Collamer intraocular contact lens to correct high myopia

White-to-white corneal diameter: normal values in healthy humans obtained with the Orbscan II topography system

PURPOSE

The corneal horizontal diameter (white-to-white) is abnormal in diseases like microcornea, relative anterior microphthalmos, and corneal dystrophies. Because normal values are described imprecisely in the literature, the purpose of this study was to reevaluate the horizontal corneal diameter as a scientific parameter.

METHODS

The horizontal corneal diameter was measured with the Orbscan II system in 370 right eyes and 373 left eyes of 390 healthy white subjects aged 10-80 years. There were 148 female subjects and 242 male subjects. Each measurement was repeated twice. Differences in gender, between right and left eyes, and age-related alterations were analyzed statistically.

RESULTS

The average corneal diameter was 11.71 +/- 0.42 mm. The average corneal diameter was 11.77 +/- 0.37 mm in males compared with 11.64 +/- 0.47 mm in females. The resulting normal ranges were 11.04 to 12.50 for males and 10.70 to 12.58 mm for females. Differences in gender were not significant in the t test for independent samples (P = 0.071). There were no statistically significant differences between right and left eyes in the t test for dependent samples (P = 0.16). Corneal diameters decreased slightly with age.

CONCLUSIONS

With the obtained normal values, more precise determination of microcornea and macrocornea will be possible in the future. The horizontal corneal diameter was not significantly greater in males than in females. Further studies are needed to show the reasons for the age-related decrease in measurements.

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.

Long-term results of implantation of phakic posterior chamber intraocular lenses

PURPOSE

To study the incidence and progression of lens opacification after implantation of phakic posterior chamber intraocular lenses for myopia and its correlation with vaulting and endothelial cell density (ECD).

SETTING

Department of Ophthalmology, University of Vienna Medical School, Vienna, Austria.

METHODS

An implantable contact lens (ICL V4, Staar Surgical Inc.) was inserted in 76 myopic eyes. Patients were prospectively followed preoperatively and at 1, 3, 6, 12, 24, and 36 months. The uncorrected visual acuity and best corrected visual acuity (BCVA) were determined. Vaulting was measured optically with a Jaeger II pachymeter, and the crystalline lens was examined at the slitlamp for the presence and characteristics of opacification. Endothelial cell morphometry was performed by specular microscopy, and the ECD was calculated. Eyes in which lens opacification developed were followed for at least 12 months to determine the degree and course of visual impairment.

RESULTS

Lens opacification occurred in 11 eyes (14.5%). Opacification was correlated with intraoperative trauma to the crystalline lens, age older than 50 years, and decreased ECD values throughout the observation period. Vaulting of the ICL did not correlate with the risk for lens opacification. After onset of lens opacification, 6 eyes (55%) had a stable BCVA within +/-0.5 lines and 5 eyes had progressive opacification, losing between 3.5 lines and 0.5 lines (mean 1.8 lines +/- 1.1 [SD]). Three eyes (3.9%) in the progressive group had a 1- to 2-line loss of BCVA over preoperative values and subsequently had cataract surgery.

CONCLUSIONS

Risk factors for lens opacification after implantation of the model V4 ICL included intraoperative trauma to the crystalline lens and older age. Decreased ECD in eyes with opacification suggests ongoing inflammation as a cause. Patients younger than 45 years may have a significantly lower incidence of opacification.

Phakic posterior chamber intraocular lens for high myopia

PURPOSE

To evaluate the efficacy, predictability, stability, and safety of the surgical correction of high myopia using a phakic posterior chamber intraocular lens (PPC IOL).

SETTING

Centro Oftalmológico de Valencia-CEOVAL, Valencia, Venezuela.

METHODS

A retrospective study was performed to analyze 18 eyes of 12 patients who had implantation of a modified PPC IOL, the implantable contact lens (ICL), for the treatment of high myopia. The target postoperative spherical equivalent (SE) refraction was emmetropia.

RESULTS

The mean follow-up was 26.6 months +/- 11.3 (SD) (range 12 to 36 months). The mean preoperative SE was -15.27 +/- 3.47 diopters (D) (range -10.0 to -21.25 D) and the mean postoperative SE, -0.62 +/- 0.81 D (range -2.75 to +0.75 D). Eleven eyes (61.1%) had an SE within +/-1.00 D of emmetropia. The best spectacle-corrected visual acuity was maintained or improved in all except 1 eye, which lost more than 2 lines of Snellen visual acuity. Two eyes (11.1%) developed pupillary block the first day after surgery. Four eyes (22.2%) had moderate pigmentary dispersion. Two eyes (11.1%) had lens opacification, 1 with mild peripheral anterior capsule opacification and the other eye with central anterior subcapsular opacification. One eye (5.5%) had a significant decrease in anterior chamber depth after surgery.

CONCLUSIONS

Implantation of an ICL was effective for the correction of high myopia. Predictability must be improved and the long-term safety of the ICL determined. The main concerns over potential cataract formation, pigmentary dispersion, and angle-closure glaucoma remain.

United States Food and Drug Administration clinical trial of the Implantable Collamer Lens (ICL) for moderate to high myopia

PURPOSE

To report on 3-year postoperative safety and efficacy outcomes with the Myopic Implantable Collamer Lens (ICL).

DESIGN

Prospective nonrandomized clinical trial.

PARTICIPANTS

Five hundred twenty-six eyes of 294 patients with between 3.0 and 20.0 diopters (D) of myopia participating in the United States Food and Drug Administration clinical trial of the ICL for myopia.

INTERVENTION

Implantation of the ICL.

MAIN OUTCOME MEASURES

Uncorrected visual acuity (VA), refraction, best spectacle-corrected VA (BSCVA), adverse events, operative and postoperative complications, lens opacity analysis, subjective satisfaction, and patient symptoms.

