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.     

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.     

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.     

Changes of the accommodative amplitude and the anterior chamber depth after implantation of an accommodative intraocular lens

Background

Modern cataract surgery is interested in recovery of the accommodative power. This investigation aimed at determining pseudophakic accommodation in subjects implanted with the accommodative Human Optics 1 CU intraocular lens after drug-induced ciliary muscle stimulation by measuring the objective refraction and the changes in anterior chamber depth in comparison with a PMMA intraocular lens with rigid haptics.

Methods

The studied sample involved 30 eyes of 30 patients undergoing cataract surgery due to age-related cataract. Patients were between 50 and 77 years of age (67.71±8.0). No randomization was performed. The 1 CU accommodative intraocular lens and the PMMA intraocular lens were implanted in 15 eyes of patients with an expected visual acuity of at least 0.7. Objective refraction under pilocarpine-stimulated ciliary muscle contraction was determined with a Hartinger coincidence refractometer. The anterior chamber depth was measured with Jäger’s Haag–Streit slit-lamp attachment. The accommodative amplitude and the anterior chamber flattening were calculated from the measured values.

Results

Twelve weeks after surgery the average accommodative amplitude in eyes with a 1 CU intraocular lens calculated from the refractive change under drug-induced stimulation was 0.48±0.36 D (with a maximum of 1.25 D). The measured change of anterior chamber depth under drug-induced stimulation was 0.3±0.32 mm (at a maximum of 0.9 mm). In the reference group with PMMA lenses, the mean accommodative amplitude derived from the refractive changes under drug-induced stimulation was 0.34±0.27 D (at a maximum of 0.85 D). The measured change in anterior chamber depth under drug-induced stimulation was 0.18±0.09 mm (at a maximum of 0.31 mm). No statistically significant differences were found between the two groups of lenses concerning change in anterior chamber depth and accommodative amplitude.

Conclusions

This investigations indicate a mean anterior 1 CU shift of only 0.32 mm and a maximum of 0.9 mm. The accommodative amplitudes measured with the Hartinger coincidence refractometer (mean value 0.47 D) correspond to these values. Similar conclusions may be drawn from existing investigative results of the reference group, which are on the same order of magnitude as those of the 1 CU group. Objective accommodation measurements are needed to evaluate commercially available accommodative intraocular lenses in a scientifically satisfactory manner. Objectively measurable parameters include changes of the anterior chamber depth as well as refraction, as determined for instance by coincidence refractometry and streak retinoscopy. Future studies should also consider the IOL properties, astigmatism, and pupillary diameter. This is the only way to identify pseudoaccommodation and a decisive factor for further development of accommodative artificial lenses.     

植入可调节人工晶状体和多焦点人工晶状体后视功能的对比研究

目的比较超声乳化白内障吸除术后植入可调节人工晶状体和多焦点人工晶状体的视功能。方法32例年龄相关性白内障患者根据自愿原则,采用非随机对照方式分成两组,试验组13例患者（24只眼）植入1CU可调节人工晶状体,对照组19例患者（30只眼）植入Array多焦点人工晶状体。术后3个月使用标准对数视力表检测患者最佳矫正视力及在最佳矫正视力基础上获得的近视力、近点及调节幅度、立体视觉。检查结果以年龄作为协变量,进行成组设计定量资料一元协方差分析。结果随诊期间所有患者均无明显的术后并发症。术后3个月试验组最佳矫正视力为4．96±0．15,对照组为5．02±0．08,两组比较差异无统计学意义（P=0．085）。试验组术后最佳矫正视力基础上获得的近视力为4．65±0．15,对照组为4．60±0．10,两组比较差异无统计学意义（P=0．398）。试验组术后主观近点为（56±9）cm,对照组为（61±11）cm,两组比较差异无统计学意义（P=0．80）。试验组术后调节幅度为（1．30±0．40）D,对照组为（1．20±0．36）D,两组比较差异无统计学意义（P=0．093）。试验组术后立体视觉为43．24”±18．25”,对照组为60．00”±23．09”,两组比较差异无统计学意义（P=0．543）。结论植入1CU可调节人工晶状体的患者术后可在保持最佳远视力的同时获得一定的近视力。两种人工晶状体在矫正远视力、远矫下近视力、主观近点、术后调节幅度及近距矫正基础上的立体视觉检查方面均无统计学意义。     

