An angle-supported foldable phakic intraocular lens for correction of myopia: A five-year follow-up

OBJECTIVE

To evaluate the efficacy and safety of an angle-supported foldable phakic intraocular lens (pIOL) for the correction of moderate to high myopia after 5 years follow-up.

METHODS

Prospective and retrospective, observational, longitudinal, non-randomised consecutive series of cases conducted on a total of 100 eyes of 67 patients with moderate to high myopia implanted with an Acrysof Cachet pIOL (Alcon Laboratories Inc.) with the aim of minimising the refractive error. The ages ranged between 18 to 60years. Uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity (CDVA), endothelial cells density, pIOL position, intraocular pressure, and complications were recorded preoperatively and during the 5 year follow-up.

RESULTS

Five years after implantation, the mean manifest spherical equivalent refraction reduced significantly from -11.62±3.35 dioptres (D) to -0.33±0.85D. UDVA was 20/20 or better in 5 of 25 cases (20%), and 20/40 or better in 22 cases (88%). CDVA was 20/20 or better in 17 cases (68%), and 20/32 or better in 23 cases (92%) of eyes. The residual refractive error was within ±0.50D of emmetropia in 12 cases (48%), and within ±1.00D in 19 cases (76%). Mean endothelial cell loss at 5 years was 11.8% central, and 13.7% peripheral. Mean endothelium-pIOL distance was 2.11±0.18mm, and mean pIOL-crystalline distance was 0.88±0.20mm.

CONCLUSIONS

This angle supported pIOL provided a favourable refractive correction and predictability, as well as acceptable safety in patients with moderate to high myopia. Although endothelial cell density decreased over 5years, the results are within the range reported in previous studies with other pIOLs.

Asymptomatic haptic migration of phakic anterior chamber intraocular lens through the peripheral iridectomy

OBJECTIVE

Case series of haptic migration in patients with angle-supported phakic anterior chamber intraocular lens (PAC-IOL: Phakic6H) through the superior peripheral iridectomy (PI).

METHODS

Charts of 23 patients (35 eyes) with at least 6 months' postoperative follow-up were retrospectively reviewed. Evaluation included preoperative and postoperative cycloplegic and manifest refractions, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), slit-lamp examination, fundoscopy, corneal topography, and biometry.

RESULTS

Mean UCVA was 1.67 ± 0.30 (1.17-2.00) for all 35 eyes preoperatively and 0.35 ± 0.25 (0.00-1.00) postoperatively (p < 0.001; 95% CI 1.21-1.44). BCVA had a mean of 0.31 ± 0.26 for all 35 eyes preoperatively, and a mean of 0.22 ± 0.25 postoperatively (p < 0.001; 95% CI 0.04-0.14). Haptic migration into the superior PI was noted in 8 eyes (23%). The first migration was noted 2 years postoperatively and the last 8 years after implantation (mean, 5.6 ± 2 years). There was no statistically significant difference in the BCVA and UCVA before and after haptic migration. Follow-up ranged from 8 months to 8.5 years.

CONCLUSIONS

Angle-supported PAC-IOL implantation resulted in significant improvement in both UCVA and BCVA. However, there is a 23% incidence of haptic migration in our series with no sequelae on BCVA or harmful effect on the intraocular structures. This IOL movement may be explained by changes in aqueous dynamics at the level of the PI leading to migration of the haptic into the area of least resistance.

Three-year stability of an angle-supported foldable hydrophobic acrylic phakic intraocular lens evaluated by Scheimpflug photography

PURPOSE

To examine the postoperative positional stability of a new angle-supported, hydrophobic acrylic phakic intraocular lens (pIOL).

SETTING

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

METHODS

In this prospective nonrandomized clinical trial, eyes with moderate to high myopia had implantation of an angle-supported pIOL (AcrySof Cachet). Scheimpflug imaging was performed preoperatively and postoperatively at 1, 3, 6 to 12, and 24 to 36 months. The main outcome measures were the distance between the corneal endothelium and the IOL and between the IOL and the crystalline lens. The overall significance threshold was P = .05.

RESULTS

Twenty-one of the 26 eyes (26 patients) evaluated were included in the statistical analysis. Analysis of variance showed no statistically significant differences in absolute endothelium-IOL or IOL-crystalline lens measurements at any postoperative visit. The mean endothelium-IOL distance was 2.05 mm +/- 0.25 (SD) at 1 month and 2.15 +/- 0.29 mm at 24 to 36 months and the mean IOL-crystalline distance, 0.92 +/- 0.23 mm and 0.86 +/- 0.22 mm, respectively. A 1-way t test showed a small but significant difference compared with zero in the overall change in the endothelium-IOL distance (mean 0.08 +/- 0.16 mm) and thus in the overall calculated anterior chamber depth (mean 0.07 +/- 0.08 mm); the difference was not significant for the IOL-crystalline lens change (mean -0.05 +/- 0.13 mm).

