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PURPOSE: To describe and compare corneal densitometry, subjective refraction, visual acuity, and corneal higher order aberrations (HOA) after corneal refractive surgery using either alcohol-assisted photorefractive keratectomy (aaPRK) or single-step transepithelial PRK (tPRK). METHODS: We conducted a retrospective and observational study. We analyzed 120 right eyes from 120 healthy consecutive myopic patients who underwent aaPRK or tPRK to correct myopia of up to 6 diopters and astigmatism of up to 2 diopters. The WaveLight EX500 excimer laser (Alcon Laboratories, Inc.) was used in all cases. Visual acuity, subjective refraction, and Pentacam AXL® measurements were performed at the preoperative visit and at 6-months follow-up visit. Pentacam AXL® software was used to assess corneal optical density in various annuli for different corneal depths and anterior corneal HOA (6 mm area of analysis). RESULTS: Preoperative spherical equivalent values were similar between groups preoperatively (-3.07 ± 1.52 and -3.38 ± 1.46 in the aaPRK and tPRK groups, respectively). There were no statistically significant differences in visual acuity and postoperative refraction between groups. Postoperative corneal densitometry did not show statistically significant differences in any of the areas studied and both surgical procedures obtained similar results. However, analysis of HOA showed statistically significant differences between the techniques (1.42 ± 0.39 and 1.80 ± 0.62 for the aaPRK and tPRK groups, respectively; p = 0.000). CONCLUSIONS: Both aaPRK and single-step tPRK gave comparable visual, refractive, and corneal density outcomes. Some differences were observed in HOA but were not clinically relevant.

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PURPOSE: To evaluate the effectiveness of ab-externo canaloplasty using the iTrack canaloplasty microcatheter (Nova Eye Inc, Fremont, California), with or without suture, in glaucoma patients with high myopia. METHODS: This was a prospective, single-center, single-surgeon, observational study comparing the outcomes of ab-externo canaloplasty performed with a tensioning suture (suture group) and without a tensioning suture (no-suture group) in mild to severe glaucoma patients with high myopia. Twenty-three eyes received canaloplasty as a standalone procedure, 5 in combination with phacoemulsification. Primary efficacy endpoints included intraocular pressure (IOP) and the number of glaucoma medications. Safety was assessed based on reported complications and adverse events. RESULTS: Twenty-nine eyes of 29 patients with a mean age of 61.2 ± 12.3 years; 19 eyes in the no-suture group and 10 eyes in the suture group. All eyes demonstrated a significant reduction in IOP 24 months postoperatively, from 21.9 ± 7.22 to 15.4 ± 4.86 mmHg in the suture group and from 23.8 ± 7.58 to 19.7 ± 3.68 mmHg in the no-suture group. The mean number of anti-glaucoma medications reduced from 3.1 ± 0.6 to 0.4 ± 0.7 in the suture group and 3.3 ± 0.9 to and 0.2 ± 0.6 in the no-suture group at 24 months. IOP was not significantly different at baseline between the 2 groups, but it was statistically different at 12 and 24 months. There was no statistically significant difference in the number of medications between the groups at baseline, 12 and 24 months. No serious complications were reported. CONCLUSION: Ab-externo canaloplasty performed either with or without a tensioning suture demonstrated good effectiveness in highly myopic eyes with a significant reduction in IOP and number of anti-glaucoma medications. The suture group achieved a lower postoperative IOP. However, the no-suture modification provides a similar reduction in medications with reduced tissue handling.

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PURPOSE: To evaluate changes in angle κ after the implantation of a trifocal intraocular lens (IOL) and to assess the postoperative outcomes of patients with different angle κ values. SETTING: IOA Madrid Innova Ocular, Madrid, Spain. DESIGN: Prospective trial. METHODS: Sixty-three eyes from 63 patients who had bilateral implantation of a diffractive trifocal IOL (POD F, PhysIOL) were included. Pupil offset was used as the best estimate of angle κ and was measured using Pentacam (Oculus) preoperatively and at 3 months postoperatively. Postoperative refractive outcomes (sphere, cylinder, and manifest refraction spherical equivalent) and visual outcomes at far, intermediate, and near distance were assessed and compared between eyes with small pupil offset and eyes with large pupil offset. Quality of vision was assessed using a subjective questionnaire. RESULTS: There was a significant decrease in pupil offset values postoperatively (mean: 0.197 ± 0.12 mm) compared with those preoperatively (mean: 0.239 ± 0.12 mm), with a mean decrease of -0.042 mm (P = .0002). The same significant decrease was found for both right and left eyes, when analyzed separately. No statistically significant difference was found in any of the refractive and visual acuity outcomes between eyes with small pupil offset and eyes with large pupil offset. The majority of patients (14 of 16) complaining of significant halos had eyes with small pupil offset. CONCLUSIONS: Large pupil offset did not negatively affect visual and refractive outcomes. The tolerance to larger pupil offset might be due to the IOL optical design, with the first diffractive ring being larger than other commonly used multifocal IOLs. More studies comparing various diffractive IOL models would be useful to confirm such hypothesis.