可调节型与普通人工晶状体植入术效果对比

目的比较并分析非球面可调节IOL与普通非球面IOL植入术后早中期的临床效果差异。方法双眼老年性白内障行超声乳化IOL植入术45例（60只眼）,随机分为两组,A组植入非球面可调节IOL,20例（30只眼）;B组植入普通非球面IOL,25例（30只眼）,观察两组术后1个月和6个月的裸眼远视力、最佳矫正远视力、裸眼近视力、最佳矫正近视力、伪调节力及6个月时的对比敏感度。结果随访期间,两组患者的裸眼远视力、最佳矫正远视力及最佳矫正近视力差异均无统计学意义（P〉0．05）;裸眼近视力两组比较各时期差异均有统计学意义（P〈0．05）。术后伪调节力1个月时A组为（1．33±0．26）D,B组为（0．75±0．25）D;6个月时A组为（1．53±0．21）D,B组为（0．5±0．25）D;各期两组比较差异均有统计学意义。6个月时视远对比敏感度两组比较差异无统计学意义（P〉0．05）,但视近时在6c．d-1和12c．d-1空间频率对比敏感度两组比较差异具有统计学意义（P〈0．05）。结论非球面可调节IOL可以使白内障患者术后早期获得良好的裸眼远、近视力,提高患者视远、视近时的对比敏感度,获得良好的视觉质量。     

两种拟调节型人工晶状体植入术后视功能对比分析

目的 比较超声乳化术后植入可调节人工晶状体和多焦点人工晶状体的视功能.方法 30例白内障患者按自愿原则,采用非随机对照方式分成两组,试验组①10例患者(10只眼)植入Tetraflex可调节人工晶状体.试验组②20例患者(30只眼)植入+3.0D ReSTOR多焦点人工晶状体.术后6个月以ETDRS视力表检测患者最佳矫正远视力及在最佳矫正远视力基础上获得的近视力、中距离视力,综合验光仪检测近点及调节幅度.结果 随访期间所有患者均无明显的术后并发症.试验组①最佳矫正远视力为(-0.21±0.06)LogMAR,近视力为J3/40cm,试验组②为(-0.23±0.09)LogMAR,近视力为J1/35cm,两组比较近视力差异有统计学意义(P=0.035).试验组①术后主观近点为(39±10)cm,试验组②为(35±9)cm,两组比较差异无统计学意义(P=0.80).试验组①术后调节幅度为(1.94±0.13)D,试验组②为(2.08±0.63)D,两组比较差异有统计学意义(P=0.048).结论 可调节人工晶状体与多焦点人工晶状体植入术后均可使患者的视近困难得以改善.医生应根据患者情况为其选择合适的人工晶状体.

Abstract：

Objective To compare the visual performance of accommodative IOLS and that of multifocal IOLs implantation after phacoemulsification. Methods A total of 40 eyes from 30 patients undergoing phacoemulsification received intraocular lens based on the principle of voluntary. Ten eyes from 20 patients who had implantation of Tetraflex accommodative intraocular lens were randomized into group 1. Thirty eyes from 20 patients who had implantation of +3.0 aspheric ReSTOR multifocal intraocular lens were randomized into group 2. Main outcome measures included best corrected distance visual acuity, distance corrected near vision, near point, intermediate vision, and the accommodation amplitude. All the clinical data were obtained at 6months postoperatively. Results No patients had undergone any complications. At 6 months postoperatively,best corrected distance visual acuity were similar between the groupl and group2 (-0.23± 0.09LogMAR versus-0.14 ± 0.08LogMAR, P =0.085). Distance corrected near vision were similar between the two groups (J3/40cm versusJ1/35cm, P =0.035). Subjective near point were similar between the two groups [(39± 10) cm versus (35± 9) cm F=0.065, P=0.80]. The accommodation amplitude were similar between the two groups [(1.94± 0.13)D versus (2.08± 0.63)D, P =0.093]. The defocus line showed a double-peak in group 2 and single peak in group 1 which declined at intermediate distance. Conclusions Both accommodative IOLs and multifocal IOLs can correct presbyopia effectively after operation. It is best to prefer the proper IOLs for patients.     

