[Complication profiles of posterior chamber intraocular lenses IOL). An analysis of 586 foldable and 2077 rigid explanted intraocular lenses]

A pilot study of intraocular lens explantation in 69 eyes in Chinese patients

AIM

To study the effects of intraocular lens (IOL) explantation and demographic characteristics.

METHODS

Retrospective non-comparative case series. Clinical data recorded from patient charts included the following: demographic, preoperative and postoperative characteristics; complications; surgical methods, and changes in visual acuity.

RESULTS

A total of 69 eyes in 67 Chinese patients who received IOL explants were studied. The patients' mean age at the time of explantation was 46.1 years old [SD 22.5 (6-85)], and 37 patients were female (55.2%). Regarding employment, 47.8% were farmers, 23.9% were retired, 16.4% were students, 4.5% were unemployed, 3% were workers, and 4.5% were other (including staff members, teachers and officers). The main reasons for explantation were dislocation/decentration in 41 cases (59.4%) and retinal detachment in 10 cases (14.5%). The third most prevalent cause was incorrect lens power in 7 eyes (10.1%). The remaining reasons were endophthalmitis in 6 cases (8.7%), posterior capsular opacity in 3 eyes (4.3%), and impacting retinal surgery operation in 2 cases (2.9%). The main comorbidities were high myopia in 18 eyes (26.1%), trauma in 8 eyes (11.6%), retinal detachment in 6 eyes (8.7%), congenital cataracts in 8 eyes (11.6%), and Marfan's syndrome in 2 eyes (2.9%). The mean time from implantation to explantation was 4.0y [SD 4.2 (0.005-15)]. Treatment after explantation included posterior chamber IOL implantation in 44 eyes (63.8%) and aphakia in 25 eyes (36.2%). After surgery, the best corrected visual ability (BCVA) was improved in 50 cases (72.5%), including 28 patients (40.6%) in whom visual ability was improved by more than two lines.

CONCLUSION

Dislocation/decentration is the main cause for explantation, and high myopia is a main risk factor. Posterior chamber IOL implantation remains the most elected treatment after explantation.

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.

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.

Rates and causes of intraoperative removal of foldable and rigid intraocular lenses: clinicopathological analysis of 100 cases

PURPOSE

To analyze the rates of and reasons for intraoperative explantation of foldable and rigid intraocular lenses (IOLs) to determine the complication profile of each IOL design.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

The study comprised data analysis of foldable (n = 85) and rigid (n = 15) IOL specimens that were explanted immediately after primary implantation.

RESULTS

Eighty-five foldable intraoperative explants were accessioned. These comprised 14.5% of the 586 foldable IOL explants received between January 1988 and September 2000. There were 15 rigid poly(methyl methacrylate) (PMMA) intraoperative explants out of 2077 rigid explant specimens (0.7%). Fifty-one (60%) of the foldable IOLs requiring intraoperative explantation were the 1-piece silicone plate-haptic large-hole design, and 29 (34.1%) were the 3-piece silicone polyimide-haptic design. The most frequent reason for explantation of both designs was optic damage, 37.3% in the large-hole design and 55.2% in the polyimide design. Optic damage did not occur in rigid PMMA IOLs.

CONCLUSION

Some foldable IOL designs have a higher risk of damage during surgical insertion than rigid designs. Two modern foldable IOLs, the silicone plate-haptic large-hole and the silicone polyimide-haptic, appear to be more prone to damage during folding, loading, and implantation than other IOLs.