CONCLUSION

The angle-supported foldable hydrophobic pIOL maintained adequate central clearance distances to the corneal endothelium and the natural crystalline lens over 3 years.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Refractive stability of LASIK with the Visx 20/20 excimer laser vs ZB5m phakic iol implantation in patients with high myopia (>-10.00 d): a 10-year retrospective study

PURPOSE

To compare the long-term outcomes of LASIK and ZB5M phakic intraocular lens implantation (PIOL) (Domilens) for high myopia (>-10.00 diopters [D]).

METHODS

This long-term (10 years) follow-up retrospective interventional case series study included 126 eyes that underwent LASIK and 52 eyes that underwent ZB5M angle-supported PIOL implantation. Both groups of eyes were similar in terms of preoperative spherical equivalent refraction (SE), corrected distance visual acuity (CDVA), and age.

RESULTS

Mean preoperative SE was -14.33 D in the LASIK group and -14.84 D in the PIOL group. At 10-year follow-up, mean postoperative SE was -1.47±2.00 D in the LASIK group and -1.01±1.36 D in the PIOL group (P=.21). In the LASIK group, 67% of eyes were within ±1.00 D of emmetropia at 2 years after surgery, compared to 42% at 10 years. In the PIOL group, 68% of eyes were within ±1.00 D of emmetropia 2 years after implantation compared to 53% at 10 years. In the LASIK group, 43.5% of eyes achieved UDVA of 20/40 or better 10 years after surgery compared to 67.9% in the PIOL group (P=.02).

CONCLUSIONS

The ZB5M angle-supported PIOL was shown to have better predictability and stability compared to LASIK over 10 years. However, reductions in endothelial cell count over time were observed in eyes with PIOLs.

Outcomes of ZB5M Angle-supported Anterior Chamber Phakic Intraocular Lenses at 12 Years

PURPOSE

To evaluate the visual and refractive stability and the potential long-term risks associated with ZB5M phakic intraocular lens (PIOL) implantation.

METHODS

A retrospective, non-randomized, cumulative clinical study was performed over 12 years in a consecutive group of 225 eyes implanted with the ZB5M PIOL. The main analyzed variables were visual and refractive outcomes (best spectacle-corrected visual acuity [BSCVA], uncorrected visual acuity [UCVA], and spherical equivalent), endothelial cell density, and postoperative complications.

RESULTS

Mean preoperative spherical equivalent refraction was -17.23 +/- 7.69 diopters (D) and 12 years postoperatively it was -1.80 +/- 0.80 D. Mean BSCVA at 1- and 12-year follow-up was 0.38 +/- 0.19 and 0.57 +/- 0.18, respectively (Wilcoxon test, P < .001). At 12 years postoperatively, 3.5% of eyes lost > or = 2 lines of BSCVA. An initial 10.6% reduction in endothelial cell density was noted in the first year, followed by a mean annual rate of decrease of 1.78%. The cumulative incidence of pupil ovalization was 34.7% (78 eyes), and there was no statistical correlation with endothelial cell impairment. Bilateral hypertensive uveitis was diagnosed in 3 (1.33%) eyes.

CONCLUSIONS

The ZB5M PIOL offers good refractive outcomes and stability in the long-term; however, endothelial cell loss increases over 12 years, requiring annual endothelial cell counts.

[GBR foldable anterior phakic intraocular lens with angular supports: a 3-year experience]

PURPOSE

The purpose of this study was to evaluate the efficiency, predictability, and safety of the GBR foldable anterior chamber implant with angular supports to correct high myopia after 3 years of follow-up.

MATERIAL

and methods: A GBR anterior chamber lens with angular supports was implanted in 44 eyes between November 2001 and February 2004. These eyes were highly myopic (preoperative mean of -10.65 +/- 2.62 diopters (D) (range, -6.25 to -16.50 D). Visual acuity, refraction, biomicroscopy, and quality of vision were estimated with a follow-up of 3 years. The potential complications required endothelial density, mobility of the pupil, intraocular pressure, and gonioscopy measurements.

RESULTS

No severe intra- or postoperative complications required an ablation of the lens. Increased intraocular pressure in three cases and decentration in one were the most serious side effects reported. Eighteen eyes (40.9%) presented pupil ovalization; 68.2% of the eyes reached the attempted correction +/-0.50 D. Implants seemed stable in their position and refractive results. Functional signs included night glare for eight patients (18.2%) and glare in the sun for 11 (25%). There was no significant decrease in cellular endothelial density mean during follow-up.

CONCLUSION

The GBR implant (Ioltech) is the pioneer of foldable anterior chamber implants, a concept in full expansion. Long-term satisfaction of the operated patients is encouraging. However, the medium-term anatomical modifications noted require monitoring and a search for the responsible mechanism.

Corneal edema and penetrating keratoplasty after anterior chamber phakic intraocular lens implantation

Phakic intraocular lens (IOL) implantation is an increasingly popular option in surgical correction of refractive error. To date, reports of long-term morbidity are infrequent in the literature. We encountered 3 patients who experienced corneal decompensation and cataract progression following angle-fixated anterior chamber phakic IOL placement.

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.

