Teresa Ferrer-Blasco

Prevalence of corneal astigmatism before cataract surgery.

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 J45 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. 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.

Analysis of the possible benefits of aspheric intraocular lenses: Review of the literature

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.

Toric intraocular lens versus opposite clear corneal incisions to correct astigmatism in eyes having cataract surgery

PURPOSE: To compare toric intraocular lens (IOL) implantation with paired opposite clear corneal incisions (OCCIs) for astigmatism correction in patients having cataract surgery. SETTING: Ophthalmology Service, Donostia Hospital, San Sebastián, Spain. METHODS: This randomized prospective clinical study comprised eyes with more than 1.00 diopter (D) of preexisting corneal astigmatism. One group had AcrySof toric IOL implantation and the other, paired 2.75 mm/3.20 mm OCCIs in the steep axis with spherical IOL implantation. Uncorrected (UCVA) and best corrected (BCVA) visual acuity, refraction, corneal and total higher‐order aberrations (HOAs), photopic and mesopic contrast sensitivity, and toric IOL axis were measured 3 months postoperatively. RESULTS: Forty eyes (40 patients) were evaluated. In the toric group, 95% of eyes achieved 20/40 or better UCVA and 70%, 20/25 or better. In the OCCI group, 80% of eyes achieved 20/40 or better UCVA and 50%, 20/25 or better. All eyes achieved 20/25 or better BCVA. Mean refractive cylinder decreased significantly from preoperatively to postoperatively (−1.75 ± 0.71 to −0.62 ± 0.46 D, toric group; −1.61 ± 0.67 to −0.97 ± 0.51 D, OCCI group) (P<.01). In the toric group, 95% and 100% of eyes were within ±0.50 D for J0 and J45, respectively. In the OCCI group, the percentages were 70% and 100%, respectively. No significant differences in HOA were found between groups (P>.1). Contrast sensitivity was similar except at the highest spatial frequency, being better in the toric group (P<.01). CONCLUSION: Toric IOL implantation achieved a slight enhanced effect over OCCIs in treating preexisting astigmatism.

Implantable Collamer Posterior Chamber Intraocular Lenses: A Review of Potential Complications

PURPOSE To review the peer-reviewed literature reporting postoperative complications of the most recent models of Visian Implantable Collamer posterior chamber intraocular lenses (ICL, STAAR Surgical Co). METHODS A literature search of the PubMed database was performed to identify all articles related to ICL complications. Articles were obtained and reviewed to identify those that reported complications using the latest ICL designs. RESULTS Cataract was the major postoperative complication reported: 136 (5.2%) in 2592 eyes. Of those, 43.4% (n=59) were reported within 1 year, 15.4% (n=21) between 1 and 3 years, and 35.3% (n=48) ≥ 3 years after ICL implantation. Twenty-one (15.4%) cataracts were reported as surgically induced, 46 (33.8%) eyes had poor vault (<200 μm), and cataract surgery was carried out in 27.9% (n=38) of eyes. Early acute intraocular pressure increase was also reported to be relatively frequent, whereas acute pupillary block was less frequent and mostly resolved with additional iridotomies. A total of 42 ICLs were explanted due to cataract and IOP. Reported endothelial cell loss varied from 9.9% at 2 years to 3.7% 4 years postoperatively. This loss was reported to be more pronounced within the first 1 to 2 years, with stability or lower progression after that time. CONCLUSIONS The majority of reported complications after ICL implantation are cataract formation. The improvements in lens geometry and more accurate nomograms applied to the selection of the lens to be implanted, in addition to the surgeons learning curve, might be factors in the decreased occurrence of postoperative complications reported currently.

