Anterior chamber intraocular lens for high myopia: five year results

Bioptics by Angle-Supported Phakic Lenses and Photorefractive Keratectomy

PURPOSE

To assess efficacy and safety of the combination of angle-supported phakic intraocular lenses (IOLs) and photorefractive keratectomy (PRK) for the correction of myopia and astigmatism.

METHODS

Prospective, non-randomized single-surgeon study on 48 patients (76 eyes) undergoing angle-supported phakic IOL implantation with surgical peripheral iridectomy, followed 2 to 3 months later by PRK to correct residual refractive error. Twenty-three patients (33 eyes) achieved good uncorrected visual acuity with IOL implantation alone and did not undergo PRK. Thus, the study was completed by 25 patients (43 eyes) with preoperative mean defocus equivalent (DEQ) of 15.73 D (SD 4.67 D) and mean astigmatism of -2.87 D (SD 1.39 D).

RESULTS

Eight months after PRK, mean spherical equivalent was -0.08. Mean DEQ was 0.47 D (SD 0.37); 42/43 eyes (98%) were within +/-1 D of DEQ, and 33/43 eyes (77%) within +/-0.5 D. Mean uncorrected visual acuity was 0.7 (SD 1.9). Safety index was 1.25; efficacy index 1.11. Best-corrected visual acuity improvement (0.16) was statistically significant (95% CI: 1.1 to 2). Halos were moderate in 6/25 patients (24%); severe in 1/25 patients (4%). Endothelial cell density decreased by -6.6%. Pain after PRK was severe in 3/25 patients (12%) and moderate in 13/25 patients (52%). Complications were recurrent iridocyclitis in one eye, transient ocular hypertension in two eyes, and incomplete iridectomy in one eye.

CONCLUSIONS

Angle-supported phakic IOLs followed by adjustment by PRK offer good efficacy, predictability, and safety to manage large refractive myopic errors.

Iris atrophy and erosion caused by an anterior-chamber angle-supported phakic intraocular lens

We report a case in which an angle-supported phakic IOL was implanted to correct high myopia. Subsequently, the patient experienced photophobia, glare, halo, and loss of visual acuity and became concerned about the cosmetically deforming aspect of her eye. Findings included endothelial cell loss, cataract, pupil ovalization, and severe iris atrophy. The pIOL was removed and cataract surgery was performed, followed by implantation of a bag-in-the-lens IOL, but successful surgical repair of the iris was not possible because of severe iris atrophy.

FINANCIAL DISCLOSURE

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

Anterior segment optical coherence tomography of long-term phakic angle-supported intraocular lenses

PURPOSE

To evaluate the long-term age-related anterior chamber changes by anterior segment optical coherence tomography (OCT) and the impact of such changes on the stability and behavior of angle-supported phakic intraocular lenses (IOLs).

DESIGN

A retrospective consecutive observational cohort study.

METHODS

A total of 23 eyes with high myopia implanted with an angle-supported phakic IOL between 1990 and 1996 at Vissum Corporación Oftalmológica de Alicante were included in the study. Patients were evaluated using OCT. Anterior chamber depth, anterior chamber width, crystalline lens rise, and the distance between phakic IOL and endothelium were measured.

RESULTS

Fifteen years after implantation, anterior chamber depth was 2.9 ± 0.3 mm, crystalline lens rise 748.18 ± 393.13 μm, and phakic IOL-endothelium distance 2.1 ± 0.30 mm. The predictive model showed that 30 years after implantation, endothelial cell count was less than 600 cells/mm(2) in patients with a preoperative spherical equivalent of -25 diopters (D). Twenty years after implantation, the safety zone of 1.5 mm between endothelium and the lens will not be respected in patients with a preoperative spherical equivalent of -20 D.

CONCLUSIONS

The findings of this study could have an important influence on the decision about the indication to implant angle-supported phakic IOLs in young patients with a long postoperative life expectancy, as age-related changes in the anatomy of the anterior segment may create a long-term hazard for the implanted eye.

Comparison of Anterior Chamber Depth Measurement Between Orbscan IIz and Ultrasound Biomicroscopy

PURPOSE

To compare the measurement of anterior chamber depth exclusive of corneal thickness using Orbscan IIz and ultrasound biomicroscopy (UBM) and evaluate the repeatability of each method.