Position of angle-supported, iris-fixated, and ciliary sulcus-implanted myopic phakic intraocular lenses evaluated by Scheimpflug photography

PURPOSE

To examine postoperative positional stability of myopic phakic intraocular lenses (IOLs).

DESIGN

Prospective, nonrandomized clinical study.

METHODS

The study included 46 eyes which received an anterior chamber angle-supported (Bausch & Lomb NuVita; 10 eyes), anterior chamber iris-fixated (Ophtec Artisan; 20 eyes) or ciliary sulcus-implanted phakic IOL (Staar ICL; 16 eyes). The distance between the phakic IOL and the crystalline lens and the cornea as well as rotation around the optical axis was evaluated using Scheimpflug photography at 1, 3 to 6, and 12 months postsurgery.

RESULTS

The anterior chamber phakic IOLs showed no significant movement in anteroposterior direction. The posterior chamber phakic IOL showed a significant movement toward the crystalline lens between postoperative months 3 and 12. The median amount of rotation around the optical axis between the 3- and the 12-month evaluation was 1.9 degrees (range = 0.0-33.5 degrees) for the NuVita, 0.6 degrees (range = 0.0-3.5 degrees) for the Artisan, and 0.9 degrees (range = 0.2-2.3 degrees) for the ICL. Four NuVita IOLs rotated more than 10 degrees.

CONCLUSIONS

The angle-supported anterior chamber phakic IOLs showed a generally stable position regarding distance to cornea and natural lens, but rotation was observed in four IOLs. The iris-fixated phakic IOL showed the highest overall stability. The posterior chamber phakic IOL was stable in terms of rotation but had a tendency to decrease in distance toward the crystalline lens. Intraocular lenses implanted in phakic eyes followed for 12 months demonstrate stable IOL position overall.

Long-term complications of bilateral posterior chamber phakic intraocular lens implantation

A 34-year-old woman had posterior chamber phakic intraocular lens (PCP IOL) implantation to correct high myopia in both eyes. Five years postoperatively, the patient presented with a decrease in visual acuity from central anterior subcapsular cataract formation in both eyes and IOL dislocation in the left eye. In vivo confocal microscopy of the cornea showed markedly decreased endothelial cell density in both eyes and the presence of bright endothelial microdeposits possibly related to pigmentary dispersion. Gonioscopy showed angle pigmentary deposits with no intraocular pressure increase. The patient was successfully treated by removing the PCP IOLs and performing phacoemulsification with in-the-bag IOL implantation in both eyes. This led to a recovery of visual acuity. This case report presents the rare occurrence and surgical management of cataract formation, IOL dislocation, and severe endothelial cell loss as a late complication of PCP IOL implantation.

Phakic intraocular lenses and refractory lensectomy for myopia

Phakic intraocular lens implantation (IOLs) and clear lens extraction for high to extreme myopia have grown in popularity recently as a consequence of potentially unsatisfactory results with corneal refractive surgery in higher ranges of refractive errors. The refractive outcome of these alternative modalities has been encouraging to date, yet the potential for significant complications exists. Current evidence shows that the risk of retinal detachment after clear lens extraction for myopes is high. Trials with angle-supported phakic IOLs revealed unacceptable rates of pupillary ovalization, IOL rotation, and endothelial cell loss. Iris-fixated and posterior chamber phakic IOLs have proven sufficient safety, but long-term follow-ups of current cohorts are still to be awaited. The implantation of either of the latter two phakic IOLs followed by laser in situ keratomileusis or photorefractive keratectomy (bioptics) provides another option in refractive surgery for high ametropia.

Correction of pseudophakic anisometropia with the Staar Collamer implantable contact lens

PURPOSE

To assess the role of the Staar Surgical implantable contact lens (ICL) for the correction of pseudophakic anisometropia.

SETTING

Oxford Eye Hospital, Oxford, and Rosen Eye Center, Alexandra Hospital, Manchester, United Kingdom.

METHODS

Six patients with pseudophakic anisometropia ranging from 2.0 to 7.9 diopters (D) (mean 4.4 D) had ICL implantation as an alternative to intraocular lens (IOL) exchange or conventional piggyback IOLs.

RESULTS

All patients had a reduction in anisometropia to asymptomatic levels. The mean reduction was 3.15 D. No patient experienced adverse effects.

CONCLUSIONS

The implantable contact lens offers an alternative approach to the management of pseudophakic anisometropia that avoids some of the risks associated with IOL exchange, corneal refractive surgery, and conventional piggyback IOLs.

Ultrasound biomicroscopy of ZSAL-4 anterior chamber phakic intraocular lens for high myopia

PURPOSE

To evaluate the intraocular location and anatomic relationship to other structures of the ZSAL-4 angle-supported anterior chamber phakic intraocular lens (IOL) for high myopia using ultrasound biomicroscopy (UBM).

SETTING

Clínica de Nuestra Señora de la Concepción, Fundación Jiménez Díaz, and Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Madrid, Spain.

