Explantation of intraocular lenses

Intraocular lens explantation following cataract surgery: Indications, techniques, and video demonstrations

As techniques for modern cataract surgery have expanded and premium intraocular lens (IOL) use is now widespread, patient expectations are high. The need for IOL explantation, whilst still low, remains an ongoing issue. Intraocular lens explantation can be challenging for a number of reasons and as such we have introduced an additional technique to add to the surgeon's repertoire. Bimanual haptic stripping of fibrosis at the specific area where the haptic is adherent to the capsular bag is an effective strategy to aid in dissection of haptics without compromising the capsule or zonules. Given the challenges associated with IOL explantation, newly designed IOLs need to avoid these "sticking points" at which the IOLs interact with the fibrosed capsule. Techniques we have evolved and which are described below should assist anterior segment surgeons to facilitate IOL removal in an efficient and safe way.

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.

Diode laser transscleral cyclophotocoagulation for uveitis-glaucoma-hyphema syndrome: A case report

RATIONALE

To report a case of diode laser transscleral cyclophotocoagulation (DLTSC) for uveitis-glaucoma-hyphema syndrome (UGH).

PATIENT CONCERNS

The patient developed UGH on the right eye (OD) after vitrectomy and intraocular lens (IOL) implantation.

DIAGNOSES

Best corrected visual acuity (BCVA) was HM/50 cm, intraocular pressure (IOP) was 51.3 mm Hg on the OD. He was found to have 3+ anterior chamber cells. A B-scan ultrasound showed vitreous opacity. Ultrasound biomicroscopy (UBM) showed the chafing between the IOL and the posterior surface of the iris. Thus, he was diagnosed as UGH on the OD.

INTERVENTIONS

The patient was worried about the complications for removal of the IOL, a DLTSC approach was performed.

OUTCOMES

BCVA was 20/40 on the OD, IOP was 12 mm Hg on the OD. There were no anterior chamber inflammation and no vitreous opacity. UBM showed there was no contact between IOL and the posterior surface of the iris, the fundus of the eye was clearly visible.

LESSONS

UGH syndrome is a severe complication of cataract extraction. IOL extraction has been the traditional approach to treatment. DLTSC can be an option when the IOL is slightly tilted.

[Assessment of astigmatism associated with the iris-fixated ARTISAN aphakia implant: Anterior fixation versus posterior fixation, study of postoperative follow-up at one year]

PURPOSE

The goal of our retrospective, single-center study of a case series was to compare the total, corneal, and internal astigmatism, and the visual acuity at one year after combined or stand-alone surgery consisting of iris fixation of an iris-claw intraocular lens (ARTISAN aphakia) in aphakic patients, according to whether the lens was fixated to the anterior (n=21) or posterior (n=51) surface of the iris.

RESULTS

We did not find a significant difference between these two types of fixation for any of the studied variables. The surgically induced astigmatism was 1.67 D at 176° in group A versus 1.19 D at 11° in group P.

CONCLUSION

Although this surgery creates additional corneal astigmatism, it has not been proven that it differs depending on the type of fixation of the iris-claw. If we adhere to the notion that the posterior fixated iris-claw decreases the risk of endothelial decompensation in case the implant becomes disenclavated, then reverse iris fixation of the iris-claw makes sense.

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.

Confocal laser method for quantitative evaluation of critical optical properties of toric intraocular lenses

PURPOSE

To present a proof-of-concept study on the development and implementation of an innovative confocal laser method platform for precise quantitative evaluation of critical optical properties unique to toric intraocular lenses (IOLs).

SETTING

U.S. Food and Drug Administration, Optical Therapeutics and Medical Nanophotonics Laboratory, Silver Spring, Maryland, USA.

DESIGN

Experimental study.

METHODS

The optical properties of hydrophobic toric IOLs were evaluated with a confocal laser method that was modified to isolate the 2 planes of focus that are observed with toric IOLs.

RESULTS

The results show the confocal laser method has the potential to measure the orthogonally separated optical powers and then calculate them to the commonly referenced spherical equivalent and cylinder powers of toric IOLs with high accuracy (≤1 μm of focal length measurement). Furthermore, the proposed confocal laser method design includes a new component for precise differentiation of the 2 focal planes and isolation of the 2 focal points, and thus for accurate measurement of the anterior cylinder axis of toric IOLs.

