Endothelial study of iris-claw phakic lens: four year follow-up

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.

OUTCOMES OF RETROPUPILLARY IRIS CLAW INTRAOCULAR LENS IMPLANTATION COMBINED WITH PARS PLANA VITRECTOMY

PURPOSE

To report 12-month visual outcomes, incidence of intraocular pressure (IOP) changes and postoperative complications after pars plana vitrectomy with retropupillary implantation of an iris claw intraocular lens (IOL) in aphakic eyes after complicated cataract surgery and eyes with a dislocation of the IOL.

METHODS

This is a retrospective analysis of eyes undergoing implantation of an iris claw IOL combined with pars plana vitrectomy from 1st of January 2009 until 30th of June 2018 after complicated cataract extraction with capsular loss (Group A) or dislocation of an IOL (Group B). Corrected distance visual acuity was analyzed in logarithm of the minimum angle of resolution (logMAR) units, IOP was recorded in mmHg.

RESULTS

Eyes in Group A (n = 49) improved from a preoperative median visual acuity of 0.523 logMAR (Snellen 20/65) to 0.201 logMAR (Snellen 20/30), P < 0.01. Eyes in Group B (n = 126) showed stable median visual acuity, preoperative 0.301 logMAR (Snellen 20/40) versus postoperative 0.222 logMAR (Snellen 20/30), P > 0.05. During 12 months in Group A, IOP >21 mmHg occurred in 9 (18.4%) eyes; no eye had an IOP <6 mmHg. In Group B, IOP >21 mmHg occurred in 15 (11.9%) eyes, IOP <6 mmHg in 5 (4%) cases. None of the eyes in Group A and B had IOP >21 mmHg or <6 mmHg at 12 months follow-up.

CONCLUSION

The retropupillary implantation of an iris claw IOL with pars plana vitrectomy provides adequate visual rehabilitation and seems to be safe in IOP changes.

Myopic Correction with Iris-Fixated Phakic Intraocular Lenses: Twelve-Year Results

PURPOSE

To evaluate a 12-year follow-up of myopic patients after iris-fixated phakic intraocular lenses (IF pIOLs) implantation. Setting. Ophthalmology Department, Military University Hospital in Prague (Czech Republic).

DESIGN

Single-center retrospective cohort study.

METHODS

We describe the results of a cohort study that included 85 eyes of 46 myopic patients who underwent implantation of Verisyse myopia, Veriflex, and Verisyse myopia toric (all Abbott Medical Optics, Inc.) intraocular lenses. Refractive functions and adverse events were assessed preoperatively, at 6 months, and 1, 2, 5, and 12 years after IF pIOL implantation.

RESULTS

Mean spherical equivalent was measured as -9.37 ± 2.87 D, 0.14 ± 0.61 D, and -0.42 ± 1.08 D, preoperatively, at 6 months and 12 years postoperatively, respectively. There was a significant reduction in the cylinder after surgery. At 12 years postoperatively, 90% of eyes had uncorrected distance visual acuity (UDVA) of 20/40 and 64% of 20/20. The safety index was 1.10 for the whole postoperative follow-up period. We found cataract formation in 3 eyes (3.5%). The endothelial cells loss (EC loss) directly caused by IF pIOL implantation was 6.0%, 8.10%, 12.8%, and 11.9%, at 1, 2, 5, and 12 years, respectively. In our cohort, 95% of eyes lost a higher percentage of EC than would be expected from a physiological loss at 12 years postoperatively. We found a significant negative interaction between preoperative pachymetry and EC loss, indicating that the lower pachymetry leads to a faster decline in endothelial cells density (ECD). IF pIOL re-enclavation was found in 28% of eyes. 7% of subluxations were caused by trauma. The mean time of nontraumatic re-enclavation was 6 years postoperatively.

CONCLUSIONS

The study confirmed the advantages of IF pIOL implantation due to rapid visual recovery and stable visual function over the 12-year follow-up and also showed the influence of lower corneal pachymetry regarding EC loss.

Retropupillary Iris-Claw Intraocular Lenses: A Literature Review

Retropupillary iris-claw intraocular lenses (ICIOLs) have been increasingly chosen by surgeons nowadays as a primary or secondary procedure of IOL implantation in eyes with insufficient capsular or zonular support. They have gained popularity due to their simple fast technique, favourable functional outcomes, and safety. The transition in the ICIOL fixation from prepupillary to a more biologically appropriate retropupillary position and change in the optic design from biconvex to convex-concave have provided better visual outcomes and improved safety. A peer-reviewed literature search was conducted in Medline (PubMed), Embase, and Cochrane Library using the keywords "retropupillary iris claw" and "iris claw". The search yielded 310 articles that were screened. Forty-three articles on retropupillary ICIOLs were finally found to be relevant and reviewed in full-text versions. The functional outcomes following retropupillary implantation of ICIOLs have been acceptable in eyes with no ocular co-morbidities otherwise. However, the indications for surgery may affect the outcomes. The major postoperative complications directly associated with ICIOLs include pupil ovalization and redislocation. Nevertheless, the rate of disenclavation depends on the experience and skill of the surgeon. This review is based on a literature review, and it focuses on the preoperative evaluation, surgical technique, postoperative outcomes, and associated complications. Prospective randomized trials with a larger sample size and longer follow-up are needed for comparison with other techniques of IOL fixation and confirmation of long-term safety profile.