METHODS

Eight phakic myopic eyes corrected by ZSAL-4 angle-supported anterior chamber phakic IOLs were examined by UBM. The distance between the corneal endothelium and the IOL at the central and peripheral cornea and between the phakic IOL and the iris was measured.

RESULTS

The mean distance between the central cornea and the IOL was 2361.37 microm +/- 109.62 (SD); between the edge of the IOL optic and the endothelium, 1646.24 +/- 27.06 microm; and between the IOL and the iris, 354.46 +/- 41.61 microm. The IOL footplates appeared to be correctly positioned in the anterior chamber angle in all eyes.

CONCLUSION

The space between the IOL and the endothelium was greater in eyes with the ZSAL-4 angle-supported phakic IOL than in eyes with other angle-supported phakic IOLs. The possibility of intermittent contact between the IOL edge and the midperipheral cornea plays a minor role in the mechanism of endothelial damage with this lens model.

Safety of posterior chamber phakic intraocular lenses for the correction of high myopia: anterior segment changes after posterior chamber phakic intraocular lens implantation

OBJECTIVE

To assess the safety of posterior chamber phakic intraocular lens (PCPIOL) implantation in patients with high myopia.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

Twenty eyes of 10 patients were included.

INTERVENTION

Staar Collamer Implantable Contact Lens PCPIOLs were implanted for the correction of high myopia.

MAIN OUTCOME MEASURES

Intra- and postoperative complications were recorded. Specular microscopy, lens fluorophotometry, laser flare-meter, and ultrasound biomicroscopy were performed before surgery and at different stages of the follow-up period to evaluate endothelial cell density, crystalline lens transmittance, aqueous flare, and anatomic relations of the implanted lenses with the other structures of the anterior segment.

RESULTS

There were no intraoperative complications. One patient experienced pupillary entrapment by the lens in the immediate postoperative period, which was resolved without incident. Pigmentary dispersion or cataracts did not appear during the postoperative period. All the lenses remained correctly centered, and no patient reported night halos or glare. Anterior chamber depth showed a statistically significant reduction, between 9% and 12%. Central endothelial density was significantly decreased after surgery. The percentages of cell loss after 3, 6, 12, 18, and 24 months were 4.41%, 4.83%, 5.17%, 5.46%, and 6.57%, respectively. Aqueous flare increased by 49.19% in the first postoperative month in relation to preoperative values. Afterward, it decreased and then remained above preoperative values for the entire follow-up period (33.76% at month 3, 27.81% at month 6, 27.65% at month 12, 23.39% at month 18, and 27.27% at month 24). Crystalline lens transmittance decreased by 0.72% at month 3, by 1.44% at month 6, by 1.95% at month 12, by 2.25% at month 18, and by 2.24% at month 24. Finally, by ultrasound biomicroscopy it was observed that the PCPIOL and the crystalline lens were in contact on the peripheral level in 12 patients (60%) and in the center in another three patients (15%) during at least one checkup. In all the patients, contact between the PCPIOL and the posterior iris surface could be observed.

CONCLUSIONS

Posterior chamber phakic IOL implantation for the surgical correction of high myopia is a safe procedure with regard to immediate visual and refractive results. The short-term clinical benefit and lack of immediate surgical complications are impressive. However, the increase in flare, the endothelial cell loss, the decrease in crystalline lens transmittance, and the iris-PCPIOL and crystalline lens-PCPIOL contact are findings that suggest caution regarding the long-term safety of this lens implant.

Surgical correction of severe myopia with an angle-supported phakic intraocular lens

PURPOSE

To evaluate the effectiveness, predictability, and safety of a fourth-generation angle-supported anterior chamber phakic intraocular lens (IOL) in patients with severe myopia.

SETTING

Refractive Surgery and Cornea Unit, Alicante Institute of Ophthalmology, Miguel Hernández University School of Medicine, Alicante, Spain.

METHODS

In this prospective study, 23 eyes (16 patients) with a mean preoperative myopia of -19.56 diopters (D) +/- 1.76 (SD) (range -16.75 to -23.25 D) were implanted with the ZSAL-4 phakic IOL. Basic examinations were performed before and after surgery in all patients. Eighteen eyes were also studied by clinical specular microscopy, and the endothelium was analyzed for cell density, coefficient of variation in cell size, and hexagonality. The location of the IOL in the anterior chamber was evaluated in 10 eyes by A-scan biometry. To evaluate haptic geometry, a theoretical mechanical model was used. The follow-up was 24 months in all patients.

RESULTS

Uncorrected visual acuity was 20/40 or better in 13 eyes (56.0%) 12 months after surgery and in 14 eyes (60.8%) at 24 months. Best spectacle-corrected visual acuity improved 0.19 at 12 and 24 months (0.1 = 1 line) from preoperative values. The efficacy index was 1.12 at 24 months and the safety index, 1.45. The mean postoperative spherical equivalent was -0.65 +/- 0.65 D at 24 months. The postoperative spherical equivalent was within +/-1.00 D of emmetropia in 19 eyes (82.6%) at 12 and 24 months. The mean endothelial cell loss was 3.50% at 12 months and 4.18% at 24 months. The coefficient of variation in cell size decreased from 0.34 before surgery to 0.28 at 24 months after surgery. The IOL was located 0.79 +/- 0.24 mm in front of the crystalline lens. Postoperative complications included night halos in 6 eyes (26.1%) at 12 and 24 months and pupil ovalization in 4 eyes (17.4%). Intraocular lens rotation was observed in 10 eyes (43.5%) at 24 months. Two eyes (8. 7%) developed a slight inflammatory response during the first 6 months. Our mechanical model predicted that the compression forces against the angle structures were greater at the first footplate than at the second.

