Refractive surgery for high myopia. The Worst-Fechner biconcave iris claw lens

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses

Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.

Surgical Management of Paediatric Aphakia in the Absence of Sufficient Capsular Support

There are several available options for the demanding surgical correction of paediatric aphakia without sufficient capsular support. The literature suggests the implantation of a transscleral fixated posterior chamber-intraocular lens (PCIOL), an intrascleral fixated PCIOL, an iris-sutured intraocular lens (IOL), or an anterior chamber iris-claw IOL. We searched for reports on the management of paediatric aphakia in case of inadequate capsular support that delineated the diverse surgical approaches and their postoperative results. Analysis demonstrated that different complications can be encountered depending on IOL placement technique, such as suture rupture, IOL dislocation, secondary glaucoma, endophthalmitis, vitreous hemorrhage, and endothelial cell loss. However, it was shown that various IOL designs have similar visual outcomes. Taking into consideration the advantages and disadvantages of each surgical technique, ophthalmic surgeons can determine the safest and most efficient approach for paediatric aphakic patients.

[Assessment of astigmatism associated with the iris-fixated ARTISAN aphakia implant: Anterior fixation versus posterior fixation, study of postoperative follow-up at one year]

PURPOSE

The goal of our retrospective, single-center study of a case series was to compare the total, corneal, and internal astigmatism, and the visual acuity at one year after combined or stand-alone surgery consisting of iris fixation of an iris-claw intraocular lens (ARTISAN aphakia) in aphakic patients, according to whether the lens was fixated to the anterior (n=21) or posterior (n=51) surface of the iris.

RESULTS

We did not find a significant difference between these two types of fixation for any of the studied variables. The surgically induced astigmatism was 1.67 D at 176° in group A versus 1.19 D at 11° in group P.

CONCLUSION

Although this surgery creates additional corneal astigmatism, it has not been proven that it differs depending on the type of fixation of the iris-claw. If we adhere to the notion that the posterior fixated iris-claw decreases the risk of endothelial decompensation in case the implant becomes disenclavated, then reverse iris fixation of the iris-claw makes sense.

Is an iris claw IOL a good option for correcting surgically induced aphakia in children? A review of the literature and illustrative case study

Refractive correction of aphakia in childhood can be a complex management issue following lensectomy for congenital cataract or ectopia lentis. Some children have inadequate capsular support to allow an 'in the bag' or sulcus fixated intra-ocular lens (IOL). In such cases, options for refractive correction include spectacles, contact lenses, or surgically fixed IOLs. Many methods of IOL fixation have been described, but none are widely adopted in children. In recent years, the iris-fixated Artisan Aphakic IOL has gained popularity, but there is still significant concern about the rate of corneal endothelial cell loss and IOL de-enclavation. Here, we review the current literature on the use of iris-fixated IOLs in children, the published data on endothelial cell loss and de-enclavation rates. We present a case illustrating the significant improvements in quality of life, which can be seen in selected children, and also the rate of endothelial cell loss, which can be encountered after initial surgery, and a re-enclavation event. We make the case that until more data are available on normal endothelial cell decline in early childhood, in addition to age-specific rates of endothelial cell loss and de-enclavation rates following surgery, the use of iris-fixated IOLs in children will continue to be a moot point and is unlikely to be widely adopted.

Using a slit lamp-mounted digital high-speed camera for dynamic observation of phakic lenses during eye movements: a pilot study

Purpose

To evaluate a digital high-speed camera combined with digital morphometry software for dynamic measurements of phakic intraocular lens movements to observe kinetic influences, particularly in fast direction changes and at lateral end points.

Materials and methods

A high-speed camera taking 300 frames per second observed movements of eight iris-claw intraocular lenses and two angle-supported intraocular lenses. Standardized saccades were performed by the patients to trigger mass inertia with lens position changes. Freeze images with maximum deviation were used for digital software-based morphometry analysis with ImageJ.

Results

Two eyes from each of five patients (median age 32 years, range 28–45 years) without findings other than refractive errors were included. The high-speed images showed sufficient usability for further morphometric processing. In the primary eye position, the median decentrations downward and in a lateral direction were −0.32 mm (range −0.69 to 0.024) and 0.175 mm (range −0.37 to 0.45), respectively. Despite the small sample size of asymptomatic patients, we found a considerable amount of lens dislocation. The median distance amplitude during eye movements was 0.158 mm (range 0.02–0.84). There was a slight positive correlation (r=0.39, P<0.001) between the grade of deviation in the primary position and the distance increase triggered by movements.

Conclusion

With the use of a slit lamp-mounted high-speed camera system and morphometry software, observation and objective measurements of iris-claw intraocular lenses and angle-supported intraocular lenses movements seem to be possible. Slight decentration in the primary position might be an indicator of increased lens mobility during kinetic stress during eye movements. Long-term assessment by high-speed analysis with higher case numbers has to clarify the relationship between progressing motility and endothelial cell damage.

Pediatric refractive surgery

This article reviews current thoughts regarding pediatric refractive surgery. This encompasses current trends in adult refractive surgery, differences between adult and pediatric refractive surgery, and future possibilities for refractive technology for the pediatric population.

Phakic iris-claw IOL implantation, with Bursa technique, through a self-sealing scleral tunnel and without iridotomy or iridectomy

PURPOSE

To present a novel technique for the implantation of phakic iris-claw intraocular lenses (IOL) in highly myopic cases.

METHODS

Twelve cases, under the age of 40, with high myopia were included in this retrospective study. The mean follow-up span was 14.4+/-5.8 months. Phakic iris-claw IOL implantation was performed, through a 5.5 or 6.5 mm self sealing scleral tunnel with Bursa technique. No suturing and opening a peripheral iridectomy or iridotomy was required in our study. Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity, best-corrected visual acuity (BCVA), induced astigmatism, and intraocular pressure (IOP) assessments.

RESULTS

All eyes gained one to nine lines of BCVA of the Snellen chart. The vector analysis revealed an induced astigmatism of 0.63 D. No significant IOP change was detected throughout the follow-up.

