Purpose To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates. Setting University of Valencia, Valencia, Spain. Methods Refractive and keratometric values were measured before surgery in patients having cataract extraction. Descriptive statistics of refractive and keratometric cylinder data were analyzed and correlated by age ranges. Results Refractive and keratometric data from 4540 eyes of 2415 patients (mean age 60.59 years ± 9.87 [SD]; range 32 to 87 years) differed significantly when the patients were divided into 10-year subsets. There was a trend toward less negative corneal astigmatism values, except the steepest corneal radius and the J 45 vector component, in older groups (Kruskal-Wallis, P Conclusions Corneal astigmatism less than 1.25 D was present in most cataract surgery candidates; it was higher in about 22%, with slight differences between the various age ranges. This information is useful for intraocular lens (IOL) manufacturers to evaluate which age ranges concentrate the parameters most frequently needed in sphere and cylinder powers and for surgeons to evaluate which IOLs provide the most effective power range.

Prevalence of corneal astigmatism before cataract surgery.

Purpose To examine tear film, contact lens, medical, and patient-related factors associated with self-reported contact lens-related dry eye. Methods Four hundred fifteen contact lens wearers were recruited and enrolled in this phase of a larger cross-sectional study. A variety of tear film (e.g., interferometry, osmolality, phenol red thread, meibography, fluorescein, and lissamine green staining), contact lens (i.e., water content, refractive index, material), and patient-related (e.g., gender, sociodemographic, education, income, and medical health) factors were examined in relation to dry eye status. Univariate and multivariate logistic regression models were used to examine the relation between these tear film, contact lens, and patient-related factors associated with dry eye status. Results Of the 415 enrolled, the data from 360 were used in the analyses. The average age was 31.1 +/- 11.5 years, 245 (68%) participants were female, and 55.3% were classified as having-contact lens-related dry eye via self-report. Overall, 327 (90.8%) were hydrogel lens wearers and 33 (9.2%) were gas-permeable lens wearers. Several factors were shown to be related to dry eye status in multivariate modeling, including female gender (P = 0.007), lenses with higher nominal water content (P = 0.002), rapid prelens tear film thinning time (P = 0.008), frequent usage of over-the-counter pain medication (P = 0.02), limbal injection (P = 0.03), and increased tear film osmolality (P = 0.05). Conclusions Contact lens-related dry eye may be explained mechanistically by increased tear film thinning times (evaporation or dewetting) resulting in increased tear film osmolality. Other contributing factors include the use of high-water-content lenses, which have traditionally been reported to be associated with less patient comfort than lower-water-content lenses, potentially due to spoilation and deposition. As found in other studies of dry eye, women are more likely to report contact lens-related dry eye than are men.

/pdf/tear-film-contact-lens-and-patient-related-factors-411t8p5is0.pdf

Tear film, contact lens, and patient-related factors associated with contact lens-related dry eye.

Purpose: To determine whether posterior capsule opacification (PCO) is influenced by intraocular lens (IOL) material.

Setting: A British teaching hospital eye department.

Methods: Ninety eyes were prospectively randomized to receive a poly(methyl methacrylate) (PMMA), silicone, or AcrySof® IOL. All lenses had 6,0 mm optics and PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with capsulorhexis. Patients having surgical complications were excluded, and all patients had standardized medication and follow-up. Posterior capsule opacification was assessed by a digital retroillumination camera using a dedicated software program based on the analysis of texture in the image and calculated as the percentage area of opacified capsule. Data were analyzed 2 years postoperatively.

Results: There was a significant difference in percentage of PCO at 2 years among the three lens types (P < .0001). The AcrySof lenses were associated with less PCO (median 11.75%) than PMMA (43.65%) and silicone (33.50%) lenses (P < .001 and P = .025, respectively). The difference between PMMA and silicone lenses was not statistically significant.

Conclusion: Intraocular lenses made from AcrySof were associated with a significantly reduced degree of PCO.

Relationship between intraocular lens biomaterials and posterior capsule opacification.

