frequency ultrasound and Scheimpflug imaging, have been reviewed, and a critical review of commercial claims regarding intraocular lens technologies has been included. Clinical studies of phakic intraocular lenses demonstrate increasing promise for the correction of refractive errors not amenable to mainstream excimer laser refractive surgery. The main issues currently revolve around adequate lens design (VHF ultrasound study suggests that custom-design and sizing may be the most effective and safest approach for every phakic IOL model), because these devices will be required to remain physiologically inert and anatomically compatible with internal ocular structures and relations for several decades. The possibility of safe removing or exchanging the IOL should remain a feasible option over time. It is of utmost importance that we continue to critically evaluate current encouraging short-term outcomes, which are being extrapolated to the longer term by ongoing high resolution imaging and monitoring of the anatomical and functional relations of implanted phakic IOLs.

Some Factors Governing the Efficacy of Positional Pseudoaccommodative Intraocular Lenses

PURPOSE

To examine the effects of ametropia (spherocylindrical), corneal curvature, target anterior chamber depth (ACD), misplacement, and some design features on the performance of positional pseudoaccommodative intraocular lenses (PPAIOLs).

DESIGN

Theoretical investigation based on computer models to determine the practical limitations of PPAIOLs.

METHODS

Using a suitable model eye featuring gradient index optics within the cornea, the PPAIOL curvatures were calculated for axial ametropia ranging from -10 diopters (D) to +10 D, where the IOL was located at an ACD of 4.05 mm. The change in refraction (y) of the hypothetical pseudophakic eye was calculated for each millimeter of forward movement (x) of the PPAIOL up to 1 mm from the pole of the corneal back surface. The computations were repeated for a range of hypothetical PPAIOL refractive indices (1.49-1.70), ACDs, equiconvex and meniscus (back surface radius, -10 mm and -25 mm), corneal astigmatism (-1 D to -5 D), and radii (after corneal refractive surgery).

MAIN OUTCOME MEASURES

Diopter/millimeter values represent the gradient of the relationship between x and y. Mathematical models describe the association between the diopter/millimeter gradient and key clinical dependent variables.

RESULTS

(1) For a polymethyl methacrylate (refractive index, 1.49) PPAIOL of equiconvex design and 4.05-mm ACD, the predicted diopter/millimeter value is a function of ametropia (a), where diopter/millimeter = 1.666+0.136a+0.0018a2. (2) For 6-mm ACD and a refractive index of 1.7, diopter/millimeter = 1.836+0.159a+0.0027a2. (3) The equiconvex design benefits hyperopic but not myopic eyes. (4) For PPAIOLs correcting >4 D of astigmatism, more than 0.5 D of residual astigmatism is present at near after 1 mm of IOL displacement. (5) In emmetropic cases, the predicted diopter/millimeter value is a function of the corneal radius (r) where diopter/millimeter = 7.376-1.162r+0.0545r2. (6) Positional pseudoaccommodative IOL misplacement does not significantly affect the accommodative ability.

CONCLUSIONS

(1) Hyperopic eyes with relatively steep corneas should benefit more from the PPAIOL than myopic eyes with relatively flat corneas. (2) A full, binocular, near refraction should be performed to correct any residual spheroastigmatism in anisometropia and cases in which the PPAIOL is toric.

Contrast and glare sensitivity after implantation of AcrySof and Human Optics 1CU intraocular lenses

PURPOSE

To evaluate contrast and glare sensitivity of a newly developed, potentially accommodative intraocular lens.

METHODS

The clinical interventional prospective randomized study included 20 patients (23 eyes) undergoing standard phacoemulsification with clear cornea incision in topical anesthesia. In the study group (10 eyes), the 1CU Human Optics intraocular lens (optics diameter 5.5 mm) was implanted. The control group (13 eyes) received the monofocal AcrySof intraocular lens (optics diameter: 6.0 mm). Using a newly developed contrast measuring device, contrast and glare sensitivity were tested 4 weeks after surgery.

RESULTS

The study group and control group did not vary significantly in contrast (p=0.38) or glare sensitivity (p=0.52).