CONCLUSIONS

The data suggest that nonfoldable iris fixated phakic IOL implantation, through a self-sealing incision with Bursa technique, is safe and requires no iridectomy or iridotomy in cases with deep anterior chambers.

Current thoughts in pediatric refractive surgery

The goal of this article is to review current literature regarding the emerging field of pediatric refractive surgery. This encompasses current thought in adult refractive surgery, published literature in pediatric refractive surgery, and future possibilities for refractive technology in the pediatric population. This study includes a comprehensive review of literature in the general refractive surgery, cornea, and pediatric literature.

Position of rigid and foldable iris-fixated myopic phakic intraocular lenses evaluated by Scheimpflug photography

PURPOSE

To evaluate the postoperative intraocular positional stability of 1 rigid poly(methyl methacrylate) (PMMA) phakic intraocular lens (pIOL) model and 2 foldable polysilicone-PMMA iris-fixated pIOL models.

SETTING

Department of Ophthalmology, Johann Wolfgang Goethe-University Frankfurt am Main, Germany.

METHODS

One of 3 iris-fixated pIOL models (Artisan, Artiflex I, and Artiflex II, Ophtec BV) was implanted in 45 eyes of 26 patients with myopia or myopic astigmatism. The central distance between the pIOL and corneal endothelium and between the pIOL and anterior surface of the crystalline lens was evaluated using Scheimpflug photography 6 and 12 months after surgery.

RESULTS

The mean preoperative spherical equivalent was -9.32 diopters +/- 1.78 (SD) (range -6.5 to -13.5 D). Each IOL model was implanted in 15 eyes. The median distance from the central corneal endothelium to the anterior surface of the pIOL at 6 months and 12 months was 2.65 mm and 2.64 mm, respectively, in the Artisan group, 2.47 mm and 2.50 mm, respectively, in the Artiflex I group, and 2.48 mm and 2.52 mm, respectively, in the Artiflex II group. The median distance between the posterior surface of the pIOL and the anterior surface of the crystalline lens at 6 months and 12 months was 0.40 mm and 0.48 mm, respectively, in the Artisan group, 0.53 mm and 0.55 mm, respectively, in the Artiflex I group, and 0.68 mm and 0.66 mm, respectively, in the Artiflex II group. At 12 months, the distance between the pIOL and crystalline lens was statistically significantly greater in the Artiflex II group than in the Artisan group (P<.01).

CONCLUSION

The intraocular position of rigid pIOLs and foldable silicone iris-supported pIOLs showed a difference between the 3 pIOL models in space to the crystalline lens and the corneal endothelium, which may affect long-term results in terms of IOL interaction with surrounding tissue.

Long-term endothelial changes in phakic eyes after Artisan intraocular lens implantation to correct myopia: five-year study

PURPOSE

To evaluate long-term endothelial cell changes in eyes that had implantation of an iris-fixated phakic Artisan intraocular lens (IOL) for moderate to high myopia.

SETTING

Casa di Cura Villa Igea, Ancona, Italy.

METHODS

Forty-nine eyes of 30 patients having implantation of Artisan IOL for moderate to high myopia were prospectively examined. Preoperative specular microscopy and serial postoperative specular microscopy (Noncon Robo SP 8000, Konan Medical) were performed to evaluate endothelial cell changes over 5 years. Endothelial cell images were collected in the central region of the cornea before surgery and 4, 12, 24, 36, 48, and 60 months after surgery. The endothelial cell density (ECD), coefficient of variation, and percentage of hexagonal cells were determined.

RESULTS

Preoperatively, the mean ECD was 2616 cells/mm(2) +/- 347 (SD), the mean coefficient of variation was 39.6% +/- 4.7%, and the mean percentage of hexagonal cells was 49.2% +/- 6.7%. The mean endothelial cell loss from preoperatively was 2.3% at 4 months, 3.5% at 12 months, 4.7% at 24 months, 6.7% at 3 years, 8.3% at 4 years, and 9.0% at 5 years. Five years after surgery, the mean coefficient of variation was 35.9% +/- 6.9% (P = .1946) and the percentage of hexagonal cells was significantly higher (mean 54.7% +/- 10.3%) (P = .087).

CONCLUSIONS

Continuous endothelial cell loss was observed after surgery during a 5-year follow-up, especially during the first 2 years. A decrease in the coefficient of variation and an increase in the percentage of hexagonal cells were observed over time, reflecting the increasing stability and remodeling of the corneal endothelial cells 5 years postoperatively.

Posterior synechias following implantation of a foldable silicone iris-fixated phakic intraocular lens for the correction of myopia

A 45-year-old white woman with unilateral high myopia had uneventful implantation of a -9.0 diopter, foldable, iris-fixated Artiflex I anterior chamber phakic intraocular lens (pIOL) (Ophtec B.V.) in the right eye. Despite application of topical antibiotic and steroid agents for 4 weeks after surgery, iris pigment dispersion developed on the anterior surface of the crystalline lens. Two weeks later, the iris dispersion increased and posterior synechias developed from the iris to the crystalline lens next to the pIOL haptic at the 3 o'clock position. Consequently, pIOL re-enclavation was performed without surgically removing the posterior synechias. Initial and interim mydriatic and steroid eyedrops were administered 4 times a day. Regular follow-up examinations after re-enclavation (at 2, 3, 6, 12, and 24 months) confirmed a stable pIOL position by Scheimpflug photography. Two years after implantation, posterior synechias persisted at the 3 o'clock position, with iris dispersion on the crystalline lens and the posterior side of the pIOL, but with no signs of anterior chamber inflammation and no visual acuity loss.

Magnification and accommodation with phakic intraocular lenses

BACKGROUND AND PURPOSE

The calculation of phakic lenses (PL) was described by van der Heijde et al. [Klin. Monatsbl. Augenheilkd (1988) Vol. 193, pp. 99-102], but a formalism for estimating relative magnification compared with spectacle correction and accommodation effects are not yet published. The purpose of this study was to describe a mathematical strategy for calculating PL and relative magnification as a function of object vergence (phakic accommodation).