The Quest for Spectacle Independence: A Comparison of Multifocal Intraocular Lens Implants and Pseudophakic Monovision for Patients with Presbyopia

ABSTRACT

We performed a literature review comparing multifocal intraocular lens (IOL) implantation with pseudophakic monovision to treat presbyopia. Multifocal IOLs utilize refractive or diffractive principles to treat both distance and near vision, with a single lens implant. Monovision uses traditional monofocal lens implants to treat the dominant eye for emmotropia, and the non-dominant eye for myopia. This planned anisometropia is designed to enhance intermediate or near vision. Generally, distance vision was similar with both types of lens implantation, near vision was better with multifocal IOLs, and intermediate vision appeared to be better in the monovision group. For patients requiring cataract surgery, both multifocal IOLs and monovision appear to address presbyopia with a high level of patient satisfaction. More patients reported complete spectacle independence with multifocal IOLs, but more glare and halos were reported by multifocal IOL patients as well.     

Spherical aberration, visual performance and pseudoaccommodation of eyes implanted with different aspheric intraocular lens

Purpose: To compare spherical aberration, visual performance and pseudoaccommodation in pseudophakic eyes implanted with aspheric intraocular lenses (IOLs) of Tecnis Z9001 with negative spherical aberration (AMO Inc.), aspheric aberration‐free IOLs of Akreos AO (Bausch & Lomb Inc.) and spherical IOLs of KS‐1 (Cannon Staar Inc.). Methods: A total of 196 patients presenting for cataract surgery were randomly assigned to receive one of three types of IOLs in one eye. Spherical aberration, best‐corrected far visual acuity (BCFVA), distance corrected near visual acuity (DCNVA), contrast sensitivity, glare sensitivity and pseudoaccommodation were measured and compared 3 months postoperatively. Results: At 3 months postoperatively, the mean spherical aberration Z(4,0) for 5 mm pupil size in eyes with Tecnis Z9001 IOLs, Akreos AO IOLs, and KS‐1 IOLs were 0.022 ± 0.071 µm, 0.141 ± 0.070 µm and 0.210 ± 0.108 µm, respectively (P < 0.001), and significant difference was also found in two aspheric IOLs (P < 0.001). Compared with spherical KS‐1 IOLs, Tecnis Z9001 IOLs significantly improved the contrast sensitivity at 4.0°, 2.5° visual angle and glare sensitivity at 4.0°, 2.5°, 2.0°, 1.6° visual angle, Akreos AO IOLs significantly improved contrast sensitivity at 2.5° and glare sensitivity at 4.0°, 2.5°, 2.0°, but no difference statistically significance were found between two aspheric IOLs at any visual angle. In addition, there was no significant difference among three IOLs regarding BCFVA, DCNVA and pseudoaccommodation. Conclusions: All the studied IOLs can provide good visual acuity. Compared with spherical IOLs, both aspheric IOLs can significantly decrease spherical aberration and improve visual performance without the reduction of pseudoaccommodation amplitude.     

