Cracked acrylic intraocular lens requiring explantation

Early intraocular lens explantations: 10-year database analysis

BACKGROUND

The aim of this study was to analyze the causes and characteristics of IOL explantation within the first year after primary implantation.

METHODS

In this retrospective, cross sectional database study, a database consisting of over 2500 IOL explants sent from 199 national and international doctors over the past 10 years was analyzed. All IOLs explanted within the first year after implantation were included in this analysis. Explants with insufficient information as well as phakic and Add-on IOLs were excluded. Main outcome measures were the reason for explantation, the time between implantation and explantation, as well as IOLs' and patients' characteristics. Additionally, the explanted IOLs were microscopically and histologically analyzed, as required.

RESULTS

Of all explanted IOLs from the database, 1.9% (n = 50) were explanted within the first year after implantation. The most frequent reasons for early IOL explantation were IOL dislocation (32%), visual intolerance (26%), opacification (20%), and intraoperative complications (16%). The time between implantation and explantation was the shortest in cases with intraoperative complications (1.5 ± 3.1 days), followed by IOL dislocation (90.9 ± 103.9 days), visual intolerance (98.3 ± 86.5 days), opacifications (253.5 ± 124.0 days) and other indications (249.7 ± 124.0 days). Calcification of hydrophilic IOLs was the main type of opacification (80%). Notably, seven IOLs required immediate intraoperative exchange due to an intraoperative crack in the optic or a torn off haptic.

CONCLUSION

Indications for early IOL explantation were IOL dislocation, visual intolerance, opacification, and intraoperative complications. Especially intraoperative damages to the IOL and early calcification show a potential for improvement of affected IOLs and implantation systems.

Prospective evaluation of intraoperative intraocular lens stress fracture during cataract surgery

PURPOSE

To determine the incidence and risk factors of intraocular lens (IOL) stress fracture during cataract surgery.

SETTING

Ivey Eye Institute, London, Ontario, Canada.

DESIGN

Prospective, randomized cohort study.

METHODS

Patients scheduled for routine cataract surgery were randomized into 2 study groups. The 2 groups only differed in the use of Monarch IOL delivery cartridges for insertion of an Acrysof IQ SN60WF IOL. The cartridge C group used Monarch cartridge C, and the cartridge D group used Monarch cartridge D. Patients were examined for IOL stress fractures.

RESULTS

A total of 386 study eyes were enrolled. The overall incidence of IOL stress fracture was 6.22%. The incidence of IOL stress fracture with cartridge C and cartridge D groups were 3.16% and 9.18%, respectively (P = .01). The IOL stress fracture rate for IOL power less than 18.0 D was 3.45%, IOL power between 18.0 D to 23.5 D was 6.49%, and IOL power over 23.5 D was 10.81%. A total of 24 IOL stress fractures were observed. Among IOL stress fractures, 45.8% were equal to or less than 1.0 mm in length. Two thirds of stress fractures were located over the central 4 mm of the IOL optic. No subjective adverse visual outcomes were reported from any of the observed IOL stress fractures.

CONCLUSION

Intraocular lens stress fracture is recognizable risk during cataract surgery. Risk factors for IOL stress fracture include smaller IOL delivery cartridges and IOLs of higher refractive powers. There was a low risk for IOL stress fracture resulting in adverse subjective visual outcomes.

Foldable versus rigid intraocular lenses in conjunction with pars plana vitrectomy and other vitreoretinal procedures

PURPOSE

To compare the results of foldable acrylic intraocular lens (IOL) implantation through a clear corneal incision with those of rigid IOL implantation in eyes having pars plana vitrectomy (PPV).

SETTING

Tertiary referral-based university institute.

METHODS

A consecutive retrospective comparative chart review was performed in all eyes that had PPV and foldable IOL implantation between May 15, 1999, and November 1, 2000 (n = 30), and all eyes that had PPV and rigid IOL implantation between April 1, 1996, and May 14, 1999 (n = 30). Preoperative baseline data and postoperative outcome data were recorded. Pars plana vitrectomy and associated vitreoretinal procedures were performed as indicated according to individual circumstances. A minimum of 1 week of follow-up information was available for all eyes.

RESULTS

Baseline characteristics in both groups of patients, including age, sex, eye involved, and phakic state, were similar. The preoperative visual acuities were also similar, ranging from 20/30 to hand motions; the mean visual acuity was 20/200. The IOL was implanted in all eyes uneventfully and did not restrict fundoscopy. The mean follow-up was significantly longer in the rigid IOL group (20 months) than in the foldable IOL group (7 months) (P<.001), probably because of the earlier case acquisition. The mean postoperative best corrected visual acuity was 20/200 in the foldable IOL group and 20/100 in the rigid IOL group. There was no difference between the 2 groups in the rate of postoperative retinal detachment, recurrent macular hole, or repeat PPV. Elevated intraocular pressure (IOP) on the first postoperative day was more common in the rigid IOL group than in the foldable IOL group (P =.078) because more patients in the rigid IOL group had surgery for diabetic ocular complications and these patients had a greater IOP rise.

CONCLUSION

Acrylic IOLs can be safely implanted in conjunction with PPV in selected cases.

In-the-bag dislocation of a hydrophilic acrylic intraocular lens

We report a case of a dislocated hydrophilic acrylic intraocular lens (IOL) inducing astigmatism and causing chronic pain and cystoid macular edema as a result of a folded haptics, which mechanically irritated the iris. Scanning electron micrographs of the explanted IOL, including the capsular bag, showed a folded IOL haptic incarcerated in the capsular bag.

Spontaneous disinsertion of a haptic from a 3-piece acrylic foldable intraocular lens after surgery

A 49-year-old man with cataracts had uneventful phacoemulsification, continuous curvilinear capsulorhexis, and implantation of an MA30BA acrylic foldable intraocular lens (IOL) in the bag. One week later, 1 haptic spontaneously dropped off and the optic dislocated into the anterior chamber. The IOL was surgically removed and replaced with a new acrylic foldable IOL. Examination of the explanted IOL revealed that the loop hole was not created in the middle of the side face, leading to in vivo detachment of the haptic postoperatively.

Intraocular lens materials and styles: a review

Biomaterial science has lead to the development of a variety of foldable intraocular lens (IOL) biomaterials. This literature review examines these lenses from both a basic science and a clinical perspective. By most parameters, hydrogel, soft acrylic and silicone IOL are better than polymethylmethacrylate (PMMA) lenses. Plate haptic silicone IOL have the lowest incidence of cystoid macula oedema and posterior capsule opacification, but these lenses require an intact anterior capsularhexis and posterior capsule. Yttrium aluminium garnet (YAG) laser capsulotomy must be delayed at least 3 months to avoid posterior lens dislocation. Silicone has the lowest threshold for YAG laser damage of all IOL materials and also adheres irreversibly to silicone oil with subsequent optical impairment. Three piece silicone IOL with polypropylene haptics have a higher incidence of decentration, pigment adherence and capsule opacification compared with PMMA haptics. Hydrogel lenses are very biocompatible and resistant to YAG laser damage, but pigment adheres to the surface more readily than PMMA. Soft acrylic IOL unfold slowly, resulting in controlled insertion, but it is possible to crack the lens and some lenses develop glistenings due to water accumulation. There are significant socioeconomic implications to the large differences in posterior capsule opacification rates between the various biomaterials and the lens styles.