METHODS

Parameters used for the calculations are the spectacle refraction before and after (target refraction) surgery, the vertex distance, corneal refraction, and the predicted position of the phakic intraocular lens. The lens power is determined as the difference in vergences between the spectacle-corrected eye and the uncorrected eye at the reference plane of the predicted lens position. If we simplify the crystalline lens to a single refracting surface located at the principal plane of the crystalline lens, the vergence of the eye with spectacle correction and with PL is determined as a function of object distance [object vergence 0 D (infinity) to 10 D (object at a distance of 10 cm)] to evaluate accommodation effects of the crystalline lens.

RESULTS

The method was applied to two clinical examples. In example 1 we calculated the power of a PL for correction of a 10-D myopia and determined the relative magnification and the vergence at the principal plane of the crystalline lens as a function of object vergence. Magnification gain increases with objects at near from 17% to 26%, whereas the vergence at the principal plane of the crystalline lens changes by 3.04 D less than in the spectacle-corrected eye. In example 2, a 20-D myopia was corrected with a PL. The gain in magnification changed from 33% to 58% with nearer objects. The change in vergence at the principal plane of the crystalline lens with objects at near was much higher with the PL compared with the spectacle correction, which implies that the refractive change necessary for focusing objects at near distance is much higher in the PL correction.

CONCLUSIONS

Even if the predictability of postoperative refraction with PL is comparable or better than in other methods of correcting high or excessive ametropia, the effects of lateral magnification change and accommodation have to be considered to avoid image-size disparities (aniseikonia) and to maintain binocular vision, especially with monocular PL implantation and anisometropia.

Unilateral lens extraction for high anisometropic myopia in children and adolescents

INTRODUCTION

A subpopulation of children with anisometropic myopia, amblyopia, and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated using lensectomy alone (clear lens extraction) or lensectomy with simultaneous implantation of an intraocular lens (refractive lens exchange).

METHODS

Clinical course and outcome data were collated retrospectively in a group of 7 children and adolescents (mean age, 9.1 years; range, 4-20 years) with neurobehavioral disorders and noncompliance with spectacle wear for anisometropic myopia. Myopia in the 7 eyes ranged -11.9 to -24.5 D (mean, -16.7 D). Goal refraction was 0 to + 4 D. Correction was achieved by lensectomy in 5 eyes and lensectomy with intraocular lens implantation in 2 eyes. Primary posterior capsulectomy/subtotal vitrectomy was performed during the primary procedure in 5 eyes (71%). Mean follow-up was 3.8 years (range, 0.5-5.4 years).

RESULTS

Myopia correction averaged 17.3 D. A total of 86% (6 eyes) were corrected within +/- 3 D of the goal refraction and the remaining 14% to within +/- 4 D. Uncorrected visual acuity improved postoperatively in all 7 eyes, albeit modestly (average gain 0.14 Snellen fraction; gain from a mean 20/2550 to a mean 20/130). Myopic regression averaged approximately 0.43 D/year. Capsular opacification necessitated YAG-laser membranectomy in the 2 eyes that had preservation of the posterior capsule at the primary procedure. Retinal detachment has not occurred in any of the eyes during the follow-up period.

CONCLUSIONS

Refractive myopic lensectomy reduced high anisometropia and improved functional vision in children who have high myopia beyond the range of excimer laser correction and who will not wear glasses. Further study is indicated to determine the long-term safety of this procedure in similar pediatric populations.

[Study of pupillary motility after implantation of an iris claw lens (Artisan) in a phakic population with severe myopia]

PURPOSE

To assess the effect of the Artisan lens on pupillary motility in a highly phakic myopic population.

PATIENTS AND METHODS

Eleven patients (21 eyes) were enrolled in a nonrandomized prospective study between September 2002 and August 2003, with a 6- to 11-month follow-up. A portable Colvard pupillometer was used to measure pupil diameters before and after surgery under two different light conditions: one with scotopic surroundings with absolute darkness in the examination room and the other maximal simulated photopic surroundings, caused by the instillation of a pilocarpine 2% drug until a nonreactive myosis could be observed. Under such light conditions, both the horizontal and vertical pupil motion ranges were measured. Measures were then sorted into five temporal segments in order to have enough samples per temporal segment for a cohesive data analysis. Mean values and confidence intervals were then derived per temporal segment according to Student's law. Constraints on the pupil motion range were identified.

RESULTS

After implantation of an Artisan lens, the pupil motion range was limited to both horizontal and vertical axes. For the horizontal axis, the motion range was 4.3+/-0.2mm (p=0.1) before claw implantation and was 2.7+/-0.5mm (p=0.1) 9 months after claw implantation. For the vertical axis, the motion range was 4.46+/-0.28mm before claw implantation and 3.08+/-0.89mm 9 months after claw implantation.

CONCLUSIONS

The Artisan lens durably restrains the pupil in its motion range and introduces a noticeable oval deformation under extreme light condition variations. This side effect is, however, not visible under regular conditions but only in maximal photopic surroundings.

Refractive surgery for high bilateral myopia in children with neurobehavioral disorders: 2. Laser-assisted subepithelial keratectomy (LASEK)

INTRODUCTION

A subpopulation of children with high myopia and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated bilaterally using excimer laser technology.

METHODS

Clinical course and outcome data were collated prospectively in a group of 9 children (mean age, 10.2 years; range, 3-16 years) with neurobehavioral disorders exacerbated by chronic noncompliance with spectacle wear, causing profoundly low functional vision. Myopia in the 18 eyes ranged from -3.75 to -11.5 D (mean -16.6 D) and the desired refraction was approximately +1D. Correction was achieved by bilateral laser-assisted subepithelial keratectomy (ie, LASEK) performed under brief general anesthesia. Mean follow-up was 17 months (range, 6-36 months).

RESULTS

Myopia correction averaged 7.9 D. Eighty-nine percent (16/18 eyes) were corrected to within +/-1 D of goal refraction. Uncorrected acuity improved postoperatively in all 18 eyes, with commensurate gains in behavior and environmental visual interaction in 88% (15/17 children). Myopic regression averaged approximately 0.8 d/year. the only complication encountered was mild (1+) corneal haze in 35% of treated eyes.