Pseudophakic accommodation and pseudoaccommodation under physiological conditions measured with partial coherence interferometry

PURPOSE: To distinguish pseudophakic accommodation from pseudoaccommodation by measuring the physiologically and pharmacologically induced anterior chamber depth (ACD) shifts. SETTING: Department of Ophthalmology, University of Debrecen, Debrecen, Hungary. METHODS: This study comprised 100 pseudophakic eyes of 79 patients. Forty patients (Group 1) received the AcrySof MA60AC intraocular lens (IOL) (Alcon Laboratories), 50 patients (Group 2) received the SA60AT IOL (Alcon Laboratories), and 10 patients (Group 3) received the apodized diffractive SA60D3 ReSTOR IOL. Visual function was evaluated a mean of 10.2 months +/- 9.2 (SD) postoperatively, and the total pseudoaccommodative amplitude was determined with a defocusing technique. To distinguish pseudophakic accommodation from pseudoaccommodation, ACD measurements were performed using partial coherence interferometry during distance fixation and physiologic accommodation after pharmacologic relaxation of the ciliary muscle. RESULTS: Best corrected distance and near visual acuities were similar in the 3 groups (P = .75 and P = .08, respectively). Distance corrected near visual acuity was significantly better in Group 3 (P < .001), with all eyes achieving J1 or better. Three percent in Group 1 and 8% in Group 2 achieved J1 or better. Subjective accommodation was similar in Groups 1 and 2 (-0.82 +/- 0.18 diopter [D] and -1.00 +/- 0.35 D, respectively; P = .3). Group 3 had an accommodation curve with 2 peaks. Intraocular lens movement differences between the groups were not significant (physiologic stimulus: P = .07; cyclopentolate: P = .46), and significant ACD shifts from baseline were not detected (physiologic stimulus: P = .14; cyclopentolate: P = .10). CONCLUSIONS: Pseudoaccommodative amplitude of the investigated monofocal IOLs was independent of IOL movement. Anterior shift did not affect good near visual acuity with the AcrySof ReSTOR IOL.     

可调节人工晶状体的研究进展

在白内障手术后老视问题的各种解决方法中,可调节人工晶状体(accommodating intraocular lenses,IOL)能够提供不戴镜的近、中、远视力,这些IOLs利用焦点的移动来进行调节。本文通过对其设计原理、发展历程、选择依据、材质比较、临床研究等多方面探讨,全面分析可调节人工晶状体,并对其未来发展进行展望。     

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.     

Fellow eye comparison between the 1CU accommodative intraocular lens and the Acrysof MA30 monofocal intraocular lens

PURPOSE: To examine the near visual clinical performance of an accommodative intraocular lens (IOL) when compared with a standard monofocal IOL in a fellow eye comparison. DESIGN: Prospective, randomized fellow eye comparison. METHODS: Thirty patients (60 eyes) with bilateral cataracts but otherwise normal eyes were recruited from a single university hospital cataract waiting list. Patients were randomized to receive either the 1CU accommodative IOL in their first eye or the Acrysof MA30 monofocal IOL. The alternative lens was then implanted in the second eye 4 to 6 weeks later. At all follow-up visits, a full assessment was made of distance, near and reading visual performance, and accommodative amplitude. RESULTS: Data are available for all patients at 6 months and 20 patients at 1 year. At 6 months, no difference was found in distance-corrected visual acuity between the two IOLs. Of the 1CU eyes, nine patients (30%) could read J6 or better at a reading speed of 80 words/min or better. In these nine patients, the mean difference in the amplitude of accommodation between the two eyes was 0.71 diopters. CONCLUSIONS: No measurable variable distinguished eyes that developed functional reading vision from those that did not. The accommodative IOL appears to produce improved near vision in some eyes, but it does not work in all eyes, and in eyes where there is apparent accommodation, there is a discrepancy between subjective reading performance and the modest measured increase of accommodative amplitude.     