RESULTS

At 3 years, 59.3% had 20/20 or better VA, and 94.7% had 20/40 or better uncorrected VA if BSCVA was 20/20 and patients were targeted for emmetropia; 67.5% of patients were within 0.5 D and 88.2% were within 1.0 D of predicted refraction. The mean improvement in BSCVA ranged between 0.5 and 0.6 lines. At 3 years postoperatively, 3 eyes (0.8%) decreased by >or=2 lines of BSCVA, in contrast to 40 eyes (10.8%) that improved by a similar amount. Contrast sensitivity improved postoperatively. Cumulative 3-year corneal endothelial cell loss was under 10%. Early largely asymptomatic, presumably surgically induced anterior subcapsular opacities (trace or greater) were seen in 14 eyes (2.7%), with only 2 being clinically significant. Five eyes (0.9%) of 3 patients developed nuclear opacities of grade >2 at 2 to 3 years postoperatively. Three (0.6%) ICL removals with cataract extraction and IOL implantation have been performed. Only 0.6% reported dissatisfaction; 97.1% of patients reported they would choose ICL implantation again. Incidences of patient symptoms, glare, halos, double vision, night vision problems, and night driving difficulties decreased or remained unchanged after ICL surgery.

CONCLUSION

Three-year results from this standardized, multicenter clinical investigation support the safety, efficacy, and predictability of ICL surgery to treat moderate to high myopic refractive errors.

Phakic refractive lens implantation in high myopic patients: one-year results

PURPOSE

To evaluate the efficacy and safety of implantation of a new posterior chamber phakic refractive lens (PRL, Ciba Vision Surgical) in highly myopic eyes.

SETTING

Department of Ophthalmology, Medical School, University of Crete, Vardinoyannion Eye Institute of Crete, Crete, Greece.

METHODS

Thirty-four myopic eyes of 19 patients were treated for high myopia with implantation of a silicone PRL in the posterior chamber. Mean patient age was 29.0 years +/- 7.9 (SD) (range 18 to 44 years). Manifest refraction in spherical equivalent (MR), uncorrected (UCVA) and best corrected (BCVA) visual acuity (decimal scale), intraocular pressure, higher-order aberrations (root-mean-square [RMS] wavefront error measured with a Shack-Hartmann wavefront sensor WASCA analyzer [Carl Zeiss, Meditec]), possible complications, and subjective symptoms were evaluated.

RESULTS

Phakic refractive lenses were successfully implanted in all eyes. Mean follow-up was 17.17 +/- 3.76 months (range 12 to 24 months). There was a statistically significant reduction in the MR (from -14.70 D +/- 2.65 D [range -20.75 D to -10.50 D] to -0.61 D +/- 0.89 D [range -2.25 D to 1.00 D]) (P<.001). Twenty-seven (79%) and 15 eyes (44%) were within +/-1.00 D and +/-0.50 D of target refraction, respectively. Mean UCVA significantly improved (from counting fingers to 0.62 +/- 0.28 (range 0.08 to 1.20) (P<.001). Mean BCVA also improved from 0.70 +/- 0.24 (range 0.10 to 1.00) to 0.85 +/- 0.24 (range 0.10 to 1.20) (P<0.001). Overall, there was a mean increase in BCVA of 1.5 +/- 1.5 lines (range loss of 2 lines to gain of 5 lines). There was no statistically significant difference in higher-order aberrations after PRL implantation (pre-PRL RMS: 0.18 microm +/- 0.08 microm [range 0.09 microm to 0.38 microm]; post-PRL RMS: 0.21 microm +/- 0.08 microm; [range 0.05 microm to 0.38 microm]) (P =.12).

CONCLUSION

The PRL showed encouraging results in treating high myopia. Additional patients and longer follow-up period are needed to detect the long-term efficacy and safety of this refractive lens.

Corneal endothelial assessment after ICL implantation

PURPOSE

To evaluate the 3- to 4-year effects of the Implantable Contact Lens (ICL) on the corneal endothelium.

SETTING

Multicenter study.

METHODS

Noncontact specular microscopy was performed as a subgroup study in a Phase III U.S. Food and Drug Administration clinical trial. Endothelial cell images were collected in the central region of the cornea before surgery and 3, 12, 24, and 36 months after surgery, with a few at 48 months. The images were recorded and analyzed later by a central reading center. The cell density, coefficient of variation, and percentage of hexagonal cells were determined.

RESULTS

The cumulative endothelial cell loss was between 8.4% and 8.9% over the first 3 years and between 8.4% and 9.5% over the first 4 years depending on the method of calculation. The cell loss between baseline and 3 months was 2.1%; 3 months and 1 year, 0.9%; 1 year and 2 years, 2.3%; 2 years and 3 years, 3.2%; and 3 years and 4 years, -0.1%. The coefficient of variation decreased over the course of the study, and the proportion of cases with hexagonal cells increased slightly.

CONCLUSIONS

The cell loss between 1 year and 3 years in the absence of an increase in the coefficient of variation and/or a decrease in the percentage of hexagonal cells is most readily explained by prolonged corneal remodeling following the surgical procedure rather than ongoing cell loss. The cell loss observed between 3 years and 4 years (0.1% gain) was negligible. Regardless of the cause of the change in endothelial cell density over the first 3 years, the available 4-year data suggest there was no ongoing chronic loss.

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.

Effect of accommodation and pupil size on the movement of a posterior chamber lens in the phakic eye

PURPOSE

Although a posterior chamber phakic intraocular lens provides effective refractive correction of high myopia and hyperopia, mechanical contact between the implantable contact lens (ICL) and the crystalline lens and inadequate aqueous circulation in the prelenticular space could cause subcapsular opacification. To assess whether and to what extent such mechanical contact occurs, changes in the distance between the STAAR Collamer ICL and the crystalline lens under various conditions were investigated.

DESIGN

Open pilot study.

PARTICIPANTS

Thirteen eyes of 11 myopic and 2 hyperopic patients with a mean age of 38 years (range, 19-53 years) were examined at least 6 months after ICL implantation.

METHODS

A noninvasive, high-resolution biometry technique, partial coherence interferometry, was used to measure distance changes between the ICL and the crystalline lens during subjective accommodation, after instillation of pilocarpine, and under changing light conditions.

MAIN OUTCOME MEASURES

Mean distance changes from the posterior corneal surface to the ICL, from the posterior corneal surface to the anterior surface of the crystalline lens, and the distance between the ICL and the crystalline lens.