Retropupillary iris-claw intraocular lens implantation in aphakic patients

Purpose:

To evaluate the outcomes of implantation of an iris-claw intraocular lens (IC-IOL) in retropupillary position in aphakic patients.

Methods:

We conducted a prospective interventional study, including 36 aphakic eyes with inadequate capsular support. The postoperative examination included best-corrected visual acuity (BCVA), intraocular pressure (IOP) measurement, central corneal thickness (CCT), and anterior segment examination with emphasis on the anterior chamber reaction and shape of pupil. Follow-up was done for 3 months.

Results:

Thirty-six eyes of 34 patients, including 22 right eyes and 14 left eyes were included. Indications for surgery were complicated cataract surgery in 38.9% (n = 14), aphakia in 27.8% (n = 10), pseudophakic bullous keratopathy in 16.7% (n = 6), dislocated posterior chamber IOL (PCIOL) in 11.1% (n = 4), IC drop in 2.8% (n = 1), and subluxated PCIOL in 2.8% (n = 1). Postoperatively, the visual acuity improved by at least two lines in 32 (88.9%) and worsened in four (11.1%) eyes at the end of three months. Mean postoperative IOP at the end of the third month was 12.42 mmHg (standard deviation [SD] 2.57; range 11.55–13.29 mmHg). The mean postoperative CCT at the end of the third month was 542.42 microns (SD 13.77; range 537.76–547.07 microns). Sixteen eyes (44.4%) had horizontally oval pupil, eleven eyes (30.6%) had round pupil, and nine eyes (25%) had irregular pupil. Twenty-three eyes (63.9%) presented with significant anterior chamber reaction and seven eyes (19.4%) had corneal stromal edema on postoperative day 1.

Conclusion:

Our study demonstrated that retropupillary IC-IOL implantation in eyes without adequate capsular support is an effective and safe procedure with a good visual outcome and fewer complications.

Efficacy and safety of iris-supported phakic lenses (Verisyse) for the treatment of high myopia: 5-year results

PURPOSE

Evaluating efficacy and safety of iris-supported phakic lenses (Verisyse) for high myopia treatment.

METHODS

Patients treated with Verisyse (Abbott Medical Optics, Santa Ana, CA, USA) intraocular lens (IOL) implants were evaluated retrospectively. Patients with follow-up periods of more than 5 years were included in the study. Pre- and postoperative fifth-year spheric equivalent (SE) of manifest refraction values, uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively), and endothelial cell density (ECD) values were recorded. Complications were evaluated.

RESULTS

Forty-seven eyes of 31 patients were included in the study. Pre- and postoperative fifth year mean SE was - 12.50 ± 3.51D and - 0.72 ± 0.40D, respectively. Pre- and postoperative fifth-year UDVA was 1.56 ± 0.22 and 0.33 ± 0.18 logMAR (p < 0.001), respectively. The safety index (pre- and postoperative CDVA) was 1.39 ± 0.63 at the 5-year follow-up (p > 0,05). The efficacy index (ratio of mean postoperative UDVA to mean preoperative CDVA) of the patients was 1.14 ± 0.60. The mean postoperative endothelial cell loss at 5 years was -7.42%. None of the patients had lost 25% of their preoperative endothelial cells at 5-year follow-up. The mean postoperative endothelial cell loss was -3.05% at 1 year, -1.23% between years one and three, -1.02% between the third and fifth years.

CONCLUSION

Verisyse IOL implantation is an effective and safe for high myopia surgical treatment. However, the 5-year follow-up period is not sufficient to evaluate the safety profiles in terms of endothelial cells.

Sutureless Intrascleral Posterior Chamber Intraocular Lens Fixation: Analysis of Clinical Outcomes and Postoperative Complications

PURPOSE

To report a technique for performing sutureless intrascleral fixation of a posterior chamber intraocular lens (PC-IOL) and analyzing the clinical outcomes and postoperative complications. Study Design. 68 eyes of 66 patients who received the technique were studied retrospectively.