CONCLUSIONS

Implantation of the ZSAL-4 IOL in the anterior chamber of phakic eyes was effective and predictable in correcting severe myopia. However, the ZSAL-4 did not prevent pupil ovalization, IOL rotation, or low-grade postoperative uveitis. Improvements in haptic design following our mechanical model could decrease these haptic-related complications.

Advances in refractive surgery: 1975 to the present

PURPOSE

To review the major advances in the field of refractive surgery occurring over the past 25 years.

METHODS

Literature review.

RESULTS

The major developments in refractive surgery over the past 25 years are reviewed.

CONCLUSIONS

The past 25 years have witnessed great changes in refractive surgery. As a result of advancements in technology, instrumentation, and technique, we have seen improvements in the treatment of all types of ametropias. In this article, we review some of the successes and failures of the past quarter-century.

Phakic intraocular lenses: which to choose

Phakic intraocular lenses have been increasingly popular with refractive surgeons because of the good refractive results achieved and because there are few serious complications. The purpose of this review is to compare the different types of phakic intraocular lenses, regarding implant selection, surgical technique, refractive outcome, and anatomical evaluation. New uses of phakic intraocular lenses are also presented. Although phakic intraocular lenses have gone a long way, the quest for the ideal lens remains a challenge.

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 posterior chamber lenses for high myopia: functional and anatomical outcomes

PURPOSE

To evaluate the functional and the anatomical outcomes after implantation of phakic posterior chamber intraocular lenses (IOLs) in highly myopic eyes.

SETTING

Service d'Ophtalmologie, Hôpital Purpan, Toulouse, France.

METHODS

Fifty-eight eyes of 46 patients that had implantation of phakic posterior chamber lenses for high myopia were evaluated. Predictability, efficiency, safety, and subjective and objective quality of vision were evaluated preoperatively and at least 6 months postoperatively. The effect of the procedure on the cornea, aqueous humor, pupil, anterior chamber angle, crystalline lens, and retina were studied.

RESULTS

Mean preoperative myopia was -13.85 diopters (D) +/- 3.1 (SD) (range -8.00 to -19.25 D). Mean postoperative spherical equivalent was -1.22 +/- 0.83 D (range +0.75 to -3.50 D); 56.9% of eyes were within +/-1.00 D of the predicted result, and 77.6% gained 1 or more lines of best corrected visual acuity. All contact-lens-intolerant patients had improved quality of vision for day and night driving, distance vision, and vision under dim illumination. The mean postoperative level of contrast sensitivity without correction was higher than the mean preoperative level with correction. Adverse events were 2 cases of crystalline lens opacification 16 and 18 months after surgery and 2 cases of pigment deposits in the angle with increased intraocular pressure, which was controlled by beta-blockers.

CONCLUSION

Implantation of posterior chamber phakic IOLs is effective and predictable; however, long-term follow-up is needed.

High incidence of cataract formation after implantation of a silicone posterior chamber lens in phakic, highly myopic eyes

OBJECTIVE

To assess the effectiveness and safety of implantation of a negative, silicone, posterior chamber intraocular lens (IOL) in the ciliary sulcus of phakic, highly myopic eyes.

DESIGN

Noncomparative consecutive interventional series.

PARTICIPANTS

Eighteen eyes of 10 patients suffering from high-degree myopia (spherical equivalent < -10 diopters) undergoing implantation of a Fyodorov 094M-1 IOL by the same surgeon (P.H.B.) were evaluated.

INTERVENTION

A standard surgical technique was used in all patients under peribulbar anesthesia. The IOL was implanted in the ciliary sulcus immediately in front of the natural lens under protection of a viscoelastic substance (Healon) through a 3.5-mm temporal or nasal clear-corneal tunnel. No sutures were necessary in any case. A peripheral iridectomy was performed intraoperatively in 14 eyes, whereas 4 additional eyes received a yttrium-aluminum-garnet peripheral iridectomy after surgery. At the end of surgery, gentamicin and dexamethasone were given both topically and subconjunctivally.

MAIN OUTCOME MEASURES

Visual acuity and refraction were measured before surgery, as well as 1 day, 3 months, 6 months, and 2 years after surgery. Postoperative complications were recorded.

