Initial results of endothelial cell counts after Artisan Lens for Phakic Eyes

Comparison of the Biometric Characteristics After Long-term Implantation of Iris-fixated Phakic Intraocular Lens in Explanted and Nonexplanted Groups of Eyes

PURPOSE

To evaluate and compare the biometric characteristics of the anterior chamber of a group of patients with significant endothelial cell loss (ECL) who required phakic intraocular lens (pIOL) explantation and a group of patients who did not fulfill the explantation criteria related to corneal decompensation.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

The study included all consecutive patients receiving a pIOL implantation at Oftalmosalud Instituto de Ojos, Lima, Peru, between 2001 and 2012. The explanted group (E group) consisted of eyes in which the pIOLs were explanted due to ECL, and the nonexplanted group (NE group) consisted of eyes randomly selected in which the pIOL was not explanted with a minimum follow-up time of 8 years. Slit-lamp biomicroscopy, visual acuity, refraction, endothelial cell count, and anterior segment optical coherence tomography were assessed at the preoperative evaluation for both groups and before explantation in the E group and 8 years post-implantation in the NE group.

RESULTS

pIOLs were implanted in 265 eyes. The annual percentage of ECL was 1.47% and 5.55% in the NE group and E group, respectively (P < .001). The mean minimum endothelial lens distance (ELD) was 1.44 ± 0.22 mm and 1.05 ± 0.23 mm in the NE group and E group, respectively (P < 0.001). The mean time for explantation was 12.58 ± 3.79 years for the E group. Annual ECL could accurately discriminate between the NE group and E group; a cutoff point of 3.5 (%/year) or 86.5 (cells/years) had a 100% sensitivity and specificity. A cutoff of 1.21 mm in the minimum ELD has a 91% sensitivity and 79% specificity to discriminate between the E group and NE group.

CONCLUSIONS

pIOL explantation due to ECL occurs in eyes with a significantly postoperative lower minimum ELD. Annual ECL and minimum ELC can effectively discriminate between the E and NE groups.

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses

Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses

Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.

Five-year clinical outcomes of rigid iris-fixated phakic intraocular lens in northern Chinese

PURPOSE

To investigate the 5-year clinic outcomes of rigid iris-fixated pIOL on the visual performance, complications and intraocular light scattering in northern Chinese.

METHODS

Thirty eyes implanted with iris-fixated phakic IOLs (pIOLs group) and 34 eyes with high myopia (myopia group) were involved in this study. At preoperatively, 6 months, 1, 3, and 5 years postoperatively, the uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), endothelial cell density (ECD), and intraocular pressure (IOP) were measured in pIOLs group. The objective scatter index (OSI), modulation transfer function cut off (MTF cut off), and Strehl ratio were measured by Optical Quality Analysis System and a pseudophakic dysphotopsia questionnaire (PDQ) was used to evaluate the subjects' satisfaction in pIOLs and myopia groups.

RESULTS

At 5 years postoperatively, an UCVA of 20/20 or better was found in 43.33% of eyes in pIOLs group. At 6 months, 1, 3, and 5 years postoperatively, the mean ECD decrease were 1.29% ± 0.45%, 2.59% ± 1.30%, 6.67% ± 2.26%, and 10.80% ± 3.48%. The value of OSI in pIOLs group was significantly higher than that in myopia group (P < 0.001). The PDQ results showed that the subjects in myopia group complained less with intolerance of bright lights than those in pIOLs group. The values of Strehl ratio and MTF cut off in pIOLs group were significantly lower than that in myopia group (P < 0.001).

CONCLUSIONS

Iris-fixated pIOL induce more intraocular light scattering. A significant decrease in ECD was observed at 5 years postoperatively. An annual evaluation of ECD is necessary for patients undergoing pIOL implantation.

Middle- and long-term results after iris-fixated phakic intraocular lens implantation in myopic and hyperopic patients: a meta-analysis

The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects. The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects of iris-fixated pIOLs on myopic and hyperopic eyes with a follow-up of at least 2 to 4 years. Visual and refractive results after implantation for correction of myopia are positive and the complication rate is low. Endothelial cell loss appears to be at an acceptable rate, although the range of endothelial cell change is too wide to draw firm conclusions. Care should be taken when considering an iris-fixated pIOL for hyperopic eyes because complication rates, particularly pigment dispersion, might be higher than those in myopic eyes. More well-designed, long-term studies are needed, especially in hyperopic eyes. The authors advocate for standardized reporting of refractive surgery data. Initiatives proposed by journal authors and editors to achieve uniformity should be supported.

