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PubMed2005

Uveitis-associated flap edema and lamellar interface fluid collection after LASIK.

PURPOSE: To report two cases of corneal pathology associated with anterior uveitis after laser in situ keratomileusis (LASIK). DESIGN: Observational case report. METHODS: A 47-year-old man and a 50-year-old woman who experienced vision loss and corneal changes associated with acute anterior uveitis after LASIK were examined. RESULTS: The 47-year-old man, who had undergone LASIK for low myopia developed an interlamellar fluid pocket at the level of the flap interface, whereas the 50-year-old woman, who underwent LASIK for hyperopia, developed marked flap edema without interface fluid collection. CONCLUSIONS: These two cases demonstrated acute corneal fluid accumulation associated with episodes of acute anterior uveitis in eyes that had undergone LASIK. Uveitis should be considered a risk factor for vision threatening corneal complications after LASIK.

Acute Disease↗

PubMed2005

Correction of large amblyopiogenic refractive errors in children using the excimer laser.

PURPOSE: We sought to determine whether laser subepithelial keratomileusis (LASEK) and photorefractive keratectomy (PRK) are effective methods for correcting amblyopiogenic refractive errors in children. METHODS: Thirty-six eyes in 35 amblyopic children, who ranged in age from 4 to 16 years (mean, 8.4 years), received treatment for large magnitude ametropia. Seventy-two percent (25/35) of the children had a neurobehavioral disorder and/or were noncompliant with spectacle or contact lens wear. Myopia ranged from -3.25 to -24.25 D (mean, -11.48 D); one patient had hyperopia of +5.87 D. Correction was tailored to match the refractive error of the nonamblyopic eye. VISX Star S2/S3 excimer lasers were used in manual or auto-tracking modes, and corneal centration was achieved using brief, general anesthesia. Mean follow-up was 29.2 months (range, 4-42 months). RESULTS: Myopia correction averaged -8.95 +/- 2.89 D (range, -3.25 to -15.50). Eighty-nine percent (31 children) were corrected to within +/- 1.00 D of goal refraction and the remaining 11% to within 2.0 D of the goal (most were undercorrected). Acuity improved postoperatively in 97%; by 1 optotype line in 37% and by 2 or more in 60%. No child lost acuity. Binocularity improved in 69% (24/35) and remained the same in 31%. Corneal haze measured grade 0-1 in 78%, grade 2 in 14%, and grade 3-4 in 8%. Myopic regression exceeding congruent with 1.0 D/year (0.08 D/month) occurred in 50% (18/36) of eyes treated. No substantial differences were observed in PRK- (n = 18) versus LASEK- (n = 17) treated children. CONCLUSIONS: Laser refractive surgery is effective for correcting anisometropic myopia in amblyopic children. Recurrence of myopia is common. Further study is indicated to determine long-term stability and safety of the procedure in this population.

Adolescent↗

PubMed2004

Surgery for 4 refractive errors in 1 patient.

We report a case of cataract extraction with implantation of a multifocal intraocular lens (IOL) after photorefractive keratectomy for myopia and astigmatism and subsequent laser thermal keratoplasty for surgically induced hyperopia. Good refractive results were obtained using standard biometry techniques for calculation of the IOL power.

Cornea↗

PubMed2004

Laser in situ keratomileusis after conductive keratoplasty.

We present a patient in whom laser in situ keratomileusis was used to treat residual hyperopia with astigmatism after conductive keratoplasty (CK). Previous CK did not affect initial flap creation, the ability to lift the flap manually 3 weeks after its initial preparation, or the refraction, topography, and refractive stability after the flap was created.

Aged↗

PubMed2004

Changes in keratometric corneal power and refractive error after laser thermal keratoplasty.

