Iris color and visual functions.

BACKGROUND: The aim of this study was to evaluate if iris color is associated with differences in visual functions such as intraocular straylight (IOSL), contrast sensitivity (CS), or best-corrected visual acuity (BCVA). METHODS: In this retrospective cohort study, which is a subgroup analysis of a large prospective trial about visual impairments in European car drivers, we included 853 persons between 20 and 80 years of age and without a history of ocular surgery or any eye disease including cataract. Subjects participated in an ophthalmological examination, grading of lens opacity, and the measurement of visual functions such as IOSL, CS, and BCVA. Dependent on iris color, participants were divided into four groups: light-blue, blue-grey, green-hazel, and brown. RESULTS: Independent of age, IOSL was significantly (all p values < 0.0001, Fisher's LSD test) higher in participants with light-blue colored iris (1.14 log(IOSL) [95 % CI: 1.11-1.17]) compared to participants with blue-grey (1.07 log(IOSL) [95 % CI: 1.05-1.09]), green-hazel (1.06 log(IOSL) [95 % CI: 1.04-1.08]) or brown (1.06 log(IOSL) [95 % CI: 1.04-1.08]) iris color. CS was also lower in participants with light-blue pigmented irises (1.60 log(CS) [95 % CI: 1.58-1.62]) than in the other groups, but statistically significant (p = 0.013, Fisher's LSD test) only compared to brown iris color. For BCVA we could not found any difference between the four groups. CONCLUSIONS: We could show in this study that iris color has a significant impact on IOSL and to a lower degree on CS, but not on BCVA. Persons with light-blue iris color who showed significantly higher IOSL values therefore may experience disability glare in daily situations such as driving at night more often than others.

Straylight effects with aging and lens extraction.

PURPOSE: To assess possible gains and losses in straylight values among the population to consider straylight as added benefit of lens extraction. DESIGN: In this cross-sectional design, data from a multicenter study on visual function in automobile drivers were analyzed. METHODS: On both eyes of 2,422 subjects, visual acuity (logarithm of the minimum angle of resolution [logMAR] in steps of 0.02 log units), straylight on the retina (psychophysical compensation comparison method), and lens opacity (slit-lamp scoring using the Lens Opacities Classification System III [LOCS III] system) were determined. Three groups were defined: 220 pseudophakic eyes, 3,182 noncataractous eyes (average LOCS III score, <1.5), and 134 cataractous eyes (average LOCS III score, >3.0). RESULTS: Noncataractous straylight values increases strongly with age as: log(s) = constant + log(1 + (age / 65)(4)), doubling by the age of 65 years, and tripling by the age of 77 years. Population standard deviation around this age norm was approximately 0.10 log units. The cataract eyes (in this active driver group) had relatively mild straylight increase. In pseudophakia, straylight values may be very good, better even than in the noncataract group. Visual acuity and straylight were found to vary quite independently. CONCLUSIONS: Lens extraction holds promise not only to improve on the condition of the cataract eye, but also to improve on the age-normal eye. Lens extraction potentially reverses the strong age increase in straylight value, quite independently from visual acuity.

Randomized controlled clinical trial to evaluate different intraocular lenses for the surgical compensation of low to moderate-to-high regular corneal astigmatism during cataract surgery.

PURPOSE: To evaluate vector analysis, rotational stability, and visual outcomes after implantation of toric IOLs with low (<2.25 diopter [D]) toric values (Acrysof IQ SN6AT3 or SN6AT4) and moderate-to-high toric (3.00 D to 6.00 D) values (Acrysof IQ SN6AT5, SN6AT6, SN6AT7, SN6AT8, or SN6AT9) versus after implantation of a nontoric IOL (Acrysof SN60WF) in eyes with regular topographic corneal astigmatism. SETTING: Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria. DESIGN: Randomized controlled clinical trial. METHODS: The study included eyes of patients undergoing phacoemulsification and IOL implantation. Patients were randomized into 3 groups to bilaterally receive the nontoric IOL, the low toric IOL, or the moderate-to-high toric IOL. Over a 6-week follow-up period, rotational stability and astigmatic changes were evaluated in the 2 toric IOL groups using the Alpins vector method. RESULTS: The study included 78 eyes of 39 patients. Postoperatively mean refractive astigmatism decreased significantly from 1.45 D ± 1.18 (SD) to 0.36 ± 0.44 D in the low toric group and from 1.92 ± 1.09 D to 0.31 ± 0.46 D in the moderate-to-high toric group. There was no significant difference between mean difference vectors in the low toric IOL group and the moderate-to-high toric IOL group. A significant difference in the correction index was detected, revealing overcorrection with low toric IOLs (1.03 ± 0.12 D) and undercorrection with moderate-to-high toric IOLs (0.95 ± 0.12 D). CONCLUSIONS: Implantation of low toric IOLs and medium-to-high toric IOLs in patients with low to moderate-to-high corneal astigmatism was shown to be effective in correcting regular corneal astigmatism. Undercorrection in the moderate-to-high group could be related to misalignment. FINANCIAL DISCLOSURE: This research project was financially supported by the Fuchs Foundation for the Promotion of Research in Ophthalmology, Salzburg, Austria. Alcon Inc. financially supports the Fuchs-Foundation as the clinical research center of the Department of Ophthalmology of the Paracelsus Medical University Salzburg, Salzburg, Austria (Grant Number 2010-37). No author has a financial or proprietary interest in any material or method mentioned.

