Role of capsular tension rings in preventing capsule contraction

Lens Epithelial Cell Removal in Routine Phacoemulsification: Is It Worth the Bother?

PURPOSE

To review the literature on crystalline lens epithelial cell (LEC) removal in routine phacoemulsification and determine whether it should be incorporated as part of a surgeon's standard technique.

DESIGN

Perspective.

METHODS

Expert commentary with video demonstrations on techniques of removal of LECs and associated potential complications. Discussion incorporates the importance of LEC removal, a review of techniques to prevent posterior capsular opacification (PCO), and the effects of intraocular lens design on LEC proliferation and PCO.

RESULTS

The evidence suggests that LEC removal should be routinely performed as it can be carried out safely and with considerable short- and long-term benefits for patients. With effective cleanup, there is reduced anterior capsule opacification, fibrosis, and decentration of the capsular bag as well as reduced rates of posterior capsular opacification. Techniques for removal are easy to learn, with very low complication rates, and can reduce the risk of the long-term need for technically complex procedures such as intraocular lens explantation.

CONCLUSIONS

LEC removal from both the anterior and posterior capsule is part of a continuous, incremental improvement of cataract surgery and should be introduced to ophthalmology trainees during their formative years as part of their regular cataract surgery armamentarium.

Ultrasound Biomicroscopy for Zonular Evaluation in Eyes with Ocular Trauma

Purpose

To evaluate the role of ultrasound biomicroscopy (UBM) in detecting zonular abnormalities in eyes with ocular trauma.

Patients and Methods

Prospective study of 143 eyes of 143 patients with ocular trauma and having opaque media was evaluated using a UBM. The presence or absence of zonular damage (zonular tears and/or zonular stretching) was examined and the clock-hour involvement was noted.

Results

One-hundred and one eyes had blunt trauma (70.63%; group 1), while 42 eyes had penetrating trauma (29.37%; group 2) The mean age of the patient population was 48.01±17.93 years with a male:female ratio of 2.11:1. Group 1 had significantly greater visual acuity than group 2 (p = 0.03). Zonular damage was present in 79 (55.2%) eyes, including zonular tears (48 eyes; 33.6%) and zonular stretching (31 eyes; 21.7%). Zonular damage was seen significantly more in eyes with blunt trauma (64.28%) as compared to penetrating trauma (25.74%) (p = 0.015). On quantitative analysis, zonular damage between 3 and 6 clock hours was most frequent, both in eyes having zonular tears (70.83%) and zonular stretching (96.77%). Additionally, 3–6 clock hours of zonular stretching was seen significantly more in blunt trauma as compared to penetrating trauma (p = 0.015).

Conclusion

UBM is an effective imaging modality to diagnose zonular abnormalities in patients with ocular trauma having opaque media. The ability to detect the presence of zonular weakness and their quantification by performing a UBM is critical to formulate the optimal surgical approach and avoid any untoward surgical complications.

Weight of Different Intraocular Lenses: Evaluation of Toricity, Focality, Design, and Material

Purpose

To evaluate the weight of intraocular lenses (IOLs) depending on their material, dioptric power, toricity, focality, and haptic design.

Methods

Twenty-eight different IOL models from nine different medical companies (a total of 38 IOLs) and 1 capsular tension ring (CTR) were evaluated. IOLs were weighed using a precision scale, in hydrated conditions, as an approximation to their intraocular status.

Results

Hydrophilic IOLs were heavier than hydrophobic lenses (p < 0.001). Regarding toricity, no statistical differences were found comparing toric to non-toric models (p=0.1). Likewise, no differences were found between multifocal IOLs and monofocal IOLs (p=0.19). Dioptric power did not affect IOL weight: IOLs of <15DP had similar weights to those of ≥15D and IOLs of ≥24D had similar weights to those of <24 D (p=0.86 and p=0.59, respectively). Plate-design IOLs were significantly heavier than 1-piece C-loop (p < 0.001), 3-piece C-loop (p < 0.001), and 4-haptic lenses (p=0.001).

Conclusions

Of the characteristics analyzed that might influence IOL weight, lenses with hydrophilic material and plate-haptic design were found to be heavier. Toricity, focality, and dioptric power had no influence on IOL weight.