RESULTS

In the nonaccommodated state, the mean distance between the ICL and the crystalline lens was 457 microm (range, 123-924 microm). During subjective accommodation, a significant (P<0.01) decrease and, after topical application of pilocarpine, a nonsignificant (P=0.35) decrease of anterior chamber depth was accompanied by a nonsignificant (P = 0.71) reduction of the ICL-crystalline lens distance. Under photopic conditions, a significant mean reduction (P<0.01) of the ICL-crystalline lens distance of -28 microm (range, -16 to -188 microm) was observed.

CONCLUSIONS

Partial coherence interferometry biometry enabled noninvasive high-precision investigation of ICL dynamics. No significant changes between the ICL and the crystalline lens were detected during subjective accommodation and after application of pilocarpine. However, under photopic conditions, with constriction of the pupil, the distance between the ICL and the crystalline lens was significantly reduced. This mechanism might cause inadequate aqueous circulation in the prelenticular space and might be one of the causes of subcapsular opacification in some of the eyes after ICL implantation.

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.

Outcome after treatment of ametropia with implantable contact lenses

OBJECTIVE

To evaluate long-term results after insertion of implantable contact lenses (ICLs) in phakic eyes.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

Seventy-five phakic eyes (65 myopic, 10 hyperopic eyes) of 45 patients aged 21.7 to 60.6 years were included.

INTERVENTION

STAAR Collamer Implantable Contact Lenses (STAAR Surgical Inc., Nidau, Switzerland) were implanted for correction of high myopia and hyperopia.

MAIN OUTCOME MEASURES

Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were determined. Presence of lens opacification and the distance between the ICL and the crystalline lens were assessed by slit-lamp examination before surgery and at 1, 3, 6 months, and yearly after lens implantation.

RESULTS

Preoperative mean spherical equivalent was -16.23+/-5.29 diopters (D) for myopic eyes and +7.88 +/-1.46 D for hyperopic eyes. After ICL implantation, mean residual refractive error was -1.77+/-2.17 D in myopic patients and +0.44+/-0.69 D in hyperopic patients. Preoperative mean UCVA was Snellen 0.03+/-0.03 for myopic patients and Snellen 0.12+/-0.16 for hyperopic patients. Preoperative mean BCVA was Snellen 0.49+/-0.23 for myopic patients and Snellen 0.82+/-0.23 for hyperopic patients. After ICL implantation, mean UCVA up to the end of individual observation time was Snellen 0.36+/-0.36 for myopic patients and Snellen 0.58+/-0.28 for hyperopic patients. Mean BCVA was Snellen 0.73+/-0.26 for myopic and Snellen 0.80+/-0.24 for hyperopic patients. Mean preoperative IOP was 14.2+/-2.7 mmHg, and mean postoperative IOP was 13.46+/-2.1 mmHg over all follow-up investigations. The main complication was the development of subcapsular anterior opacifications of the crystalline lens in 25 eyes (33.3%), 2 of which showed direct contact to the ICL. Eleven eyes (14.7%) were stable in opacification and 14 eyes (18.7%) had progressive opacifications. The median time to opacification was 27.1 months. In 8 patients (10.7%), the subjective visual impairment mandated cataract surgery.

CONCLUSIONS

The most significant long-term complication after ICL implantation is the formation of opacifications of the crystalline lens with the risk of the necessity of subsequent cataract surgery (10.7%). Old age, female gender, and contralateral opacification are independent significant risk factors for early formation of opacifications in this patient group.

Ultrasound biomicroscopy of silicone posterior chamber phakic intraocular lens for myopia

PURPOSE

To study the intraocular position and anatomic relationships of PRL-III (phakic refractive lens) (PRL) posterior chamber phakic intraocular lens (PCP IOL) for high myopia using ultrasound biomicroscopy (UBM).

SETTING

Centro Oftalmológico Real Vision, and Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain.

METHODS

Sixteen phakic myopic eyes that had had PRL implantation were examined by UBM 1 month after surgery. The PRL position, PRL-crystalline lens peripheral distance, and central distance between the corneal endothelium and the PRL were measured.

RESULTS

Both haptics were on the zonule in 6 eyes, in the ciliary sulcus in 5 eyes, and impacted in the ciliary body in 1 eye. In the 4 remaining eyes, the haptics were in mixed positions. The mean PCP IOL crystalline lens peripheral distance in the minor axis was 588.1 microm +/- 232.5 (SD), and the mean PCP IOL-endothelium central distance was 2082.8 +/- 277.6 microm.

CONCLUSIONS

Phakic refractive lens implantation should be done carefully because of the sulcus location of the haptics in many cases. This, with the iris-PRL contact, suggests caution for the long-term outcome.

Comparison of implantable contact lens and laser assisted in situ keratomileusis for moderate to high myopia

PURPOSE

To compare the results of laser assisted in situ keratomileusis (LASIK) and implantable contact lenses (ICL) in the correction of moderate/high myopia.

METHODS

Five hundred fifty-nine LASIK eyes from the Davis Duehr Eye Center, Madison, WI, and 210 ICL eyes from the 14-site U.S. FDA Clinical Trial for ICL for Myopia were compared. These series were concurrently operated on with 8 to 12 D of preoperative myopia and were examined at 1 day, 1 week, 1 month, 6 months, and 1 year postoperatively. The mean baseline myopia was slightly higher in the ICL group, (ICL: -9.8 +/- 1.7 D; LASIK: -9.1 +/- 0.97 D). BSCVA, UCVA, and refractions were collected prospectively in both series.

RESULTS

Every index of BSCVA, UCVA, predictability of refraction, and stability of refraction studied favored the ICL over the LASIK procedure. All but one of the indices (UCVA % 20/40 or better) were statistically significant in at least half of the time periods studied. At 6-month follow-up, both the loss of two or more lines (ICL: 0%; LASIK: 2%; p = 0.05) and gain of two or more lines (ICL: 7%; LASIK: 3%; p = 0.04) of BSCVA were better with the ICL. Similarly, efficacy outcomes with the ICL were better with predictability (attempted versus achieved +/-1.0 D) of the ICL at 90%; 76% with LASIK (p < 0.001). In this highly myopic series, UCVA 20/20 or better was 50% with ICL compared with 35% with LASIK (p < 0.001). No serious complications occurred in either series of cases.