Reliability of automatic biometric iris recognition after phacoemulsification or drug-induced pupil dilation.

PURPOSE: To investigate the reliability of a biometric iris recognition system for personal authentication after cataract surgery or iatrogenic pupil dilation. METHODS: This was a prospective, nonrandomized, single-center, cohort study for evaluating the performance of an iris recognition system 2-24 hours after phacoemulsification and intraocular lens implantation (group 1) and before and after iatrogenic pupil dilation (group 2). RESULTS: Of the 173 eyes that could be enrolled before cataract surgery, 164 (94.8%) were easily recognized postoperatively, whereas in 9 (5.2%) this was not possible. However, these 9 eyes could be reenrolled and afterwards recognized successfully. In group 2, of a total of 184 eyes that were enrolled in miosis, a total of 22 (11.9%) could not be recognized in mydriasis and therefore needed reenrollment. No single case of false-positive acceptance occurred in either group. CONCLUSIONS: The results of this trial indicate that standard cataract surgery seems not to be a limiting factor for iris recognition in the large majority of cases. Some patients (5.2% in this study) might need "reenrollment" after cataract surgery. Iris recognition was primarily successful in eyes with medically dilated pupils in nearly 9 out of 10 eyes. No single case of false-positive acceptance occurred in either group in this trial. It seems therefore that iris recognition is a valid biometric method in the majority of cases after cataract surgery or after pupil dilation.

Intraindividual aqueous flare comparison after implantation of hydrophobic intraocular lenses with or without a heparin-coated surface.

PURPOSE: To assess the efficacy of a heparin-surface-modified (HSM) hydrophobic acrylic intraocular lens (IOL) (EC-1YH PAL) and the same IOL without heparin coating (EC-1Y-PAL) by the flare and cell intensity in the anterior chamber after uneventful cataract surgery. SETTING: Department of Ophthalmology, Paracelsus Medical University Salzburg, Austria. DESIGN: Comparative case series. METHODS: Routine phacoemulsification with randomized implantation of an HSM IOL in 1 eye (HSM IOL group) and an uncoated IOL (uncoated IOL group) in the fellow eye was performed. Postoperative inflammation was assessed objectively using a laser flare-cell meter (FM-600) preoperatively as well as 1 day and 1 and 3 months postoperatively. Aqueous cells in the anterior chamber, distance visual acuities, and subjective manifest refraction were also evaluated at each visit. RESULTS: One hundred eyes (50 patients) were enrolled. In both groups, the mean flare values increased significantly from preoperatively to 1 day postoperatively (P<.001) and nearly reached preoperative values by 3 months postoperatively. One day postoperatively, the mean flare value was statistically significantly lower in the HSM IOL group (14.92 photons per millisecond [ph/ms] ± 7.47 [SD]) than in the uncoated IOL group (mean 16.73 ± 7.81 ph/ms) (P=.04); there was no statistically significant difference between groups 1 and 3 months postoperatively (both P>.58). The HSM IOL group had a greater and quicker decrease in aqueous cells, reaching statistical significance 1 month postoperatively (P=.01). CONCLUSION: The HSM IOL showed a significant lower inflammatory reaction in the early postoperative stage with a faster disappearance of inflammatory signs. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

The effect of steroids in combination with optic nerve decompression surgery in traumatic optic neuropathy.