Rapid Capsular Contraction with Secondary Intraocular Lens Dislocation Associated with Unspecified Rod-Cone Dystrophy: A Case Report

Purpose

We report an unusual case of rapid and severe anterior capsular contraction associated with secondary intraocular lens (IOL) dislocation following cataract surgery in a patient with unspecified rod-cone dystrophy.

Case Report

A 68-year-old woman with a history of uncharacterized bilateral rod-cone dystrophy presented with blurry vision 1 month after cataract surgery. Best corrected visual acuity was 20/40 in the operative eye. Slit-lamp exam showed severe anterior capsular phimosis limiting view of the fundus. Our patient underwent 2 sessions of Nd:YAG anterior capsulotomy with limited success. Limited anterior vitrectomy was then performed without success due to densely adherent capsular tissue to the anterior surface of the IOL and additional secondary IOL dislocation. She ultimately underwent pars plana vitrectomy, removal of the capsular bag, and IOL exchange with a scleral fixated IOL.

Conclusion

Rapid and severe anterior capsular contraction following cataract surgery is rare but appears to be associated with rod-cone dystrophy.

Visual outcomes in patients with zonular dialysis following cataract surgery

PurposeTo evaluate the visual outcomes of patients with zonular dialysis following cataract surgery.Patients and methodsMedical records of all patients with documented zonular dialysis, either pre- or peri-operatively, undergoing cataract surgery between 2004-2010 at Queen Alexandra Hospital, Portsmouth, were retrospectively reviewed. Baseline demographics and biometry were analysed, and ocular co-morbidities documented. Intraoperative complications and the use of a capsular tension ring (CTR) were identified. Early and late best-corrected visual acuity (BCVA) post surgery were determined using LogMar values. Univariate and multivariate linear regression analysis was performed to determine associations with BCVA post surgery, and further subgroup analysis performed in groups determined by CTR use.ResultsThe records of 22 312 consecutive eyes undergoing cataract surgery were reviewed. The incidence of zonular dialysis was 0.50% (111 eyes). A CTR was inserted in 46 eyes. Using a multivariate linear regression model, better initial pre-operative BCVA (P=0.019), the use of a CTR (P=0.014), and the absence of vitreous loss during surgery (P=0.008, β 0.45) were associated with improved early postoperative BCVA (mean follow-up 6.6 weeks). Better medium-term postoperative BCVA was significantly associated with preoperative BCVA (P=0.002) and the use of a CTR during surgery (P=0.004, β -0.41).ConclusionsThe overall incidence of zonular dialysis is low. CTR use intra-operatively suggests improved early and medium-term BCVA and should be considered in all cases of zonular dialysis.

Epidemiology, Etiology, and Prevention of Late IOL-Capsular Bag Complex Dislocation: Review of the Literature

Posterior chamber intraocular lens (PC-IOL) subluxation is uncommon but represents one of the most serious complications following phacoemulsification. Late spontaneous IOL-capsular bag complex dislocation is defined as occurring three months or later following cataract surgery. Unlike early IOL dislocation, late spontaneous IOL dislocation is due to a progressive zonular dehiscence and contraction of the capsular bag many years what seemed to be uneventful surgery. In recent years, late in-the-bag IOL subluxation or dislocation has been reported with increasing frequency, having a cumulative risk of IOL dislocation following cataract extraction of 0.1% after 10 years and 1.7% after 25 years. A predisposition to zonular insufficiency and capsular contraction is identified in 90% of reviewed cases. Multiple conditions likely play a role in contributing to this zonular weakness and capsular contraction. Pseudoexfoliation is the most common risk factor, accounting for more than 50% of cases. Other associated conditions predisposing to zonular dehiscence are aging, high myopia, uveitis, trauma, previous vitreoretinal surgery, retinitis pigmentosa, diabetes mellitus, atopic dermatitis, previous acute angle-closure glaucoma attack, and connective tissue disorders. The recognition of these predisposing factors suggests a modified approach in cases at risk. We review certain measures to prevent IOL-bag complex luxation that have been proposed.