RESULTS

Best-corrected visual acuity remained unchanged (1 eye) or improved (6 eyes by 1, 5 eyes by 2, and 2 eyes by 3 Snellen lines, respectively) in 14 of 17 eyes, whereas 3 eyes experienced a decrease in best-corrected visual acuity by 1 Snellen line. Postoperative refraction approached the desired slight undercorrection at all times of examination. Cataract formation of the anterior subcapsular (8 eyes) or nuclear (only 1 eye) type was observed in overall 9 (52.9%) of 17 eyes. When considering only the patients with a follow-up of 2 years, the incidence of cataract formation was 81.9% (9 of 11 eyes).

CONCLUSIONS

The high incidence of cataract formation should discourage the implantation of the type of IOL used in this study in phakic eyes to correct high-degree myopia.

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.

Scleral Fixation for a Phakic Anterior Chamber Disc Intraocular Lens

BACKGROUND

Angle-supported phakic anterior chamber intraocular lenses (IOLs) require a high degree of anterior vaulting, but this can cause an inadequate distance between the IOL and the cornea, especially during rubbing or squeezing of the eye.

METHODS

A vaultless implant was designed by anchoring 3 supple hepatics through the anterior chamber into the sclera. Thus, a suspended rather than a wedged implant was achieved.

RESULTS

The lens was implanted in 3 eyes of 2 patients in 1990. Good tolerance of the IOL was maintained over 7 years of follow-up.

CONCLUSION

A suspended anterior chamber phakic IOL maintains an adequate position with lack of bowing and shows promising results.

Endothelial study of iris-claw phakic lens: four year follow-up

PURPOSE

To study quantitative and morphometric endothelial changes in phakic eyes implanted with the Worst iris-claw lens to correct high myopia.

SETTING

Department of Ophthalmology, University Hospital "La Fe", Valencia, Spain.

MATERIAL AND METHODS

This retrospective study involved 111 phakic eyes (73 patients) implanted with the Worst iris-claw lens. Noncontact specular microscopy and computer-assisted analysis was performed preoperatively and 6 months and 1, 2, 3, and 4 years postoperatively.

RESULTS

The mean cell loss was 3.85% at 6 months, 6.59% at 1 year, 9.22% at 2 years, 11.68% at 3 years, and 13.42% at 4 years. At 2 years, the hexagonality and coefficient variation in cell size were close to the preoperative levels. No major complications were seen; early postoperative corneal touch required intraocular lens (IOL) removal in 1 case (0.9%). Four eyes (3.6%) needed a reoperation because of poor IOL fixation (2 eyes), traumatic subluxation of the IOL (1 eye), and miscalculation of the IOL power (1 eye).

CONCLUSIONS

Although there was a slight progressive cell loss after IOL implantation, the morphometric changes recovered and were close to the preoperative levels. This suggests that endothelial damage occurred primarily during the surgical procedure.

Staar Collamer posterior chamber phakic intraocular lens to correct myopia and hyperopia

PURPOSE

To evaluate the efficacy, safety, stability, and predictability of implanting a collagen polymer (Staar Collamer), posterior chamber phakic intraocular lens (IOL) to correct myopia and hyperopia.

SETTING

Centre for Advanced Refractive Eye Surgery at the BMI Alexandra Hospital, Cheadle, Manchester, United Kingdom.

METHODS

A Staar Collamer posterior chamber phakic IOL was implanted in 25 eyes of 14 patients with a mean age of 37.9 years (range 20 to 50 years). Seven patients were men and seven, women. Sixteen were myopic and 9, hyperopic. Before treatment, each patient had a thorough evaluation including refractive, general, ocular, and social and personal histories. The examination included visual acuity, refraction, tonometry, topography, biometry, biomicroscopy, pupil size in dim illumination, and posterior segment evaluation by a vitreoretinal specialist. Patients were informed about the surgical process and expected outcome, their own expectations were discussed, and their consent to surgery was obtained. Surgical implantation was performed through a less than 3.0 mm clear corneal sutureless incision using brief general anesthesia on a day-case surgical basis.

RESULTS

At 3 months postoperatively, all eyes had a significant increase in uncorrected visual acuity, allowing all but two patients (three eyes) to manage most activities without spectacles. Adjustment by incisional corneal surgery was planned for undercorrected myopic eyes (n = 3). Pupil block glaucoma and pigment deposits occurred in one patient each.

CONCLUSION

In this short-term study, the posterior chamber phakic IOL was predictable, safe, and efficacious in the correction of myopic and hyperopic refractive errors, with good refractive stability. Long-term follow-up is required to validate that the absence of significant complications in most patients is a lasting phenomenon.

Posterior Chamber Phakic Intraocular Lens for Myopia of -8 to -19 Diopters

PURPOSE

To examine the efficacy, predictability, stability, and safety of posterior chamber phakic intraocular lens (IOL) implantation in patients with extreme myopia.

METHODS

We analyzed the results of 124 eyes that received a posterior chamber hydrogel collagen plate phakic IOL (Staar Collamer Implantable Contact Lens, ICL) for the correction of their myopia. The target postoperative spherical equivalent refraction was emmetropia. Mean follow-up was 11 months (range 1 to 36 mo).