PURPOSE: To evaluate the effect of laser thermal keratoplasty (LTK) on corneal power and refractive error to develop a logical approach to calculating accurate intraocular lens (IOL) power for cataract surgery. SETTING: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. METHODS: Laser thermal keratoplasty was performed in 27 eyes of 23 patients. Preoperatively and postoperatively, the refractive error was measured and the corneal power obtained by manual keratometry and topography. The changes in keratometric corneal power and refractive error after LTK were compared. RESULTS: The mean age of the 15 women and 8 men was 45.0 years +/- 4.6 (SD) (range 43 to 61 years). The mean preoperative refractive error was +1.43 +/- 0.97 diopters (D) (range 0 to +3.63 D) at the spectacle plane and +1.46 +/- 1.01 D (range 0 to +3.79 D) at the corneal plane. The mean postoperative refractive error was -0.44 +/- 1.07 D (range -2.24 to +2.18 D) at the spectacle plane and -0.44 +/- 1.08 D (range -2.18 to +2.23 D) at the corneal plane. After surgery, corneal powers measured by manual keratometry were significantly smaller than those measured by topography (P<.001) and refractive error changes were significantly smaller than keratometric changes (P<.001). CONCLUSIONS: After LTK, corneal power measured by manual keratometry was smaller than that measured by corneal topography and changes in corneal power measured by conventional keratometric instruments were greater than changes in refractive error. This difference should be considered in calculating IOL power in post-LTK eyes to prevent undesirable hyperopia after cataract surgery.

Adult↗

PubMed2004

Secondary procedures after presbyopic lens exchange.

PURPOSE: To assess the indications, incidence, and outcome of secondary procedures after presbyopic lens exchange (PRELEX). SETTING: Private practice, Siena, Italy. METHODS: This prospective nonrandomized single-surgeon study comprised 52 patients having PRELEX by phacoemulsification and multifocal intraocular lens (IOL) implantation. The preoperative mean spherical equivalent (SE) was +2.50 diopters (D) +/- 1.38 (SD) (range 0 to +6.0 D). RESULTS: Monocular PRELEX was performed in 8 patients who canceled the fellow-eye surgery because of halos; in this group, the residual refractive error was corrected by photorefractive keratectomy (PRK) in 4 eyes, but this did not alleviate halos and IOL exchange was ultimately needed in 7 eyes. Binocular PRELEX was completed in 44 patients; in this group, 14 eyes (8 patients) had PRK for a residual error. The postoperative mean absolute SE in the 18 PRK-treated eyes was 0.33 D (95% confidence interval [CI] of improvement, 0.57-1.32) and the mean uncorrected visual acuity, 0.8 (95% CI of improvement, 0.32-0.45). The final SE was within +/-0.5 D in 15 eyes (83.0%) and within +/-1.0 D in 18 eyes. Halos after PRK were unchanged in 6 patients, slightly improved in 4, and improved in 2. Photorefractive keratectomy or IOL exchange was needed in eyes with a preoperative SE between plano and +1.75 D (15/40 eyes, 38%) and not needed in eyes with a preoperative SE greater than +1.75 D (0%) (95% CI of difference, 23%-53%). CONCLUSIONS: Presbyopic lens exchange in eyes with emmetropia and low hyperopia was associated with a significantly higher percentage of secondary procedures. Photorefractive keratectomy enhancement can improve distance vision but has a limited effect on halos.

Accommodation, Ocular↗

PubMed2005

Change in pupil size after implantation of an iris-fixated toric phakic intraocular lens.

PURPOSE: To evaluate the changes in pupil size after implantation of an iris-supported toric phakic intraocular lens (TPIOL) for correction of myopia and hyperopia with astigmatism. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: Twenty-two myopic eyes and 9 hyperopic eyes were included in the study. The mean age of the 2 groups was 34 years and 40 years, respectively. The scotopic pupil size was measured with a handheld infrared pupillometer (Colvard, Oasis Medical) before and 6 months after implantation of the TPIOL. All examinations were performed under scotopic conditions after 2 minutes of dark adaptation with the fellow eye covered. Intraindividual comparisons were made between preoperative and postoperative pupil sizes. The relationship between implanted IOL power and postoperative pupil width in each group was studied to determine whether lens magnification could lead to misinterpretation of the results. The difference between horizontal and vertical postoperative pupil diameters was assessed in eyes with horizontally aligned IOLs to determine the potential mechanical effect of the TPIOL on pupil size. RESULTS: The mean scotopic pupil diameter decreased significantly from 4.7 mm (range 3.0 to 6.0 mm) preoperatively to 3.6 mm (range 2.0 to 5.0 mm) postoperatively in myopic eyes and from 5.0 mm (range 4.0 to 6.0 mm) to 4.0 mm (range 2.0 to 5.0 mm) in hyperopic eyes. No significant correlation between the power of the TPIOL and the postoperative pupil size diameter was found, confirming that the IOL did not distort measurements of pupil size. Comparing horizontal and vertical pupil diameters under medical mydriasis revealed reduced pupil size in the axis of enclavation. CONCLUSIONS: The scotopic pupil diameter decreased by a mean of 1.1 mm in myopic eyes and 1.0 mm in hyperopic eyes after implantation of the iris-supported TPIOL. Postoperative pupil size was not related to IOL power, patients' emotional states, or other factors. The slightly smaller pupil diameter in the axis of enclavation suggests that this fixation method restricts pupil size under scotopic conditions, which could reduce the incidence of postoperative photic phenomena.