CONCLUSIONS

The ICL was safer and more effective than LASIK and appears to be a viable alternative to corneal refractive excimer surgery in the treatment of moderate to high myopia.

Implantable contact lens for moderate to high myopia: relationship of vaulting to cataract formation

PURPOSE

To study cataract formation in eyes with an implantable contact lens (ICL) used for moderate to high myopia.

SETTING

University Eye Hospital, Lausanne, Switzerland.

METHODS

An ICL (model V3 or V4, Staar Surgical AG) was implanted in 75 eyes. Three months after surgery and again at the last follow-up examination, the transparency of the crystalline lens was assessed on transilluminated photographs and the vaulting of the ICL over the crystalline lens was evaluated. Central vaulting was measured precisely on digitized photographs taken with a 75 SL Zeiss slitlamp camera, while peripheral vaulting was estimated on photographs obtained with a Scheimpflug camera. The minimum follow-up was 12 months; the mean was 21.8 months.

RESULTS

At the last follow-up, 20 of the 75 eyes (27%) had an ICL-induced anterior subcapsular cataract (ASCC). The number of cataracts increased with the duration of the follow-up. Cataracts developed more commonly in older patients than in younger patients. All 20 cataracts occurred when the central vaulting was equal to or less than 0.09 mm. In 26 eyes with the same range of vaulting (among which 11 had no vaulting), the lenses were clear at the last visit. The 20 patients with cataract and the 26 patients with clear lenses matched in age and duration of follow-up but not in myopia. No touch between the ICL and the crystalline lens was encountered when the central vaulting was equal to or greater than 0.15 mm. Vaulting showed a slight decrease over time. No statistically significant difference in vaulting was found between models V3 and V4.

CONCLUSION

Central and/or peripheral contact between the ICL and the crystalline lens may be responsible for the high incidence of ASCC formation in this study. Central vaulting greater than 0.09 mm appears to protect the crystalline lens from cataract formation. However, we recommend aiming for higher central vaulting (0.15 mm) to avoid contact between the ICL and the crystalline lens. This should be attainable by implanting longer ICLs.

Lens opacities after posterior chamber phakic intraocular lens implantation

PURPOSE

To describe a case series to determine the incidence of lens opacities after posterior chamber phakic intraocular lens (IOL) implantation (STAAR Surgical, Monrovia, CA) for very high ametropias.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Fourteen eyes of 170 consecutive eyes with high ametropias in whom lens opacities developed after posterior chamber phakic IOL implant (PCPIOL).

INTERVENTION

Posterior chamber phakic intraocular lens implant.

MAIN OUTCOME MEASURES

Lens opacity appearance, localization, and clinical course.

RESULTS

Fourteen eyes developed lens opacities 125 +/- 116 days after phakic IOL implant. All eyes had anterior subcapsular opacities, and two eyes also developed nuclear sclerosis. The anterior opacities did not extend posteriorly within the lens, and there were no posterior subcapsular cataracts. Seventy-one percent of opacities were first seen </=3 months, and 86% were seen </=7 months postoperatively. Seventy-nine percent of opacities were seen in the first or second implants of surgeons being trained; 19% of the first 16 cases and 0% of the next 43 cases of one surgeon developed opacities. Mean follow-up after opacity diagnosis was 9.1 +/- 6.8 months. Nine of the 14 (64%) opacities were asymptomatic. Two eyes developed nocturnal glare, with no loss of best-corrected visual acuity (BCVA) and one had loss of BCVA. Two additional eyes with both nuclear sclerotic and anterior subcapsular lens opacities had visual symptoms and/or loss of BCVA and underwent phakic IOL explantation, cataract extraction by phacoemulsification, and PCPIOL implant with good visual outcome. In the entire series, 5 of 170 (2.3%) implantations had symptomatic opacities in which 111 implantations were the first or second case of the implanting surgeon.

CONCLUSIONS

Lens opacities are a potential complication of phakic IOL implantation. Most lens opacities were first seen in the early postoperative period and were most likely due to surgically induced trauma. The anterior subcapsular type was most common and tended not to be rapidly progressive during the follow-up period. The presence of nuclear sclerotic cataract was visually significant and progressive. Long-term follow-up is warranted to evaluate the rate of progression and course of lens opacities after phakic IOL implant surgery.

U.S. Food and Drug Administration clinical trial of the Implantable Contact Lens for moderate to high myopia

PURPOSE

To assess the safety and efficacy of the Implantable Contact Lens (ICL) to treat moderate to high myopia.

DESIGN

Prospective nonrandomized clinical trial.

PARTICIPANTS

Five hundred twenty-three eyes of 291 patients with between 3 and 20.0 diopters (D) of myopia participating in the U. S. Food and Drug Administration clinical trial of the ICL for myopia.

INTERVENTION

Implantation of the ICL.

MAIN OUTCOME MEASURES

Uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), adverse events, operative and postoperative complications, lens opacity analysis (Lens Opacity Classification System III), subjective satisfaction, and symptoms.

RESULTS

Twelve months postoperatively, 60.1% of patients had a visual acuity of 20/20 or better, and 92.5% had an uncorrected visual acuity of 20/40 or better. Patients averaged a 10.31-line improvement in UCVA, 61.6% of patients were within 0.5 D, and 84.7% were within 1.0 D of predicted refraction. Only one case (0.2%) lost > 2 lines of BSCVA. Gains of 2 or more lines of BSCVA occurred in 55 cases (11.8%) at 6 months and 41 cases (9.6%) at 1 year after ICL surgery. Early and largely asymptomatic, presumably surgically induced anterior subcapsular (AS) opacities were seen in 11 cases (2.1%); an additional early AS opacity (0.2%) was seen because of inadvertent anterior chamber irrigation of preservative-containing solution at surgery. Two (0.4%) late (> or = 1 year postoperatively) AS opacities were observed. Two (0.4%) ICL removals with cataract extraction and intraocular lens implantation have been performed. Patient satisfaction (very/extremely satisfied) was reported by 92.4% of subjects on the subjective questionnaire; only four patients (1.0%) reported dissatisfaction. Slightly more patients reported an improvement at 1 year over baseline values for the following subjective symptoms: quality of vision, glare, double vision, and night driving difficulties. Only a 3% difference between pre-ICL and post-ICL surgery was reported for haloes.