PURPOSE: To evaluate the results of AcrySof toric intraocular lens (IOL) (Alcon) implantation to correct preexisting astigmatism in patients having cataract surgery. SETTING: Ophthalmology Service, Donostia Hospital, San Sebastian, Spain. METHODS: This prospective observational study included 30 eyes of 15 consecutive patients with more than 1.00 diopter (D) of preexisting corneal astigmatism having cataract surgery. Bilateral implantation of the AcrySof toric IOL was performed after phacoemulsification. The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), residual refractive sphere, residual keratometric and refractive cylinders, and toric IOL axis were measured. RESULTS: The UCVA was 20/40 or better in 93.3% of eyes and 20/25 or better in 66.6%. All eyes achieved 20/25 or better BCVA. The mean refractive cylinder decreased significantly after surgery from 2.34 D G 1.28 (SD) to 0.72 G 0.43 D (P<.01). Vector analysis of attempted versus achieved correction showed that 100% of eyes were within G1.00 D and 80% and 93.9% were within G0.50 D for J0 and J45, respectively. The mean toric IOL axis rotation was 3.63 G 3.11 degrees, with rotation less than 10 degrees in 96.7% of eyes. CONCLUSIONS: The results indicate that phacoemulsification and posterior chamber AcrySof toric IOL implantation is an effective option to correct preexisting astigmatism in cataract surgery. The AcrySof toric IOL showed good rotational stability.

/pdf/foldable-toric-intraocular-lens-for-astigmatism-correction-3kh3risc5x.pdf

Foldable toric intraocular lens for astigmatism correction in cataract patients.

The AcrySof Toric intraocular lens in subjects with cataracts and corneal astigmatism: a randomized, subject-masked, parallel-group, 1-year study.

Purpose To determine the efficacy and rotational stability of a toric posterior chamber silicone intraocular lens (IOL) to correct preoperative astigmatism in cataract patients. Setting Department of Ophthalmology, University Hospital of Vienna, Vienna Austria. Methods Between 1993 and 1998, foldable toric single-piece plate-haptic silicone IOLs were implanted in 37 eyes (30 patients). The cylindrical IOL power was 2.00 diopters (D) (n = 29), 3.50 D (n = 7), or 4.00 D (n = 1). Phacoemulsification was performed through a scleral or a corneal sutureless self-sealing incision. Outcomes of Snellen visual acuity (without, with spherical, and with best correction), refractive and keratometric astigmatism, and IOL rotation after early postoperative (mean 15.9 days ± 10.1 [SD]) and long-term (mean 20.3 ± 16.6 months) follow-ups were evaluated. Results At last follow-up, 31 eyes (83.8%) had a spherically corrected and 34 (91.9%) a best corrected visual acuity of 0.5 (20/40) or better. Mean preoperative refractive and keratometric astigmatism was 2.68 and 2.70 D, respectively. At the last postoperative follow-up, mean refractive astigmatism was reduced to 0.84 D; keratometric astigmatism was 2.30 D. In 7 eyes (18.9%), the IOL axis was rotated a maximum of 25 degrees. In all 37 eyes, the axis of the toric IOL remained within 30 degrees of rotation. Conclusion Early postoperative and long-term follow-ups showed effective and stable correction of astigmatism after implantation of a foldable toric posterior chamber silicone IOL.

Astigmatism correction with a foldable toric intraocular lens in cataract patients.

Purpose To evaluate the long-term endothelial cell changes in phakic eyes after implantation of a posterior chamber phakic intraocular lens to correct high ametropia. Setting Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria. Methods Thirty-four eyes of 21 patients having implantation of an implantable contact lens (ICL, Staar Surgical) for high myopia or hyperopia were prospectively examined. The minimum follow-up was 2 to 4 years. Preoperative and serial postoperative specular microscopy (Noncon Robo SP 8000, Konan) was performed to evaluate the long-term endothelial cell changes. Results The mean preoperative endothelial cell density was 2854 cells/mm2. The mean endothelial cell loss from preoperatively was 1.8% at 3 months, 4.2% at 6 months, 5.5% at 12 months, 7.9% at 2 years (n = 34), 12.9% at 3 years (n = 13), and 12.3% at 4 years (n = 11). All other endothelial cell characteristics remained stable during the 4-year follow-up. Conclusions Continuous endothelial cell loss was observed after ICL implantation during a 4-year follow-up. There was rapid cell loss until 1 year postoperatively, after which the rate of loss was no longer statistically significant. The percentage of hexagonal cells (polymorphism) and the coefficient of variation (polymegethism) remained stable during the 4-year follow-up.