Long-Term Destiny of Corneal Endothelial Cells in Anterior Chamber Intraocular Lens-Implanted Eyes

Purpose

To investigate the long-term changes of corneal endothelial cells (EC) in anterior chamber intraocular lens- (AC-IOL-) implanted eyes.

Methods

Retrospective study. We included 37 eyes (25 patients) that received AC-IOL implantation previously in the Eye and ENT Hospital of Fudan University between 1995 and 2016. Follow-up outcomes included the best-corrected visual acuity (BCVA), endothelial cell density, hexagonality, coefficient of variance, and central corneal thickness.

Results

In total, 23 eyes (62.16%) with phakic and 14 eyes (37.84%) with aphakic AC-IOLs were included. Among these, 3 eyes (8.11%) were angle-supported AC-IOLs and 34 eyes (91.89%) were Artisan iris-fixated AC-IOLs. The mean age of patients was 41.40 ± 17.17 years, and the mean follow-up time was 12.12 ± 4.71 years in our study. At the follow-up time, corneal decompensation existed in 3 angle-supported AC-IOL eyes with a rate of 100% and 15 iris-fixated AC-IOL eyes with a rate of 44.12%. AC-IOL displacement occurred in 14 (41.18%) iris-fixated AC-IOL eyes. In the 19 iris-fixated AC-IOL eyes without corneal decompensation, significant changes also took place in corneal endothelial cells. The endothelial cell density decreased from 2843.26 ± 300.76 to 2015.58 ± 567.99 cells/mm² (29.1% loss, P < 0.001) and hexagonality decreased from 51.21 ± 7.83 to 42.53 ± 9.17 (%) (16.9% loss, P < 0.001). The Kaplan–Meier survival curve also demonstrated the accumulated expectation rates of corneal endothelial cell decomposition for AC-IOLs with a median survival time of 12 years.

Conclusion

We reported a significant chronic loss and long-term decompensation destiny of corneal endothelial cells in AC-IOL eyes. Semiannual or annual follow-up and evaluation of endothelial cells should be conducted in AC-IOL-implanted patients.

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.

Phakic Intraocular Lens Implantation After Deep Anterior Lamellar Keratoplasty: Retrospective Case Series Analysis With Long-Term Follow-Up

Purpose

To report outcomes of phakic intraocular lens (IOL) implantation after deep anterior lamellar keratoplasty (DALK) to correct high ametropia.

Setting

Centro Hospitalar Universitário do Porto, Portugal.

Methods

Retrospective case series with 11 eyes submitted to phakic IOL implantation after DALK. Main outcomes measured were uncorrected and corrected distance visual acuity (UDVA and CDVA), refractive error components, tomographic parameters and endothelial cell density (ECD). The minimum follow-up was 3 years for all cases.

Results

Mean ECD loss was 8.7±6.7% at 1 year, 13.1±8.6% at 3 years (n=11; p=0.016, p=0.007, respectively) and 14.0±20.4% at 5 years (n=5, p=0.212). Mean logMAR UDVA increased from 1.27±0.90logMAR preoperatively to 0.16±0.15logMAR postoperatively (p≤0.001) and no statistically significant differences were registered during follow-up. All patients gained at least 5 lines of UDVA. 54.5% of the eyes gained 1 line in CDVA postoperative and only one eye lost one CDVA line through follow-up. Efficacy and safety indexes at 1 and 3 years were 1.01–0.97 and 1.24–1.21, respectively. Mean spherical equivalent was reduced from −7.84±4.63 D preoperatively to −1.05±1.07 D postoperatively (p=0.001). Mean percentage of reduction in refractive cylinder and spherical error was 83.8±15.8% and 73.1±31.5%, respectively, p≤0.001 for both. In one eye there was a significantly gradual ECD loss over 5 years follow-up and the patient will be submitted to IOL explant.

Conclusion

Phakic IOLs were effective for correction high ametropia after DALK, showing high efficacy and safety indexes with stability over time. However, it was registered a continuing endothelial cell loss postoperatively, which assumed to be higher than those reported in eyes without DALK.

Phacoemulsification in phakic iris-claw lens with cataract

In this new technique of cataract surgery in patients with iris-fixated phakic intraocular lens with cataract, phakic IOL is explanted at the end of surgery. Phakic IOL remains stable and securely enclaved to the iris during phacoemulsification which is performed through a small 2.2 mm incision. Endothelial protection is provided by viscodispersive OVD above the phakic IOL and space for surgery is created by high molecular weight viscocohesive OVD beneath the phakic IOL. This technique provides significant advantages from the previously described techniques in terms of chamber stability, endothelial protection, iris trauma and surgical ease.

Visual acuity, endothelial cell density and polymegathism after iris-fixated lens implantation

PURPOSE

The purpose of this study was to evaluate the visual acuity as well as endothelial cell density (ECD) and polymegathism after iris-fixated lens (Artiflex® AC 401) implantation for correction of moderate to high myopia.

