Phakic Refractive Lens Implantation Research Articles

Clinical efficacy of posterior chamber phakic refractive lens implantation in the treatment of ultra-high myopia

Clinical efficacy of posterior chamber phakic refractive lens implantation in the treatment of ultra-high myopia

English

Abstract This article presents two cases of phakic refractive lens (PRL) complications in China. Case 1 presents a highly myopic patient with PRL's footplate partly subluxated into the anterior chamber by blunt trauma one year after implantation. The PRL was repositioned successfully without other complications. Case 2 represents a case of pigment dispersion glaucoma developed seven years after PRL implantation. Intraocular pressure (IOP) lowering therapy was initiated and the IOP continued to be in the normal range for both affected eyes with ongoing follow-up. The preciseness in sulcus-to-sulcus measurements is important to minimize the risk of dislocation and crystalline lens touch; thus, a careful preoperative evaluation should be performed to exclude the presence of glaucoma, and the patients undergoing the procedure need to be informed about the increased risk for glaucoma. In summary, a comprehensive ophthalmic evaluation is essential to optimize both patient and PRL selection to minimize the risk for potential complications, and the PRL implantation warrants long-term follow-up.

Long-term Results of Phakic Refractive Lens Implantation in Eyes With High Myopia

To evaluate the long-term results of phakic refractive lens (PRL; Carl Zeiss Meditec) implantation in eyes with high myopia. In this retrospective, noncomparative, interventional case series, 143 myopic eyes of 82 patients were treated for high myopia with the implantation of the silicone PRL in the posterior chamber. Mean follow-up was 3.8±1.7 years (range: 1 to 6 years). Six years postoperatively (n=34), a statistically significant reduction was noted in the cycloplegic spherical equivalent from -14.08±4.00 diopters (D) (range: -24.88 to -4.75 D) before PRL implantation to -0.45±0.62 D (range: -1.00 to 1.00 D) (P<.001). At 6 years, 67.6% (23 eyes) and 91.2% (31 eyes) were within ±0.50 and ±1.00 D of target refraction, respectively. Mean logMAR uncorrected and corrected distance visual acuity improved significantly (P<.001) (counting fingers preoperatively in all eyes to 0.17±0.15 [range: 0.54 to -0.06] and 0.19±0.19 [1.00 to -0.08] to 0.07±0.10 [range: 0.30 to -0.10], respectively). Complications included anterior capsule damage (3 eyes), temporary intraocular pressure increase (14 eyes), pigment dispersion (1 eye), and PRL decentration (1 eye). No eyes presented any signs of cataract up to 6 years postoperatively. Long-term results show that PRL implantation is an effective and safe method for treating high myopia.

Phakic Refractive Lens (Medennium) for Correction of +4.00 to +6.00 Diopters: 1-year Follow-Up

To study the efficacy and safety of phakic refractive lens (PRL) implantation to correct high hyperopia. Inclusion criteria for this prospective, observer-masked, interventional study were spherical equivalent > or =+4.00 diopters (D) of cycloplegic hyperopia, best spectacle-corrected visual acuity (BSCVA) > or =0.5, anterior chamber depth > or =3 mm, and mesopic pupil size < or =6 mm. Lenses were implanted in all cases under regional anesthesia using forceps. Sixteen eyes of nine patients were included in the study. Mean preoperative spherical equivalent refraction was +5.65+/-1.41 D (range: +3.25 to +5.75 D). Mean 1-year postoperative spherical equivalent refraction was +0.07+/-0.43 D (range: -0.50 to 0.75 D). Fifteen (93.75%) eyes were within +/-0.50 D of emmetropia, and 16 (100%) eyes were within +/-1.00 D of emmetropia. Safety and efficacy indexes were 0.9 and 0.8, respectively. Eight (50%) eyes needed LASIK to correct residual astigmatism. Five (31.25%) eyes lost one line of BSCVA; no eye lost two or more lines of BSCVA. The BSCVA did not increase in any eye. No significant intraocular complications developed. Phakic refractive lens implantation to correct high hyperopia seems to be a safe and accurate procedure. A mild but significant loss in BSCVA can be anticipated.