CONCLUSIONS

The results support the safety, efficacy, and predictability of ICL implantation to treat moderate to high myopia.

Ultrasound biomicroscopy examination of posterior chamber phakic intraocular lens position

OBJECTIVE

To better elucidate the in vivo position of the Collamer posterior chamber phakic intraocular lens (PCPIOL) and its relationship to the iris and the crystalline lens and to analyze possible variations over time.

DESIGN

Prospective observational case series.

PARTICIPANTS

Eighteen eyes of nine patients were included.

INTERVENTION

A Staar Collamer implantable PCPIOL was implanted for the correction of high myopia.

MAIN OUTCOME MEASURES

The eyes were studied with a 50-MHz ultrasound biomicroscopy UBM 840. The exact PCPIOL position and the distances between it and the crystalline lens were measured at 3, 6, and 12 months after surgery.

RESULTS

There were no intraoperative complications. In 13 eyes (72.22%), contact between the PCPIOL and the crystalline lens was found at some time during follow-up. In 3 eyes (16.6%), central contact could be demonstrated. We also observed that the contact zone and its extension can vary over time. In 2 eyes, rotation of the lens was observed.

CONCLUSIONS

We found contact between the PCPIOL and the crystalline lens in a high percentage of cases. There was also mobility of the lens in the posterior chamber, especially in the anteroposterior plane, and, as a consequence, both the contact zone and its extension would vary over time.

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.

Phakic refractive lens experience in Spain

PURPOSE

To evaluate the efficacy, predictability, and safety of a phakic refractive lens (PRL) for high myopia and hyperopia.

SETTING

Instituto Oftalmológico Hoyos, Barcelona, Spain.

METHODS

A PRL was implanted in 31 eyes (17 myopic, 14 hyperopic) with a mean preoperative spherical equivalent (SE) of -18.46 diopters (D) (range -11.85 to -26.00 D) for myopia and +7.77 D (range +5.25 to +11.00 D) for hyperopia. All eyes had a thorough ophthalmologic examination before and after surgery. The follow-up was at least 12 months.

RESULTS

At 1 year, the mean postoperative SE in the myopic group was -0.22 D +/- 0.87 (SD) and 82% were within +/-1.00 D of the desired refraction. The mean postoperative SE in the hyperopic group was -0.38 +/- 0.82 D, and 79% were within +/-1.00 D. Snellen lines of visual acuity were gained in 65% of the myopic eyes (8 eyes gained 1 line, 3 eyes gained 2 lines), and no eye lost lines. In the hyperopic group, 1 eye gained 1 line of acuity and 1 eye lost 1 line. In the hyperopic group, complications included pupillary block in 2 eyes and pigment dispersion signs without intraocular hypertension in 1 eye. In the myopic group, 1 eye had a corticosteroid-induced intraocular pressure rise, 1 eye had a spot of anterior cortical lens opacity immediately after surgery that did not progress, and 3 eyes with the PRL model 100 had decentration that required replacement of the lens. Four patients (2 myopic, 2 hyperopic) reported night halos in both eyes.

CONCLUSIONS

Results indicate that PRL implantation to correct high myopia and hyperopia is a relatively rapid, safe, predictable, and stable method that in many cases also improves the best corrected visual acuity. Complications such as visually significant progressive cataract and pigmentary glaucoma were not observed.

Incidence of Lens Opacities and Clinically Significant Cataracts With the Implantable Contact Lens: Comparison of Two Lens Designs

PURPOSE

To compare the incidence of anterior subcapsular lens opacities, clinically significant cataracts, secondary lens-related surgical reinterventions, and vaulting characteristics of the now discontinued V3 and currently used V4 Staar Surgical Implantable Contact Lens (ICL) phakic intraocular lens designs.

METHODS

In this non-randomized prospective clinical trial, 87 eyes were implanted with the V3 and 523 eyes with the V4 ICL as part of the U.S. FDA clinical trial for myopia. LOCS III assessment of lens opacities, clinically significant cataract, ICL vaulting (clearance between ICL and crystalline lens), and secondary ICL-related surgeries were the main outcome measures. Mean follow-up in the V3 series was 30.7 +/- 10.0 months (range 10.8 to 49.3 mo) and in the V4 series, 17.3 +/- 6.9 months (range 0.25 to 38.5 mo).

RESULTS

Incidence of anterior subcapsular opacities was significantly higher with the V3 vs. V4 ICL (12.6% vs. 2.9%, P<.001). The difference was largely due to the higher rate of late-appearing opacities (> or = 1 year after surgery; 9.2% vs. 0.6%, P<.001). The V3 group had a greater proportion of eyes with poor vault (23.6% vs. 4.3%, P<.001) and the presence of poor vault was highly associated with the development of late anterior subcapsular opacities (P<.001). Clinically significant cataract was more frequent in the V3 vs. V4 ICL (9.2% vs. 0.8%, P<.001), as was cataract extraction (6.9% vs. 0.2%, P<.001), and need for ICL replacement (5.7% vs. 1.1%, P<.001). Differences in opacity rate between the V3 and V4 designs were not due to differences in postoperative follow-up.

CONCLUSION

Implantation of the currently used V4 Staar Surgical model ICL resulted in significantly less anterior subcapsular opacities, clinically significant cataracts, and secondary ICL-related surgery.

Long-term endothelial changes in phakic eyes with posterior chamber intraocular lenses

PURPOSE

To evaluate the long-term endothelial cell changes in phakic eyes after implantation of a posterior chamber phakic intraocular lens to correct high ametropia.

SETTING

Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria.

METHODS

Thirty-four eyes of 21 patients having implantation of an implantable contact lens (ICL, Staar Surgical) for high myopia or hyperopia were prospectively examined. The minimum follow-up was 2 to 4 years. Preoperative and serial postoperative specular microscopy (Noncon Robo SP 8000, Konan) was performed to evaluate the long-term endothelial cell changes.

RESULTS

The mean preoperative endothelial cell density was 2854 cells/mm(2). The mean endothelial cell loss from preoperatively was 1.8% at 3 months, 4.2% at 6 months, 5.5% at 12 months, 7.9% at 2 years (n = 34), 12.9% at 3 years (n = 13), and 12.3% at 4 years (n = 11). All other endothelial cell characteristics remained stable during the 4-year follow-up.