Adult↗

PubMed2004

Continuous monitoring of corneal thickness changes during LASIK with online optical coherence pachymetry.

PURPOSE: To assess the continuous intraoperative monitoring of central corneal thickness (CCT) changes during laser in situ keratomileusis (LASIK) using online optical coherence pachymetry (OCP). SETTING: Department of Ophthalmology, Vivantes Klinikum Neukolln, Berlin, Germany. METHODS: In this prospective nonrandomized comparative clinical case series of consecutive patients, 32 eyes having LASIK for myopia, myopic astigmatism, or hyperopia were continuously monitored intraoperatively in real time with online OCP integrated into a clinical excimer laser. The intraoperative values were compared to the postoperative flap and residual stromal thicknesses measured with corneal optical coherence tomography (OCT) as well as the calculated myopic ablation depth. RESULTS: Continuous monitoring with online OCP enabled intraoperative visualization of the CCT changes during LASIK. The CCT, flap thickness after the microkeratome pass, time-resolved ablation, and residual stromal thickness were assessed. Intraoperatively, the mean flap thickness was 135 microm +/- 38 (SD) and the mean residual stromal thickness, 286 +/- 59 microm. The mean intraoperative flap and residual stromal thickness values were 43.7 microm and 15.4 microm lower, respectively, than the postoperative values assessed with corneal OCT (P<.001 and P=.005, respectively). The optically determined myopic ablation depth was 118 +/- 37 microm, which was 28 microm higher than the nominal ablation depth. There was a significant correlation (P<.001) between the postoperative flap (r=0.79) and residual (r=0.88) thickness measured with corneal OCT as well as the calculated myopic ablation depth (r=0.95). CONCLUSIONS: Intraoperative online OCP could be an important safety feature to monitor the flap and residual stromal thicknesses during LASIK. The individual ablation depth and possible dehydration effects were also monitored continuously.

Adult↗

PubMed2005

Clinical outcomes of phakic refractive lens in myopic and hyperopic eyes: 1-year results.

PURPOSE: To confirm the safety, efficacy, and predictability of the surgical correction of myopia and hyperopia with the phakic refractive lens (PRL) (Medennium Inc.). SETTING: St. Eriks Eye Hospital, Stockholm, Sweden. METHODS: This was a prospective clinical study of 20 eyes, 14 myopic and 6 hyperopic, that had PRL implantation at St. Eriks Eye Hospital from April to November 2002. Examinations were performed preoperatively and 1 day, 1 week, 3 months, and 1 year postoperatively. Follow-up included evaluation of the PRL rotation with retroillumination photography, evaluation of the distance between the PRL and the crystalline lens with Scheimpflug image, laser flare, endothelial cell count, uncorrected (UCVA) and best corrected (BCVA) visual acuity, residual refractive error, refractive stability, intraocular pressure, and induced cataract. RESULTS: Postoperatively, 11 eyes (55%) gained 1 or more lines, 5 eyes (25%) had no change, and 4 eyes (20%) lost 1 line of BCVA. No eye lost 2 or more lines. Mean UCVA was 0.87+/- 0.29 postoperatively. Laser flare values were highest 1 day after operation with normalization at 3 months and without changes at 1 year (P<.05). A rotation of 10 degrees or more was found in 15 eyes (75%) during the first year. The distance between the PRL and crystalline lens was considerably less at 1 year than at baseline (P<.05). There was no statistically significant endothelial cell loss induced by the PRL (P<.05). No induced cataract, glaucoma, or inflammation was observed. In 1 hyperopic eye, horizontal iris transillumination defects were noticed at 1 year. CONCLUSION: Safety and efficacy indexes were high at 1-year follow-up. The PRL rotated slightly in the posterior chamber. The distance between the PRL and the crystalline lens was considerably less at 1 year than at baseline.