Medennium Posterior Chamber Phakic Refractive Lens to Correct High Myopia

To determine the efficacy and safety of phakic refractive lens implantation to correct high myopia. In this prospective study, a phakic refractive lens was implanted in 90 myopic eyes in which refractive errors ranged from -6.00 to -20.00 diopters (D) and laser refractive surgery was contraindicated. Uncorrected visual acuity (UCVA) and best-spectacle corrected visual acuity (BSCVA), manifest and cycloplegic refractions, and intraocular pressure (IOP) were assessed during a 1-year follow-up period. Possible complications, including endothelial cell counts, were evaluated. Spherical equivalent refraction measurements revealed a significant change from the preoperative mean value of -11.90+/-5.00 D to 0.04+/-0.20 D 1 year postoperatively (P=.001). The UCVA and BSCVA significantly improved postoperatively (P=.001 and P=.01, respectively). Seventy-two (80%) eyes and 61 (68%) eyes were within +/-1.00 D and +/-0.50 D of the target refraction, respectively. A significant increase in IOP was found at every postoperative visit (P=.01). There was a trend toward decreased endothelial cell density postoperatively, although the difference did not reach significance. No major complications were found during the 1-year follow-up period. The implantation of a phakic refractive lens seems to be a predictable and well-tolerated procedure for correcting high myopia. Complications such as development of cataract, implant dislocation, decreases in endothelial cell counts, or development of glaucoma did not occur in this study.

Optical Coherence Tomography of the Anterior Segment in Eyes with Phakic Refractive Lenses

To evaluate the dynamics of the phakic refractive lens (PRL) in myopic and hyperopic eyes in the nonaccommodated state and during subjective accommodation with Visante optical coherence tomography (OCT). Cross-sectional study. Forty-one myopic eyes and 11 hyperopic eyes of 52 patients (mean age, 34 years; range, 24-49) were examined at least 1 year after PRL implantation using Visante OCT. Thirty-one myopic eyes had the PRL model 101 and 10 eyes had the smaller PRL model 100 implanted. The hyperopic model, PRL 200, is available in only one size. Noninvasive high-resolution anterior OCT was used to measure distance changes between the PRL and adjacent intraocular structures in the nonaccommodative state (baseline) and during accommodation. Mean distance changes from the anterior lens surface (ALS) to the PRL and from the corneal posterior surface to the ALS and the PRL, and changes in the pupil diameter. At baseline, the mean distances between the PRL and crystalline lens were 0.38, 0.30, and 0.32 mm for the PRL 101, PRL 100, and PRL 200, respectively. The PRLs were significantly closer to the crystalline lens with increasing patient age. Three PRLs were in contact with the crystalline lens (6%), and there were lens opacities in 2 of these eyes. During accommodation, the ALS of all PRL models showed significant forward movement (P<0.05), whereas the distance between the PRL and crystalline lens decreased significantly with the PRL 101 and PRL 200 (P<0.05). The distance between the PRL 100 and crystalline lens remained unchanged during accommodation. The PRL moved forward during accommodation in all eyes, with the distance preserved between the PRL and the ALS with the PRL 100. The distance decreased with the other 2 models. In 85% of cases, there was no mechanical contact with the ALS during accommodation.

Clinical results with the Medennium phakic refractive lens for the correction of high myopia

Purpose To evaluate the predictability, safety, stability, complications, and biocompatibility of the phakic refractive lens (PRL) as a posterior chamber intraocular lens to correct high myopia. Methods Fifty eyes of 31 patients who underwent posterior chamber PRL implantation were evaluated prospectively. Mean preoperative myopia was -12.54 +/- 4.22 diopters (D) (range: -4.50 to -23.50 D) and mean astigmatic refractive power was -1.38 +/- 1.24 D (range: -1.00 to -4.50 D). Surgical implantation was performed through a 3.0- to 4.0-mm clear cornea sutureless incision using parabulbar (sub-Tenon's) anesthesia. Intra- and postoperative complications were recorded. Results Three months after surgery, the mean spherical equivalent refraction was -0.21 +/- 0.42 D (range: +1.00 to -1.75 D). At 6 and 12 months, mean spherical equivalent refraction was -0.23 +/- 0.38 D (range: 0 to -1.25 D). At the last examination, uncorrected visual acuity was > or = 20/40 in 41 (82%) eyes and > or = 20/20 in 22 (44%) eyes. Best spectacle-corrected visual acuity (BSCVA) was > or = 20/40 in 42 (84%) eyes and > or = 20/20 in 27 (54%) eyes. Comparison of pre- and postoperative BSCVA at 12 months showed that 12 (36.4%) of 33 eyes gained > or =1 lines of BSCVA and 7 (21.2%) of 33 eyes gained > or =2 lines. One (2%) eye developed anterior subcapsular cataract requiring lens exchange, and 1 (2%) eye developed acute angle closure glaucoma requiring YAG-iridotomy. One (2%) eye developed macular hemorrhage. Conclusions At 6 months and 1 and 2 years, PRL implantation yielded encouraging visual and refractive results with excellent biocompatibility. The efficacy, stability, and short-term safety of this lens was established. Serious complications, such as cataract and acute angle closure glaucoma, may occur, and long-term safety needs to be evaluated.