PATIENTS AND METHODS

In this retrospective cross-sectional study, 55 eyes from 29 patients undergoing iris-fixated lens implantation for correction of myopia (-5.00 to -15.00 D) from 2007 to 2014 were evaluated. Uncorrected visual acuity, best spectacle-corrected visual acuity, refraction, ECD and polymegathism (coefficient of variation [CV] in the sizes of endothelial cells) were measured preoperatively and 6 months postoperatively.

RESULTS

In the sixth month of follow-up, the uncorrected vision acuity was 20/25 or better in 81.5% of the eyes. The best-corrected visual acuity was 20/30 or better in 96.3% of the eyes, and more than 92% of the eyes had a refraction score of ±1 D from the target refraction. The mean corneal ECD of patients before surgery was 2,803±339 cells/mm2, which changed to 2,744±369 cells/mm2 six months after surgery (p=0.142). CV in the sizes of endothelial cells before the surgery was 25.7%±7.1% and six months after surgery it was 25.9%±5.4% (p=0.857).

CONCLUSION

Artiflex iris-fixated lens implantation is a suitable and predictable method for correction of moderate to high myopia. There was no statistically significant change in ECD and polymegathism (CV in the sizes of endothelial cells) after 6 months of follow-up.

Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients

Aim:

To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries.

Settings and Design:

Retrospective, noncomparable consecutive case series study.

Materials and Methods:

Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected.

Results:

Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or <20/1000. Within a 1.1–4.2-year follow-up period, a significant increase, equal to or better than 20/66, in UCVA was observed in six (55%) cases, and in best-corrected VA (BCVA) was observed in nine (82%) cases. Postoperative BCVA was 20/40 or better in seven cases (64%). After combined surgery, the iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients.

Conclusions:

Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support.

Creeping posterior synechiae following hyperopic iris-fixated phakic implants

The purpose of this study was to report on the occurrence and management of posterior synechiae (PS) in three hyperopic eyes after iris-fixated anterior chamber phakic IOL implantation. This is a case report of a 55-year-old man and a 55-year-old lady who had undergone iris-fixated anterior chamber phakic IOL implantation to correct hyperopic astigmatism (one eye) and hyperopia (both eyes), respectively. The three eyes developed creeping PS and pigment dispersion within 4-6 weeks of surgery. Synechiolysis and pupil stretching in one eye did not work as the synechiae promptly recurred. Definitive management in the form of removal of the phakic implant and phacoemulsification with lens implant was successful in restoring normal vision in all three eyes. Although implantation of phakic intraocular lenses has been reported to be very effective for the correction of moderate to high degrees of ametropia, this complication can occur in hyperopic eyes. Pigment dispersion has been reported in myopic eyes also, but PS seem to be more an issue with hyperopic eyes. Age of the patient may also be a factor. This information is important in the selection and counselling of patients.

Corneal endothelial cell density after vitrectomy with silicone oil for complex retinal detachments

PURPOSE

To evaluate the endothelial cell density changes in eyes with silicone oil tamponade after vitrectomy for complex rhegmatogenous retinal detachment.

METHODS

A prospective controlled study with 81 eyes with complex rhegmatogenous retinal detachment undergoing vitrectomy and silicone oil tamponade. Fellow eyes that fulfilled specific inclusion criteria served as controls. Endothelial cell density (in cells per square millimeter), coefficient of variance (standard deviation per mean cell area × 100), percentage of hexagonal cells, and corneal thickness were documented preoperatively and compared with values obtained at 3, 6, and 12 months postoperatively. For the purpose of the study analysis, all study eyes were divided into 5 groups, according to their lens status during the follow-up.

RESULTS

High endothelial cell density loss was found in Group 3, (eyes that underwent an additional phacoemulsification procedure) and Group 4 (eyes that underwent lens and/or intraocular lens removal during the follow-up) at 12 months with a mean cell loss of 19% and 39%, respectively (P < 0.001).

CONCLUSION

An intact natural or artificial lens-iris diaphragm may provide a protective barrier against corneal endothelial cell damage from long-term silicone oil tamponade.

Comparison of surgically induced astigmatism following iris-claw PIOL insertion with scleral, limbal, or corneal incisions

PURPOSE

To compare surgically induced astigmatism (SIA) based on incision site and evaluate the clinical results and astigmatic stability of iris-claw phakic intraocular lens (Artisan lens; Ophtec BV, Groningen, Netherlands) implantation.