CONCLUSION

The modifications to the confocal laser method platform enabled the quantitative evaluation of optical properties attributed to toric IOLs.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Stability and safety of MA50 intraocular lens placed in the sulcus

PURPOSE

To describe the safety and stability of sulcus placement of the MA50 intraocular lens (IOL).

PATIENTS AND METHODS

Consecutive patients with MA50 IOLs placed in the sulcus at the University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA, from 1997 to 2012 were identified. Inclusion criteria included patients with over 4 weeks of follow-up data. AEL was compared with incidence of IOL decentration using at two-tailed Student's t-test.

RESULTS

Fifty eyes of 49 patients meeting the inclusion criteria were identified. Four weeks post-operatively, the average best-corrected visual acuity was 20/30. IOL decentration occurred in 14% of patients; patients with decentered IOLs had a significantly longer average AEL (25.37 mm) than patients whose IOL remained centered (23.94 mm, P=0.017). Other complications included uveitis-glaucoma-hyphema syndrome (12%), iritis (8%), and glaucoma (6%). There were no cases of pigment dispersion syndrome or need for lens exchange. Twelve eyes (24%) had intra-operative optic capture by the anterior capsule, none of which had post-operative decentration.

CONCLUSION

The MA50 IOL is a reasonable, stable option for placement in the sulcus, with a low-risk profile; however, in eyes with longer AEL and presumably larger anterior segment, surgeons should consider placing an IOL with longer haptic distance than the MA50 to maintain centration. Optic capture of the MA50 IOL by the anterior capsule should be considered for longer eyes, as it is protective against decentration.

Assessing the effect of laser beam width on quantitative evaluation of optical properties of intraocular lens implants

The design and manufacture of intraocular lenses (IOLs) depend upon the identification and quantitative preclinical evaluation of key optical properties and environmental parameters. The confocal laser method (CLM) is a new technique for measuring IOL optical properties, such as dioptric power, optical quality, refractive index, and geometrical parameters. In comparison to competing systems, the CLM utilizes a fiber-optic confocal laser design that significantly improves the resolution, accuracy, and repeatability of optical measurements. Here, we investigate the impact of changing the beam diameter on the CLM platform for the evaluation of IOL dioptric powers. Due to the Gaussian intensity profile of the CLM laser beam, the changes in focal length and dioptric power associated with changes in beam diameter are well within the tolerances specified in the ISO IOL standard. These results demonstrate some of the advanced potentials of the CLM toward more effectively and quantitatively evaluating IOL optical properties.

Cell-by-cell alignment of repeated specular microscopy images from the same eye

PURPOSE

Modern specular microscopes (SM) robustly depict the same central area of the corneal endothelium at different time points through a built-in fixation light. However, repeated image acquisitions slightly shift and rotate because of minute changes in head position in the chin and forehead rest. This prevents the manual retrieval of individual corneal endothelial cells (CECs) in repeated measurements because SM images usually lack obvious landmarks. We devised and validated an image registration algorithm that aligns SM images from the same eye to make corresponding CECs coincide.

METHODS

We retrospectively selected 27 image pairs for the presence of significant image overlap. Each image pair had been recorded on the same day and of the same eye. We applied our registration method in each image pair. Two observers independently validated, by means of alternation flicker, that the image pairs had been correctly aligned. We also repeatedly applied our registration method on unrelated image pairs by randomly drawing images and making certain that the images did not originate from the same eye. This was done to assess the specifity of our method.

RESULTS

All automated registrations of the same-day and same-eye image pairs were accurate. However, one single image incorrectly failed to trigger the non-match diagnosis twice in 81 registration attempts between unrelated images. As it turned out, this particular image depicted only 73 CECs. The average number of CECs was 253 (range 73-393).

CONCLUSION

Repeated non-contact SM images can be automatedly aligned so that the corresponding CECs coincide. Any successful alignment can be considered as proof of the retrieval of identical CECs as soon as at least 100 CEC centroids have been identified. We believe our method is the first to robustly confirm endothelial stability in individual eyes.