METHODS

The best-corrected visual acuity (BCVA), intraocular pressure (IOP), anterior chamber depth (ACD), IOL tilt and decentration, corneal topography (K1 and K2), and postoperative complications were determined at 3 months.

RESULTS

The mean preoperative BCVA was 1.63 ± 1.24 logMAR units, and the mean postoperative BCVA was 0.74 ± 0.59 logMAR units at 3 months (P < 0.05). The mean preoperative IOP was 21.9 ± 12.6 mmHg, and the mean postoperative IOP was 16.9 ± 4.5 mmHg at 3 months (P = 0.001). The mean preoperative corneal topography (K1 and K2) was K1 = 42.14 ± 1.91 and K2 = 43.54 ± 1.51; the mean postoperative corneal topography (K1 and K2) was K1 = 43.03 ± 2.18 and K2 = 43.40 ± 1.71 at 3 months (P = 0.678 and 0.468, respectively). The mean preoperative spherical equivalent was +11.00 ± 13.19 diopters (D), and the mean postoperative spherical equivalent was +0.06 ± 0.86 D (P < 0.005). The mean IOL tilt was 2.4 ± 1.7°, and the mean decentration was 0.35 ± 0.21 mm. The mean ACD was 4.31 ± 0.29 mm.

CONCLUSIONS

The 27-gauge sutureless intrascleral PC-IOL implantation technique minimizes intraoperative injury, simplifies procedure, and provides good PC-IOL fixation with few postoperative complications.

Long-term results of Descemet-stripping automated endothelial keratoplasty for endothelial failure caused by phakic intraocular lenses

PURPOSE

To describe the surgical approach and long-term outcomes of Descemet-stripping automated endothelial keratoplasty (DSAEK) for endothelial failure secondary to phakic intraocular lenses (pIOL).

METHODS

Retrospective, interventional case series of 18 eyes of 13 patients who developed endothelial failure secondary to pIOL implant. Patients were submitted to pIOL explant and DSAEK for visual rehabilitation, with or without phacoemulsification plus posterior-chamber intraocular lens implant. The minimum follow-up time was 3 years and the main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD) and percentage of endothelial cell loss (ECL), intraoperative and postoperative complications.

RESULTS

Patients' mean age was 47.44 (7.86) years with a mean follow-up time of 55.61 (14.13) months. Sixteen eyes (88.9%) had an angle-supported pIOL. The mean pIOL implant-to explant time was 8.17 (2.73) years. BCVA improved from 1.00 (0.36) logMAR preoperatively to 0.29 (0.36) logMAR at 1 year of follow-up (p < 0.001), remaining stable over the entire follow-up period (p > 0.05). At the last visit, all corneas were clear, with a mean ECD of 724.74 (325.57) cells/mm². During the follow-up, two eyes (11.1%) required a re-DSAEK due to early graft failure (<3 months).

CONCLUSION

Our outcomes reveal that an individualized and careful approach may result in a stable visual rehabilitation in young patients with corneal decompensation following pIOL implant.

Artisan iris-claw intraocular lens implantation in vitrectomised eyes

OBJECTIVES

To present the visual acuity (VA) results and complication rates following Artisan intraocular lens (IOL) insertion in vitrectomised eyes.

METHODS

Outcome data were collected for all vitrectomised patients who had undergone Artisan IOL insertion between January 2014 and May 2019 at Moorfields Eye Hospital. All those with follow-up greater than 2 months were included in the analysis.

RESULTS

Sixty-nine eyes from 61 patients were included. Average follow up was 2 years. Fifty-five (80%) eyes had at least one ocular comorbidity prior to Artisan IOL insertion. At final follow up 46 (67%) eyes had best-corrected VA better than 6/12. Sixty-three eyes (91%) either gained or maintained VA. Mean post-operative spherical equivalent was -0.2D. Two (3%) lenses became de-enclavated requiring further surgery. Two (3%) eyes developed acute post-operative cystoid macular oedema. Two (3%) required additional topical IOP-lowering therapy to their pre-operative glaucoma regimen. One eye had mild corneal oedema, which persisted for 1 year following surgery and subsequently resolved.

CONCLUSIONS

Artisan IOL insertion is a safe and effective option for the surgical correction of aphakia in vitrectomised eyes lacking capsular support. Refractive results comparable to posterior chamber IOL placement can be achieved with these lenses.

Visual outcome and surgical results in children with Marfan syndrome

IMPORTANCE

To determine visual and surgical results in children with Marfan syndrome.

BACKGROUND

Marfan syndrome involves ocular complications which can lead to visual disturbance and amblyopia. Data about the visual and surgical results in children with Marfan syndrome is vital for the clinical management of these patients.

DESIGN

Retrospective data analysis.