DISCUSSION/CONCLUSIONS

Bilateral excimer laser surgery is effective for improving functional vision substantially in highly myopic, neurobehaviorally impaired children who have difficulties wearing glasses. Myopic regression is common. Further study is indicated to determine the long-term safety of these and alternative refractive procedures in similar pediatric populations.

Recurrent intraocular inflammation after implantation of the Artiflex phakic intraocular lens for the correction of high myopia

We describe a 54-year old man who developed a severe cell deposition 1 week after implantation of a foldable Artiflex phakic intraocular lens (pIOL) (Ophtec B.V.) with a silicone optic and poly(methyl methacrylate) (PMMA) haptics in the left eye for the correction of high myopia. Nine months after implantation, many cell deposits remained visible on the posterior surface of the IOL, causing severe glare, especially during daylight conditions. We explanted the Artiflex pIOL and exchanged it for a PMMA Artisan pIOL. One month after the exchange, the uncorrected visual acuity was 20/20 and the patient's glare complaints had disappeared. Slitlamp examination showed no signs of inflammation in the anterior segment or cell deposits on the PMMA Artisan pIOL. Scanning electron microscopy demonstrated multiple cell deposits on the explanted Artiflex pIOL.

Refractive surgery for high bilateral myopia in children with neurobehavioral disorders: 1. Clear lens extraction and refractive lens exchange

INTRODUCTION

A subpopulation of children with high myopia and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated using lensectomy alone (clear lens extraction), or lensectomy with simultaneous implantation of an intraocular lens (refractive lens exchange).

METHODS

Clinical course and outcome data were collated prospectively in a group of 13 children (mean age 10.4 years, range 1 to 18 years) with neurobehavioral disorders exacerbated by chronic noncompliance with spectacle wear, causing profoundly low functional vision. Myopia in the 26 eyes ranged from -14.25 to -26.00 D (mean -19.1 D). Goal refraction was approximately +1 D. Correction was achieved by lensectomy alone in 10 eyes, and lensectomy with intraocular lens implantation in 16 eyes. Primary posterior capsulectomy/subtotal vitrectomy was performed during the primary procedure in 11 eyes (42%). Mean follow-up was 4.5 years (range 1.3 to 7.5 years).

RESULTS

Myopia correction averaged 19.9 D. Eighty-one percent (21 eyes) were corrected to within +/-2 D of goal refraction and the remaining 19% (5 eyes) to within +/-4 D. Uncorrected acuity improved substantially (ie, an average 2 log units) in all 26 eyes, with commensurate gains in behavior and environmental visual interaction in 85% [corrected] of children (11/13) [corrected] Myopic regression averaged -0.16 D/year. Capsular regrowth and/or opacification necessitated vitrector or YAG-laser membranectomy in 13 [corrected] eyes (50%) [corrected] Focal retinal detachment (successfully repaired) occurred after eye contusion in one eye (4%) with cicatricial retinopathy of prematurity.

CONCLUSIONS

Bilateral refractive lensectomy is effective for improving functional vision in neurobehaviorally impaired children who have high myopia (beyond the range of excimer laser correction: see companion publication) and difficulties wearing glasses. Posterior capsule regrowth/opacification is common, necessitating secondary membranectomy. Further study is indicated to determine the long-term safety of this procedure in similar pediatric populations.

Evaluation of Pupil Dynamics After Implantation of Artisan Phakic Intraocular Lenses

PURPOSE

To compare pre- and postoperative horizontal and vertical pupil diameters after horizontal Artisan phakic intraocular lens (PIOL) (Ophtec BV, Groningen, The Netherlands) implantation for correction of myopia.

METHODS

The pre- and postoperative scotopic pupil diameters measured by the Colvard pupillometer (Oasis Medical, Glendora, Calif) were compared in 71 eyes after Artisan PIOL implantation (Artisan Colvard group). Analysis of pupil shape (vertical vs horizontal diameter, V/H ratio) after horizontal Artisan PIOL implantation was performed with the Procyon pupillometer (Procyon Instruments Ltd, London, United Kingdom) in 121 eyes (Artisan Procyon group) under scotopic, mesopic-low, and mesopic-high conditions and compared to an age- and refraction-matched control group of 121 eyes of refractive surgery candidates (Procyon control group).

RESULTS

After horizontal Artisan PIOL implantation, the mean horizontal pupil diameter decreased from 6.231 +/- 0.70 mm preoperatively to 5.34 +/- 0.68 mm postoperatively in the Artisan Colvard group (P < .01). The mean horizontal scotopic diameter was 5.60 +/- 0.66 mm, the mesopic-low diameter was 4.94 +/- 0.71 mm, and the mesopic-high diameter was 3.98 +/- 0.54 mm for the Artisan Procyon group. The mean horizontal scotopic diameter was 6.29 +/- 0.91 mm, the mesopic-low diameter was 5.40 +/- 0.96 mm, and the mesopic-high diameter was 4.16 +/- 0.80 mm in the Procyon control group. A significant increase was noted in V/H ratio under scotopic, mesopic-low, and mesopic-high conditions from 1.02, 1.02, and 1.01, respectively, in the Procyon control group to 1.17, 1.12, and 1.06, respectively, in the Artisan Procyon group (P < .01).

CONCLUSIONS

Horizontal pupil size was significantly decreased after horizontal Artisan PIOL implantation and might be attributed to a mechanical restriction of the iris in the horizontal meridian.

Long-Term Complications of Iris-Claw Phakic Intraocular Lens Implantation in Weill-Marchesani Syndrome

PURPOSE

This study was designed to report the long-term complications of iris-claw phakic intraocular lens implantation in a patient with Weill-Marchesani syndrome.

METHODS

Case report and literature review.