[Iritis with destabilization of the intraocular pressure due to dislocation of a posterior chamber intraocular lens]

This report concerns the case of a 67-year-old male patient who underwent uncomplicated phacoemulsification with implantation of a posterior chamber intraocular lens (IOL). After an interval of 2 months the patient developed iritis together with an uncontrollable increase in intraocular pressure. After a detailed examination a dislocated haptic of the IOL was identified as the cause of the symptoms. The dislocation had led to uveitis-glaucoma-hyphema syndrome although no hemorrhage was observed. In addition to this complication the haptic had arroded the zonular complex which made implantation of an anterior chamber lens necessary. Although improvements in operating techniques, lens materials and designs have been made uveitis-glaucoma-hyphema syndrome has to be kept in mind. Surgical intervention is the only therapeutic option.

Clinical efficacy and complications of intraocular lens exchange for opacified intraocular lenses

PURPOSE

To evaluate the clinical efficacy and complications of intraocular lens (IOL) exchange.

METHODS

A review of medical records was performed for 52 eyes that had undergone an IOL exchange due to IOL opacification. Surgical complications and their incidences were analyzed. The mean best corrected visual acuity (BCVA) after the IOL exchange was compared with the mean pre-exchange BCVA and with the mean BCVA after the initial IOL implantation. Prediction error of refraction and biometric data obtained for the IOL exchange were, if available, compared with those obtained for the initial IOL implantation. The prediction error for the IOL exchange, calculated from the biometric data obtained before the IOL exchange, was compared with that calculated from the measurements obtained before the initial IOL implantation.

RESULTS

The overall complication rates were low and no serious complications were found. The mean BCVA improved significantly after the IOL exchange and was not significantly different from that obtained after the initial IOL implantation. However, the refractive prediction for the IOL exchange was not as good as it was for the initial IOL implantation, which was thought to be related with difficulties in axial length (AL) measurements. Biometric data taken before the initial IOL implantation was associated with a significantly better refractive prediction than those taken before the IOL exchange.

CONCLUSIONS

IOL exchange was both efficacious and safe for visual recovery. However, IOL exchange was related with increased difficulty of predicting postoperative refraction; difficulties in AL measurements are the suggested cause.

Management of dislocated intraocular lenses

PURPOSE

The purpose of this study was to characterize the contemporary clinical presentation and treatment results of patients with dislocated intraocular lenses (IOLs).

DESIGN

Retrospective, noncomparative, single-surgeon interventional case series.

PARTICIPANTS

Two hundred eighty-four eyes of 277 patients operated for dislocated IOLs; 184 eyes with >3 months follow-up information were analyzed for visual outcomes.

METHODS

Review of preoperative, intraoperative, and postoperative clinical features from patient charts.

MAIN OUTCOME MEASURES

Best-corrected visual acuity, reoperations, and complications such as retinal detachment and postoperative refraction.

RESULTS

The study included eyes with polymethyl methacrylate IOLs (n = 113), silicone plate IOLs (n = 51), 3-piece silicone IOLs (n = 38), acrylic IOLs (n = 60), and others (n = 12). There were 51 (18%) with "in-the-bag" IOL dislocations; their proportion increased during the study period and were associated with pseudoexfoliation (P = 0.01), ocular trauma (P = 0.013), and time after implantation of IOL (P = 0.006). Recurrent dislocation (17 eyes; 6%) and decentration (11 eyes; 4%) of IOLs occurred, and resulted in further surgery in 18 (6%) eyes, but were not related to the types of IOL or surgical technique. The most common complication was cystoid macular edema (29 eyes; 10%); retinal detachment occurred after management of dislocated IOL in 11 (4%) eyes. Visual results and median postoperative refractive changes for the 184 eyes with follow-up >3 months were similar regardless of surgical techniques.

CONCLUSIONS

Currently, IOL dislocation more commonly involves foldable IOLs and in-the-bag dislocation. Existing techniques of IOL repositioning with or without scleral suture fixation or IOL exchange are effective for contemporary dislocated IOLs. Preexisting conditions and postoperative complications may limit the visual outcomes.

Late postoperative complications of backward implantation of a Vivarte phakic intraocular lens

A 34-year-old man had bilateral implantation of a Vivarte phakic intraocular lens (pIOL) (Ciba Vision) to correct high myopia. Postoperatively, both pIOLs appeared to have been implanted backward. After a few weeks, the position of the pIOL in the right eye was corrected in a second procedure. For unknown reasons, the pIOL in the left eye was untouched. Three years after the initial implantation, the patient visited our hospital for a second opinion. He presented with a decrease in visual acuity from an intrapupillary membrane in the left eye. Endothelial cell count of the left cornea showed markedly decreased endothelial cell density. The patient was successfully treated by removing the IOL and excising the intrapupillary membrane, leading to recovery of visual acuity. This case presents the rare occurrence and management of late postoperative complications of backward implantation of a Vivarte pIOL.