Long-term endothelial changes in phakic eyes with posterior chamber intraocular lenses.

Purpose: To evaluate the efficacy of topical anesthesia as an alternative to peribulbar anesthesia in clear corneal cataract surgery. Setting: Department of Ophthalmology, University of Vienna, Austria. Methods: In this prospective, double-blind clinical trial, 36 patients had bilateral cataract surgeries performed from 1 to 3 months apart. Half of the patients had topical anesthesia for the first surgery and peribulbar anesthesia for the second surgery. The other half had peribulbar first and then topical. All surgery was done using a temporal clear corneal approach and bimanual phacoemulsification followed by in-the-bag intraocular lens implantation. Subjective pain was assessed using a visual analog scale of no pain (0%) to worst pain imaginable (100%) and intraoperative motility using a rank scale of adverse motility (−5) to ideal patient cooperation (+5). Results: Subjective pain was comparable whether topical or peribulbar anesthesia was used (mean 10.75 versus 10.97%; P > .6). Patient cooperation (motility) was significantly better when topical anesthesia was used (+2.16 versus +1.11; P = .03). There were no significant differences in complications. A peribulbar block was given in addition to the topical anesthesia in two cases. Conclusions: Topical anesthesia is a safe, effective alternative to peribulbar anesthesia in clear corneal cataract surgery.

Topical versus peribulbar anesthesia in clear corneal cataract surgery.

Purpose: To determine whether a small clear corneal temporal incision produces less surgically induced astigmatism than a larger incision. Methods: One hundred three consecutive cases of postoperative astigmatism after clear corneal incision cataract surgery were studied for a minimum of 1 year. Only self-sealing incisions from the temporal side were made as follows: 3.2 mm (Group A); 4.0 mm (Group B); 5.2 mm (Group C). We considered the amount and axes of the keratometric readings at different times as well as their course over time. Induced astigmatism was calculated using three methods. Axial changes were also analyzed. Results: Immediately after the surgery, there was a small, surgically induced, withthe-rule astigmatic shift in all groups, which in most cases decreased to near preoperative levels with time. One year postoperatively, mean induced astigmatism was 0.09 diopter (D) in Group A, 0.26 D in Group B, and 0.54 D in Group C. Most cases had minimal axial changes. In Group A, 86% had an axial change of fewer than 30 degrees; in Group B, 76%; and in Group C, 73%. Conclusion: The smallest incision group had the least surgically induced astigmatism and axial change. All incision groups remained stable and had satisfactory clinical results.

Long-term course of induced astigmatism after clear corneal incision cataract surgery

We studied postoperative astigmatism in 107 patients who were followed for 12 months after phacoemulsification and posterior chamber lens implantation. A scleral incision of 3.5 mm was used in Group A patients and one of 4.5 mm in Group B patients. In both groups a no-stitch wound closure technique was used. A high correlation between preoperative and 12-month postoperative height and time shift of keratometric values was found. In both groups the mean difference was less than 0.60 diopters (D). The mean postoperative cylinder increase was less than 0.50 D; it was less than 0.25 D after six months. The induced astigmatism was confirmed by three different methods. Immediately after surgery, a negative induced astigmatism was found in both groups. After 12 months, induced astigmatism in Group A was -0.37 D and in Group B, -0.67 D. Immediately after surgery there was an axis change; a decrease of with-the-rule astigmatism occurred concurrently with an increase toward oblique and against-the-rule astigmatism. This axis change was somewhat evident after 12 months.

U. Scholz

Papers

Astigmatism correction with a foldable toric intraocular lens in cataract patients.

Long-term endothelial changes in phakic eyes with posterior chamber intraocular lenses.

Topical versus peribulbar anesthesia in clear corneal cataract surgery.

Long-term course of induced astigmatism after clear corneal incision cataract surgery

Postoperative astigmatism after no-stitch, small incision cataract surgery with 3.5 mm and 4.5 mm incisions.