Clinical Results With the Medennium Phakic Refractive Lens for the Correction of High Myopia

To evaluate the predictability, safety, stability, complications, and biocompatibility of the phakic refractive lens (PRL) as a posterior chamber intraocular lens to correct high myopia. Fifty eyes of 31 patients who underwent posterior chamber PRL implantation were evaluated prospectively. Mean preoperative myopia was -12.54 +/- 4.22 diopters (D) (range: -4.50 to -23.50 D) and mean astigmatic refractive power was -1.38 +/- 1.24 D (range: -1.00 to -4.50 D). Surgical implantation was performed through a 3.0- to 4.0-mm clear cornea sutureless incision using parabulbar (sub-Tenon's) anesthesia. Intra- and postoperative complications were recorded. Three months after surgery, the mean spherical equivalent refraction was -0.21 +/- 0.42 D (range: +1.00 to -1.75 D). At 6 and 12 months, mean spherical equivalent refraction was -0.23 +/- 0.38 D (range: 0 to -1.25 D). At the last examination, uncorrected visual acuity was > or = 20/40 in 41 (82%) eyes and > or = 20/20 in 22 (44%) eyes. Best spectacle-corrected visual acuity (BSCVA) was > or = 20/40 in 42 (84%) eyes and > or = 20/20 in 27 (54%) eyes. Comparison of pre- and postoperative BSCVA at 12 months showed that 12 (36.4%) of 33 eyes gained > or =1 lines of BSCVA and 7 (21.2%) of 33 eyes gained > or =2 lines. One (2%) eye developed anterior subcapsular cataract requiring lens exchange, and 1 (2%) eye developed acute angle closure glaucoma requiring YAG-iridotomy. One (2%) eye developed macular hemorrhage. At 6 months and 1 and 2 years, PRL implantation yielded encouraging visual and refractive results with excellent biocompatibility. The efficacy, stability, and short-term safety of this lens was established. Serious complications, such as cataract and acute angle closure glaucoma, may occur, and long-term safety needs to be evaluated.

Biomicroscopie ultrasonore des implants phaques de chambre postérieure : étude comparative des modèles ICL et PRL

To evaluate the anatomic relationships of the implantable contact lens (ICL) and the phakic refractive lens (PRL) posterior chamber phakic intraocular lenses (PCP IOL) using ultrasound biomicroscopy (UBM).Seventeen phakic myopic eyes corrected with ICL, and 14 phakic myopic eyes that had had PRL implantation, were examined retrospectively using UBM. The main parameters measured and compared were anterior chamber depth, central and peripheral distance between PCP IOL and the crystalline lens, and exact lens haptic position.The mean distance between the PCP IOL and the central endothelium was 2398+/-203 microm and 2640+/-230 microm in the ICL and PRL groups, respectively. The central vault between the implant and the crystalline lens was greater in eyes with ICL (ICL, 402+/-194 microm; PRL, 256+/-187 microm, p<0.05). However, the incidence of lens contact on the peripheral level was higher in the ICL group (41%) than in the PRL group (29%), and the difference between the two implants in the peripheral crystalline lens-PCP IOL distance was significant (p<0.05). Both IOL haptics appeared to be correctly positioned in the sulcus in 13 (76%) eyes of the ICL group, and on the zonule in eight eyes (57%) of the PRL group.PCP IOL implantation is a safe procedure for the correction of high myopia with regard to refractive results. UBM provides a unique tool to noninvasively evaluate the relations of these implants within the posterior chamber, and helps to analyze the mechanisms of crystalline lens and iris complications.

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

To confirm the safety, efficacy, and predictability of the surgical correction of myopia and hyperopia with the phakic refractive lens (PRL) (Medennium Inc.). St. Eriks Eye Hospital, Stockholm, Sweden. 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. 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. 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.

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 μm ± 0.08 μm [range 0.09 μm to 0.38 μm]; post-PRL RMS: 0.21 μm ± 0.08 μm; [range 0.05 μm to 0.38 μm]) ( 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.

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 μm ± 232.5 (SD), and the mean PCP IOL–endothelium central distance was 2082.8 ± 277.6 μm. 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.

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.

Pigment vacuum iridectomy for phakic refractive lens implantation

I present a technique designed to ensure an atraumatic patent basal iridectomy for phakic refractive lens implantation. The technique divides the iridectomy procedure into 2 steps. First, the stromal layer is removed by surgical excision. Then, the pigment layer is removed by gentle vacuum aspiration with a 25 gauge cannula. Atraumatic, small, basal peripheral iridectomies that are functional and cosmetically pleasing have been performed in 12 eyes. There were no cases of large amounts of pigment debris deposited in the trabecular meshwork as checked by gonioscopy. Pigment vacuum iridectomy may be a reliable procedure to ensure a proper basal iridectomy in any type of anterior segment eye surgery.