METHODS

Three consecutive measurements of anterior chamber depth were prospectively performed using Orbscan IIz and Paradigm 50-MHz UBM in 40 eyes in 20 individuals. Mean values were compared using the paired t test. For 12 eyes in 6 individuals, anterior chamber depth measurements were performed 5 times to estimate the repeatability of each method by a coefficient of variation. Refractive errors were measured to correlate with anterior chamber depth.

RESULTS

The mean anterior chamber depth was 2.82 +/- 0.46 mm with the Orbscan IIz and 2.91 +/- 0.43 mm in UBM. This difference was statistically significant (P < .001), but not clinically meaningful. The coefficient of variation was 1.15% and 1.10% in Orbscan IIz and UBM, respectively. A negative correlation between anterior chamber depth and spherical equivalent refraction was noted within the range of -5.50 to +3.00 diopters.

CONCLUSIONS

The mean anterior chamber depth of Orbscan IIz was 0.087 mm less than that of UBM. Both methods were precise. Orbscan IIz seems to be a useful and more convenient method to measure anterior chamber depth for phakic intraocular lens implantation.

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.

Correction of high myopia with the PRL phakic intraocular lens

PURPOSE

To assess the predictability, efficacy, safety, and complications of the PRL (CIBA Vision) phakic intraocular lens (pIOL) in the correction of high myopia.

SETTING

Clínica Oftalmológica Pasteur, Santiago, Chile.

METHODS

This prospective study comprised 53 eyes of 39 patients who received a PRL pIOL. The spherical equivalent (SE), uncorrected visual acuity (UCVA), efficacy index (postoperative UCVA/preoperative best spectacle-corrected visual acuity [BSCVA]), safety index (BSCVA/preoperative BSCVA), intraocular pressure (IOP), iridocorneal angle, and distance between the crystalline lens and PRL were prospectively assessed during the follow-up period.

RESULTS

The mean patient age was 39 years. The mean power of the implanted pIOL was -12.73 diopters (D) +/- 2.87 (SD) (range -20.00 to -7.00 D), for a preoperative SE of -17.27 +/- 4.58 D (range -31.50 to -8.75 D). The mean preoperative BSCVA was 0.50 +/- 0.70 (logMAR equivalent), and the mean follow-up was 8 +/- 9.4 months. The mean postoperative SE was -0.23 +/- 1.05 D; 71.2% of eyes were within +/-1.00 D. Sixty percent of patients had UCVA of 20/40 or better, and 88.2% of patients had BSCVA of 20/40 or better. Ninety-two percent maintained or gained 1 or more lines of BSCVA; 5.7% lost more than 1 line. There was no significant change in IOP (P = .40), and the mean distance between the crystalline lens and pIOL was 370 microm (ultrasound) and 604 microm (optical coherence tomography). Late complications included 1 case each of retinal detachment and lens subluxation.

CONCLUSIONS

Although PRL implantation in high myopia was predictable and effective, retinal detachment and IOL subluxations occurred. Other posterior chamber pIOLs should be used until the complications associated with the PRL pIOL are resolved.

Correction of high myopia with different phakic anterior chamber intraocular lenses: ICARE angle-supported lens and Verisyse iris-claw lens

PURPOSE

To evaluate the efficacy, predictability and safety of implanting two models of anterior chamber IOLs for high myopia. Comparison of the refractive results between two groups of patients implanted with different IOLs.

MATERIALS AND METHODS

Forty eyes were implanted with phakic IOLs. The ICARE myopia lens was implanted in 20 eyes of 12 patients with preoperative myopia that ranged from -21.875 to -10.0. The mean patients' age was 30 years. The Verisyse IOL was implanted in 20 eyes of 12 patients with spherical equivalent of the refractive error from -21.625 to -10.375D, and the mean patients' age was 32.25 years. The dioptric power of the intraocular lens was calculated by considering refraction, keratometry, and anterior chamber depth. The follow-up period was 12 months.

RESULTS

Twelve months after surgery, the mean refractive error (SE) was -0.19D (100% of eyes were within +/-1.0D of the target refraction) in the ICARE group, and -0.86D (95% of eyes were within +/-1.0D of the target refraction) in the Verisyse group. The postoperative refraction remained stable during the entire follow-up period. The mean uncorrected visual acuity was 0.7 in the ICARE group, and 0.69 in the Verisyse group 1 year postoperatively. There was no loss in visual acuity 1 year after surgery in the ICARE implanted eyes, one patient in the Verisyse group lost 1 line of BCVA as compared to the preoperative state. Mean endothelial cell density loss was 6.12% and 6.79% in the ICARE and Verisyse groups, respectively. There were no statistically significant differences regarding the analyzed outcome parameters between the two study groups.