METHODS

Eighty-five eyes of 53 patients with myopia who underwent Artisan lens implantation with a 6.2-mm incision and follow-up of 6 months were retrospectively observed. SIA was assessed using keratometric astigmatism at 6 months postoperatively for the incision sites of the sclera, limbus, and cornea, and the efficacy, safety, predictability, and astigmatic stability were also calculated.

RESULTS

SIA obtained using Naeser's polar method (KP[90]SIA) was -0.48 ± 0.35 for scleral incisions, -0.99 ± 0.35 for limbal incisions, and -1.14 ± 0.54 for corneal incisions. Corresponding net astigmatism values, as calculated with KP(90)SIA and KP(135)SIA, were 0.70 ± 0.48 (177°), 1.04 ± 0.37 (175°), and 1.21 ± 0.57 (1°), respectively, with SIA increasing the nearer the incision was to the cornea center. Six months after surgery, the efficacy index was 1.03 and the safety index was 1.08. Ninety-eight percent of patients were within 1.50 diopters of attempted refraction.

CONCLUSIONS

The values of SIA after Artisan lens insertion showed significant differences among three incision locations, despite the absence of significant differences in preoperative steep corneal axis astigmatism values at the incision locations. It would be applicable for refractive surgery in the aspect of minimizing astigmatism after surgery.

Pediatric refractive surgery

This article reviews current thoughts regarding pediatric refractive surgery. This encompasses current trends in adult refractive surgery, differences between adult and pediatric refractive surgery, and future possibilities for refractive technology for the pediatric population.

Intraocular pressure after implantation of the Visian Implantable Collamer Lens With CentraFLOW without iridotomy

PURPOSE

To compare the intraocular pressure (IOP) values during a 3-month period after implantation of the new Visian Implantable Collamer Lens (ICL; STAAR Surgical Company, Nidau, Switzerland) V4c design with CentraFLOW technology without iridotomy using a standard procedure followed by implantation of the conventional ICL V4b model.

DESIGN

Retrospective cohort study.

METHODS

This study included 17 eyes implanted with the ICL V4b model and 18 eyes implanted with the ICL V4c model. The mean preoperative spherical equivalent refractions were -7.48 ± 5.00 diopters and -8.66 ± 4.2 diopters, respectively. We compared the best-corrected distance visual acuity before surgery with the uncorrected distance visual acuity after surgery. The intraocular pressure (IOP) was measured 1 week, 1 month, and 3 months after surgery. The central vault at 3 months was measured using optical coherence tomography.

RESULTS

Three months after surgery, the mean uncorrected distance visual acuities were -0.09 ± 0.12 logarithm of the minimal angle of resolution units with the V4b and -0.07 ± 0.11 logarithm of the minimal angle of resolution units with the V4c. The mean distances between the ICL and the anterior crystalline lens surface were 557 ± 224 μm and 528 ± 268 μm for the V4b and V4c, respectively (P = .73). After 1 week and 1 month, the mean IOPs were 13.7 and 13.3 mm Hg and 14.7 and 15.1 mm Hg, respectively. There were no significant differences in IOP within or between groups during the follow-up period (P > .05, for all comparisons).

CONCLUSIONS

The new ICL with the CentraFLOW design seems to provide similar results as its predecessors for the correction of moderate to high myopia and maintenance of safe IOP levels without iridotomy.

Advances in Refractive Surgery

PURPOSE

The objective of this study was to review advances in the field of refractive surgery as reported in the peer-reviewed literature over the previous year.

DESIGN

This was a literature review.

METHODS

We conducted a PubMed search for terms related to refractive surgery and reviewed prominent international ophthalmic journals published from May 2012 through April 2013. All pertinent articles were reviewed, and selected articles with the greatest relevance were included.

RESULTS

Many studies over the previous year have highlighted progress in the field of refractive surgery; topics included keratoconus screening, photorefractive keratectomy and laser in situ keratomileusis, corneal cross-linking, small-incision lenticule extraction, phakic intraocular lenses, corneal inlays, presbyopic corneal treatments, and femtosecond laser-assisted astigmatic keratotomy.

CONCLUSIONS

The field of refractive surgery continues to provide exciting developments. Improvements in established procedures and promising new surgical options make the current climate an appealing one for refractive surgeons and patients.

Artiflex Toric foldable phakic intraocular lens: short-term results of a prospective European multicenter study

PURPOSE

To evaluate the short-term efficacy, predictability, stability, and safety of the foldable Artiflex Toric phakic intraocular lens (pIOL; Ophtec) for the correction of myopia with astigmatism.

DESIGN

Prospective, nonrandomized multicenter study.