Adult↗

PubMed2005

Biometry of phakic intraocular lens using Scheimpflug photography.

PURPOSE: To examine lateral and axial positioning of phakic intraocular lenses (IOLs) with iris fixation in the anterior chamber and to examine short-term stability of the IOL position. SETTING: The Netherlands Opthalmic Research Institute, Amsterdam, the Netherlands. METHODS: Thirty patients participated in the study. Thirty-one eyes were implanted with the 204 type myopia IOL, 14 eyes with the 206 myopia IOL, and 8 eyes with the 203 hyperopia IOL. Scheimpflug slitlamp photographs were made through the optical axis along 4 meridians of the eyes. Ray tracing was used to obtain the lateral and axial position of the IOLs. RESULTS: Centration of the IOL with respect to the pupil's center and the tilt angle of the IOL with respect to the optical axis of the eye were measured. Standard deviation of decentration was 0.21 mm vertically and 0.16 mm horizontally. Standard deviation of tilt was 1.30 degrees vertically and 0.90 degrees horizontally. Tilt and decentration are proportional to each other. Vaulting, the distance between the crystalline lens and the IOL, was constant over a period of 24 months, ranging from 0.2 to 0.8 mm, depending primarily on the radius of curvature of the crystalline lens. A geometric model for this dependence was formulated. CONCLUSION: Phakic IOLs with iris fixation can be positioned in the eye with submillimeter precision. Axial position of iris-fixated phakic IOLs over time is excellent. Axial position and vaulting can be predicted when the radius of curvature of the crystalline lens is known. The IOL behaves as if mounted slightly above a sphere-the anterior surface of the crystalline lens.

Biometry↗

PubMed2005

Measurement of the spatial shift of the pupil center.

PURPOSE: To evaluate the effectiveness of the pupil center as an anatomic landmark for excimer laser treatments. SETTING: Sekal-Microchirurgia-Rovigo Centre, Rovigo, Italy. METHODS: Pupillometry with the Costruzione Strumenti Oftalmici S.R.L. (CSO) pupil-measuring module (incorporated in Eye Top videokeratoscope) was performed in 52 patients with a diagnosis of myopia and in 25 patients with a diagnosis of hyperopia. Measurements both in mesopic and photopic conditions consisted of pupil diameters, spatial shift of the pupil center, and the distance between the pupil center and keratoscopic axis. RESULTS: The mean pupil diameter in photopic conditions of illumination in myopic eyes was 3.52 mm +/- 0.56 (SD), while in mesopic conditions it was 5.37 +/- 0.78 mm; in hyperopic eyes the mean photopic pupil diameter was 3.01 +/- 0.46 mm, while the mean mesopic diameter was 5.12 +/- 0.48 mm. The mean spatial shift of the pupil center in myopic eyes was 0.086 mm (maximum 0.269 mm), while in the hyperopic eyes it was 0.095 mm (maximum 0.283 mm). The mean distance between the pupil center and keratoscopic axis in myopic eyes was 0.226 +/- 0.13 mm (maximum 0.75 mm), while in hyperopic eyes it was 0.45 +/- 0.19 mm (maximum 0.8 mm). CONCLUSIONS: The mean of the measured pupil sizes was greater in myopic eyes than in hyperopic eyes. The spatial shift of the pupil center, as the pupil dilates, was relatively small in all groups; therefore, the pupil center is a good anatomic landmark for both traditional refractive surgery and wavefront-guided treatments. The mean distance between the keratoscopic axis and pupil center was greater in the hyperopic group than in the myopic group. Therefore, centration of any laser treatment on the basis of the keratoscopic analysis should be done carefully, especially in hyperopic eyes and in cases in which the pupil center is meaningfully shifted from keratoscopic axis, even in photopic conditions of illumination.