PARTICIPANTS

Eighty-two eyes of 41 patients with a genetically proved diagnosis of Marfan syndrome.

METHODS

Medical records of patients with Marfan syndrome were reviewed between 2007 and 2017. Ocular complications, visual acuity (VA) of patients with/without lensectomy and surgical method were evaluated.

MAIN OUTCOME MEASURES

VA outcomes of patients with Marfan syndrome with/without surgical repair of ectopia lentis.

RESULTS

In 27 (66%) of the 41 patients a bilateral subluxation of the lens was visible and 14 (52%) patients received lensectomy. The mean age at initial presentation was 12.3 ± 9 years and mean follow-up was 3 years (range 1-7). VA varied from 1.2 to -0.1 logMAR at first examination. At initial presentation, mean VA was 0.1 ± 0.7 logMAR in patients with a normal lens status (n = 14) and 0.3 ± 0.5 logMAR in patients with subluxation of the lens (n = 27) (P < .01). VA improved from 0.2 ± 0.5 logMAR to 0.1 ± 0.5 logMAR (P = .06) in children with subluxation of the lens who did not need a lensectomy (n = 12) and from 0.5 ± 0.5 logMAR to 0.2 ± 0.5 logMAR (P = .02) in patients who were referred to lensectomy with/without secondary lens implantation.

CONCLUSIONS AND RELEVANCE

In Marfan syndrome subluxation of the lens was found in the majority of children. Improvement of VA resulted in children with subluxation of the lens and following lensectomy.

Changes in Endothelial Cell Count Up to Three Years After Implantation of Toric Implantable Collamer Lenses

PURPOSE

To determine the temporal effect of toric implantable collamer lens (TICL) implantation and location on corneal endothelial cell density (ECD) over a period of 36 months after surgery.

METHODS

ECD [number of cells per square millimeter estimated using the Specular Microscope SP-1P (Topcon Europe Medical B.V., Netherlands)] data were collected from cases deemed suitable for the TICL (VTICMO, VTICM5; STAAR Surgical, Nidau, Switzerland). The preoperative refractive error (sphere and cylinder) ranged from -1.00 to -22.25 diopter sphere and from -0.50 to -5.50 diopter cylinder. ECD was evaluated at preoperative and all postoperative sessions.

RESULTS

Key findings were as follows: the mean ECD (±SD, 95% confidence interval) was 2720 cells/mm (±272, 2620-2820 cells/mm) preoperatively, which was reduced to 2372 cells/mm (±325, 2250-2490 cells/mm) at 36 months postoperatively (P < 0.001). Linear regression revealed the following significant correlations between the (1) log of the change in ECD (y1) and log of preoperative ECD (x1) at 2 years postoperatively, y1 = 2.513x1-6.2816 (n = 62, r= 0.3503, P = 0.005); (2) mean ECD (y2) and log time (in months, x2), y2= 2543.7-36.997x2-38.99x2 (r=-0.9654, n = 7, P = 0.0004); and (3) mean axial distance between the front surface of the crystalline lens and the TICL back surface (y3) and time postoperatively (in months, x3), y3 = 0.1035x3-5.2808x3 +473.18 (r = 0.8512, n = 7, P = 0.015).

CONCLUSIONS

Expected ECD loss after TICL implantation by 2 years postoperatively is predictable. On average, over 3 years after implantation, there is (1) an initial rapid decline in ECD, followed by a gradual fall in the rate of cell loss, and (2) a gradual fall in the distance between the TICL and the crystalline lens by 2 years postoperatively, followed by a reversal by the third year.

Five-year follow-up of secondary iris-claw intraocular lens implantation for the treatment of aphakia: Anterior chamber versus retropupillary implantation

BACKGROUND

Though several procedures of IOL implantation have been described (sutured scleral fixation, intra-scleral fixation, angle-supported anterior chamber, and anterior chamber or retropupillary iris-claw IOLs), there are no randomized trials which are comparing different techniques. Hence, the surgical treatment of aphakia still remains controversial and challenging. The purpose of this study was to compare the long-term efficacy and the rate of complications of anterior versus posterior Iris-claw intraocular lenses (IOL) implantation to correct for the treatment of aphakia without sufficient capsule support.