CONCLUSIONS

The results suggest that the newly developed 1CU Human Optics intraocular lens and the standard AcrySof intraocular lens do not vary significantly in glare and contrast sensitivity.

Drug-induced intraocular lens movement and near visual acuity after AcrySof intraocular lens implantation

PURPOSE

To evaluate the factors influencing AcrySof intraocular lens (IOL) (Alcon Laboratories) movement and near visual acuity after cyclopentolate 1% and pilocarpine 2%.

SETTING

Department of Ophthalmology, University of Ankara, Ankara, Turkey.

METHODS

Thirty eyes of 22 patients with AcrySof IOL implantation were included in this prospective study. Near visual acuity (Jaeger) at 35 cm through best distance correction without an add and pupil diameter were measured and correlated with anterior chamber depth (ACD) measured with ultrasound biomicroscopy (UBM) after application of cyclopentolate 1% and pilocarpine 2%, respectively. The magnitude of the change in the ACD was correlated with the accommodation amplitude, patient age, time interval between surgery and imaging, preoperative axial length, capsulorhexis diameter, ACD during cycloplegia, IOL diameter, and presence of posterior capsule opacification (PCO).

RESULTS

Near visual acuity significantly decreased after application of cyclopentolate 1% and increased after application of pilocarpine 2% (P < .001) in all eyes. The IOL moved anteriorly in 8 (26%) eyes and posteriorly in 22 (74%) eyes after pilocarpine 2%. There was no correlation between the ACD and near visual acuity under cyclopentolate 1% (r = 0.06, P > .05) or pilocarpine 2% (r = 0.04, P > .05). There was a moderate correlation between the anterior IOL movement and accommodation amplitude (P < .05, r = 0.42). There was no correlation between the magnitude of the IOL movement and patient age, time interval between surgery and imaging, the preoperative axial length, capsulorhexis diameter, ACD during cycloplegia, IOL diameter, and the presence of PCO (P > .05).

CONCLUSIONS

There was better near visual acuity in all eyes with the AcrySof MAIOL, although most IOLs move slightly backward after of pilocarpine 2%. This points out pseudoaccommodation rather than pseudophakic accommodation. Ultrasound biomicroscopy is useful in determining the ACD and the relation between the IOL and the surrounding tissues after cataract surgery.

Early visual results with the 1CU accommodating intraocular lens

PURPOSE

To prospectively assess the clinical outcome after implantation of the 1CU accommodating intraocular lens (IOL) and a foldable acrylic IOL (AcrySof, Alcon).

SETTING

Department of Ophthalmology, Tokyo Dental College, Ichikawa Hospital, Ichikawa, and Minami Aoyama Eye Clinics, Tokyo, Yokohama, Japan.

METHODS

Twenty-two eyes of 16 patients with cataract had phacoemulsification implantation of 1CU accommodating IOL. Twenty eyes of 10 age-matched and sex-matched patients with cataract had the same surgery but with a foldable acrylic IOL. All patients had assessments of the amplitude of accommodation, refraction, uncorrected and best corrected distance and near visual acuity, and distance corrected near visual acuity before surgery up to 12 months after surgery. Contrast visual acuities were measured 1 year after surgery. Anterior segment photography, intraocular pressure measurements, specular microscopy, and computerized topography were also performed.

RESULTS

The final best corrected distance visual acuity was above 20/25 in all eyes with the 1CU and the AcrySof IOLs. The mean distance corrected near visual acuity was significantly higher in the 1CU IOL group than in the acrylic IOL group after 3 months. None of the eyes with the AcrySof IOL implants displayed an accommodative response at any examination. The peak mean amplitude of accommodation with the 1CU IOLs was observed at 3 months and was 0.5 diopters +/- 0.44 (SD). Accommodation amplitude declined after 6 months.

CONCLUSION

The 1CU IOL provided additional near acuity postoperatively, but the benefit disappeared at 12 months with a concomitant decrease in accommodation amplitude owing to an increase in anterior and posterior capsular opacities.