RESULTS

The mean preoperative spherical equivalent refraction was -13.38 +/- 2.23 D (range, -8.50 to -18.63 D). Mean postoperative spherical equivalent refraction at last examination was -0.78 +/- 0.87 D (range, +1.63 to -3.50 D), with 69% (86 eyes) within +/-1.00 D and 44% (55 eyes) within +/-0.50 D of emmetropia. The refraction remained stable with a statistically insignificant change (p > 0.05 at each interval) during follow-up. A gain of two or more lines of spectacle-corrected visual acuity was seen in 36% (45 eyes) at last examination. One eye (0.8%) lost two or more lines of spectacle-corrected visual acuity from a retinal detachment.

CONCLUSION

Posterior chamber phakic IOL implantation with the Staar Collamer plate lens is an effective and safe method for reducing or correcting myopia between -8 and -19 D. Gains in spectacle-corrected visual acuity were common, and results suggested good refractive stability. Improvements in phakic IOL power calculation formulas are needed to improve the predictability of refractive outcome.

Angle-fixated Anterior Chamber Phakic Intraocular Lens for Myopia of -7 to -19 Diopters

PURPOSE

To assess the safety and efficacy of a second generation, anterior chamber phakic intraocular lens (Baikoff Model ZB5M) in patients with high myopia.

METHODS

One hundred and twenty-one patients (134 eyes) with myopia of -7.00 to -18.80 D were implanted with the ZB5M lens and followed for 18 to 52 months; the number of eyes evaluated was: 6 months (104 eyes), 1 year (91 eyes), 18 months (78 eyes), 2 years (68 eyes), and 3 years (35 eyes).

RESULTS

Postoperative spherical equivalent refraction averaged -1.00 D and the error in refractive correction (achieved minus intended) averaged -0.40 D during the first 2 years, increasing -to -1.30 D refraction and -0.60 D error in refractive correction at 3 years. At 2 years, approximately 40% of eyes had a spherical equivalent refraction within +/-0.50 D, and 65% within +/-1.00 D. The uncorrected distance visual acuity was 0.048 at baseline and 0.5 at 3 years; near visual acuity was 0.21 at baseline and approximately 0.7 over the 3 years of follow-up. Spectacle-corrected distance visual acuity at baseline was 0.54; it improved to 0.7. Near visual acuity was 0.65 at baseline and it improved to approximately 0.75. Endothelial cell counts in the central and peripheral cornea were reduced by an average 3.3% at 6 months, declining an additional 1% to 2% over the remaining follow-up period. Regression analyses indicated that most of the endothelial cell loss was due to surgery. Additional complications included halos/glare in 37 of 133 eyes (27.8%) and iris retraction with pupillary ovalization in 30 of 133 eyes (22.6%). The intraocular lens was exchanged in four of 133 eyes (3.0%) and removed in three of 133 eyes (2.3%), the latter because of halos (one eye) and a flat anterior chamber with severe inflammation (two eyes).

CONCLUSIONS

Implantation of the Baikoff ZB5M lens in the anterior chamber of phakic eyes significantly reduced high myopia and produced a stable refractive outcome over the 3 years, accompanied by marked improvement in uncorrected distance visual acuity and minimal, non-progressive damage to the corneal endothelium. Frequent complications included pupillary ovalization and halos/glare. Improvements in accuracy of IOL power calculations are needed.

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.

Ultrasound Biomicroscopy of Baikoff Anterior Chamber Phakic Intraocular Lenses

BACKGROUND

The purpose of the study was to analyze qualitatively and quantitatively anatomic relationships of anterior chamber Baikoff phakic intraocular lenses (IOL) to the cornea, angle, iris, and lens in myopic eyes.

METHODS

Thirteen phakic myopic eyes (-9.00 to -15.00 diopters) corrected by minus power, angle-supported, anterior chamber intraocular lenses of the ZB5M style (Chiron-Domilens), with a mean follow-up of 25 months (range 18 to 36 months), were examined clinically and by ultrasound biomicroscopy.

RESULTS

The mean distance (+/- SD) between the central cornea and the IOL was 2.05 +/- 0.18 mm (range 1.8 to 2.47 mm); mean distance between the corneal periphery and the IOL was 1.56 +/- 0.17 mm (range 1.33 to 1.95 mm); and the mean distance between the IOL and the lens was 0.58 +/- 0.12 mm (range 0.48 to 0.81 mm). IOL footplates seemed to be correctly positioned in the angle in all eyes. We observed no goniosynechiae. In six eyes, we found localized posterior indentation of the iris caused by the haptics. Four of these six eyes exhibited oval pupils associated with an oversized IOL.

CONCLUSIONS

High frequency ultrasound biomicroscopy can define anatomic relationships of anterior chamber phakic IOLs, and help analyze the mechanisms of corneal and iris complications.

Experience during the learning curve of laser in situ keratomileusis

PURPOSE

To identify pitfalls and offer hints on achieving a successful outcome during the early laser in situ keratomileusis (LASIK) learning process.

SETTING

Gimbel Eye Centre, Calgary, Alberta, Canada.