METHODS AND FINDINGS

Consecutive eyes having secondary implantation of aphakic iris-fixated IOLs with a follow-up of at least 5 years were considered. Mean correct distance visual acuity (CDVA) changes, percentage of eyes with CDVA improvement, mean corneal endothelial cell density (CECD) loss and the rate of other complications were used for statistical analysis. The study evaluated a total of 180 eyes (Group A: 87 anterior chamber iris-claw fixation, Group B: 93 retropupillary iris-claw implantation) of 180 consecutive different patients, with aphakia of various reasons. CDVA improved significantly in both groups after surgery (P<0.001, ANOVA), and was remarkably higher than baseline in both groups from first week and during the entire follow-up (P<0.001, Tukey's Honest Significant Difference). There was no statistically significant difference in CDVA between the two groups during each follow-up visits (P = NS, unpaired t-test) and in the CDVA improvement percentage between the two groups (P = 0.882, Chi-square test). No significant changes in CECD were noted after surgery in both groups (ANOVA Group A: P = 0.067, Group B: P = 0.330P). No intra-operative complications occurred in both groups. There was no statistically significant difference in the rate of complications between the two groups (P = NS, Chi-square test), except for pigment precipitates which were higher in Group A (P<0.05, Chi-square test).

CONCLUSIONS

Five-year follow-up shows that secondary implantation of aphakic IOLs is effective and safe for the correction treatment of aphakia in eyes without capsule support.

Dependency of endothelial cell loss on anterior chamber depth within first 4 years after implantation of iris-supported phakic intraocular lenses to treat high myopia

PURPOSE

To evaluate the effect of the anterior chamber depth (ACD) on the central corneal endothelial cell density (ECD) in eyes after implantation of an iris-fixated phakic intraocular lens (pIOL).

SETTING

Department of Ophthalmology, Goethe-University, Frankfurt, Germany.

DESIGN

Retrospective nonrandomized case series.

METHODS

An Artisan pIOL was implanted in eyes of highly myopic patients. Follow-up examinations at 1, 12, 24, 36, and 48 months included evaluation of ECD and adverse events. Three cohorts based on the ACD were established and their ECDs compared. All eyes had 1-year and 4-year postoperative ECD measurements available. Statistical analysis included linear regression analysis to evaluate the influence of ACD on ECD.

RESULTS

The study comprised 95 eyes (52 patients). Four years after surgery the mean spherical equivalent changed from -11.06 diopters (D) ± 4.77 (SD) to -0.42 ± 0.47 D. Severe adverse events were not detected. There was a significantly higher ECD loss after 4 years in patients with an ACD of less than 3.00 mm than in those with an ACD greater than 3.40 mm (-224 cells/mm²) (P < .01). There was no significant difference in ECD between eyes with an ACD of 3.00 to 3.39 mm and eyes with an ACD less than 3.00 mm (P = .23) or more than 3.40 mm (P = .08).

CONCLUSIONS

The iris-claw pIOL precisely and safely corrected high myopia. However, the loss in ECD can be considerable. Establishing stricter exclusion criteria for ACD might reduce this loss.

FINANCIAL DISCLOSURE

Proprietary or commercial disclosures are listed after the references.

A Survey of Intraocular Lens Explantation: A Retrospective Analysis of 23 IOLs Explanted during 2005

Purpose

To evaluate the indications, lens styles, perioperative findings, and results of intraocular lens (IOL) explantation or exchange performed in the authors department in 2005.

Methods

The retrospective analysis comprised 22 patients (23 eyes). Twenty-one eyes had previous phacoemulsification and IOL implantation, one eye secondary aphakic IOL, and one eye phakic IOL implantation. The indications for IOL explantation/exchange and perioperative complications were evaluated. The best-corrected visual acuity (BCVA) before and after surgery was compared.

Results

Time from initial surgery to explantation/exchange varied from 1 to 121 months, median value was 46 months. The IOLs were explanted using local anesthesia and in 21 eyes replaced with new lens. Indications for IOL removal were opacification of the IOL in 12 eyes, malposition of the IOL in 5 eyes, postoperative refractive error in 2 eyes, recurrent toxic anterior segment syndrome in 1 eye, pseudophakic dysphotopsia in 1 eye, endothelial cell loss in phakic anterior chamber IOL in 1 eye, and visual discomfort with intraocular telescopic lens in 1 eye. The mean BCVA (decimal scale) before and after IOL explantation/exchange was 0.562±0.279 and 0.627±0.276, respectively. There was no significant difference in visual acuity before and after IOL exchange (Wilcoxon test).

Conclusions

The most frequent indications for IOL explantation/exchange were opacification of the IOL and IOL malposition. Surgeries were uneventful in most cases. Final visual results have been largely good. Long-term follow-up of patients with various types of IOLs should be maintained.

Long-Term Endothelial Cell Loss in Patients with Artisan Myopia and Artisan Toric Phakic Intraocular Lenses: 5- and 10-Year Results

PURPOSE

To evaluate the long-term change in endothelial cell density (ECD) after the implantation of 2 types of rigid iris-fixated phakic intraocular lenses (pIOLs) for the treatment of myopia and astigmatism.

DESIGN

Prospective, clinical cohort study.