RESULTS

A 26-year-old man with a history of glaucoma had bilateral phakic lens implantation for high myopia 10 years previously. Two years later, the left implant dislocated and was repositioned. Slit-lamp examination of both eyes revealed phakic implants of the iris-claw variety. There were moderate iridocorneal adhesions in the areas in which the lens haptics pinched the iris in both eyes and moderate epithelial and stromal edema over the temporal one-third of the left cornea. The crystalline lenses were clear with 3+phacodonesis OU. Dilated fundus examinations revealed bilateral severe optic nerve cupping. Crystalline lens diameters were measured at 7.5mm in the right eye and 8 mm in the left. Anterior chamber depths were 2.63 mm OD and 2.40 mm OS. Specular microscopy revealed central endothelial cell counts of 1133 and 587 cells/mm OD and OS, respectively. Axial lengths were 23.3 mm OD and 25 mm OS. Gonioscopic examination revealed bilateral angle closure with marked peripheral anterior synechiae. Based on our findings of short stature, shortened and thickened fingers, relatively normal axial length, microspherophakia, high myopia, and glaucoma, we diagnosed the patient with Weill-Marchesani syndrome.

CONCLUSION

Iris claw-lens phakic lenses may be an effective surgical alternative to correct high myopia in select patients; however, it may produce long-term complications in eyes with specific features.

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.

Intraokularlinsen zur Korrektur von Refraktionsfehlern

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses which are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for posterior chamber lenses these are mainly cataract formation and pigment dispersion. RLE is preferable in cases of high ametropia in which the natural lens has lost its accommodative effect. The main complications for myopic RLA include retinal detachment, while hyperopic refractive lens exchange may be associated with surgical problems in the narrower anterior eye segment.

Intraokularlinsen zur Korrektur von Refraktionsfehlern

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or the removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses that are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for anterior chamber lenses these are mainly pupil ovalization and endothelial cell loss.

Artisan Toric Phakic Intraocular Lens for Correction of Astigmatism

PURPOSE

To assess the safety and efficacy of implanting Artisan toric phakic intraocular lenses (PIOLs) (Ophtec BV, Groningen, The Netherlands) in eyes with high degrees of compound myopic, hyperopic, and mixed astigmatism.

METHODS

Twenty-five eyes (20 patients) presenting with high astigmatism were implanted with Artisan toric PIOLs and followed for 1 year. Group 1 included 8 eyes (myopic astigmatism), group 2 included 9 eyes (hyperopic astigmatism), and group 3 included 8 eyes (mixed astigmatism).

RESULTS

In the myopic astigmatism group, 8 (100%) of 8 eyes had preoperative uncorrected visual acuity (UCVA) of < or = 20/50, and at 6-month follow-up, 5 (62.5%) of 8 eyes had UCVA of > or = 20/40 (P = .005). In this group, 75% of eyes were within +/- 1.00 diopter (D) of the intended correction. In the hyperopic astigmatism group, 8 (88.9%) of 9 eyes had preoperative UCVA of < or = 20/40, and at 6-month follow-up, 6 (66.6%) of 9 eyes had UCVA of > or = 20/32 (P = .199). Approximately 77.8% of eyes were within +/- 1.00 D of the intended correction. In the mixed astigmatism group, 8 (100%) of 8 eyes had preoperative UCVA of < or = 20/50, and at 6-month follow-up, 6 (87.5%) of 8 eyes had UCVA of > or = 20/40 (P = .007). In this group, 87.5% of eyes were within +/- 1.00 D of the intended correction. The safety index of the procedure was 1.6, 1.3, and 1.3 in the myopic, hyperopic, and mixed astigmatism groups, respectively. The efficacy index of the procedure was 1.2, 1.0, and 1.0 in the myopic, hyperopic, and mixed astigmatism groups, respectively.

CONCLUSIONS

Artisan toric PIOLs are safe for the correction of high degrees of astigmatism associated with myopic or hyperopic spherical refractive defect.

Phakic intraocular lenses to correct high myopia

PURPOSE

To evaluate the feasibility and safety of using phakic intraocular lenses (IOLs) to correct high myopia by comparing 3 IOL models: Adatomed, Staar, and Artisan.

SETTING

La Fe University Hospital, Department of Ophthalmology, and the Fundación Oftalmológica del Mediterráneo, Valencia, Spain.

METHODS

In this prospective comparative study, a phakic IOL was implanted in 217 highly myopic eyes (118 patients). Fifty-nine eyes received an Adatomed IOL, 21 eyes a Staar IOL, and 137 eyes an Artisan IOL. The mean preoperative spherical equivalent was -15.39 diopters (D) +/- 2.83 (SD), -16.00 +/- 5.05 D, and -16.17 +/- 2.75 D in the Adatomed, Staar, and Artisan groups, respectively. The mean follow-up was 32.4 months (range 19 to 46 months) in the Adatomed group, 18.3 months (range 11 to 21 months) in the Staar group, and 121.4 months (range 38.4 to 154.3 months) in the Artisan group. At the follow-up examinations, intraocular pressure (IOP), IOL pigment deposits, cataract formation, and visual acuity were evaluated.

RESULTS

The best corrected and uncorrected visual acuities improved in all eyes. No significant differences in visual acuity improvement were observed with the 3 materials, although the improvement was somewhat greater in eyes with the Artisan and Staar IOLs. The difference in mean IOP between preoperatively and the last follow-up examination was 1.5 mm Hg in the Staar group, 1.3 mm Hg in the Adatomed group, and 1.7 mm Hg in the Artisan group (P =.36, P =.26, and P =.32, respectively). The incidence of pigment deposits was similar in the Adatomed and Staar groups, with deposits in 32 eyes (54.23%) and 8 eyes (38.1%), respectively. Anterior cataract formation was higher in the Adatomed group (44.06%) than in the Staar group (9.52%); nuclear cataract developed in 2 Adatomed eyes (1.46%) only.

CONCLUSIONS

There was a higher incidence of anterior subcapsular cataract formation in the Adatomed group than in the Staar group. Delayed cataract development and the cataract type in patients with Artisan IOLs indicate that age and axial length may be prognostic factors. Factors such as IOL design, material, and placement probably affect cataract formation in eyes with posterior chamber IOLs for high myopia, particularly the Adatomed IOL.