The IOL horizon: accommodative intraocular lenses

BACKGROUND

For more than half a century, intraocular lenses have been used effectively to correct vision after cataract extraction. New developments in intraocular lens design have led to the creation of lenses that may have a significant role in the restoration of accommodation as well.

PURPOSE

Accommodative lens technology is constantly evolving. Many different lens designs are currently under development. It is important for optometrists to be familiar with this technology and the various lenses being developed, as accommodative intraocular lenses stand to become the mainstay for cataract surgery, as well as for the surgical treatment of presbyopia.

METHOD

The literature is reviewed in order to summarize the developments in accommodative lens technology.

Accommodative intraocular lenses: current status

PURPOSE OF REVIEW

The possibility of using a monofocal IOL with accommodative ability allows refractive cataract surgery with a clearly decreased potential of photic phenomena. Three IOLs of different designs and materials have demonstrated accommodative ability, but the degree of accommodative amplitude has been reported to different extents and variabilities. The plate-haptic CrystaLens has a hinged design that might permit forward movement of the optic as a result of pressure changes in the vitreous cavity. The 1CU has modified haptics that bend in the bag as the lens capsule contracts, which are supposed to cause anterior displacement of the lens optic. With the dual-optic one-piece Synchrony, springlike haptics separate a high-plus anterior lens from a posterior minus lens. With accommodative effort, the capsular bag expands and the springs express kinetic energy, which might allow the optics to separate as the anterior lens moves forward.

RECENT FINDINGS

This article seeks to clarify and distinguish the concepts of true accommodation and pseudo accommodation. Current designs of accommodative IOLs are supposed to work by the focus-shift principle to allow true pseudophakic accommodation. Studies that biometrically assessed optic shift found no or only low amplitudes of forward movement. The amount of forward movement, if present, was highly variable between patients. To date, most studies present psychophysical data for the proof of concept, which alone seems insufficient. Capsule bag performance and posterior capsule opacification with accommodative IOLs seem worse than those with standard intraocular lenses.

SUMMARY

The potential clinical benefits of accommodative IOL technology for both cataract patients and refractive patients may place accommodative IOLs in a competitive position with multifocal IOL technology.

Surgical treatment of presbyopia: scleral, corneal, and lenticular

PURPOSE OF REVIEW

Having solved most of the problems concerning myopia, hyperopia, and astigmatism, it is perfectly understandable that the surgical treatment of presbyopia should be next on the agenda. It is a new challenge where every possible aspect is explored.

RECENT FINDINGS

The past five years have been troubled by the debate over von Helmholtz theory on accommodation. Numerous investigations have been carried out on the primate and humans using various procedures. The more we learn about this mechanism, the nearer we will be to finding a solution to presbyopia. It appears essential to refer to recent works confirming von Helmholtz theory. Therefore, understanding presbyopia requires a great deal of optical ingenuity such as monovision, scleral modifications, which still remain controversial, or clear lens exchange or refilling.

SUMMARY

In 2003, with all the different techniques available, the surgeon has a wide choice to offer patients that are satisfactory from a practical, theoretical, and ethical point of view. However, these techniques must only be proposed once the patients have been carefully informed.

Accommodating intraocular lenses

PURPOSE OF REVIEW

With the advent of interest in accommodative lenses as a solution for presbyopia and the growing baby-boomer demographic, ophthalmic surgeons will have the opportunity to provide this technology to facilitate near, intermediate, and distance vision for their patients.

RECENT FINDINGS

At present, six corporate entities and lens designs are attempting to commercialize accommodative intraocular lens devices. One Food and Drug Administration (FDA) clinical trial has been completed and the first FDA-approved accommodating lens is available.

SUMMARY

For the first time, ophthalmic surgeons will be able to provide a full range of visual focus in each eye of a patient to maintain binocular function while also avoiding the unwanted mesopic and scotopic visual disturbances that are experienced with monovision and multifocal lens technologies. Accommodative intraocular lenses could revolutionize not only cataract visual rehabilitation but also the surgical approach to presbyopia.