METHODS

One hundred fifteen eyes of 73 patients were implanted with an Artiflex Toric pIOL. Mean implanted spherical and cylindrical powers were -7.10 ± 2.70 diopters (D) and -2.14 ± 0.80 D, respectively. Total follow-up was 6 months. Outcome parameters included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), subjective manifest refraction (used for vector analysis), intraocular pressure, and endothelial cell density (ECD).

RESULTS

At 6 months, 99.0% of eyes had a UCVA of ≥20/40, and 81.8% of eyes were ±0.5 D of the intended refraction. In 74.5% postoperative UCVA was equal to or better than preoperative BSCVA; 2 eyes lost 2 or more lines of BSCVA postoperatively because of the development of synechiae. In 75.5% of eyes the remaining cylinder was ±0.5 D. There was a significant decrease in ECD after 3 months (4.8% ± 11.9%), with no additional decline between 3 and 6 months. There were few complications, except for the incidence of pigment and nonpigment precipitates (14.8% and 12.2%, respectively at 6 months). Mean misalignment was 0.6 ± 1.5 degrees (range 0-8).

CONCLUSIONS

The Artiflex Toric pIOL effectively and safely corrects myopia and astigmatism in the short term, with stable and predictable visual results after 6 months, when strict inclusion criteria are applied. Deposition of pigment and nonpigment precipitates on the pIOL warrants further investigation.

Foldable iris-fixated phakic intraocular lens implantation for the correction of myopia: two years of follow-up

Purpose:

To evaluate the safety, efficacy and potential risks of Artiflex foldable iris-fixated phakic intraocular lens (pIOL) implantation for the management of myopia.

Materials and Methods:

Seventy-eight eyes of 40 consecutive patients with a mean spherical refraction of –11.70 ± 3.77 diopters (D; range –5.50 to –17.5 D) were included in this prospective, noncomparative, interventional case series. Main parameters assessed were uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), corneal topography (Orbscan II, BauchandLomb, Rochester, NY, USA), manifest and cycloplegic refractive errors, endothelial cell density (ECD) and applanation tonometry.

Results:

After 2 years, BSCVA was 20/40 or better in 82% of the eyes and UCVA was 20/40 or better in 84% of the eyes. After 1 month, 1 year, and 2 years, 51.3% (37 of 72 eyes), 58.9% (46 of 78 eyes) and 76.0% (38 of 50 eyes) of eyes gained 1 line or more of BSCVA, respectively. Compared to preoperative values, the mean endothelial cell loss was 2.6% at 1 month, 4.9% at 1 year and 7.4% at 2 years. Pigmented or non-pigmented precipitates were observed in17 eyes (21.7%) which were treated with topical corticosteroids. At the second postoperative year, pigmented precipitates persisted in nine eyes. However, this was not associated with a loss of BSCVA.

Conclusion:

The implantation of Artiflex pIOL is an effective surgical option for the management of high myopia. The most common complication observed within 2 years of follow-up was accumulation of pigmented precipitates with no effect on the final BSCVA.

Refractive lens exchange versus phakic intraocular lenses

PURPOSE OF REVIEW

To review the evidential basis of current practice in refractive lens exchange (RLE) vs. phakic intraocular lens (pIOL).

RECENT FINDINGS

Visual outcomes after pIOLs are better than RLE. With RLE, there still remain risks of retinal detachment, cystoid macular oedema, glare, halos and posterior capsule opacification. With pIOLs, risks include pigment dispersion, cataract formation, glaucoma and inflammation. The decision to choose between either is broadly based on age and type of refractive error, and the choice follows thorough evaluation and counselling taking into consideration patient's needs and expectations.

SUMMARY

With advancing technology, newer IOL models for RLE and phakic correction are becoming available. pIOLs provide better visual outcomes for distance correction and currently do not provide near-vision correction possible with RLE.

Collagen crosslinking and toric iris-claw phakic intraocular lens for myopic astigmatism in progressive mild to moderate keratoconus

PURPOSE

To report the long-term results of combined collagen crosslinking (CXL) and toric phakic intraocular lens (pIOL) implantation to correct myopic astigmatism in patients with progressive mild to moderate keratoconus.

SETTING

Instituto de Microcirugia Ocular, Barcelona, Spain.

DESIGN

Case series.

METHODS

From November 2006 to July 2009, CXL was performed in eyes with proven progressive keratoconus. Once refraction and topography stabilized, toric Artiflex/Artisan pIOL implantation was performed to correct residual myopic astigmatism. A complete ophthalmologic examination, including manifest refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, biomicroscopy, tonometry, fundoscopy, keratometry, corneal tomography, and central endothelial cell count (ECC), was performed before each procedure and postoperatively at 3 months and at yearly intervals up to 5 years. Main outcome measures were accuracy and stability of the spherical equivalent (SE) and cylinder, keratometry, UDVA (efficacy), CDVA (safety), central ECC, and complications.