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PURPOSE: To determine normative corneal densitometry values in relation to age, sex, refractive error, corneal thickness, and keratometry, measured using the Oculus Pentacam system. METHODS: Three hundred and thirty-eight healthy subjects (185 men; 153 women) with no corneal disease underwent an exhaustive ocular examination. Corneal densitometry was expressed in standardized grayscale units (GSU). RESULTS: The mean corneal densitometry over the total area was 16.46 ± 1.85 GSU. The Pearson correlation coefficient for total densitometry was r = 0.542 (p < 0.001). Statistically significant differences were found between men and women for the total area (p = 0.006), with readings of 16.22 ± 1.54 GSU and 16.60 ± 1.83 GSU, respectively. When the cornea was divided into layers of different depths, a significant correlation was found for all layers and age: r = 0.447 (p < 0.001), r = 0.563 (p < 0.001), and r = 0.520 (p < 0.001) for the anterior, central, and posterior layers, respectively. However, when the cornea was divided into concentric annuli starting from the center of the cornea, densitometry was strongly correlated only with age in the 6-10-mm annulus (p < 0.001). Neither mean keratometry nor spherical equivalent was correlated with corneal densitometry in any zone of the cornea (p > 0.05). CONCLUSIONS: This is the first report of normative corneal densitometry values in relation to keratometry, corneal thickness, and spherical equivalent measured with the latest Oculus Pentacam software. Corneal densitometry increases with age, but corneal keratometry and refractive parameters do not affect light scattering in the human cornea.

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PURPOSE: To assess the repeatability, reproducibility, and agreement of the Pentacam HR single-camera and Galilei G2 dual-camera Scheimpflug devices in anterior segment analysis. SETTING: Begitek Clínica Oftalmológica, San Sebastián, Spain. DESIGN: Prospective randomized observational study. METHODS: Healthy young individuals had 3 consecutive tests by 2 examiners. Analyzed parameters were anterior and posterior cornea simulated keratometry (K), K flat, K steep, astigmatism magnitude and axis, J(0) and J(45) vectors, asphericity, total corneal higher-order wavefront aberrations (root mean square [RMS], coma, trefoil, spherical aberration), central cornea and thinnest-point thicknesses, and anterior chamber depth. Repeatability and reproducibility were evaluated by calculating the within-subject standard deviation (S(w)), some derived coefficients, and the intraclass correlation coefficient. Agreement was assessed with the Bland-Altman method. RESULTS: The single-camera device reproducibility (S(w)) was simulated K, 0.04 diopter (D); J(0), 0.03 D; J(45), 0.04 D; total power, 0.04 D; spherical aberration, 0.02 µm; higher-order aberrations (HOAs), 0.02 µm; central corneal thickness (CCT), 3.39 µm. The dual-camera device S(w) was simulated K, 0.07 D; J(0), 0.13 D; J(45), 0.04 D; total power, 0.08 D; spherical aberration, 0.02 µm; HOAs, 0.11 µm; CCT, 1.36 µm. Agreement was good for most parameters except total corneal power (mean difference 1.58 D ± 0.22 (SD) and HOA RMS (mean difference 0.48 ± 0.19 µm) (both P<.00). CONCLUSIONS: Repeatability and reproducibility were good for all parameters. The single-camera device was more precise for curvature, astigmatism, and corneal wavefront error measurements and the dual-camera device for pachymetry measurements. Agreement was good with some relevant exceptions. FINANCIAL DISCLOSURE: Dr. Aramberri is consultant to Costruzione Strumenti Oftalmici, Firenze, Italy. No other author has a financial or proprietary interest in any material or method mentioned.

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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 J(0) and J(45), 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.

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