Adolescent↗

PubMed2005

Refractive results with secondary piggyback implantation to correct pseudophakic refractive errors.

PURPOSE: To assess the efficacy and safety of implanting a second intraocular lens (IOL) to correct pseudophakic refractive errors. SETTING: Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel. METHODS: This prospective noncomparative case series included 10 pseudophakic eyes, 5 with a myopic residual refractive error and 5 with a hyperopic residual refractive error. All eyes had secondary piggyback IOL implantation with the IOL placed in the ciliary sulcus. Five types of IOLs were used to correct the residual refractive error. RESULTS: The mean preoperative myopia was -6.6 diopters +/- 3.3 (SD), and the refractive outcome was within 0.5 +/- 0.7 D of the desired refraction (range -1.5 [undercorrected] and +1.0 D [overcorrected]). The mean preoperative hyperopia was +3.8 +/- 0.8 D, and the refractive outcome was within 0.46 +/- 0.4 D of the desired refraction (range 0 and 1.0 D overcorrected). All patients showed visual acuity improvement. Best spectacle-corrected visual acuity improved from 20/44 to 20/30 (P<.05). CONCLUSION: An IOL type that is appropriate for implantation in the ciliary sulcus is a viable option for correcting pseudophakic refractive error using the piggyback technique.

Adult↗

PubMed2005

Results of cataract extraction after implantable contact lens removal.

PURPOSE: To evaluate the visual results following insertion of implantable contact lenses (ICLs) in ametropic eyes and the development of subcapsular opacification with visual loss and to examine the anterior capsule, including the subcapsular tissue alteration, by light microscopy. SETTING: Department of Ophthalmology, Schlosspark-Klinik, affiliated hospital of the Charité Berlin, Humbold University, Berlin, Germany. METHODS: A prospective noncomparative interventional case series of anterior subcapsular cataracts in 9 of 127 (7.1%) patient eyes receiving ICLs to correct myopia and hyperopia was studied. The cataracts were phacoemulsified due to visual loss, and an intraocular lens (IOL) was implanted in the bag. After capsulorhexis, the anterior capsule was withdrawn for light microscopy examination. Visual acuity in each eye was measured before and after ICL implantation and before and after cataract extraction. The age range of cataract patients was 39 to 53 years. RESULTS: Implantable contact lens removal and phacoemulsification with IOL implantation for emmetropia resulted in an increased visual acuity compared to initial vision. Four of 28 hyperopic eyes (14.3%) developed subcapsular central opacification after ICL implantation, whereas 5 of 99 myopic patients (5.1%) developed opacifications. CONCLUSIONS: Patients should be informed prior to ICL implantation, there is a possibility of secondary subcapsular cataract formation and vision reduction. Although the posterior chamber inlay as well as the cataract can be removed and better acuity can be restored, a possible complication due to the ICL implantation cannot be avoided and the accommodation in young patients lost.

Adult↗

PubMed2006

Intraocular lens power calculation after laser in situ keratomileusis: Aphakic refraction technique.

PURPOSE: To evaluate the accuracy of a new method of intraocular lens (IOL) power calculation for eyes having cataract extraction after previous laser in situ keratomileusis (LASIK). SETTING: Clinical private practice and ambulatory surgical center, Astoria, New York, USA. METHODS: This retrospective study was of 12 eyes of 9 patients who presented for cataract extraction after previous LASIK. Cataract removal was performed under topical anesthesia without IOL implantation. Approximately 30 minutes later, a manifest aphakic refraction was performed. The calculation of the IOL power was obtained by using an algorithm derived from previous experience with secondary IOL implantation (Mackool algorithm). The patient then returned to the operating room for lens implantation (aphakic refraction technique). RESULTS: The refractive error 2 weeks postoperatively, defined as the difference between the intended and actual refractive outcome, ranged from 0.50 diopter (D) of unintended hyperopia to 0.75 (D) of unintended myopia. CONCLUSIONS: The aphakic refraction technique provided an extremely accurate postoperative refraction in eyes having cataract with IOL implantation surgery after previous LASIK. Although the pool sample was small (12 eyes) and the range of the aphakic refraction was limited (+8.50 to 12.375 D), the technique was found to be remarkably accurate.