CONCLUSION

The implantation of both anterior chamber phakic intraocular lenses to correct high myopia resulted in a stable and predictable refractive outcome. Efficacy and safety of surgery for both implanted lens models are very high.

Iridocyclitis associated with angle-supported phakic intraocular lenses

PURPOSE

To evaluate incidence, features, risk factors, and prognosis of iridocyclitis after angle-supported phakic intraocular lens (IOL) implantation.

SETTING

Private practice, Siena, Italy.

METHODS

This retrospective analysis comprised 356 consecutive eyes of 212 patients. In myopic eyes, the ZSAL-4 IOL (205 eyes of 125 patients) or the ZSAL-4 Plus IOL (106 eyes of 63 patients) was used. In hyperopic eyes (45 eyes of 24 patients), the Type 54 IOL was implanted. Haptic posterior angulation was 19 degrees (ZSAL-4), 23 degrees (ZSAL-4 Plus), and 14 degrees (Type 54).

RESULTS

Clinically significant iridocyclitis occurred in 11 eyes (3.1%) of 11 patients. Mean patient age was 37.3 years +/- 9.4 (SD). Sixty-four percent were male (odds ratio [OR], 3.0; 95% confidence interval [CI], 0.8 to 7.4, not statistically significant). Iridocyclitis was observed in 4.4% of hyperopic eyes (OR, 1.6; 95% CI, 0.3 to 7.4; not statistically significant) and in 2.9% of myopic eyes. In myopic eyes, it followed the implantation of ZSAL-4 IOL in 3.9% of eyes (OR, 4.1; 95% CI, 0.5 to 33.6; not statistically significant), and of ZSAL-4 Plus IOL in 1%. Mean time from surgery was 8.5 +/- 10.6 months). Presentation included aqueous flare (100%), posterior synechiae (82%), blurred vision (82%), redness (36%), pain (27%), IOL precipitates (18%), and angular synechiae (9%). Only 1 patient had recurrences, leading to IOL explantation and cataract surgery. After topical therapy, best spectacle-corrected visual acuity was fully recovered in 9 of 11 eyes.

CONCLUSION

Iridocyclitis can occur months or years after the implantation of angle-supported phakic IOLs. No statistically significant risk factors were identified. Functional prognosis is generally good.

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.

Correction of Myopia of 7 to 24 Diopters With the Artisan Phakic Intraocular Lens: Two-year Follow-up

PURPOSE

To evaluate the safety and efficacy of the iris claw phakic intraocular lens (Artisan; Ophtec BV, Groningen, The Netherlands) in patients with high myopia.

METHODS

Between May 1999 and July 2001, 93 Artisan phakic intraocular lenses (IOLs) were implanted in 60 patients affected by high myopia. All patients underwent 24-month follow-up. The power of the lenses ranged from -7.5 to -22.0 diopters (D). Patients were divided into two groups: group 1 (68 eyes), myopia -6.75 to -15.50 D (SE), and group 2 (25 eyes), myopia -16.0 to -23.0 D (SE). Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), endothelial cell count, intraocular pressure, complication rate, safety, and efficacy.

RESULTS

At 4 months, 83.8% (57/68) (group 1, myopia -6.75 to -15.50 D) and 68% (17/25) (group 2, myopia -16.0 to -23.0 D) of eyes achieved UCVA of > or =20/40. The BSCVA remained the same or improved in 100% of eyes. After 4 months, 69.1% (47/68) of eyes in group 1 and 52% (13/25) of eyes in group 2 were within +/-1.00 D of the desired refraction; the mean refraction was stable between 4 and 24 months. Of the intraoperative complications, 69.2% were observed in the first 25 lenses implanted; postoperative complications included iris atrophy in 11.8% (11/93), lens decentration in 5.4% (5/93), and night glare in 6.4% (6/93) of eyes. No IOLs were removed. Mean endothelial cell loss was 2.8% at 4 months, 3.9% at 12 months, and 5.4% at 24 months.