OBJECTIVES/HYPOTHESIS: Traumatic optic neuropathy (TON) is an important cause of severe visual impairment following blunt or penetrating head trauma. Treatment options include steroids, decompression, or both. Studies have failed to show a clear benefit for either steroids or surgery or a combined therapy. This study describes the visual outcome in surgically managed patients with or without steroid treatment. STUDY DESIGN: Retrospective analysis. METHODS: In a retrospective chart review we included patients (n = 42) with TON who were managed with optic nerve decompression surgery with or without steroids. Comparison of initial and final visual acuity was the primary outcome parameter. RESULTS: In 42 consecutive patients, steroids were used in 21 cases (50%). Ten patients received a high-dose systemic regimen of more than 500 mg methylprednisolone initial dose, and 11 patients were treated with a lower dose. The overall visual improvement rate was 33%, no change was noted in 50%, and no outcome data were available in 17%. The visual improvement rate of patients treated with decompression surgery and steroids was lower (29%, 6 of 21) than those treated with surgery alone (53%, 8 of 15). Comparing both groups, additional steroids had no beneficial effect on the visual outcome (P = .97). There was no case with a deterioration of visual function due to therapy. CONCLUSIONS: In patients with traumatic optic neuropathy who were treated with optic nerve decompression surgery, steroids had no beneficial effect on the visual outcome. LEVEL OF EVIDENCE: 2c.

Profiles of intraocular pressure in human donor eyes during femtosecond laser procedures--a comparative study.

PURPOSE: To compare four different femtosecond laser devices (IntraLase FS, Zeiss VisuMAX, and Ziemer Femto LDV, and a prototype Schwind SmartTech Nanolaser) in human donor eyes with regard to their effects on IOP during femtosecond laser flap cutting. In order to get cuts parallel to the corneal surface, the cornea has to be forced into a defined shape and current femtosecond laser devices either use a flat or a curved patient interface design to achieve applanation. METHODS: IOP was measured in enucleated eyeballs (n = 46) not suitable for keratoplasty by direct cannulation of the vitreous body. A second cannula was inserted to adjust IOP to a baseline pressure of 20 mm Hg. The eyeballs were lifted by custom made supporting stands to achieve an appropriate height and put under the femto-LASIK devices. RESULTS: The flat patient interfaces gave rise to higher IOPs (IOP max = 328.3 ± 29.8, 228.8 ± 28.4, and 201.09 ± 21.4 mm Hg), whereas the curved patient interface caused lower IOPs in response to attachment and suction (IOP max = 104.9 ± 13.4 mm Hg). CONCLUSIONS: Based on previous findings of visual field defects after LASIK, and as a consequence of the present study, it seems feasible to design patient interfaces in a more physiologic manner to prevent high IOPs during refractive procedures.

Bilateral reading performance of 4 multifocal intraocular lens models and a monofocal intraocular lens under bright lighting conditions.

PURPOSE: To compare changes in reading performance parameters after implantation of 4 multifocal intraocular lens (IOL) models and a monofocal IOL. SETTING: Department of Ophthalmology, Paracelsus Medical University, Salzburg, Austria. DESIGN: Prospective randomized controlled clinical trial. METHODS: Patients with bilateral cataract without additional ocular pathology were scheduled for bilateral implantation of Acri.Smart 48S monofocal, Acrysof Restor SN6AD3 apodized multifocal, AT LISA 366D diffractive multifocal, Tecnis ZMA00 diffractive multifocal, or Rezoom refractive multifocal IOLs. Bilateral corrected and uncorrected reading acuity, reading distance, mean and maximum reading speeds, and smallest log-scaled print size of a Radner reading chart were evaluated under bright lighting conditions (500 lux) using the Salzburg Reading Desk. Pupil size was not measured throughout the trial. The minimum follow-up was 12 months. RESULTS: The diffractive multifocal groups had significantly better uncorrected reading acuity and uncorrected smallest print size than the monofocal and refractive multifocal groups 1, 6, and 12 months postoperatively. The diffractive IOL groups had comparable uncorrected reading distance of approximately 32 cm, which was larger in the monofocal group (38.9 ± 8.4 cm) and refractive multifocal group (37.1 ± 7.3 cm) at the last visit. Patients with diffractive IOLs could read print sizes of approximately 0.74 to 0.87 mm, which was much better than in the monofocal and refractive multifocal groups. The diffractive AT LISA IOL provided the best reading speed values (mean and maximum, corrected and uncorrected). CONCLUSION: Multifocal IOLs with a diffractive component provided good reading performance that was significantly better than that obtained with a refractive multifocal or monofocal IOL. FINANCIAL DISCLOSURE: Drs. Grabner and Dexl were patent owners of the Salzburg Reading Desk technology (now owned by SRD-Vision, LLC). No other author has a financial or proprietary interest in any material or method mentioned.