Phakic posterior chamber intraocular lens pupillary block

A 49-year-old woman developed bilateral pupillary block after implantation of a phakic posterior chamber intraocular lens despite patent-appearing but nonfunctional peripheral iridotomies. This case serves as a basis to identify clinical signs that distinguish this diagnosis from other causes of elevated intraocular pressure and types of pupillary block.

Artisan Phakic Iris Claw Intraocular Lens for High Primary and Secondary Hyperopia

PURPOSE

To evaluate the efficacy, predictability, and safety of the Artisan iris claw phakic intraocular lens for the correction of high primary and secondary hyperopia.

METHODS

Fifty-seven eyes were divided into two groups: 29 eyes had primary hyperopia (mean refraction 6.06 +/- 1.26 D, and 28 eyes had secondary hyperopia, (mean refraction 5.88 +/- 1.88 D) induced or residual following a previous corneal refractive procedure. Consecutive implantation of the Artisan iris claw phakic intraocular lens was performed. Main outcome measures recorded were BSCVA, UCVA, refraction, and astigmatic change, intraocular inflammation, and endothelial cell loss.

RESULTS

Primary hyperopic group: Preoperatively, mean UCVA was 0.4 +/- 0.7 and mean BSCVA was 0.2 +/- 0.6. After implantation, mean UCVA was 0.3 +/- 0.6 and BSCVA was 0.1 +/- 0.6. Mean cycloplegic residual spherical refractive error after surgery was 0.10 +/- 0.57 D (range -1 to +2 D). Mean surgically induced astigmatism was 1.48 +/- 0.89 D. Safety index was 1.11. Efficacy index was 0.83. Secondary hyperopic group: Preoperatively, mean UCVA was 0.5 +/- 0.7 and mean BSCVA was 0.2 +/- 0.6. Postoperatively, mean UCVA was 0.4 +/- 0.7 and mean BSCVA was 0.2 +/- 0.6. Mean cycloplegic residual spherical refractive error was 0.55 +/- 1.49 D. Mean surgically induced astigmatism was 1.85 +/- 1.19 D. Safety index was 1.05. Efficacy index was 0.7. Postoperative iridocyclitis was observed in one eye (3.4%) in the primary group and in three eyes (10.7%) in the secondary group. Overall corneal endothelial cell loss at 1 year of follow-up was 9.4%.

CONCLUSION

The Artisan iris claw phakic intraocular lens was reasonably safe and predictable for correcting high hyperopia.

Anterior chamber intraocular lens for high myopia: five year results

PURPOSE

To evaluate the effectiveness of the surgical correction of high myopia 5 years after anterior chamber intraocular lens (IOL) implantation and to analyze the lens position and related complications.

SETTING

Federal University of São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.

METHODS

This prospective study comprised 26 eyes that were implanted with an anterior chamber IOL (model ZB5M) and had a minimum follow-up of 5 years. Before and after surgery, manifest and cycloplegic refractions were done; slitlamp examination was performed; anterior chamber depth was measured; and keratometry, ophthalmoscopy, and central corneal endothelial cell count were performed. At the last follow-up, computerized biomicroscopy of the anterior segment was also done.

RESULTS

The spherical equivalent decreased from -16.5 diopters (D) +/- 4.1 (SD) preoperatively to -0.9 +/- 0.9 D postoperatively. At the last examination, 57.7% of eyes had a spherical equivalent refraction within +/-1.0 D of emmetropia. Of eyes with a preoperative best spectacle-corrected visual acuity of 20/40 or better, 73.3% had an uncorrected visual acuity of 20/40 or better postoperatively. The mean tilt caused by the IOL was 4.4 +/- 2.7 degrees (range 0.5 to 12.2 degrees) and the mean IOL decentration, 0.3 +/- 0.2 mm (range 0.02 to 0.8 mm). The mean decrease in the endothelial cell count was 1.5%, with a mean cell density of 2808 +/- 305 cells/mm2 preoperatively and 2765 +/- 242 cells/mm2 postoperatively. Pupillary ovalization was observed in 12 eyes (46.1%).

CONCLUSIONS

The anterior chamber IOL safely and effectively corrected high myopia.

Posterior Chamber Phakic Intraocular Lenses to Correct High Myopia: A Comparative Study Between Staar and Adatomed Models

PURPOSE

To determine the feasibility of using posterior chamber phakic intraocular lenses (PIOLs) to treat high myopia, comparing two different models, Staar and Adatomed.

METHODS

Twenty-four eyes from 12 patients were studied prospectively. A phakic Staar IOL was implanted in one eye of each patient, and the other eye received a phakic Adatomed IOL. Patients with uveitis or ocular trauma prior to ocular surgery, diabetic retinopathy, or capsular pseudoexfoliation were excluded. The mean preoperative spherical equivalent refraction was -16.00 +/- 5.05 D for the Staar group and -15.39 +/- 2.83 D for the Adatomed group. Average follow-up was 32.4 months (range, 19 to 46 mo) for the Adatomed group and 18.3 months (range, 11 to 21 mo) for the Staar group and included evaluation of intraocular pressure, intraocular lens pigment deposits, lens decentration, anterior subcapsular cataract, and visual acuity.

RESULTS

Spectacle-corrected and uncorrected visual acuity improved in all eyes in both groups. No statistically significant differences in visual acuity gain were observed with the two materials (Student t-test, P = .08 for the Staar group and P = .6 for the Adatomed group), although the gain in visual acuity was somewhat greater with the Staar PIOLs. The difference in mean intraocular pressure before surgery and at last follow-up was 1.5 mmHg for the Staar group and 2.3 mmHg for the Adatomed group (P = .36). The incidence of lens pigment deposits was the same in both groups (41.66%), with deposits in 5 of the 12 eyes in both groups. The incidence of lens decentration was higher in the Adatomed group (5/12; 41.66%) than in the Staar group (2/12; 16.7%). Anterior subcapsular cataract was higher in the Adatomed group (4/12; 33.3%) than in the Staar group (3/12; 25%).