PARTICIPANTS

A total of 507 eyes of 289 patients receiving the Artisan Myopia or Artisan Toric (Ophtec B.V., Groningen, The Netherlands) iris-fixated pIOL for the treatment of myopia or astigmatism at the University Eye Clinic Maastricht as of January 1998.

METHODS

A total of 381 myopic and 126 toric pIOLs were implanted. Five- and 10-year follow-ups were completed by 193 and 127 eyes implanted with the myopic pIOL and by 40 and 20 eyes implanted with the toric pIOL, respectively.

MAIN OUTCOME MEASURES

Chronic endothelial cell (EC) loss, percentage of eyes with a decrease of ≥25% in ECD, and percentage of eyes with an ECD <1500 cells/mm².

RESULTS

Chronic EC loss was calculated from 6 months postoperatively to the end of follow-up and showed an annual ECD decline of 48 cells/mm² (standard error, 3.14) and 61 cells/mm² (standard error, 6.30) in the myopic (P < 0.001) and toric (P < 0.001) groups, respectively, resulting in a total EC loss of 16.6% and 21.5% from 6 months to 10 years postoperatively, respectively. Ten years after implantation, ECD had decreased by ≥25% in 7.9% and 6.3%, whereas ECD was <1500 cells/mm² in 3.9% and 4.0% in the myopic and toric groups, respectively. Explantation of the pIOL occurred in 6.0% in the myopic group and 4.8% in the toric group. Risk factors for increased EC loss were a shallow anterior chamber depth (ACD) (P ≤ 0.005) and a smaller distance between the central and peripheral pIOL edge to the endothelium (P ≤ 0.005).

CONCLUSIONS

A significant linear chronic EC loss was reported after implantation with myopic or toric iris-fixated pIOLs. A smaller ACD and smaller distance between pIOL edge and endothelium were risk factors for EC loss. Modification of preoperative age-related ECD thresholds is indicated to maintain an ECD that warrants safe future combined pIOL explantation and cataract surgery.

Assessment of the safety and efficacy of primary retropupillary fixation of iris-claw intraocular lenses in children with large lens subluxations

PURPOSE

To evaluate whether retropupillary fixation of the iris-claw intraocular lens (IOL) is a safe and effective treatment option in children with large lens subluxations.

METHODS

Fourteen eyes of children between the ages of 8-17 years with lens subluxations more than 7 clock hours underwent pars plana lensectomy-vitrectomy with implantation of the iris-claw IOL in the retropupillary position as a primary procedure. The best corrected visual acuity (BCVA), intraocular pressure (IOP), corneal endothelial count (EC) and the lens position using ultrasound biomicroscopy (UBM) were assessed pre- and postoperatively.

RESULTS

Postoperatively, all patients had an increase in the BCVA with a mean of 0.351 ± 0.154 log MAR units which was statistically significant as compared to the preoperative value of 0.771 ± 0.132 log MAR units (p = 0.003). The difference between the mean preoperative IOP (13.642 ± 2.437 mmHg) and the mean postoperative intraocular pressure at the end of 6 months (13.5 ± 2.244 mmHg) was not statistically significant (p = 0.671). The mean EC decreased by 0.99% from 2838.42 ± 474.76 cells/mm² preoperatively to 2810 ± 461.24 cells/mm² at the end of 6 months postoperatively (p = 0.117). The lens position was analyzed using UBM and was found to be parallel to the iris plane in all cases at the end of 6 months.

CONCLUSIONS

Our study shows that primary retropupillary iris-claw IOL implantation can be a safe and efficacious option for children with large (>7 clock hours) lens subluxations that is at least comparable to scleral-fixated PCIOLs.

Calculation of iris-claw IOL power for correction of late in-the-bag IOL complex dislocation

Background

To assess the constants and formula for aphakia correction with iris-claw IOLs to achieve the best refractive status in cases of late in-the-bag IOL complex dislocation.

Methods

A literature search was performed. The following data were obtained: Iris-claw IOL model, Iridal or retroiridal enclavation, A-constant, ultrasound or optical biometry, formula employed and refractive outcomes. Acceptable emmetropia was considered if the resulting spherical equivalent (SE) was within ±1.00 D.

Results

The majority of the studies used SRK/T formula (66.6%). The 88.9% of the reports obtained a SE within ±1.00 D. Using A-115 for ultrasound biometry and A-115.7 for optical biometry and SRK/T formula, the emmetropia (±1.00 D) of SE, was able to get near 100% of reported cases over the pupil implantation. However, the emmetropia decreased to 80% when the enclavation is retropupilar using the same formula. The A-constant can vary from 116.7 to 117.5 for retropupilar enclavation.

