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Purpose To evaluate the differences in corneo-scleral topographic profile between healthy and keratoconus eyes, and their potential diagnostic ability for keratoconus detection. Methods Prospective comparative study including 21 keratoconic eyes (11 patients) and 88 healthy eyes (88 patients). In all cases, a complete eye exam was performed including an evaluation of the corneo-scleral profile. The diagnostic ability of corneo-scleral topographic parameters to detect keratoconus was evaluated using the receiver operating characteristic (ROC) curve. Results A significant lower inferior tangent angle at limbus (ITA) was found in the keratoconic group compared to the control group (p = 0.024). Regarding sagittal heights, significant differences between groups were found in temporal sagittal height (TSH) for 11 mm (p = 0.040), 12 mm (p = 0.041) and 13 mm corneal chords (p = 0.040), difference between temporal and nasal sagittal heights (T-NSH) for 12 mm (p = 0.025) and 13 mm (p = 0.034), and maximum sagittal height (MaxSH) for 12 mm (p = 0.043), with higher values in keratoconus. In bilateral cases, these differences were not found when comparing with the least severe keratoconus eye. Statistical significance for the ROC curve was only found for ITA (p = 0.025), 12-mm (p = 0.048) and 13-mm TSH (p = 0.042), and 13-mm T-NSH (p = 0.037), with cutoff values associated to limited values of sensitivity and specificity. Conclusions The corneo-scleral profile in keratoconus presents higher levels of asymmetry compared to healthy eyes, especially in eyes with moderate and advanced stages of the disease. The diagnostic accuracy of corneo-scleral topographic data alone for keratoconus detection is limited and must be used in conjunction with other clinical parameters.

Purpose: To evaluate the intrasession repeatability and validity of corneal curvature measurements provided by a new multifunctional device and to assess the intrasession repeatability of its ocular aberrometric measures. Methods: This prospective study comprises 37 mild to moderate keratoconus eyes of 37 patients. In all cases, 3 repeated measures of corneal topography and ocular aberrometry were performed with the iDesign 2 system (iD2; Johnson & Johnson Vision Care Inc, Jacksonville, FL) and one keratometric measurement was performed with the intraocular lens-(IOL) Master 500 (Carl Zeiss Meditec Inc, Dublin, CA) and Sirius (CSO) (SIR) systems. Results: The within-subject SD (S-w) was 0.980. S-w and ICC for the keratometric axis were 2.60 degrees and 0.992, respectively. Concerning aberrations, all S-w values for high-order Zernike terms were 0.900), and all S-w values for refraction data were 0.95), except for J(45). No statistically significant differences were found between the devices in any keratometric parameter evaluated (P >= 0.222), but the limits of agreement between the devices were clinically relevant. The magnitude of K readings and astigmatism correlated significantly with the difference in these parameters between iD2 and SIR (0.432

AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles. METHODS: A total of 40 eyes of 40 patients with a mean age of 34.1y were included. In all cases, a corneal curvature analysis was performed with IOL-Master (IOLM), iDesign 2 (ID2), and Sirius systems (SIR). Differences between instruments for flattest (K1) and steepest (K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity (Q) between SIR and ID2 were also evaluated. RESULTS: Mean differences between devices for K1 were 0.20±0.21 (P

Background: The aim was to evaluate the visual performance achieved with a new multifocal hybrid contact lens and to compare it with that obtained with two other currently available multifocal soft contact lenses. Methods: This pilot prospective comparative study comprised a total of 16 presbyopic eyes of eight patients ranging in age from 43 to 58 years. All patients were fitted with three different models of multifocal contact lens: Duette multifocal (SynergEyes), Air Optix AQUA multifocal (Alcon) and Biofinity multifocal (CooperVision). Fittings were performed randomly in each patient according to a random number sequence, with a wash-out period between fittings of seven days. At two weeks post-fitting, visual, photopic contrast sensitivity and ocular aberrometry were evaluated. Results: No statistically significant differences were found in distance and near visual acuity achieved with the three different types of multifocal contact lens (p ≥ 0.05). Likewise, no significant differences between lenses were found in the monocular and binocular defocus curve (p ≥ 0.10). Concerning contrast sensitivity, better monocular contrast sensitivities for 6, 12 and 18 cycles per degree were found with the Duette and Air Optix multifocal compared to Biofinity (p = 0.02). Binocularly, differences between lenses were not significant (p ≥ 0.27). Furthermore, trefoil aberration was significantly higher with Biofinity multifocal (p < 0.01) and Air Optix (p = 0.01) multifocal compared to Duette. Conclusions: The Duette multifocal hybrid contact lens seems to provide similar visual quality outcomes in presbyopic patients with low corneal astigmatism, when compared with other soft multifocal contact lenses. This preliminary result should be confirmed in studies with larger samples.