CONCLUSIONS

There was a higher incidence of lens decentration and anterior subcapsular cataract in the Adatomed group than in the Staar group.

Multicenter study of the Artisan phakic intraocular lens

PURPOSE

To assess the Artisan intraocular lens to correct myopia in phakic eyes.

SETTING

European multicenter study sponsored by Ophtec BV, Groningen, The Netherlands.

METHODS

In this prospective multicenter clinical study, the Artisan lens was implanted in 518 eyes between September 1991 and October 1999. The power of the lenses ranged from -5.0 to -20.0 diopters (D). Follow-up examinations were performed at 6 months and 1, 2, and 3 years. Follow-up ranged from 6 months (n = 454) to 3 years (n = 249). The preoperative uncorrected visual acuity (UCVA) was not recorded but was estimated to be worse than 0.1. The preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.67 +/- 0.26 (SD). Endothelial cell counts were done at 6 months and 1, 2, and 3 years in a subgroup of 129 eyes.

RESULTS

A UCVA of 20/40 or better was observed in 76.8% of eyes regardless of the postoperative goal. A BSCVA of 20/40 or better was observed in 93.9% of eyes and remained stable throughout the follow-up. Of the eyes with extremely high myopia (>-15.0 D), 63.3% gained 2 or more lines of BSCVA; of those with moderate myopia (-5.0 to -10.0 D), 23.5% gained 2 or more lines. The mean endothelial cell density change was 4.8% at 6 months, 2.4% at 1 year, 1.7% at 2 years, and 0.7% at 3 years. The incidence of persistent adverse events at 3 years was relatively low. Secondary surgical interventions included repositioning of the lens because of poor initial placement and lens exchange because of preoperative power calculation errors. Glare and halo effects during night driving were noted and were related to large pupils in young patients.

CONCLUSION

The Artisan lens is a safe, stable, efficacious, and predictable method to correct -5.0 to -20.0 D of myopia. This study suggests that the corneal endothelial cell loss is stabilized to the physiologically normal level after 3 years.

Long-term Results of Correction of High Myopia With an Iris Claw Phakic Intraocular Lens

PURPOSE

Anterior chamber phakic intraocular lenses (PIOLs) are one of the modalities used to correct high myopia. We report the long-term results of our prospective study on the Artisan 5-mm optic myopia lens.

METHODS

We studied 67 eyes of 38 consecutive patients with preoperative myopia ranging from -5.38 to -28.00 D. All patients were operated by one surgeon. Mean follow-up was 35 months (24 months in 67 eyes and 36 months in 61 eyes).

RESULTS

In 45 eyes (67.2%), postoperative residual refraction was within +/- 1.00 D of emmetropia. The mean refraction was stable statistically during the entire follow-up period. Mean best spectacle-corrected visual acuity improved from 20/40 to 20/32. Mean endothelial cell loss at 6 months was 5.5% (range, -52.4% to +9.3%), at 12 months, 7.21% (range, -53.2% to +20.1%), at 24 months, 9.1% (range -43.6% to +13.6%), and at 36 months, 10.9% (range, -43.0O% to +11.4%). The majority of eyes had an increase in best spectacle-corrected visual acuity; 5 eyes lost best spectacle-corrected visual acuity. We encountered no major complications.

CONCLUSION

Implanting the Artisan 5-mm optic myopia lens in high myopic eyes resulted in a stable and accurate refractive outcome. The apparent progressive corneal endothelial cell loss remains a matter of concern.

Phakic anterior chamber lenses for the correction of myopia: a 7-year cumulative analysis of complications in 263 cases

OBJECTIVE

To perform a prospective, clinical trial to determine the potential cumulative complications of patients implanted with angle-supported phakic intraocular lenses (PIOLs) for the correction of myopia.

DESIGN

Nonrandomized, prospective, comparative trial.

PARTICIPANTS

Two hundred sixty-three eyes of 160 consecutive patients were included.

INTERVENTION

Angle-supported anterior chamber intraocular lenses were implanted into phakic eyes.

MAIN OUTCOME MEASURES

Night halos and glare were recorded. Central endothelial cell count, postoperative inflammation, applanation tonometry, cataract development, retinal detachment, and pupil ovalization were recorded by the same physician.

RESULTS

Night halos and glare were reported as significant by 20.2% at 1 year and 10% at year 7 of follow-up. This complication was significantly lower in the larger optical zone PIOL (ZSAL-4) than in the ZB5M/ZB5MF group (P < 0.05). Acute postoperative iritis was observed in 4.56% of cases. High intraocular pressure that required antiglaucoma medications appeared in 7.2% of cases. Central corneal endothelial cell density was significantly decreased at postoperative month 3 (P < 0.0001). The percentages of cell loss were 3.76% at month 3 and 1.83% at year 1, and then the percentages decreased by 1.37% more at year 2, 0.72% at year 3, 0.3% at year 4, 0.6% at year 5, 0.4% at year 6, and 0.56% at year 7. The total cumulative loss of central endothelial cells after 7 years was 8.37%. Pupil ovalization was present in 5.9% of cases, although smaller degrees of this complication were observed in another 10.3%. Retinal detachment appeared in 3% of cases. The PIOL explantation was decided in 11 cases (4.18%) because of cataract development (9 cases) and extreme pupil ovalization associated with severe glare (2 cases). The Kaplan-Meier cumulative survival analysis study showed an expected period free from complication of 86.5% for IOP elevation, 98.75% for endothelial cell count inferior to 1500 cells/mm2, 86.97% for pupil ovalization, 95.43% for retinal detachment, and 89.02% for explantation.

CONCLUSIONS

Angle-supported PIOL appeared to be well tolerated by the corneal endothelium with a low rate of other complications. Pupil ovalization seemed to be a specific problem for this type of PIOL.