Fall risk in patients with pseudophakic monovision

ObjectiveVision changes can precipitate falls in the elderly resulting in significant morbidity and mortality. We hypothesized that pseudophakic monovision and ensuing anisometropia and aniseikonia impact elderly fall risk. This study assessed fall risk in patients with pseudophakic monovision, pseudophakic single vision distance (classic cataract surgery), and cataracts with no surgery.DesignRetrospective single-institution cohort studyParticipantsPatients with bilateral cataracts diagnosed at 60 years of age or older who underwent bilateral cataract surgery (monovision or single vision distance) or did not undergo any cataract surgery (n = 13 385). Patients with unilateral surgery or a fall prior to cataract diagnosis were excluded.MethodsData were obtained from the Stanford Research Repository. Time-to-fall analysis was performed across all 3 groups. Primary outcome was hazard ratio (HR) for fall after second eye cataract surgery or after bilateral cataract diagnosis.ResultsOf 13 385 patients (241 pseudophakic monovision, 2809 pseudophakic single vision, 10 335 no surgery), 850 fell after cataract diagnosis. Pseudophakic monovision was not associated with fall risk after controlling for age, sex, and myopia. Pseudophakic single-vision patients had a decreased time to fall compared with no-surgery patients (log rank, p < 0.001). Older age at cataract diagnosis (HR =1.05, 95% confidence interval [CI] 1.04–1.06, p < 0.001) or at time of surgery (HR = 1.05, 95% CI 1.03–1.07, p < 0.001) increased fall risk, as did female sex (HR = 1.29, 95% CI 1.10–1.51, p = 0.002) and preexisting myopia (HR = 1.31, 95% CI 1.01–1.71, p = 0.046) among nonsurgical patients.ConclusionsPseudophakic monovision did not impact fall risk, but pseudophakic single vision may increase falls compared with patients without cataract surgery.     

Evaluierung der Wertigkeit objektiver und subjektiver Verfahren zur Messung von pseudophaker Akkommodation

Purpose

The aim of this study was to compare the validity and plausibility of various subjective and objective measurement methods for evaluation of pseudophakic accommodation.

Setting

Eye Clinic Bellevue, Kiel, Germany.

Methods

A total of 21 patients were examined over an average period of 34 months (range 12–51 months) after implantation of a potentially accommodative, model 1CU intraocular lens (IOL, HumanOptics, Germany). The following subjective measurements were taken: near point measurement with the accommodometer (Clement Clarke, Harlow, UK), defocus curve and near visual acuity with far and near reading charts. The IOLMaster (Carl Zeiss Meditec, Germany), ACMaster (Carl Zeiss Meditec, Germany) and Shin-Nippon K 5001 AR (Shin-Nippon, Japan) were employed as objective measurement devices. With this devices information is obtained about the anterior chamber depth (ACD, preoperative and postoperative), the movement of the IOL and the refractive change of eyes during the accommodative process.

Results

Depending on the method utilized there were large variations of the examined IOL in relation to the extent of the measured accommodative effects in their entirety with the objective as well as the subjective measurement method.

Conclusions

A differentiation of pseudophakic accommodation and pseudophakic pseudoaccommodation is not possible with the conventional measurement methods applied and examined in this study. Only the ACMaster is an objective method for measurement of the axial shift of an IOL. However, subjective measurement methods can only record the total of both accommodation portions but do not allow any scientifically-founded statement about the functional principle of a potentially accommodative IOL.     

ICU人工晶状体植入术后的早期临床效果

目的:比较白内障超声乳化术联合ICU(德国HumanOptics公司)可调节人工晶状体植入术后效果与传统单焦后房型UV型(日本HOYA公司)人工晶状体植入术后效果之间的差异。方法:所有患者均行白内障超声乳化联合人工晶状体植入术。比较18例(20眼)患者ICU可调节人工晶状体植入及20例(20眼)患者UV型后房型人工晶状体植入术后1wk、1mo时的裸眼远视力、最佳矫正远视力、近视力(35cm)及矫正远视力的近视力(35cm)、主观调节近点、10g/L硝酸毛果芸香碱滴眼30min后利用A型超声波测量前房深度(anterior chamber depth,ACD)变化等多项指标之间的差异。结果:两组数据间比较,除术后远视力及最佳矫正远视力无显著性差异外,其它指标间比较均有非常显著性差异(P<0.01)。结论:ICU可调节人工晶状体相对于传统单焦后房型人工晶状体具有更高调节力、更佳的近视力,同时也具有良好的远视力。但术后调节幅度有限,长期效果如何有待进一步观察、研究。     