Purpose To validate clinically in a normal healthy population an algorithm to correct the error in the keratometric estimation of corneal power based on the use of a variable keratometric index of refraction ( n k ). Setting Medimar International Hospital (Oftalmar) and University of Alicante, Alicante, Spain. Design Case series. Methods Corneal power was measured with a Scheimpflug photography–based system (Pentacam software version 1.14r01) in healthy eyes with no previous ocular surgery. In all cases, keratometric corneal power was also estimated using an adjusted value of n k that is dependent on the anterior corneal radius ( r 1c ) as follows: n kadj = −0.0064286 r 1c +1.37688. Agreement between the Gaussian ( P c Gauss ) and adjusted keratometric ( P kadj ) corneal power values was evaluated. Results The study evaluated 92 eyes (92 patients; age range 15 to 64 years). The mean difference between P c Gauss and P kadj was −0.02 diopter (D) ± 0.22 (SD) ( P =.43). A very strong, statistically significant correlation was found between both corneal powers ( r = .994, P .01). The range of agreement between P c Gauss and P kadj was 0.44 D, with limits of agreement of −0.46 and +0.42 D. In addition, a very strong, statistically significant correlation of the difference between P c Gauss and P kadj and the posterior corneal radius was found ( r = 0.96, P .01). Conclusion The imprecision in the calculation of corneal power using keratometric estimation can be minimized in clinical practice by using a variable keratometric index that depends on the radius of the anterior corneal surface. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Objective To assess the clinical outcomes in ectatic corneas following accelerated transepithelial cross-linking (CXL) over 1 year of follow-up. Materials and methods Twenty-one eyes diagnosed with progressive corneal ectasia (19 keratoconus, 2 post-laser in situ keratomileusis ectasias) in 14 patients aged between 26 and 69 years were enrolled. All cases were treated with accelerated transepithelial CXL using the Avedro KXL® system (Waltham, MA, United States). Changes at visual, refractive, corneal topographic, and corneal aberrometric level were evaluated over a 12-month follow-up period. The demarcation was also determined using optical coherence tomography (OCT). Results The mean depth of the demarcation line measured by OCT was 202.72 µm, varying between 153 and 230 µm. One month postsurgery, a change was noted at the limit of statistical significance in sphere (p = 0.05) and in spherical equivalent (p = 0.05). Likewise, a statistically significant difference was observed in corrected distance visual acuity (CDVA) (p = 0.01). There were no significant changes in either visual acuity or refraction between 1 and 6 months (p ≥ 0.35). Although changes in trend were observed in corneal topographic and aberrometric parameters after surgery, none reached statistical significance (p ≥ 0.08). A significant change was observed only in astigmatism of the posterior surface between 1 and 12 months (p = 0.02). Conclusion Accelerated transepithelial CXL may be a useful technique for the management of progressive corneal ectasia, as it is able to maintain the topographic and aberrometric profile of the cornea with no significant changes. Longer-term studies are required to confirm this finding How to cite this article Piñero DP, Artola A, Ruiz-Fortes P, Soto-Negro R, Pérez-Cambrodi RJ. Clinical Outcomes at 1 Year following Corneal Ectasia Treatment with Accelerated Transepithelial Cross-linking. Int J Kerat Ect Cor Dis 2016;5(3):93-98.

Purpose To report the successful outcome obtained after fitting a new hybrid contact lens in a cornea with an area of donor-host misalignment and significant levels of irregular astigmatism after penetrating keratoplasty (PKP). Materials and methods A 41-year-old female with bilateral asymmetric keratoconus underwent PKP in her left eye due to the advanced status of the disease. One year after surgery, the patient referred a poor visual acuity and quality in this eye. The fitting of different types of rigid gas permeable contact lenses was performed, but with an unsuccessful outcome due to contact lens stability problems and uncomfortable wear. Scheimpflug imaging evaluation revealed that a donor-host misalignment was present at the nasal area. Contact lens fitting with a reverse geometry hybrid contact lens (Clearkone, SynergEyes Carlsbad) was then fitted. Visual, refractive, and ocular aberrometric outcomes were evaluated during a 1-year period after the fitting. Results Uncorrected distance visual acuity improved from a prefitting value of 20/200 to a best corrected postfitting value of 20/20. Prefitting manifest refraction was +5.00 sphere and .5.50 cylinder at 75°, with a corrected distance visual acuity of 20/30. Higher order root mean square (RMS) for a 5 mm pupil changed from a prefitting value of 6.83 μm to a postfitting value of 1.57 μm (5 mm pupil). The contact lens wearing was referred as comfortable, with no anterior segment alterations. Conclusion The SynergEyes Clearkone contact lens seems to be another potentially useful option for the visual rehabilitation after PKP, especially in cases of donor-host misalignment. How to cite this article Pérez-Cambrodí RJ, Ruiz-Fortes P, Llorens DPP. Reverse Geometry Hybrid Contact Lens Fitting in a Case of Donor-Host Misalignment after Keratoplasty. Int J Kerat Ect Cor Dis 2013;2(2):69-72.

Purpose: To examine the biometric characteristics of the anterior segment in a group of Sahrawi children. Methods: A total of 66 children (33 male and 33 female, aged between 8 and 13 years) participated in this prospective, observational study. The non-invasive Pentacam Scheimpflug imaging device was used to measure corneal thickness (CT) (at the thinnest corneal point), mean anterior (Km Ant) and posterior (Km Post) corneal radii, corneal volume (CVol), anterior chamber depth (ACD) and anterior chamber volume (ACVol). The contribution of age and gender to the various parameters was investigated. Results: CT values of the present group of Sahrawi children were 521.70 ± 3.92 m. Boys had thicker corneas than girls, although this difference was not significant. Strong correlations were revealed between CT and CVol (r = 0.835; p < 0.001), as well as between anterior and posterior corneal radii (r = 0.916; p < 0.001) and between ACD and ACVol (r = 0.845; p < 0.001). Weaker, but significant correlations were encountered between several other pairs of ocular parameters. Age and gender were found to influence ACD and ACVol values. Conclusions: Different measurement procedures and ethnic background preclude any direct comparison of the present results with published data, although CT in Sahrawi children was found to be lower than previously reported in children of similar age but different ethnicity. © 2012 Spanish General Council of Optometry. Published by Elsevier Espana, S.L. All rights reserved.