Conclusions

Using A-115 for ultrasound biometry and A-115.7 for optical biometry and SRK/T formula, ±1.00 D of SE, is able to get near 100% of cases. Nevertheless, ±1.00 D of SE decreased to 80% of the cases when the enclavation is retropupilar.

Visual acuity improvement in adult amblyopic eyes with an iris-fixated phakic intraocular lens: long-term results

PURPOSE

To evaluate the effect of implantation of iris-fixated phakic intraocular lenses (pIOLs) (Artisan) in adult amblyopic eyes.

SETTING

Optical Express, London, United Kingdom.

DESIGN

Retrospective case series.

METHODS

The study analyzed data from 5 years of follow-up of amblyopic eyes that were implanted with iris-fixated pIOLs and had a preoperative corrected distance visual acuity (CDVA) of 6/15 or worse. Visual acuity, refraction, endothelial cell count, and complications were assessed.

RESULTS

Data for 103 eyes were analyzed as 2 groups. Group 1 comprised 82 eyes with myopia or myopic astigmatism, and Group 2 contained 21 eyes with hyperopia or hyperopic astigmatism. The mean preoperative sphere in Group 1 was -13.42 diopters (D) ± 5.62 (SD) with a mean cylinder of -2.35 ± 1.75 D. In Group 2, the mean sphere and cylinder were +6.77 ± 1.91 D and -2.63 ± 2.43 D, respectively. The mean CDVA improved from 0.51 ± 0.15 logMAR to 0.34 ± 0.16 logMAR (P<.001) in Group 1 and from 0.54 ± 0.17 logMAR to 0.46 ± 0.14 logMAR in Group 2 (P<.005). The safety index was 1.48 in Group 1 and 1.19 in Group 2. The efficacy index was 1.21 in Group 1 and 1.00 in Group 2. The mean gain in CDVA was statistically significantly greater in Group 1 (0.17 ± 0.14 logMAR) than in Group 2 (0.08 ± 0.11 logMAR). Two or more lines of CDVA were gained by 48.8% of eyes in Group 1 and by 19.0% of eyes in Group 2.

CONCLUSION

The iris-fixated pIOL was a safe and effective option for improving visual acuity in adult amblyopic eyes.

FINANCIAL DISCLOSURE

Dr. Schallhorn is a consultant to Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Two-Year Follow-Up of Artisan Iris-Supported Phakic Anterior Chamber Intraocular Lens for Correction of High Myopia

PURPOSE

To evaluate the results of Artisan iris-supported phakic anterior chamber intraocular lens (pIOL) implantation in patients with high myopia.

METHODS

Medical records of patients who underwent Artisan pIOL implantation for surgical correction of myopia were retrospectively reviewed. Only patients with at least a two- year follow-up were included. Spherical equivalent of manifest refractive error (SE), uncorrected visual acuity (UDVA), distance corrected visual acuity (CDVA), and endothelial cell density (ECD) were analyzed at six months, one year, and two years after surgery.

RESULTS

Sixty-two eyes of 42 patients were included in the study. All patients had a minimum anterior chamber depth of 3.0 mm from the endothelium. At two years, 68% of the patients were within ±0.50 D. Mean ECD was 2723 ± 311 cells/mm(2) preoperatively and 2630 ± 291 cells/mm(2) at six months postoperatively (3.4% loss, p = 0.001). ECD loss from six months postoperatively to two years postoperatively was not statistically significantly different. In three eyes (4.8%) of two patients, a temporary, steroid-induced increase in intraocular pressure (IOP) was detected.

CONCLUSION

Artisan pIOL implantation is a safe and highly effective procedure for surgical correction of high myopia. ECD loss stabilizes in the early postoperative period.

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.

Posterior chamber phakic intraocular lens to correct myopia: long-term follow-up

PURPOSE

To evaluate the long-term safety and efficacy of a refractive phakic intraocular lens (pIOL) (PRL) to correct moderate to high myopia.

SETTING

Department of Ophthalmology, University Medicine Charité Berlin, Berlin, Germany.

DESIGN

Retrospective cohort study.

METHODS

Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure, endothelial cell loss, and adverse events were evaluated.

RESULTS

The study enrolled 53 eyes (mean spherical equivalent [SE] -12.17 diopters [D] ± 4.12 [SD]) of 29 patients. The mean age was 34.6 ± 9.2 years and the mean follow-up, 86 ± 21.2 months. The mean UDVA improved from 1.37 ± 0.28 logMAR preoperatively to 0.14 ± 0.19 logMAR at the last postoperative visit (P<.05). The mean CDVA improved from 0.10 ± 0.18 logMAR to -0.01 ± 0.09 logMAR (P<.05). The overall mean efficacy index and mean safety index were 0.9 and 1.21, respectively, at the last follow-up visit. The mean endothelial cell loss at the last follow-up was 6.4%. The complications were slight posterior chamber (PC) pIOL decentration (5 eyes, 9.4%), severe PC pIOL decentration resulting in pIOL removal (1 eye, 1.8%), glaucoma (4 eyes, 7.5%), clinically significant cortical lens opacification resulting in cataract surgery (4 eyes, 7.5%), clinically asymptomatic anterior subcapsular cataract formation (6 eyes, 11.3%), and retinal detachment (2 eyes, 3.8%).