RESULTS

The median follow-up in the 9 patients (17 eyes) was 36.9 months ± 15.0 (SD). The median interval between CXL and pIOL implantation was 3.9 ± 0.7 months. Fourteen eyes (82%) were within ± 0.50 diopter (D) of the attempted SE correction and 13 eyes (76%) were within ± 1.00 D of the attempted cylinder correction. The mean difference in simulated keratometry between preoperatively and the last follow-up was 0.17 ± 0.45 D (range -0.55 to 1.45 D). The postoperative UDVA was 20/40 or better in 16 eyes (94%). No eye lost lines of CDVA. No significant decrease in central ECC occurred (P>.05).

CONCLUSION

Combined CXL and toric iris-claw pIOL implantation effectively and safely corrected myopic astigmatism in progressive mild to moderate keratoconus.

FINANCIAL DISCLOSURE

Dr. Güell is a consultant to Ophtec. No other author has a financial or proprietary interest in any material or methods mentioned.

Management of corneal endothelial decompensation caused by iris-fixated phakic intraocular lenses with descemet stripping automated endothelial keratoplasty

PURPOSE

To describe 2 cases of corneal decompensation after iris-fixated phakic intraocular lens (pIOL) implantation requiring Descemet stripping automated endothelial keratoplasty (DSAEK).

MATERIALS AND METHODS

Case reports and literature review.

RESULTS

Two cases of corneal decompensation after pIOL implantation are reported. The average age at presentation was 52 years (range: 37 to 67 years) in 2 women. The mean presentation time of corneal decompensation after pIOL implantation was 29 months (range: 22 to 36 months). Both the affected eyes required pIOL explantation and DSAEK to treat corneal decompensation. One patient (1 eye) had concurrent cataract surgery to maximize visual rehabilitation. The mean follow-up after DSAEK surgery was 14 months (range: 12 to 16 months). The best-corrected visual acuity was 20/50 (range: 20/40 to 20/60) at the last follow-up.

CONCLUSIONS

Despite a good safety profile for iris-fixated pIOLs, some patients may still develop corneal decompensation after implantation. We report a pair of cases with corneal decompensation severe enough to warrant endothelial transplantation and pIOL explantation, with and without concomitant cataract surgery.

Prominent decrease of superior midperipheral endothelial cell density after iris-fixated phakic intraocular lens implantation

PURPOSE

To evaluate changes in endothelial cell density (ECD) in the corneal region after implantation of an iris-fixated phakic intraocular lens (PIOL).

METHODS

Forty-five eyes of 25 myopic patients implanted with Artisan iris-fixated PIOLs (Ophtec BV) and 30 eyes of 15 myopic controls were enrolled. Corneal ECD and the distance between endothelium and the PIOL optic were evaluated in five different regions (central, nasal, superior, temporal, and inferior) using noncontact specular microscopy and rotating Scheimpflug imaging.

RESULTS

In PIOL-implanted patients, significant differences between the ECD in the superior region, compared with the lowest ECD in any region, and the ECD of the central region, compared with that of the region with highest ECD, were evident. When PIOL-implanted eyes were divided based on time since operation, a significant difference was observed only in patients for whom at least 48 postoperative months had elapsed. In untreated myopic controls, the greatest ECD was observed at the superior cornea. The distance between the central corneal endothelium and PIOL was significantly longer than that of the peripheral locations.

CONCLUSIONS

The extent of ECD decrease was not consistent throughout the cornea after implantation of an iris-fixated PIOL. Therefore, ECD measurement not only at the corneal center but also at midperipheral corneal locations, especially in the superior cornea, may be important in patients with irisfixated PIOLs.

Current approaches for management of postpenetrating keratoplasty astigmatism

A successful corneal graft requires both clarity and an acceptable refraction. A clear corneal graft may be an optical failure if high astigmatism limits visual acuity. Intraoperative measures to reduce postkeratoplasty astigmatism include round and central trephination of cornea with an adequate size, appropriate sutures with evenly distributed tension, and perfect graft-host apposition. Suture manipulation has been described for minimising early postoperative astigmatism. If significant astigmatism remains after suture removal, which cannot be corrected by optical means, then further surgical procedures containing relaxing incisions, compression sutures, laser refractive surgery, insertion of intrastromal corneal ring segments, wedge resection, and toric intraocular lens implantation can be performed. When astigmatism cannot be reduced using one or more abovementioned approaches, repeat penetrating keratoplasty should inevitably be considered. However, none of these techniques has emerged as an ideal one, and corneal surgeons may require combining two or more approaches to exploit the maximum advantages.