CONCLUSIONS

Continuous endothelial cell loss was observed after ICL implantation during a 4-year follow-up. There was rapid cell loss until 1 year postoperatively, after which the rate of loss was no longer statistically significant. The percentage of hexagonal cells (polymorphism) and the coefficient of variation (polymegethism) remained stable during the 4-year follow-up.

Imaging of posterior chamber phakic intraocular lens by optical coherence tomography

We demonstrate the applicability of optical coherence tomography to visualize the distance between the intraocular lens (IOL) and the lens capsule (lens vault) after implantation of the Staar Collamer posterior phakic IOL, also known as the implantable contact lens (ICL). Maintaining a substantial lens vault may be important to avoid cataract formation, but the lens vault was found to change over time; changes in accommodation and pupil size have also been noted. Optical coherence tomography allows precise assessment of the anatomic relationship between the ICL and the crystalline lens in a noncontact, noninvasive manner, permitting dynamic monitoring of changes in accommodation and pupil size.

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.

Gonioscopic changes after implantation of a posterior chamber lens in phakic myopic eyes

PURPOSE

To evaluate the effects of posterior chamber implantation of phakic intraocular lenses on angle structures and the correlation with intraocular pressure (IOP).

SETTING

Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria.

METHODS

A Staar implantable contact lens (ICL) was implanted in 20 white patients (34 eyes) with high myopia. The patients were followed for a mean of 2.3 years (range 0.8 to 6.0 years). Two subgroups were created: One had a follow-up of 2.4 to 6.0 years and the other, 0.8 to 2.3 years. The mean spherical power of the implanted ICL was -16.8 diopters (D) (range -9.0 to -21.0 D). The angle structures were examined by gonioscopy using the Spaeth technique, and optical pachymetry and IOP were measured in dilated and undilated pupils. Trabecular pigmentation was measured semiquantitatively. The ICL models included a few prototypes (6 eyes), the V2 model (10 eyes), the V3 model (6 eyes), and the V4 model (12 eyes).

RESULTS

The anterior chamber angle was between 11 and 20 degrees in 41% of eyes, between 21 and 30 degrees in 21%, larger than 30 degrees in 21%, and 10 degrees or smaller in 17%. An apparent iris root insertion was above Schwalbe's line in 6% of eyes, behind Schwalbe's line in 12%, at the scleral spur in 67%, and in a deep angle recess behind the scleral spur in 15%. The curvature of the iris was regular in 19 eyes and steep in 15 eyes. The mean pigmentation in all 4 quadrants was 1.3. (Grade 1 was defined as trace pigmentation.) The mean pachymetry from the endothelium to the ICL anterior surface was 2.7 mm and from the endothelium to the anterior surface of the crystalline lens, 3.2 mm. The mean IOP was 14.1 mm Hg in undilated pupils and 12.1 mm Hg in dilated pupils. There was no correlation between angle pigmentation and IOP.

CONCLUSION

Trace pigmentation in the trabecular meshwork was common after ICL implantation. However, there was no direct influence on IOP. Long-term follow-up is necessary to evaluate the effect and progress of trabecular pigmentation in eyes with an ICL.

Relationships between vitreoretinal and refractive surgery

OBJECTIVE

To describe retinal complications after posterior chamber phakic intraocular lens (PCPIOL) implantation and refractive surgery complications after scleral buckling surgery.

DESIGN

Retrospective, noncomparative, small case series.

PARTICIPANTS

Four patients in whom retinal detachment developed after PCPIOL implantation and two patients with previously placed encircling scleral buckles in whom corneal steepening developed after laser in situ keratomileusis (LASIK).

INTERVENTION

The four patients with retinal detachment after PCPIOL implantation underwent vitreoretinal surgery. One of the two patients in whom corneal steepening developed after LASIK underwent buckle removal.

MAIN OUTCOME MEASURES

The main parameters evaluated were vitreoretinal findings, corneal topography, and pachymetry.

RESULTS

Retinal attachment was achieved for all patients. Mean postoperative best-corrected visual acuity (BCVA) was 20/30. One patient lost one line of BCVA. One patient with corneal steepening achieved partial corneal flattening after buckle removal.

CONCLUSIONS

Vitreous base stimulation related to PCPIOL implantation and manipulation during LASIK may trigger retinal complications. Laser in situ keratomileusis in patients with previously placed scleral buckles may result in unexpected corneal steepening.

Reversal of Myopic Anisometropic Amblyopia With Phakic Intraocular Lens Implantation

PURPOSE

To report a case of reversal of myopic anisometropic amblyopia with phakic intraocular lens implantation.

METHODS

A 6-year-old boy with anisometropic amblyopia with spherical equivalent refraction of right eye: -14.00 -3.00 x 100 degrees, left eye: -0.50 -3.25 x 90 degrees, was treated for 2 years with occlusion to the left eye, with poor results. Refractive surgery was planned because of contact lens intolerance at age 8 years. A -15.00-D iris claw Artisan intraocular lens (IOL) was implanted.

RESULTS

Following surgery, treatment of the amblyopia and spectacle correction of -4.00 D cylinder at 85 degrees in the right eye and -3.50 D cylinder at 90 degrees in the left eye was necessary. Visual acuity 6 months after surgery was 20/25 in the right eye and 20/20 in the left eye, and has remained stable 18 months after surgery.

CONCLUSION

Myopic anisometropic amblyopia in an 8-year-old boy was treated successfully with implantation of an Artisan iris claw phakic anterior chamber IOL, combined with occlusion therapy, and resulted in reversal of amblyopia.

Laser in situ Keratomileusis and Photorefractive Keratectomy for Residual Refractive Error After Phakic Intraocular Lens Implantation

PURPOSE

To determine the visual and refractive outcome of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in eyes with prior posterior chamber phakic intraocular lens implantation for high myopia.

METHODS

We studied a series of 37 consecutive eyes of 31 patients who underwent LASIK or PRK for residual refractive error following collamer posterior chamber intraocular lens (IOL) (Staar Surgical Implantable Contact Lens) implantation into a phakic eye. Twenty-eight eyes had LASIK and nine eyes had PRK. Mean follow-up was 8.1 +/- 4.7 months after laser ablation (range, 3 to 18 mo).

