Functional reading acuity and performance: Comparison of 2 accommodating intraocular lenses.

PURPOSE: To compare functional reading acuity and speed with 2 models of accommodating intraocular lenses (IOLs). SETTING: Four of 12 investigative sites in a U.S. Food and Drug Administration (FDA) clinical study. METHODS: In this observational study, which was part of an ongoing FDA clinical trial, the MNRead functional reading test was used to compare the reading performance of patients with bilateral Tetraflex IOLs (Group 1) and a consecutive series of patients with bilateral Crystalens IOLs (Group 2) presenting at approximately 1 year postoperatively at 4 ophthalmic practices. The 2 groups were well matched for age, sex, mean postoperative time, and mean level of postoperative corrected distance visual acuity. All examinations were scored at a central reading center. RESULTS: Group 1 comprised 96 patients and Group 2, 55 patients. Patients in Group 1 read better than those in Group 2 at print sizes of 20/63 (P = .004), 20/50 (P = .002), 20/40 (P = .001), 20/32 (P = .003), and 20/25 (P = .001). A statistically significantly higher proportion of patients in Group 1 than in Group 2 read 80 words per minute or more throughout the range of print sizes (P = .002). CONCLUSION: Near reading ability was better with the Tetraflex accommodating IOL than with the Crystalens accommodating IOL at all print sizes between 20/25 and 20/63.

Surface calcification of silicone plate intraocular lenses in patients with asteroid hyalosis.

PURPOSE: To report three cases in which a silicone-plate lens was explanted because of whitish deposits on the posterior optic surface. DESIGN: Observational case series with clinicopathological correlation. PATIENTS AND METHODS: In the three instances, the deposits were observed at least 2 years after uneventful cataract surgery. All of the patients had unilateral mild asteroid hyalosis in the concerned eye. After explantation of the lenses, gross and light microscopic analyses were performed. The posterior optic surfaces of the lenses also underwent scanning electron microscopy coupled with energy dispersive x-ray spectroscopy for analysis of the elemental composition of the deposits. RESULTS: Gross and light microscopic analyses revealed well-demarcated areas of whitish deposits on the posterior optic surface of the lenses, as well as multiple pits caused by Neodymium:yttrium aluminum garnet laser treatments. The deposits formed an amorphous layer with a "crustlike" appearance, which was confirmed by scanning electron microscopy. X-ray spectroscopy analyses demonstrated the composition of the deposits to be similar to hydroxyapatite. CONCLUSIONS: The material opacifying the lenses was probably derived from the asteroid bodies or from a similar process that results in this vitreous condition. We were unaware of this association between asteroid hyalosis and late postoperative dystrophic calcification of silicone lenses.

Sutured piggyback toric intraocular lenses to correct high astigmatism.

A 74-year-old woman presented for bilateral cataract surgery, which was performed 3 days apart. Corneal astigmatism was 4.25 diopters (D) in the right eye and 4.87 D in the left. After cataract extraction through 6.0 mm scleral incisions, 2 toric, plate-haptic, silicone intraocular lenses (IOLs), each with a 3.50 D cylinder add power (2.30 D at spectacle plane), were sutured together and implanted in the bag. Both eyes had limbal relaxing incisions postoperatively. Four months postoperatively, corneal astigmatism was 4.50 D in the right eye and 4.00 D in the left. Refractive astigmatism was 0.50 D with an uncorrected visual acuity of 20/40 in both eyes. No IOL rotation was observed. Suturing toric lenses together allows greater correction of astigmatism without concern about counter rotation of the lenses.

Combined toric intraocular lens implantation and relaxing incisions to reduce high preexisting astigmatism.

PURPOSE: To evaluate whether combining toric intraocular lens (IOL) implantation with astigmatic keratotomy (AK) can correct higher levels of astigmatism while minimizing undue effects on the optical qualities of the cornea. SETTING: St. Luke's Cataract and Laser Institute, Tarpon Springs, Florida, USA. METHODS: Thirteen eyes with corneal astigmatism greater than 2.50 diopters (D) (mean 5.54 D) had implantation of a Staar toric IOL combined with AK. RESULTS: All eyes had less than 1.00 D of refractive astigmatism postoperatively. Sixty-nine percent achieved an uncorrected visual acuity of 20/40 or better, and no patient lost best corrected visual acuity. CONCLUSIONS: Implanting a toric IOL in patients with high astigmatism reduced the amount of incisional surgery required. Combining techniques can correct all or most of even very high astigmatism (>5.00 D) while avoiding induced corneal irregularities.

Correcting high astigmatism with piggyback toric intraocular lens implantation.

An 86-year-old man presented for cataract surgery with corneal astigmatism of 5.12 diopters (D). After cataract extraction with small-incision techniques, 2 toric plate-haptic silicone intraocular lenses (IOLs) were implanted in the capsular bag, each with a 3.50 D cylinder add (2.30 D at the spectacle plane). Six weeks postoperatively, corneal astigmatism was 3.38 D at 70 degrees and refractive astigmatism was 1.00 D at 20 degrees. Uncorrected visual acuity was 20/40. No IOL rotation was observed. Implantation of piggybacked toric lenses may be a viable option for correcting moderate to high astigmatism.

Treating astigmatism at the time of cataract surgery.

Correcting astigmatism at the time of cataract surgery can be accomplished either by incisional techniques, such as use of a cataract incision for flattening or astigmatic keratotomy, or by implanting a toric intraocular lens. Both methods can reduce mild to moderate astigmatism. For correcting larger amounts of astigmatism, a combination of techniques can produce greater correction. New methods of analyzing the change induced by surgery provide a more complete understanding of the astigmatic change.