METHODS

This was a retrospective review of the preoperative planning, surgical procedure, intraoperative and postoperative problems, and early postoperative anatomic and refractive results in the first 73 eyes that had LASIK.

RESULTS

Intraoperative complications included failure of the keratome to make a cut, excessively thin cap, repositioning difficulty, and inadequate intraocular pressure elevation. Early postoperative complications included excessive central and peripheral wrinkling of the cap, peripheral lipid deposits, and central edema of the cap. One month postoperatively, mean spherical equivalent refraction was -0.90 diopters (D) (range +1.75 to -6.00 D), and 45 eyes had a best corrected visual acuity between 20/15 and 20/40.

CONCLUSION

Our retrospective review of the problems experienced during the early LASIK learning process should help novice lamellar refractive surgeons avoid such problems and shorten the learning curve.

Collamer intraocular contact lens to correct high myopia

PURPOSE

To determine the feasibility of using posterior chamber intraocular contact lenses to treat myopia.

SETTING

Ambulatory surgery centers in Torino, Ancona, and Ivrea, Italy.

METHODS

The phakic intraocular contact lens is made of a collagen copolymer. We implanted 15 of these lenses in 14 patients with preoperative spherical equivalents ranging from -10.8 to -24.0 diopters (D); average myopia was -15.3 D +/- 3.1 (SD). Average follow-up was 7.0 +/- 1.95 months.

RESULTS

Mean postoperative spherical equivalent was -2.0 +/- 1.6 D. Uncorrected visual acuity improved in 14 eyes. Best spectacle-corrected acuity was maintained or improved in all but one eye. No iritis or cataracts were observed. Six months postoperatively, the mean endothelial cell loss was 4%. A pupillary block requiring a superior peripheral iridectomy occurred in one eye.

CONCLUSIONS

Because of the incomplete follow-up, we cannot draw conclusions about the long-term safety of the implantable contact lens. The intimate contact between the contact lens and the natural lens raises the possibility of cataract formation. However, examination by Scheimpflug photography and ultrasound biomicroscopy showed no progressive lens opacities.

Triplet design as an intraocular lens for high myopia

We present the possibility of using a triplet as an intraocular lens (IOL). The matrix method was used to calculate the power of this triplet for high myopia. The thickness of the lens, the distances between the edges of the IOL and the endothelium, the distances between the edges of the IOL and the iris, and the nfluence of axial displacement have been analyzed. We have also compared the size, the thickness, the power, the distances between the edges of the IOL and the endothelium, and the distances between the edges of the IOL and the iris to the typical concave-plane lens that is usually implanted in highly myopic eyes. As we can see, when the anterior chamber depth is normal, our triplet presents a better geometrical form than the concave-plane lens.

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.

Clear lens extraction for the correction of high refractive error

The results of clear lens extraction and posterior chamber intraocular lens implantation in 31 eyes with high myopia and six eyes with high hyperopia were reviewed. In the myopic group, 77% of eyes achieved 20/40 or better uncorrected postoperative visual acuity and 97% achieved 20/40 or better corrected acuity. Sixty-eight percent of eyes were within 1.0 diopter (D) of emmetropia and 90% were within 2.0 D. Astigmatic keratotomy (four eyes) and radial keratotomy (one eye) were performed for postoperative refractive errors. Intraocular lens exchange was necessary to correct power in one case. In the hyperopic group, all six eyes achieved 20/40 or better uncorrected postoperative visual acuity and all were within 1.0 D of emmetropia. During the 20-month mean follow-up, no retinal detachment or cystoid macular edema was observed. Posterior capsule opacification was the major complication and it developed faster than reported in other studies.

Refractive power calculations for intraocular lenses in the phakic eye

To correct a severe refractive error and obviate thick spectacles or contact lenses, an intraocular lens can be placed in the anterior chamber in front of the normal crystalline lens as an alternative to keratorefractive procedures. The power of the intraocular lens may be determined from the recipient's spectacle correction, its vertex distance, and the corneal power in diopters. These measurements, combined with an intraocular lens constant based on its location within the anterior chamber, provide the appropriate power of the intraocular lens. These formulas were applied to seven Baikoff anterior chamber lenses and three Momose anterior chamber lenses in phakic eyes. The mean absolute prediction error was 0.42 (standard deviation, +/- 0.60) for the Baikoff lenses and 0.57 (+/- 0.64) for the Momose lenses. The accuracy of the measurements is limited by the accuracy of the preoperative refraction, the measurement of the corneal power, and the restoration of the preoperative refractive power of the cornea.

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.

Retinal detachment following anterior chamber lens implantation for the correction of ultra-high myopia in phakic eyes

The development of retinal detachment is reported in three eyes, of two patients, following implantation of an anterior chamber intraocular lens (AC-IOL) in phakic eyes for the correction of ultra-high myopia. The presence of an AC-IOL may hamper the identification of retinal breaks and removal of the intraocular lens may prove necessary to improve visualisation. Shallowing of the anterior chamber may also occur during, or following, vitreoretinal surgery with risk of endothelial contact. The risks and relative contraindications of AC-IOL implantation into phakic eyes are discussed.