Long-term results of phakic refractive lens implantation in eyes with high myopia

PURPOSE

To evaluate the long-term results of phakic refractive lens (PRL; Carl Zeiss Meditec) implantation in eyes with high myopia.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Long-term results show that PRL implantation is an effective and safe method for treating high myopia.

Late onset secondary cataract following implantation of an iris-fixated phakic intraocular lens

PURPOSE

To report a case of bilateral late onset anterior cortical cataract following implantation of an iris-fixated phakic intraocular lens (pIOL).

METHODS

Single observational case report.

RESULTS

Three and a half years following uncomplicated consecutive implantation of iris-fixated pIOL in both eyes, anterior cortical cataract changes inferiorly emanating from the site of enclavation of the lens in the right eye were noted. By 7 years after implantation, anterior cortical cataract changes were seen emanating from the enclavation sites superiorly and inferiorly in both eyes. These cataracts did not cause any loss of corrected distance visual acuity.

CONCLUSIONS

This case demonstrates that a potential complication of an iris-fixated pIOL is late onset secondary cataract formation.

Late-onset nontraumatic dislocation of anterior chamber phakic intraocular lens

Long-term stability of the position of phakic intraocular lenses (pIOLs) is important in maintaining visual acuity as well as avoiding injury to the local tissues. We report a case of late nontraumatic dislocation of an iris-fixated pIOL, with subsequent successful repositioning.

Combined Kerarings and Artisan/Artiflex IOLs in Keratectasia

PURPOSE:To evaluate the results of combined intracorneal ring (Keraring, Mediphacos Ltd) and anterior chamber, iris-fixated, phakic intraocular lens (pIOL) (Artisan and Artiflex, Ophtec BV) implantation in patients with ectatic corneal conditions and secondary high myopic and astigmatic refractive error. METHODS:Ten eyes of eight consecutive patients with different ectatic corneal diseases underwent sequential intracorneal Keraring and iris-fixated pIOL implantation. Two eyes with keratoconus, one eye with pellucid marginal degeneration, and one eye with iatrogenic corneal ectasia were implanted with the Artisan pIOL; six eyes with keratoconus were implanted with the Artiflex pIOL. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), topographic findings, and complications were recorded. RESULTS:Mean UDVA improved from 0.02+/-0.10 pre-operatively to 0.11+/-0.06 after Keraring implantation and to 0.54+/-0.18 after pIOL implantation (P<.001 for all). Mean CDVA improved from 0.18+/-0.12 preoperatively to 0.39+/-0.13 after Keraring implantation and to 0.66+/-0.18 after pIOL implantation (P<.001 for all). Mean MRSE reduced from -12.50+/-6.31 D preoperatively to +/-12.08+/-5.17 D after Keraring implantation (P=.10) and to -0.10+/-0.84 D after pIOL implantation (P<.001). No intra- or postoperative complications were observed. CONCLUSIONS:Sequential intracorneal Keraring segments and Artisan/Artiflex pIOL implantation resulted in visual and refractive improvements in patients with different corneal ectatic conditions with high myopic refractive errors.

Secondary iris claw intraocular lens implantation for the correction of aphakia after pars plana vitrectomy

PURPOSE

The purpose of this study was to evaluate the safety and efficacy of iris claw intraocular lens implantation for correction of aphakia in vitrectomized eyes without capsular support.

METHODS

This was a prospective interventional case series. Twelve aphakic vitrectomized eyes without capsular support underwent iris claw intraocular lens implantation. The main outcome measures were changes in uncorrected visual acuity, best-corrected visual acuity, spheric equivalent, corneal endothelial cell density, corneal thickness, central macular thickness, and complications.

RESULTS

Mean follow-up was 15.58 +/- 3.80 months with no intraoperative complications. Postoperatively, uncorrected visual acuity increased significantly at all follow-up visits (P < 0.05). Mean best-corrected visual acuity increased 10 letters/2 lines at the final follow-up visit (P = 0.023). Mean postoperative spheric equivalent at the last visit was -1.68 +/- 063 D, and the spheric equivalent was within +/-2.00 D of emmetropia in 9 (75%) eyes. Mean central macular thickness increased only at postoperative Month 3 (P = 0.043). Mean endothelial cell density loss was 23.87% at the last visit. Mean corneal thickness did not change during follow-up (P > 0.05). No corneal edema was observed. Complications were transient intraocular pressure increase (n = 1), cystoid macular edema (n = 1), and haptic dislocation replaced by surgery (n = 1). Retinas remained attached in all eyes.

CONCLUSION

Secondary iris claw intraocular lens implantation is clinically safe and effective to correct aphakia in vitrectomized eyes without capsular support. Larger studies with longer follow-up are warranted.