Lens Refilling

Cataract surgery has developed into a very safe and highly reproducible procedure but the ultimate goal to also restore physiological accommodation has not yet been achieved. A variety of accommodative intraocular lenses (IOLs) and surgical techniques have been suggested to cure presbyopia but all showed only poor accommodative effects by objective measurements. Complete lens refilling with flexible polymers might be an interesting alternative. Recent investigations on accommodation and presbyopia have given support to the lens refilling method. After development of suitable surgical techniques and filling materials only secondary cataract formation and the unsolved intraoperative control of refraction restrict the clinical use of this technique.     

可调节人工晶状体植入术的早期疗效观察

目的探讨超声乳化白内障吸除可调节人工晶状体植入术的临床疗效和调节幅度。方法对75例(94只眼)白内障患者行超声乳化白内障吸除1CU型可调节人工晶状体植入术,观察并记录术眼的主观屈光状态、裸眼远视力、裸眼近视力、最佳矫正远视力、30cm处远视力矫正后近视力、30cm处最佳矫正近视力、主观调节幅度(分别采用主观移近法和负镜片法测量)。术后随访时间1～12个月,对术后1周、1个月及3个月的资料进行分析。结果术后1周、1个月及3个月裸眼近视力≥Jr5者分别占81.9%(77/94)、85.1%(80/94)及84.0%(79/94);远视力矫正后近视力≥Jr5者分别占78.7%(74/94)、79.8%(75/94)及74.5%(70/94)。采用主观移近法和负镜片法检查调节幅度,术后1周分别为(1.96±0.63)D(0.75～4.50D)和(1.74±0.59)D(0.75～4.50D),术后1个月分别为(1.89±0.54)D(0.75～3.25D)和(1.68±0.47)D(0.75～3.25D),术后3个月分别为(1.77±0.53)D(0.75～2.75D)和(1.66±0.50)D(0.75～2.75D)。术后1周、1个月及3个月2种方法测量的主观调节幅度比较,差异均无统计学意义(P>0.05)。远视力矫正后近视力和调节幅度之间为正相关(P=0.00)。结论早期观察结果显示1CU型可调节人工晶状体植入术后视功能恢复良好,患者在具有较好远视力的同时,具备良好的视近能力。远期效果有待进一步观察。     

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. The author has no proprietary interest in any of the materials or equipment mentioned in this study.     

单焦点、多焦点与可调节人工晶状体植入术后患者的拟调节力观察

目的 研究超声乳化白内障摘除植入不同人工晶状体（IOL）术后患者的拟调节力。方法 前瞻性队列研究。行白内障超声乳化吸除联合IOL植入术且随访资料完整的患者73例（82眼）,依据植入IOL的不同分为3组：单焦点IOL组28例（32眼）,多焦点IOL组24例 （27眼）,可调节IOL组21例（23眼）。术后3 d、1周、1个月、3个月分别测量3组患者的裸眼远、中、近视力,最佳矫正远、近视力,及拟调节力。数据采用单因素方差分析。结果 3组的最佳矫正远、近视力及裸眼远视力差异无统计学意义,而裸眼中视力可调节IOL优于单焦点与多焦点IOL（F=4.50,P＜0.05）,裸眼近视力多焦点、可调节IOL好于单焦点IOL（F=26.06,P＜0.05）。多焦IOL可以提供（2.67±0.49）D的主观拟调节力,（0.93±0.42）D的客观拟调节力;可调节IOL可以提供（3.00±0.78）D主观拟调节力,（0.91±0.58）D客观拟调节力;优于单焦点IOL的（1.78±0.26）D的主观拟调节力（F=18.51,P＜0.05）,和（0.37±0.22）D的客观拟调节力（F=7.39,P＜0.05）。结论 多焦点IOL与可调节性IOL均可提供较好的全程视力及拟调节力。