To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates. University of Valencia, Valencia, Spain. 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. Refractive and keratometric data from 4,540 eyes of 2,415 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<.01). In 13.2% of eyes, no corneal astigmatism was present; in 64.4%, corneal astigmatism was between 0.25 and 1.25 diopters (D) and in 22.2%, it was 1.50 D or higher. 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.

To compare thickness measurements of the central 6.0 mm of the cornea obtained with the Orbscan(R) II topography system and topographical ultrasound pachymetry. School of Optometry, University of Santiago de Compostela, Galicia, Spain. In 24 right eyes, pachymetric measurements were taken at the center and 1.2 mm and 3.0 mm on the superior and inferior hemimeridians. A 1-sample t test was applied to assess the significance of the relationship between Orbscan II and ultrasound methods. The relationship between the 2 was assessed by analyzing regression and plotting the differences against the mean corneal thickness. Orbscan II data were analyzed in 3 ways: (1) without the application of an acoustic equivalent correction factor; (2) with a correction factor of 0.92, as recommended by the manufacturer; (3) with correction using the equations derived in this study. The data were systematically compared with those of ultrasound pachymetry. Before the correction factor was applied, the Orbscan II overestimated the corneal thickness at all locations, with the mean difference (48.15 microm +/- 33.74 [SD]) significantly different from zero (P <.001). Differences increased toward the periphery, and the reliability of Orbscan II readings seemed to decrease with thicker corneas. After the acoustic equivalent was applied, the differences were significantly less; however, this effect did not seem clinically significant as large differences remained. When specific corrective equations were applied for each corneal location, the level of agreement between Orbscan II and ultrasound pachymetry improved substantially; the mean (-0.11 +/- 15.22 microm) was not statistically different from zero (P >.05). The acoustic equivalent correction factor proposed by the manufacturer to obtain corneal thickness measurements with the Orbscan II compared to those from ultrasound pachymetry was not valid for all corneal topography positions. Orbscan II measurements agreed better with those of ultrasound pachymetry when equations for the central and each peripheral location across the topography were applied.

We reviewed recently published studies that analyzed the visual and optical quality in eyes with different spherical and aspheric intraocular lenses (IOLs). Recent studies focused on visual quality metrics, such as visual acuity and contrast sensitivity, under photopic and mesopic lighting conditions and optical metrics, such as wavefront aberrations, especially spherical aberration. The results in this review were used in an attempt to understand whether there is a visual and/or optical benefit of implanting aspheric IOLs over implanting spherical IOLs.

Retrospective analysis of different contact lens wearing groups suggests lens surface lubricity is the main factor influencing contact lens comfort. However, the examined commercially available contact lenses differ in material and design as well as surface properties. Hence this study isolates the contribution of lens surface properties using an ultra-thin coating technology. Nineteen habitual contact lens wearers (21.6±1.7years) wore formofilcon B soft monthly disposable contact lenses with and without coating technology modified surface properties for a month each in a randomised double-masked cross-over study. OBJECTIVE NON-INVASIVE: breakup time (NIKBUT), NIKBUT average and ocular redness (Jenvis grading scale) were evaluated (Keratograph 5M) after 1 week and 1 month of wear. Symptoms were assessed using the Contact Lens Dry Eye Questionnaire (CLDEQ-8); perceived vision quality and subjective lens comfort at insertion, mid-day and end of the day were rated with four Visual Analog Scales. Perceived visual quality (F=5.049,p=0.037), contact lens dry eye symptoms (F=14.408,p=0.001) and subjective lens comfort (F=28.447,p0.05). Lens surface wettability and ocular redness were not correlated to changes in symptoms (p>0.05). As previously hypothesised, enhancing the physical surface properties of a soft contact lens improves subjectively rated wearer comfort, which, in turn, should result in reduced contact lens discontinuation.

To evaluate the optical and visual performance after implantation of refractive or apodized diffractive multifocal intraocular lenses (IOLs). Military Health Service Institute, Warsaw, Poland. Uncorrected distance visual acuity, best distance-corrected visual acuity, best distance-corrected near visual acuity, distance contrast sensitivity under photopic conditions (CSV-1000), residual refractive error, and wavefront aberrations (LADARWave Hartmann-Shack wavefront analyzer) were measured in 23 patients who had bilateral implantation of the AcrySof ReSTOR SN60D3 IOL and 23 patients who had bilateral implantation of the ReZoom IOL.... At the 6-month postoperative visit, the mean photopic uncorrected distance acuity was 0.03+/-0.05 (SD) in the ReSTOR group and 0.02+/-0.06 logMAR in the ReZoom group (both approximately 20/20) (P= .569). In all patients, the mean photopic best distance-corrected acuity was 0.00 logMAR (approximately 20/20) and the mean photopic best distance-corrected near acuity at 35 cm was 0.10 logMAR. The photopic contrast sensitivity was within the standard normal range in both IOL groups. The difference in photopic contrast sensitivity between groups was statistically significant (P<.001). Higher-order aberrations, in particular coma and spherical aberrations, were significantly higher in the ReZoom group (all P<.001). AcrySof ReSTOR SN60D3 and ReZoom IOLs provided good visual performance at distance and near under photopic conditions. Optical quality measures were significantly worse in patients with ReZoom IOLs.