Visual acuity comparison of 2 models of bifocal aspheric intraocular lenses

PURPOSE: To compare visual acuity after bilateral implantation of 2 models of multifocal aspheric intraocular lenses (IOLs). SETTING: Fernández‐Vega Ophthalmological Institute, Oviedo, and University of Valencia, Valencia, Spain. METHODS: Prospective study of patients who had bilateral implantation of an AcrySof ReSTOR SN6AD3 IOL (Group 1) or an Acri.LISA 366D IOL (Group 2). Six months postoperatively, binocular uncorrected and best corrected distance visual acuity, uncorrected‐distance and best distance‐corrected near visual acuity, best corrected intermediate visual acuity, and the defocus curve were measured in both IOL groups. RESULTS: Group 1 comprised 36 eyes (18 patients) and Group 2, 40 eyes (20 patients). The mean binocular values in Group 1 and Group 2, respectively, were as follows: best corrected distance acuity, −0.05 ± 0.09 logMAR and −0.08 ± 0.08 logMAR (both approximately 20/20); best distance‐corrected near acuity, −0.01 ± 0.16 logMAR and −0.05 ± 0.07 logMAR; best corrected intermediate acuity at 80 cm, 0.20 ± 0.18 logMAR (approximately 20/32) and 0.16 ± 0.13 logMAR (approximately 20/25) and at 60 cm, 0.16 ± 0.16 logMAR (approximately 20/25) and 0.18 ± 0.13 logMAR (approximately 20/25). There were no statistically significant between‐group differences in visual acuity at any distance (P>.3). Defocus curves were similar between groups (2.00 to −5.00 diopters) (P>.26). CONCLUSIONS: The 2 multifocal aspheric IOL models gave similar and good high‐contrast visual acuity at distance and near. Intermediate visual acuity, also comparable between IOL models, was better than published results of a spherical IOL model.

Visual function after implantation of an aspheric bifocal intraocular lens.

PURPOSE: To evaluate distance, intermediate, and near vision after bifocal aspheric AcrySof ReSTOR SN6AD1 intraocular lens (IOL) implantation. SETTING: Fernández‐Vega Ophthalmological Institute, Oviedo, Spain. METHODS: Binocular distance best corrected visual acuity (BCVA) (4.0 m), best distance‐corrected near (40.0 cm) and intermediate (70.0, 60.0, 50.0 cm) acuities, and contrast sensitivity under photopic (85.0 candelas [cd]/m2) and mesopic (3.0 cd/m2) conditions with and without glare were measured postoperatively. A patient‐satisfaction and visual phenomena questionnaire was administered. RESULTS: Six months postoperatively, the mean acuities (logMAR) were binocular BCVA, −0.064 ± 0.049 (SD); best corrected near, −0.041 ± 0.061; best corrected intermediate, 0.147 ± 0.130 (70.0 cm), 0.036 ± 0.133 (60.0 cm), and −0.126 ± 0.077 (50.0 cm). The BCVA and best corrected near acuity were 20/25 or better in all patients. Through‐focus binocular logMAR acuities had 2 peaks at the expected far focus and near focus (0.00 diopter [D] and −2.40 D, respectively), with somewhat reduced acuity (20/32) at intermediate distances. Photopic contrast sensitivity was within the standard normal range. Mesopic contrast sensitivity was lower than under photopic conditions, particularly at higher spatial frequencies. Patients reported good performance for distance, near, and intermediate visual tasks with no or minimal difficulty with specific tasks. No patient reported severe visual phenomena; halos and glare were rated as none to moderate. CONCLUSIONS: The aspheric IOL provided good functional vision at far and near, with lower performance at intermediate distance; good photopic contrast sensitivity and lower mesopic performance; and a low incidence of visual disturbances.

The Tear Film and the Optical Quality of the Eye

The stability of the tear film plays an important role in the optical quality of the eye. Various methods have been developed to quantify the contribution of the tear film to optical quality, including the double-pass optical method, Hartmann-Shack wavefront sensing, videokeratoscopy, retroillumination analysis, and interferometry. In addition to assessing the effect of tear film irregularities, these methods can aid in the diagnosis of dry-eye related conditions and the monitoring of therapy. This review describes the methodologies used to assess the relationship between the tear film and optical quality of the eye and summarizes the most important findings obtained with these methods with regard to the healthy human eye, the dry eye, and the effect of artificial tear instillation.