Reading performance and patient satisfaction after corneal inlay implantation for presbyopia correction: two-year follow-up.

PURPOSE: To evaluate change in reading performance parameters after monocular Kamra corneal inlay implantation for the surgical correction of presbyopia. SETTING: University surgical outpatient center. DESIGN: Prospective interventional case series. METHODS: A corneal inlay was implanted in the nondominant eye. Naturally emmetropic and presbyopic patients between 45 years and 60 years old with an uncorrected distance visual acuity of at least 20/20 in both eyes without additional ocular pathology were eligible for inclusion. Bilateral uncorrected reading acuity, reading distance, mean and maximum reading speed, and the smallest log-scaled print size (lower case letter of a Radner reading chart) were evaluated using the Salzburg Reading Desk. The minimum postoperative follow-up was 24 months. RESULTS: Twenty-four patients were enrolled. The mean reading distance was 46.7 cm ± 6.3 (SD) preoperatively and 39.5 ± 6.4 cm 24 months postoperatively (P<.001). The mean reading acuity at best distance improved (0.33 ± 0.13 logRAD versus 0.23 ± 0.11 logRAD) (P=.004). The mean reading speed increased from 141 ± 20 words per minute (wpm) to 146 ± 20 wpm, respectively (P=.261), and the mean maximum reading speed from 171 ± 28 wpm to 180 ± 22 wpm, respectively (P=.110). The smallest print size improved from 1.50 ± 0.42 mm to 1.01 ± 0.22 mm, respectively (P<.001). CONCLUSION: Improving the depth of focus by monocular implantation of a small-aperture optic caused statistically significant changes in all tested reading performance parameters except reading speed metrics in emmetropic presbyopic patients.

Cataract and pseudophakia in elderly European drivers.

PURPOSE: To evaluate the prevalence and association of different types and severities of cataract or pseudophakia with visual impairments in older European drivers. METHODS: In this prospective European multicenter study, 2211 active drivers, 45 years of age and older, participated in an ophthalmologic examination, the measurement of visual functions, and were asked to fill in the NEI-VFQ-25 and another questionnaire about driving habits, driving difficulties, and self-reported accidents. RESULTS: Prevalence of moderate and severe forms of cataract in an active driving population is lower than that in the general population, but could be found in both eyes in 20% (95% confidence interval [CI] 16%-25%) and 17% (95% CI:13%-21%) of subjects 75 years of age and older. In addition, there is a strong relationship between severity of cataract and parameters such as age, visual acuity, intraocular straylight, and contrast sensitivity. CONCLUSIONS: Cataract is not as highly prevalent in the elderly active driving population as in the general population, but is frequently present in drivers over 65 years of age. Lower prevalence of severe bilateral cataracts in countries with mandatory tests of visual functions of drivers suggest that this could be a suitable measure to detect and to reduce the number of active drivers with severe bilateral cataracts.

Association of lens opacities, intraocular straylight, contrast sensitivity and visual acuity in European drivers.

PURPOSE: To study the relationship between lens opacity and intraocular straylight, visual acuity and contrast sensitivity. METHODS: We investigated 2422 drivers in five clinics in different European Union (EU) member states aged between 20 and 89 years as part of a European study into the prevalence of visual function disorders in drivers. We measured visual acuity [Early Treatment Diabetic Retinopathy Study (ETDRS) chart], contrast sensitivity (Pelli-Robson chart) and intraocular straylight (computerized straylight meter). Lens opacities were graded with the Lens Opacities Classification System III (LOCS) without pupillary dilation. Participants answered the National Eye Institute Visual Functioning Questionnaire - 25. RESULTS: Intraocular straylight was related more strongly to LOCS score than to both visual acuity and contrast sensitivity. Visual acuity and contrast sensitivity were correlated to each other well, but to intraocular straylight to a much lesser extent. Self-reported visual quality was best related to contrast sensitivity; night driving difficulty was best related to visual acuity. CONCLUSION: Straylight is found to have added value for visual function assessment in drivers, whereas if visual acuity is known contrast sensitivity has limited added value.