CONCLUSIONS

Posterior chamber phakic pIOL implantation to correct moderate to high myopia provided predictable and stable refractive results but with a high rate of serious complications over the long term.

FINANCIAL DISCLOSURE

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

Three-year follow-up of secondary anterior iris fixation of an aphakic intraocular lens to correct aphakia

PURPOSE

To evaluate the efficacy, predictability, stability, safety, and complications of secondary anterior iris fixation of the Artisan iris-fixated intraocular lens (IOL) to correct aphakia in eyes without sufficient capsule support.

SETTING

Department of Ophthalmology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China.

DESIGN

Cohort study.

METHODS

Eyes having implantation of aphakic iris-fixated IOLs for aphakia correction were followed for 3 years.

RESULTS

The study evaluated 72 eyes (72 patients). After 3 years, the uncorrected distance visual acuity improved in all eyes (P<.05); 53 eyes (73.6%) reached 20/40 or better. Two eyes had a postoperative corrected distance visual acuity (CDVA) worse than the preoperative CDVA due to postoperative ischemic optic neuropathy and retinal detachment, respectively. The mean spherical equivalent (SE) decreased from 11.65 diopters (D) ± 1.21 (SD) to -0.58 ± 0.56 D (P<.05); the SE at the last follow-up was within ±1.00 D of the target refraction in 63 eyes (87.5%). The mean endothelial cell loss 3 years postoperatively was 9.78%. There was no significant postoperative intraocular pressure increase throughout the follow-up. Twelve patients (16.7%) reported glare and halos during night driving. Iris pigment precipitates on the IOLs occurred in 4 eyes (5.6%) 3 years postoperatively. No other serious complications occurred.

CONCLUSIONS

Three-year results indicate that secondary implantation of aphakic IOLs is effective, predictable, and safe for the correction of aphakia in eyes without capsule support. However, longer follow-up with a larger cohort is necessary to confirm these conclusions.

Corneal endothelium after refractive surgery

The endothelium is vital to the health and optical clarity of the human cornea. The safety of procedures to correct refractive errors depends on preservation of an intact corneal endothelium. Disease states and genetic and environmental factors affect the corneal endothelium; an unstable corneal endothelium can impact the success of refractive surgery. Technological advances and recent laboratory findings have improved the ability to assess the endothelium. The status of the corneal endothelium after laser in situ keratomileusis, photorefractive keratectomy, phakic intraocular lenses, and adjuvants to these treatments has been the topic of numerous clinical trials. Safety guidelines for refractive surgery procedures should be followed to minimize deleterious effects on the corneal endothelium.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned.

Artiflex phakic intraocular lens implantation after corneal collagen cross-linking in keratoconic eyes

PURPOSE

To evaluate the safety, efficacy, and stability of the Artiflex (Ophtec BV) foldable anterior iris-claw phakic intraocular lens (PIOL) following corneal collagen cross-linking (CXL) in select cases of progressive keratoconus.

METHODS

This prospective, comparative study, conducted between March 2007 and June 2008, involved 11 eyes with progressive keratoconus. Inclusion criteria were progressive keratoconus (Amsler-Krumeich classification grades I and II) with no corneal opacities, corneal thickness >450 μm, endothelial cell count >2500 cells/mm(2), anterior chamber depth >3.2 mm, spherical equivalent refraction >4.50 diopters (D) (with a cylinder component <2.00 D), and no other treatment for keratoconus other than contact lens. Each patient underwent CXL in the keratoconic eye with implantation of the Artiflex IOL 6 months thereafter. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refraction and topographic profiles were examined at 1, 6, and 12 months after the CXL procedure.

RESULTS

All eyes achieved UDVA of 0.3 logMAR or better. Final spherical and cylindrical error ranged from 0 to -1.50 D and 0 to -1.75 D, respectively. No eyes lost lines of preoperative CDVA. Statistically significant reductions in mean maximum (2.14 D, P<.001) and minimum (1.17 D, P=.02) keratometry values were present 12 months after the CXL procedure. No complications were observed.

CONCLUSIONS

Combined CXL and Artiflex implantation was a safe and effective treatment in this subset of eyes with progressive keratoconus. Good results in terms of visual acuity, postoperative residual refractive error, and keratometry values were identified.

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.

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.