Rapid anterior capsular contraction after phacoemulsification surgery in a patient with retinitis pigmentosa

A decrease in the anterior capsule opening after cataract surgery has been observed in eyes with weakened lens zonules. It commonly occurs in diabetes mellitus, uveitis, pseudoexfoliation syndrome, high myopia, and elderly patients. Herein, we report the case of a middle-aged man with advanced retinitis pigmentosa who developed a rapid contraction of the anterior capsule after an uneventful phacoemulsification surgery that resulted in severe visual loss during the early postoperative period.

Multifocal IOL Implant with or without Capsular Tension Ring: Study of Wavefront Error and Visual Performance

Purpose

To evaluate visual performance and wavefront error after multifocal intraocular lens (MIOL) implant with or without capsular tension ring (CTR).

Methods

Sixty eyes of 60 candidates for phacoemulsification and MIOL implantation were included in the study and were randomly divided into 2 groups. Thirty eyes (group 1) were implanted with the AcrySof ReSTOR® SN60D3 MIOL and Corneal® ACPI 11 CTR and 30 eyes (group 2) received the same MIOL with no CTR.

Results

Twenty days and at 360 days after surgery, the uncorrected and corrected distance visual acuity at high and low contrast were not significantly different between the 2 groups. The root mean square (RMS) of ocular and internal wavefront error was significantly different in the 2 groups early after surgery and did not modify significantly over the 1-year follow-up period. The RMS of total and internal high-order aberrations and ocular and internal trefoil and coma aberrations were significantly lower in group 1 compared to group 2 (p<0.05). Ocular, corneal, internal modulation transfer function at high and low spatial frequencies and ocular, corneal, internal Strehl ratio were not significantly different between the groups. The IOL decentration and tilt were higher in group 1 compared to group 2.

Conclusions

ReSTOR MIOL was effective in improving visual performance and provided a good quality of vision due to a significant reduction of high-order spherical aberration. The implant of CTR additionally reduced the ocular wavefront error related to a reduction of third-order aberration related to better IOL position.

Late in-the-bag intraocular lens dislocation: Incidence, prevention, and management

Dislocation of an intraocular lens (IOL) with the capsular bag is a late complication of cataract surgery, reported with increasing frequency in recent years. Pseudoexfoliation, uveitis, myopia, and other diseases associated with progressive zonular weakening and capsular contraction are the predisposing conditions. Capsular tension rings probably help but do not prevent this complication. Management includes IOL exchange, replacement with an anterior or a sutured posterior chamber IOL, or suturing the IOL through the bag to the iris or the sclera.

Interim results of the United States investigational device study of the Ophtec capsular tension ring

PURPOSE

To evaluate the safety and efficacy of the Ophtec capsular tension ring (CTR) in providing capsular support during and/or after cataract extraction in cases of a weak or partially broken ciliary zonule.

DESIGN

Phase III multicenter, nonrandomized, investigational device study.

PARTICIPANTS

Twelve investigators at 9 sites enrolled 224 subjects and placed 255 CTRs.

METHODS

Capsular tension rings were placed in patients who were found to have a weakened or partially broken ciliary zonule comprising <34% of the circumference of the lens capsule. Two CTR models were evaluated, with noncompressed diameters of 12 mm and 13 mm. Patients were examined preoperatively, intraoperatively, and postoperatively at day 1 and months 1, 3, 6, and 12.

MAIN OUTCOME MEASURES

Rate of successful stabilization of the capsular bag and intraocular lens (IOL) centration, complications, and adverse events.

RESULTS

Interim results from this ongoing study indicate that immediately after surgery 98.8% of IOLs were centered and 1.2% of the IOLs implanted (3/251) were not centered. Subsequently, the prevalence of decentered IOLs was 1.7% (4/236) 3 months after surgery, 3.8% (8/211) 6 months after surgery, and 2.3% (4/172) 12 months after surgery. The primary complication was posterior capsular opacification, which is unlikely to be a complication of CTR insertion. Neodymium:yttrium-aluminum-garnet laser capsulotomies have been performed in 12.8% of eyes by 12 months (22/172).

CONCLUSIONS

Ophtec CTR models 275 and 276 safely provided capsular support during and after cataract surgery in cases where the zonule was weak or partially broken.