Asymmetric vault of an accommodating intraocular lens

We report a case of a new syndrome, late asymmetric vault of the AT45 Crystalens intraocular lens (IOL) (Eyeonics Inc.). The late vault, which occurred in 6 month after implantation of the IOL, caused a decrease in uncorrected distance and near acuities and minus-cylinder axis perpendicular to the haptics. Treatment with neodymium:YAG laser capsulotomy and fibrotic band release was successful.

Secondary intraocular lens implantation for pediatric aphakia

PURPOSE

We sought to report the outcome of secondary intraocular lens (IOL) implantation in children.

METHODS

This was a retrospective case review.

RESULTS

A total of 77 eyes were identified. An average age at secondary implantation was 7.8 +/- 5.0 years, whereas the average age at primary cataract surgery was 1.5 +/- 2.6 years. Average follow-up was 2.7 +/- 1.9 years. Thirty eyes received a hydrophobic acrylic IOL implantation whereas 47 eyes received a PMMA IOL. The sites of fixation for implanted IOLs were as follows: anterior-chamber (n = 6), sulcus (n = 42), in-the-bag (n = 14), optic-capture (n = 6), piggyback (n = 4), and sutured (n = 5). Complications included clinically significant decentration, 4 (5.2%); visual axis opacification, 4 (5.2%); dislocation of the IOL, 2 (2.6%); and pupillary capture requiring repositioning of IOL, 1 (1.3%). Clinically significant decentration requiring surgical intervention was noted only in eyes with sulcus-fixated foldable IOLs (28.6%; 4/14). None of the 29 eyes with sulcus-fixated PMMA IOL implantation developed decentration. All the decentrations were in an inferior direction and occurred in eyes of male patients (P = 0.03). Eyes with an axial length of >23 mm were 4 times more likely to develop decentration if implanted with a sulcus-fixated foldable IOL when compared with eyes measuring <23 mm (P = 0.03). Postoperative geometric mean visual acuity was significantly better than preoperative visual acuity (P < 0.001).

CONCLUSION

Secondary IOL implantation can be safely achieved in pediatric eyes. In-the-bag fixation of foldable IOLs is associated with a low rate of complications. Foldable lenses appear to have a higher rate of decentration than PMMA lenses when placed in the sulcus in eyes of myopic male patients.

Glare disability in patients with hydrophilic and hydrophobic acrylic intraocular lens implants

PURPOSE

To compare glare disability test results in patients with hydrophilic and hydrophobic acrylic intraocular lenses (IOL).

METHODS

Sixty eyes of 60 patients were studied in three groups of 20. Each eye in Group 1 had a single-piece hydrophilic acrylic (Bioacryl, Biotech, France) IOL implant, and each eye in Group 2 had a three-piece hydrophobic acrylic (AcrySof, Alcon, USA) IOL implant. Group 3 was the control group, and consisted of eyes without cataracts. Glare disability was tested using the Ophthimus glare sensitivity test (Ophthimus, Sweden). For each eye, we determined log contrast sensitivity values without exposure to glare source and with exposure to glare source. The difference between these values was recorded as the threshold contrast increase. An infrared camera was used to measure pupil diameter during glare disability testing, and pupil diameter greater than 4 mm was used as an exclusion criterion to eliminate edge design as a potential contributor to glare disability.

RESULTS

The respective mean log contrast sensitivity scores for Groups 1, 2, and 3 in the absence of the glare source were 0.80 +/- 0.03, 0.81 +/- 0.04, and 0.79 +/- 0.08. The corresponding findings with glare source were 0.84 +/- 0.07, 0.89 +/- 0.07, and 0.84 +/- 0.03. The threshold contrast increase in Group 2 (0.070 +/- 0.035) was significantly higher than that in both Group 1 (0.043 +/- 0.040) and the control group (0.045 +/- 0.026) (p < 0.05 for both comparisons). There were no significant differences between Group 1 and the control group regarding log contrast sensitivity values with glare source and threshold contrast increase (p > 0.05 for both comparisons).