RESULTS

The preoperative mean spherical equivalent refraction prior to phakic posterior chamber IOL implantation was -17.74 +/- 4.89 D (range, -9.75 to -28.00 D). Following phakic IOL implantation and prior to LASIK or PRK, mean spherical equivalent refraction was -2.56 +/- 2.34 D (range, -0.25 to -8.75 D). One month following LASIK or PRK, mean spherical equivalent refraction was -0.24 +/- 0.52 D (range, -1.50 to +1.50 D), 3 months following LASIK or PRK, mean spherical equivalent refraction was -0.19 +/- 0.50 D (range, -1.50 to +1.00 D). The refraction was within +/-1.00 D of emmetropia in 36 eyes (97.2%) and within +/-0.50 D in 31 eyes (83.7%). Three eyes developed anterior subcapsular opacities several weeks after laser ablation, one eye developed macular hemorrhage 4 weeks after laser ablation, and one eye had corticosteroid induced ocular hypertension.

CONCLUSIONS

LASIK or PRK can be used to treat the residual refractive error following posterior chamber phakic IOL implantation.

Implantable contact lens for moderate to high myopia: short-term follow-up of 2 models

PURPOSE

To confirm the safety, efficacy, and predictability of the surgical correction of moderate to high myopia by the ICM V3 and ICM V4 implantable contact lenses (ICLs), with emphasis on vaulting, intraocular pressure (IOP), and pigment dispersion.

SETTING

University Eye Hospital, Lausanne, Switzerland.

METHODS

Thirty-two eyes had implantation of an ICL. In 22 eyes with a mean spherical equivalent (SE) of -11.5 diopters (D), the target was emmetropia; in 10 eyes with a mean SE of -22.3 D, the goal was a reduction in the myopia. Nineteen eyes received the ICM V3 ICL and 13, the ICM V4 ICL. The mean follow-up was 7.4 months.

RESULTS

The mean postoperative SE in the 32 eyes was -2.16 D. Best spectacle-corrected visual acuity was maintained or improved in all eyes. In the 22 eyes targeted to achieve emmetropia, 10 (45%) were within +/-1.00 D; 15 (68%) had an uncorrected visual acuity of 20/40 or better and 4 (18%), of 20/20 or better. Vaulting of the ICL over the crystalline lens was more pronounced with the V4 than with the V3, and the difference was statistically significant. Subtle, localized anterior subcapsular opacification was encountered in 4 eyes. In 3 of them, the ICL (model V3) vaulting was minimal and 1 ICL (model V4) did not show any vaulting. Eighteen eyes had an IOP higher than the preoperative level, and the difference was statistically significant. No correlation was seen between final IOP and vaulting. Pigment dispersion on the ICL did not appear to be related to vaulting or ICL thickness.

CONCLUSION

Implantation of an ICL was effective in correcting moderate to high myopia of up to -17.50 D. Although the procedure appears to be safe, the predictability of the refractive outcome must be improved. The new generation of ICLs for myopia (ICM V4) offers a better vault over the crystalline lens than the older models (ICM V3), which should decrease the risk of cataract. No explanation was found for the IOP increase in several eyes 3 months or more after surgery.

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.

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.

Effect of intrastromal corneal ring segment shift on clinical outcome: one year results for low myopia

PURPOSE

To evaluate the effect of intrastromal corneal ring segment (ICRS) shift on clinical outcome.

SETTING

Chu Morvan Ophthalmology Service, Brest, France.

METHODS

Forty-seven eyes with myopia from -1.0 to -5.0 diopters (D) had ICRS surgery according to United States Food and Drug Administration protocol using a 2-segment implant design. Visual acuity, refractive, videotopographic, and biomicroscopic results in eyes that did not have contact between segments (Group A, n = 26) and in eyes that did have contact (Group B, n = 21) were compared.

RESULTS

Soon after surgery, migration of and subsequent contact between the implant segments occurred in 21 eyes (45%). Contact between the inferior ends was most common, occurring in 19 eyes; in the remaining 2 eyes, the superior ends of the implant touched. Superior contact was associated with superficial channels, wound-healing problems, and ICRS explantation. No segment shift was observed after the first postoperative week. No significant differences in visual acuity, qualitative vision, or density of intrastromal deposits were noted between the 2 groups. However, at 6 months there was more induced with-the-rule cylinder in Group B (mean +1.3 D +/- 0.7 [SD]) than in Group A (mean +0.7 +/- 0.5 D). Astigmatism was clinically significant in only 3 cases at 3 months.

CONCLUSIONS

Induced cylinder remains a limitation of the ICRS procedure, and segment contact appears to influence the rate of induced cylinder. Overall, however, the ICRS procedure produces promising results. Research efforts are underway to address induced cylinder and channel deposits associated with ICRS surgery.

Scanning electron microscopic characteristics of phakic intraocular lenses

OBJECTIVE

To analyze the surface quality of new generation phakic intraocular lenses (IOLs).

DESIGN

Experimental materials study.

MATERIALS

Three different new generation phakic IOLs: angle-fixated anterior chamber lens Chiron Vision NuVita MA20 (polymethylmethacrylate [PMMAD, iris-fixated anterior chamber lens Ophtec Artisan Iris-Claw (PMMA), posterior chamber lens Staar ICM (polymer from porcine collagen and 2-hydroxyethyl methacrylate [HEMA]).

METHODS

Representative samples of three different phakic IOLs underwent surface and edge-finish examination with light microscopy (LM). The phakic IOLs were then examined by use of scanning electron microscopy (SEM), and particular attention was given to optic surface quality, edge finish, haptic, and optic/haptic junction.

RESULTS

In all IOLs the LM examination showed a smooth and homogeneous surface. No irregularities, particularly at the optic front and back surface, optic edge, haptic, and the optic/haptic junctions, were detected by SEM. One exception was a minor surface roughness at the claws of an Artisan iris-fixated anterior chamber IOL.