CONCLUSIONS

Our results regarding implantation of the Artisan phakic IOL confirm that these lenses are safe and effective for the correction of high myopia, with a stable refractive outcome but with a higher than normal rate of endothelial cell loss during 2-year follow-up.

Clinical results of ZSAL-4 angle-supported phakic intraocular lenses in 190 myopic eyes

PURPOSE

To evaluate the efficacy and safety of angle-supported phakic intraocular lenses (IOLs) in myopia.

SETTING

Private practice, Siena, Italy.

METHODS

This prospective noncomparative single-surgeon interventional case series comprised 190 consecutive myopic eyes of 115 patients having implantation of a ZSAL-4 IOL (Morcher GmbH) through a 5.5 mm x 3.0 mm sclerocorneal tunnel along the steepest meridian with a surgical iridectomy. Preoperatively, the mean spherical equivalent was -14.37 diopters (D) +/- 4.40 (SD) and the mean astigmatism, 1.66 +/- 1.36 D.

RESULTS

Postoperatively, the mean defocus equivalent (DEQ) was 1.55 +/- 1.06 D and the mean astigmatism, 1.41 +/- 1.11 D. The mean surgically induced astigmatism (vector analysis) was 1.03 +/- 0.77 D (95% confidence interval [CI], 0.92 to 1.15); 146 eyes (77%) were within +/-2.0 D of the DEQ, 76 eyes (40%) were within +/-1.0 D, and 36 eyes (19%) were within +/-0.5 D. The safety index was 1.25 and the efficacy index, 0.78. The improvement in best spectacle-corrected visual acuity (0.17) was statistically significant (95% CI, 0.14 to 0.2). Complications were intraocular pressure spike due to topical steroids, 18%; chronic iridocyclitis, 1%; explantation of unstable IOL, 1%; explantation of IOL for iridocyclitis, 0.5%; pupil ovalization, 11%; halos, 18%; and macular hemorrhage, 1%.

CONCLUSIONS

Angle-supported IOLs can effectively correct high myopia, although residual refractive errors may require secondary procedures. The main intraoperative and postoperative complications were halos, steroid response, and incorrect IOL sizing. The role of surgery in inducing macular hemorrhages should be assessed further.

Angle-supported phakic intraocular lenses in eyes with keratoconus and myopia

PURPOSE

To evaluate the visual results and complications of angle-supported phakic intraocular lenses (IOLs) to correct myopia associated with early-stage keratoconus.

SETTING

Private practice, Siena, Italy.

METHODS

In a prospective noncomparative single-surgeon interventional case series, outcomes in 12 consecutive eyes of 8 patients with stage I to II keratoconus, myopia from -6.50 to -14.00 diopters (D), and astigmatism from -1.00 to -5.00 D were analyzed after the implantation of angle-supported phakic IOLs (ZSAL-4, Morcher). The minimum follow-up was 12 months. Implantation was performed through a sclerocorneal 5.5 mm x 3.0 mm tunnel along the steepest meridian, after which a surgical basal iridectomy was created.

RESULTS

The spherical error in all cases was corrected within +/-1.00 D. Astigmatism magnitude did not significantly improve. The uncorrected visual acuity (UCVA) was 20/40 or better in all cases. The best spectacle-corrected visual acuity (BSCVA) was equal or improved in all cases. The safety index (postoperative BSCVA/preoperative BSCVA) was 1.18; the efficacy index (postoperative UCVA/preoperative BSCVA) was 0.77. Three eyes had significant halos that improved considerably over 3 months. Spectacles were permanently used by 1 patient (2 eyes in the study) and only for driving by 5 patients. Complications were limited to 3 cases of mild pupil ovalization and 1 case of IOL rotation. Endothelial loss at 12 months was 7.2%.

CONCLUSIONS

Implantation of angle-supported phakic IOLs to correct myopia in patients with keratoconus stage I to II was an effective procedure. Although astigmatism did not improve by the creation of the incision, it was well tolerated by most patients. Long-term endothelial safety must be assessed.

Sutureless ciliary sulcus supported intraocular lens with transiridal anchoring haptics

We report a technique for implanting intraocular lenses (IOLs) in the ciliary sulcus in eyes without capsule support. The IOL design allows it to be implanted without fixation sutures. The lens was implanted in 3 aphakic eyes without capsule support.