Visual outcomes after cataract surgery with implantation of a +3.00 D or +4.00 D aspheric diffractive multifocal intraocular lens: Comparative study

PURPOSE: To compare the visual performance after cataract surgery with implantation of +3.00 diopter (D) or +4.00 D aspheric multifocal intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Maastricht University Medical Center, The Netherlands. METHODS: This prospective study compared the results of bilateral cataract surgery with implantation of a +3.00 D AcrySof ReSTOR SN6AD1 IOL or a +4.00 D AcrySof ReSTOR SN6AD3 IOL. The main outcome measures were binocular uncorrected (UDVA) and corrected distance visual acuities, binocular uncorrected (UNVA) and corrected near visual acuities, binocular uncorrected (UIVA) and corrected intermediate visual acuities, preferred working distance, straylight and contrast sensitivity levels, and wavefront aberrometry measurements. RESULTS: The +3.00 D IOL was implanted in 68 eyes and the +4.00 D IOL, in 46 eyes. The UIVA was significantly better in the +3.00 D IOL group than in the +4.00 D IOL group at 40, 50, 60, and 70 cm. The preferred working distance for near tasks was significantly lower in the +3.00 D IOL group (38.9 cm) than in the +4.00 D IOL group (31.0 cm). The UDVA was better in the +3.00 D IOL group; the UNVA at the preferred working distance was similar in the 2 groups. Contrast sensitivity and intraocular straylight levels were also similar. The mean levels of higher‐order and spherical aberrations were lower in the +3.00 D IOL group. CONCLUSION: Cataract surgery with the +3.00 D IOL resulted in better intermediate vision than with the +4.00 D model without compromising distance and near visual acuity. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Age-related changes in the human visual system and prevalence of refractive conditions in patients attending an eye clinic.

PURPOSE: To retrospectively report the trends of change in several parameters of the human visual system over a wide age range in patients attending an eye clinic. SETTING: University of Valencia, Valencia, Spain. METHODS: The clinical records of 2654 patients were retrospectively reviewed, and the age, sex, spherocylindrical refraction, visual acuity, keratometry, and intraocular pressure were obtained. Descriptive values for each parameter and the correlations with age and between different parameters were calculated. Vectorial components of refraction, including blur, were also derived from clinical refractive data and then analyzed. RESULTS: Several parameters changed significantly with age, particularly in patients in their sixties and older. An increase in the blur component was mainly associated with astigmatic progression and a trend toward against‐the‐rule orientation and had the highest correlation with total astigmatism (r = −0.319; P<.001) and visual acuity (r = −0.442; P<.001). Refractive conditions had the most homogeneous distribution in the first decade of life and the most heterogeneous distribution in the group between 61 years and 70 years. CONCLUSIONS: Best corrected visual acuity began to decrease after the 50s, while changes in the blur component were not patent until the 60s to 70s. This could be explained by the poorer optical quality of the human eye in adulthood and elderly persons. Clinically, these changes could be attributed to changes in ocular astigmatism and have an impact on the best visual acuity achievable with optical compensation.

Posterior chamber phakic intraocular lenses after penetrating keratoplasty

PURPOSE: To evaluate the efficacy, predictability, and safety of a phakic posterior chamber intraocular Collamer lens (ICL) after penetrating keratoplasty (PKP). SETTING: Fernández‐Vega Ophthalmological Institute, Oviedo, Spain. METHODS: A myopic or toric ICL was implanted after PKP in eyes unable to wear glasses or contact lenses and for which corneal laser surgery was contraindicated. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, and endothelial cell count were recorded preoperatively and 24 months postoperatively. RESULTS: Preoperatively, the 15 eyes had myopia from −2.00 to −17.00 diopters (D) or astigmatism from −1.50 to −7.00 D. Twenty‐four months postoperatively, the mean Snellen decimal UDVA was 0.51 ± 0.30 (SD). The UDVA was 20/40 or better in 7 eyes (46.6%). The mean CDVA was 0.79 ± 0.22. The CDVA was 20/40 or better in 12 eyes (80%) and 20/25 in 6 eyes (40%). No eye lost more than 1 line of acuity, 2 eyes gained 1 line, and 5 eyes gained more than 2 lines; 8 eyes were unchanged. The safety index was 1.58. The spherical equivalent (SE) was within ±1.00 D in 80% of eyes and within ±0.50 D in 66.6% of eyes. The mean postoperative SE was −0.95 ± 1.12 D. At 24 months, the mean vault was 2.06 ± 0.96 and the mean endothelial cell loss, 8.1%. CONCLUSION: Results indicate that phakic intraocular lens implantation is a viable treatment for myopia and astigmatism after PKP in patients for whom glasses, contact lenses, or corneal refractive surgery are contraindicated.