[Iris-fixated intraocular lenses: reinforced monitoring]

In 1986, the concept of the claw lens was applied to correct myopia in phakic patients. Since then, progress has made iris-fixated phakic intraocular lenses (IOL) relatively safe, predictable, and effective for the correction of myopia, hyperopia, and astigmatism. All these models have undergone a series of design improvements to prevent complications. Despite having excellent refractive results, the principal risk is a potential progressive endothelial cell loss. Many authors have presented encouraging results. Phakic iris-fixated IOL surgery is a potentially reversible procedure, but the surgeon cannot rule out the possibility of complications. Therefore, long-term follow-up is mandatory.

Late-onset decentration of iris-fixated phakic intraocular lenses: a case series

PURPOSE

To investigate late-onset downward decentration of iris-fixated phakic intraocular lenses (pIOL) resulting from progressive shifting of the haptics through the iris and its influence on the position of the pIOL and the amount of enclavated iris tissue.

DESIGN

Institutional, prospective, observational case series.

METHODS

Six patients (9 eyes) from among 368 eyes had 1 shifted haptic during long-term follow-up. Anterior segment optical coherence tomography (AS-OCT) was used to measure the distance between the edges of the pIOL and the corneal endothelium. Slit-lamp photography imaged the pIOL after implantation and after decentration. The images were analyzed to determine decentration and amount of iris tissue at the enclavation sites.

RESULTS

Shifting of the haptics occurred in 2.4% and was discovered at a mean follow-up of 4.8 years (range, 3 to 7 years). Mean downward decentration was 0.28 +/- 0.15 mm. Mean edge-distances on the nasal, temporal, superior, and inferior side were 1.71 +/- 0.30 mm, 1.86 +/- 0.31 mm, 1.86 +/- 0.31 mm, and 1.58 +/- 0.34 mm, respectively. Mean enclavated iris tissue on the nasal and temporal side was smaller after decentration when compared with that directly after surgery (P = .033 and P = .017, respectively). Shifting of the haptics did not result in a decreased uncorrected and best-corrected visual acuity.

CONCLUSIONS

Late-onset downward decentration resulting from progressive shifting of the haptics occurred in 2.4% and was associated with a decrease in enclavated iris tissue. AS-OCT showed a mean distance between the edge of the pIOL and the endothelium greater than the advised safety distance of 1.5 mm.

Case of late-onset corneal decompensation after iris-fixated phakic intraocular lens implantation

A 48-year-old myopic patient with bilateral anterior chamber depth of 3.1 mm and endothelial cell density (ECD) of 2525 cells/mm(2) and 2638 cells/mm(2) preoperatively had bilateral implantation of an Artisan iris-fixated phakic intraocular lens (pIOL). Five years postoperatively, unilateral corneal stromal edema was seen in a circumscribed area overlying the temporal ridge of the pIOL in the right eye; the ECD was 1631 cells/mm(2) and the pachymetry, 586 microm. Explantation of the pIOL was refused by the patient. Seven years postoperatively, the ECD was 413 cells/mm(2) in the right eye and corneal decompensation occurred. The progressive unilateral endothelial loss was explained by excessive rubbing of the eyes because of chronic itching and an anterior shift of the pIOL over the 7 years as demonstrated by anterior optical coherence tomography.

The effect of mitomycin C on corneal endothelium in pterygium surgery

PURPOSE

To evaluate the changes in endothelial cell counts in patients after pterygium surgery with mitomycin C (MMC) 0.02% and to compare them with patients undergoing pterygium excision without MMC.

DESIGN

Prospective nonrandomized study.

METHODS

Forty-three consecutive patients were included in this study. Sixteen patients underwent pterygium surgery with conjunctival autograft and MMC for recurrent pterygium and 27 patients underwent pterygium excision without MMC for primary pterygium removal (control group) at the Toronto Western Hospital. Endothelial images were acquired at the center of the cornea with a specular microscope before surgery and at one week, one month, and three months following surgery.

RESULTS

Mean preoperative endothelial cell counts were 2330 +/- 318 cells/mm(2) in the pterygium excision without MMC group and 2486 +/- 327 cells/mm(2) in the pterygium excision with MMC group (P = .13). One month after surgery, the pterygium with MMC group showed a significant endothelial cell loss of 6% which was not present in the control group (P = .03). Three months after surgery, endothelial cell loss was reduced to 4%. (P = .08 compared with the control). In the pterygium excision with MMC group, endothelial polymeghatism was increased (at one and three months) and the percentage of hexagomal cells was reduced (at one month).

CONCLUSIONS

The use of topical MMC during recurrent pterygium surgery was found to have a deleterious effect on corneal endothelium one month following surgery. Judicious use of this drug is therefore recommended.