CONCLUSIONS

Phakic IOLs are implanted either in the anterior or posterior chamber of healthy eyes, and high standards for their surface quality are required. The evaluation of surface properties with LM and SEM did not reveal any defects that contraindicate the implantation of phakic IOLs.

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.

The phakic intraocular lens implant: in-depth focus on posterior chamber phakic IOLs

Phakic Intraocular surgery has come a long way in the past 20 years, especially in the evolution of posterior chamber phakic intraocular lenses (PC PIOLs). Clinical trials worldwide are showing acceptable results concerning efficacy, predictability, stability, and safety. PC PIOLS are proving to be a promising option for patients with high and extreme ametropia who cannot benefit from conventional corneal refractive procedures. This article provides an in-depth examination of PC PIOLs, their origin and evolution, and the results of past and current clinical studies. Reports of historical importance and studies published since the 1990s in peer-reviewed journals, textbooks, and monthly eye magazines, as well as Food and Drug Administration preliminary clinical findings, are reviewed. Anterior chamber phakic intraocular lenses are mentioned briefly.

Posterior chamber silicone intraocular lens for the correction of myopia: an experimental study in rabbits

PURPOSE

To establish whether ocular lesions arise after implantation of posterior chamber silicone intraocular lenses (IOL) for the correction of high myopia.

METHODS

Twenty-three posterior chamber silicone IOL were implanted in 23 eyes of the same number of pigmented rabbits. After different follow-up time (from one week to one year) the eyes were enucleated and processed for histopathological study after determining the protein concentration in the aqueous humor. The IOL were removed for staining and examination, and adhered cells were counted. Ten eyes analogous to those operated upon were used as controls.

RESULTS

Intense inflammation was observed in the early postoperative period in all cases. Protein concentration in the aqueous humor was initially high and decreased over time, though without reaching normal values at one year. Mono- and multinucleated cells were seen adhering to the IOL, though they decreased in number over time and were practically absent after one year. Friction between the posterior surface of the iris and the IOL had no clinical repercussions. The only pigment accumulations were in the iris and in the peritrabecular zone. There were no significant differences in the accumulation of granules in relation to IOL diameter or power. Excluding three cataracts morphologically similar to traumatic cataracts, five lens opacifications were observed: two were anterior subcapsular cataracts, and the other three were only precapsular deposits. The IOL had no synechiae to the ocular tissues.

CONCLUSIONS

Opacification of the lens is the main concern with implanted posterior chamber silicone IOL. Larger series of eyes must be analysed to establish the true incidence and reversibility of these opacities.

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.

Lens opacity after neodymium: YAG laser iridectomy for phakic intraocular lens implantation

We describe a previously unreported complication of a posterior chamber intraocular lens (IOL) implanted in a phakic eye. The left eye of a 25-year-old patient with high myopia was treated prophylactically with neodymium: YAG (Nd: YAG) laser iridotomy prior to phakic IOL implantation. Slitlamp examination of the left eye disclosed an opacity of the anterior capsule of the crystalline lens under the iridotomy site. This case demonstrates a complication associated with Nd:YAG iridotomy prior to implantation of a phakic IOL.

Cataract formation after posterior chamber phakic intraocular lens implantation

Posterior chamber phakic intraocular lens (PCP IOL) implantation is an emerging refractive procedure. We report a case of cataract formation 6 months after uneventful implantation of a Staar PCP IOL to correct high myopia. Visual recovery was achieved after explantation of the phakic IOL and phacoemulsification with implantation of a foldable IOL through the same unenlarged self-sealing corneal incision.

Ultrasound Biomicroscopic Imaging of Posterior Chamber Phakic Intraocular Lens

BACKGROUND

Phakic intraocular lens (IOL) implantation represents a major technique for the correction of high myopia. The STAAR collamer posterior chamber phakic IOL--trade named Implantable Contact Lens--is an emerging technology in refractive surgery. We studied the relative position of the posterior chamber phakic IOL using ultrasound biomicroscopy.

METHODS

The posterior chamber phakic intraocular lens was inserted in 9 eyes of 8 patients with high myopia. Ultrasound biomicroscopy was performed before and after implantation of the phakic IOL to assess its relative position in the anterior segment of the eye. The parameters measured and compared were anterior chamber depth, angle opening distance 500 microns from the scleral spur, iris-crystalline lens contact distance, iris-IOL contact distance, and IOL-crystalline lens distance.

RESULTS

Ultrasound biomicroscopy showed contact between the iris and the IOL in all eyes and between the IOL and the crystalline lens in 8 eyes. Reduction in the anterior chamber depth and localized narrowing of the angle opening were observed in all eyes.

CONCLUSION

IOL-iris touch, IOL-crystalline lens touch, and anterior chamber shallowing raise concerns of pigmentary dispersion, cataractogenesis, and narrow angle glaucoma following posterior chamber phakic intraocular lens implantation. Clinical data are needed to determine if these problems occur.

Implantable contact lens for moderate to high myopia: phase 1 FDA clinical study with 6 month follow-up

PURPOSE

To assess the short-term safety and efficacy of the implantable contact lens (ICL) to treat moderate to high myopia.

SETTING

Phase 1 U.S. Food and Drug Administration clinical study of the ICL conducted at four sites in the United States.

METHODS

Ten patients with myopia of 7.00 diopters (D) or greater had implantation of a Staar Surgical ICL and were examined preoperatively (baseline) and 1 day, 1 week, and 1, 3, and 6 months postoperatively. Mean preoperative myopia was 7.75 D (range 7.25 to 9.37 D).

RESULTS

Six months postoperatively, 5 of 10 eyes (50%) had an uncorrected visual acuity (UCVA) of 20/20 or better, and all eyes had a UCVA of 20/30 or better. All eyes had a best spectacle-corrected visual acuity (BSCVA) of 20/20 or better and 6 eyes (60%), of 20/15 or better. Six eyes (60%) had an improvement of one or more lines of BSCVA. Mean postoperative spherical equivalent was -0.025 D +/- 0.47 (SD). Eight eyes (80%) were within +/- 0.250 D of emmetropia, and all were within +/- 1.125 D. No intraoperative or postoperative complications or adverse reactions were observed.

CONCLUSIONS

The results support the short-term safety, efficacy, and predictability of ICL implantation to treat moderate to high myopia.

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.