CONCLUSIONS

The eyes with hydrophilic acrylic IOL showed better glare disability results than those with hydrophobic acrylic IOL. The superior performance of the hydrophilic acrylic IOL could be related to their lower refractive index and equi-convex design.

Intraocular lens surfaces and their relationship to postoperative glare

PURPOSE

To estimate the potential for surface reflections in recently introduced intraocular lenses (IOLs) and to determine optic surface designs that will reduce surface reflections.

SETTING

Mayo Clinic, Rochester, Minnesota, USA.

METHODS

Surface-reflected glare in the unaccommodated human crystalline lens and in 6 IOLs (Bausch & Lomb SoFlex LI61U, Pharmacia CeeOn 911A, Allergan Sensar AR40, Bausch & Lomb Hydroview H60M, Alcon AcrySof MA60BM, Alcon AcrySof SA30AL) was examined in a physiologic eye model using the ZEMAX optical design program. Internal and external surface reflections were described and compared in terms of IOL surface reflectivity (%), area of the reflected glare image (mm(2)), and relative intensity of the reflected glare image.

RESULTS

Compared to surface reflections from the unaccommodated human lens with a corneal power of 43.0 diopters, all the IOLs increased the relative intensity of internal and external reflections by 3- to 36-fold except the MA60BM and the SA30AL, which increased the relative intensity of internal and external reflections by 730- to 1090-fold.

CONCLUSIONS

All the IOLs studied variably increased internal and external surface reflections when compared to the human crystalline lens. Surface reflections were minimized in optic designs with an anterior radius of curvature of approximately 17.0 mm or less.

Techniques for managing common complications of cataract surgery

Cataract surgery has evolved dramatically over the last two decades, largely as a result of technological advances. As a result, visual outcomes and patient convalescence have improved significantly. A second consequence of increased instrumentation and technology, however, is increased complexity of cataract surgery and the advent of complications unique to these advances. Cataract surgeons must be aware and capable of managing the many possible adverse events that can occur during cataract surgery. This review identifies many of the common complications of cataract surgery, describes methods to avoid these complications and discusses techniques to address complications that do occur. It is the ability to avoid, quickly identify, and properly manage complications that defines the accomplished cataract surgeon.

Cytopathology of explanted intraocular lenses and the clinical correlation

PURPOSE

To study the cytopathological features of explanted intraocular lenses (IOLs) and correlate the features with their clinical presentation.

SETTING

Ocular Pathology Department, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.

METHODS

The study comprised 61 explanted IOLs (48 posterior chamber IOLs and 13 anterior chamber IOLs) removed for the following reasons: pseudophakic bullous keratopathy (36), recalcitrant uveitis (7), retinal detachment (10), endophthalmitis (5), uveitis (7), IOL subluxation (2), and painful blind eye (1). The IOLs were stained with hematoxylin and eosin using a simple cytological technique. The cytopathological features were studied and correlated with the clinical presentations.

RESULTS

The mean time of IOL explantation was 10.1 months after surgery. Twenty-one IOLs had granulomatous and nongranulomatous inflammations and 4, nongranulomatous inflammations. One IOL had fungal filaments on the surface.

CONCLUSIONS

Intraocular lenses can produce both granulomatous and nongranulomatous inflammation. Granulomatous inflammation was the most common in this series. The surface of IOLs explanted because of intraocular infection may show infective agents.

Complications of foldable intraocular lenses requiring explantation or secondary intervention--2000 survey update

A survey of the complications associated with foldable intraocular lenses (IOLs) that required explantation or secondary intervention was sent to members of the American Society of Cataract and Refractive Surgery and was also available to members of the European Society of Cataract and Refractive Surgeons. Preoperative data about visual acuity, patient signs and symptoms, and complications were assessed, and postoperative results and outcomes were analyzed. Complications and symptoms for each of the major groups of foldable IOLs explanted were tabulated separately: 3-piece monofocal silicone; 3-piece acrylic; 1-piece (plate-type) silicone; and multifocal silicone. A total of 259 surveys returned for evaluation. Accurate IOL power measurements as well as meticulous surgical technique, IOL loading and insertion, and proper patient counseling/selection remain the most important factors in avoiding complications with foldable IOLs.