Algorithms↗

PubMed2006

Simple regression formula for intraocular lens power adjustment in eyes requiring cataract surgery after excimer laser photoablation.

PURPOSE: To develop a simple and accurate method for determining appropriate intraocular lens (IOL) power in cataract patients who had prior excimer laser photoablation for myopia or hyperopia, because laser vision corrective surgery interferes with traditional keratometry and corneal topography, rendering IOL power calculations inaccurate. SETTING: Private Practice in Century City (Los Angeles), California, and free-standing outpatient surgery centers with institutional review boards. METHODS: Based on the empiric experience of the senior author, an IOL power correction factor that was proportional to the prior laser photoablation was determined and applied to the IOL power calculated by the IOLMaster (Zeiss). It was necessary to add to the predicted IOL power in eyes with prior myopic laser ablation, whereas eyes having prior hyperopic laser vision correction required a reduction in the IOL power. The correction factor was applied to 30 eyes that required cataract surgery at some time after laser refractive surgery; 23 eyes had prior treatment for myopia, and the remaining 7 eyes had prior hyperopic laser ablation. A regression formula was generated from the IOL power correction factor that was used in the 30 eyes. RESULTS: Using the correction factor for 30 eyes, the mean deviation from the desired postcataract refractive outcome was -0.15 diopter (D) +/- 0.29 (SD); 28 of 30 eyes were within +/-0.5 D of the intended goal; the remaining 2 eyes were both -0.75 D from the desired optical result of cataract surgery. Fourteen of the 30 eyes were emmetropic. CONCLUSIONS: A simple IOL power corrective adjustment regression formula allowed accurate determination of IOL power after laser refractive photoablation surgery. The weakness of the current method is that knowledge of the amount of prior laser vision correction is necessary.

Algorithms↗

PubMed2006

Outcome of simultaneous phakic implantable contact lens removal with cataract extraction and pseudophakic intraocular lens implantation.

PURPOSE: To assess the outcome of simultaneous implantable contact lens (ICL) removal and cataract extraction with pseudophakic intraocular lens (IOL) implantation. SETTING: CODET Aris Vision Institute, Tijuana, Mexico. METHODS: This retrospective noncomparative interventional case series evaluated 14 eyes of 12 patients with ICL implantations who developed a cataract and simultaneously had ICL removal and cataract extraction with IOL implantation. The follow-up time was at least 6 months (range 6 to 24 months). Visual acuity (logMAR), manifest refraction, intraocular pressure, and adverse events were recorded. RESULTS: Of the 12 patients (14 eyes), 10 patients (12 eyes) had ICL surgery to correct high myopia and 2 patients (2 eyes), to correct hyperopia. The mean uncorrected visual acuity after ICL implantation (before cataract development), before cataract surgery, and after cataract surgery were 0.48 +/- 0.32, 0.83 +/- 0.34, and 0.40 +/- 0.27, respectively. The mean best corrected visual acuity (BCVA) before ICL implantation, after ICL implantation, and after cataract surgery were 0.31 +/- 0.21, 0.28 +/- 0.19, and 0.27 +/- 0.21, respectively. The mean final manifest spherical equivalent was 0.30 diopters (D) +/- 1.07 (SD) (range +2.38 to 2.0 D). Ten eyes (71.4%) were within +/-1.0 D of the calculated target. One eye had a tear in the posterior capsule with vitreous loss during cataract surgery. No other intraoperative, perioperative, or postoperative complications were observed. No loss of BCVA was recorded at the last postoperative visit. CONCLUSIONS: Lens opacities and cataract formation are a potential complication of ICL surgery. The removal of the ICL and the cataract with IOL implantation was found to be safe, with predictable refractive results.

Adult↗

PubMed2007

Laser in situ keratomileusis for astigmatism following laser thermal keratoplasty.

We describe 2 cases in which a staged laser in situ keratomileusis procedure was used to treat residual hyperopia and astigmatism after laser thermal keratoplasty. The procedure successfully reduced the spherical equivalent refractive error and residual astigmatism. All eyes maintained their best spectacle-corrected visual acuity and had an uncorrected visual acuity of at least 20/25 at the end of follow-up.

Adult↗

PubMed2004

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.

Accommodation, Ocular↗