Pathological examination of an explanted phakic posterior chamber intraocular lens

PURPOSE

To report the clinicopathological correlation of an explanted phakic posterior chamber intraocular lens (PPC IOL) and to study the conformation of this lens implanted into human eyes obtained postmortem.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Three silicone PPC IOLs were explanted. One lens, explanted from a 38-year-old woman with complicated cataract, was submitted for pathological analysis. In addition to gross and scanning electron microscopy (SEM), the lens was studied after experimental implantation in human eyes obtained postmortem using frontal, posterior, and side-view techniques.

RESULTS

Although gross and SEM showed that the IOL was well polished, examination of the lens in human cadaver eyes showed it was oversized and poorly fixated. It was relatively bulky in its anterior-posterior dimension and revealed evidence of significant contact with the iris and crystalline lens.

CONCLUSIONS

This study illustrates many pitfalls to be avoided in the design of a plate PPC IOL. The lens in this report was too large, and instead of ciliary sulcus fixation, it showed poor fixation through the zonules onto the posterior face of the pars plicata. Present and future PPC IOLs should be submitted for similar preclinical studies to clarify the type and site of fixation.

Iris Claw Phakic Intraocular Lens for High Myopia

BACKGROUND

The implantation of a Worst-Fechner iris claw intraocular lens (IOL) is one of the surgical procedures used for the correction of high myopia. This technique reduces myopia with stable refractive results; however, its potential long-term risks have not been evaluated. We report results in 94 eyes with a minimum follow-up of 3 years.

METHODS

We studied 94 eyes of 62 patients with myopia > or = -7.00 diopters (D) who underwent Worst-Fechner IOL implantation. Lens decentration, permeability of the blood-aqueous barrier by iris angiography, and changes in corneal endothelial density were analyzed.

RESULTS

Mean follow-up time was 48.9 months (range 36 to 72 mo). Three years after surgery, 58 eyes (61%) had an uncorrected visual acuity > or = 20/40, and 77 eyes (82%) gained two or more lines of spectacle-corrected visual acuity with respect to the preoperative value; 75 eyes (79%) were within +/- 1.00 D of emmetropia and 46 eyes (48%) were within +/- 0.50 D of emmetropia. The mean endothelial cell loss was 17.9% at 5 years after surgery, while the percentage of hexagonality and the coefficient of cell variation tended toward preoperative levels. No vision threatening complications were seen.

CONCLUSIONS

The implantation of a Worst-Fechner iris claw phakic IOL reduced high myopia with a stable refractive outcome. Endothelial cell damage was within acceptable limits. The absence of major complications makes this procedure an acceptable method for correcting high myopia.

Bilateral Cataract after Phakic Posterior Chamber Top Hat-style Silicone Intraocular Lens

BACKGROUND

New strategies have been developed for surgical treatment of high myopia. Recently, implantation of minus power posterior chamber intraocular lenses (IOL) into phakic eyes has been introduced.

METHODS

We report a 37 year-old female patient who developed bilateral anterior subcapsular cataract 7 years after minus-power, top hat-style silicone posterior chamber IOL implantation in Russia. The corrected visual acuity was right eye 20/200 and left eye 20/63. Because of the high myopia and the posterior chamber IOL in her phakic eyes, biometry for IOL calculation gave contradictory results. Both posterior chamber IOLs were found to be adherent to the crystalline lenses. After posterior chamber IOL explantation and phacoemulsification, intraoperative retinoscopy was performed. With this aphakic refraction, the IOL power was calculated and implanted. The explanted posterior chamber IOLs were examined by scanning electron microscopy.

RESULTS

After bilateral operation the corrected visual acuity increased to right eye 20/32 and left eye 20/40, respectively. On scanning electron microscopy, a membranous structure of unknown origin was noted on the entire surface of the explanted posterior chamber IOLS.

CONCLUSION

There is a potential risk of cataract formation after implantation of this top hat-style silicone posterior chamber IOL. If cataract extraction in this specific situation is needed, a different approach for calculating the aphakic IOL power is necessary, such as intraoperative retinoscopy.

Correction of High Myopia With the Worst Myopia Claw Intraocular Lens

BACKGROUND

Phakic anterior chamber lenses is one of the modalities used to correct high myopia. We report the initial results of our prospective study on the Worst myopia claw intraocular lens (IOL) that is fixated to the anterior iris.

METHODS

We studied 35 eyes in 18 patients with a preoperative myopia ranging from -6.00 to -28.00 diopters (D). The follow up ranged from 6 months (n = 15) to 12 months (n = 20).

RESULTS

In 26 (74.3%) eyes, the postoperative spherical equivalent refractive error was within 1.00 D of emmetropia. The mean refraction was stable between 1 to 2 months and 12 months. The mean spectacle-corrected visual acuity improved from 20/50 to 20/40. The straylight measurements did not show a significant increase postoperatively (p = .64). The mean endothelial cell loss was 5.6% (range, +6.3% to -22.6%) at 6 months, and 8.9% (range, +0.77% to -23.5%) at 12 months. We did not encounter major complications.

CONCLUSION

Implanting a Worst myopia claw IOL in high myopic eyes resulted in a stable, reasonably accurate refractive outcome. This group of patients will be followed longer because of concern over ocular complications with this technique.

Negative implant. A retrospective study

Implantation of a negative power intraocular lens is one of the options for surgical correction of high myopia. We studied 36 eyes with a Fechner Worst Claw Lens, implanted in Groningen between March 1987 and November 1991. The preoperative myopia ranged from -7.00 to -30.00 diopters. Twenty one eyes had a follow up period of more than 12 months. The IOL power was calculated with the van der Heyde method. Correction within 1 diopters of emmetropia has been achieved in 55.5% of the cases. Deviation of more than 2 diopters occurred in 25%. In 24 eyes the best corrected postoperative visual acuity improved. Due to the IOL the retinal image increases in size as compared to spectacle correction. In none of the cases complications were encountered during surgery. In the postoperative period one IOL had to be replaced because of an error made in the calculation of the lens power. In one case endothelial decompensation occurred, probably due to a combination of compulsive eye rubbing and a preexisting cornea guttata. The rim of the IOL optic is the part which is the closet to the endothelium. Our recommendation is that one should avoid indentation of the cornea. No other serious complications occurred in this study.