Victoria de Juan

Differences in the daily symptoms associated with the silicone hydrogel contact lens wear.

Objective: To determine the differences in symptoms associated with daily wear of silicone hydrogel (lotrafilcon B) contact lenses (CLs) after CL insertion and at the end of wear and their relationship with environmental factors and multipurpose solutions (Solo-care Aqua, CIBA Vision, Duluth, GA and Hidro Health, Disop, Spain). Methods: Fifty-four patients were fitted with lotrafilcon B CLs. Two multipurpose solutions were randomly assigned and prescribed in a double-masked crossover study with three visits. After each solution was used, two questionnaires were conducted, including a survey produced by us and Contact Lens Dry Eye Questionnaire. Our questionnaire included 10 items addressing discomfort, blurry vision, lens-handling problems, dryness, redness, tearing, burning, itching, discharge, and dissatisfaction. Patients were assigned scores from 0 (without symptoms) to 10 (symptoms unbearable) at two different times (after CL insertion and at the end of wear) and in two environments (outdoors and adverse environments). Results: The average duration of CL wear was 8.32 ± 2.27 hr/day and 5.85 ± 1.30 days/week. All symptoms became worse (P < 0.05 Wilcoxon test, except lens handling) at the end of CL wear in all visits. The results were independent of the multipurpose solution used (P > 0.05 Friedman test), except for tearing, which showed statistical differences between visits (P = 0.03 Friedman test). Contact Lens Dry Eye Questionnaire showed increased dry eye symptoms at the end of wear (P < 0.05 Friedman test). Conclusions: Daily wear symptoms associated with lotrafilcon B CL increase with the time of wear. This increase in symptoms is nonrelated with the multipurpose solutions compared in this study.

Contact lens-induced corneal peripheral swelling: Orbscan repeatability.

Purpose. To compare the repeatability and agreement of corneal thickness measurements using central and peripheral ultrasound and Orbscan pachymetry to detect contact lens (CL)-induced corneal swelling after extended wear (EW). Methods. Corneal thickness was measured in five corneal locations (central, superior, inferior, nasal, and temporal) with ultrasound and Orbscan pachymetry 1 week before CL wear commenced and after 1 week of EW. High oxygen permeability (lotrafilcon A) and low oxygen permeability (etafilcon A) CL were randomly fitted for EW in the right and left eyes of 20 subjects with normal ocular health to induce different amount of corneal swelling. Results. Poor repeatability and poor agreement in peripheral ultrasound and Orbscan pachymetry was found between corneas with and without corneal swelling. Ultrasound coefficients of repeatability (central, superior, inferior, nasal, and temporal) in corneas without (0.95, 2.1, 3.2, 3.9, and 3.8%) and with (0.91, 1.89, 2.45, 2.66, and 2.26%) corneal swelling were higher than Orbscan coefficients of repeatability without (0.74, 1.67, 1.29, 1.11, and 1.11%) and with (0.74, 1.47, 1.28, 1.78, and 1.23%) corneal swelling. Lotrafilcon A induced significantly less corneal swelling in all five corneal locations compared with etafilcon A. Peripheral corneal swelling differences between lens types were significant only with Orbscan measurements (p < 0.05, Paired t-test and re-analysis of variance). Conclusions. The assessment of corneal thickness shows higher repeatability using Orbscan pachymetry than using ultrasound to measure corneas with and without corneal swelling and could be useful to study central and peripheral corneal swelling variations in CL EW.

Refractive stabilization and corneal swelling after cataract surgery.

Purpose To determine the earliest time after cataract surgery when corneal swelling and automated refraction are stabilized sufficiently to allow reliable refractive prescription. Methods This was a prospective, nonrandomized, case series study of 124 consecutive eyes undergoing uneventful cataract surgery. Automated refraction and central corneal thickness (CCT) measurements were made at baseline before cataract surgery and on follow-up visits 1 day and weekly for 4 weeks afterward. Corneal swelling was determined as the percentage change in CCT after surgery. To determine the validity of automated refraction, it was compared with subjective refraction at the final visit. Results Corneal swelling decreased between the first postsurgical day and the first week and again between postsurgical weeks 1 and 2 (p < 0.01 each). Although thinning continued through the fourth postsurgical week, the changes were not significant. Both spherical and cylindrical refraction were stable 1 week after surgery, with the greatest change between the first postsurgical day and 1 week (p < 0.01). In replicate measurements of automated spherical refraction taken on the last visit, the intraclass correlation coefficient was 0.93. For automated cylindrical refraction, it was 0.81. Conclusions Automated refraction is highly repeatable and can be used to monitor postsurgical refractive changes. Whereas corneal swelling becomes stable 2 weeks after cataract surgery, automated refraction becomes stable after 1 week and can be used to accurately prescribe corrective lenses at that time.

Constancy of the Orbscan acoustic factor to detect contact lens‐induced corneal swelling

Purpose:  The aim of the present study was to compare central and peripheral corneal thickness measurements in corneas with and without contact lens (CL)‐induced corneal swelling, in order to establish the constancy of the Orbscan acoustic factor (AF) for reliability in detection of CL‐induced corneal swelling.

Repeatability of Wavefront Aberration Measurements With a Placido-Based Topographer in Normal and Keratoconic Eyes

PURPOSE To determine and compare the repeatability of anterior corneal higher order aberrations (HOAs) using a Placido-based topographer (Allegro Topolyzer; WaveLight Technologie AG, Alcon Laboratories, Erlangen, Germany) in a sample of normal and keratoconic eyes. METHODS Three repeated measurements of each cornea of normal and keratoconic eyes were taken with the Allegro Topolyzer. Repeatability of the HOAs (3rd- and 4th-order individual values and normalized polar Zernike coefficients, coma-like, root mean square (RMS) up to 8th-order values, HOA RMS, and total RMS for 6-mm pupil diameter) and central corneal power (3-mm pupil) were analyzed. Within-subject standard deviation (Sw), precision, repeatability, coefficient of variation (CV), and the intraclass correlation coefficient (ICC) were calculated. RESULTS Zernike coefficients were significantly different between the normal (36 eyes of 36 patients) and keratoconus (36 eyes of 36 patients) groups (P ≤ .03) except in Z(+1) 3, Z(+3) 3, Z(-4) 4, and Z(+4) 4. In the normal group, Sw was 0.031 µm or less, CV ranged from 6.49% (spherical aberration) to 37.18% (secondary astigmatism), and ICC values ranged from 0.227 to 0.982. In the keratoconus group, Sw was 0.059 µm or less, CV ranged from 2.06% (total RMS) to 25.82% (tetrafoil), and ICC values ranged from 0.839 to 0.996. In analyzing the keratoconus stages (Amsler-Krumeich classification), the repeatability of the Zernike coefficients tended to improve with increasing keratoconus stage. CONCLUSIONS The repeatability of corneal wavefront aberration provided by the Allegro Topolyzer was better in keratoconic eyes (good and moderate repeatability) than in normal eyes (moderate and poor repeatability). These results are important to eye care practitioners and refractive surgeons during refractive surgery planning or keratoconus detection, classification, and management. [J Refract Surg. 2016;32(5):338-344.].

Optical quality and intraocular scattering assessed with a double-pass system in eyes with contact lens induced corneal swelling

PURPOSE To evaluate the impact of contact lens (CL)-induced corneal swelling on the optical quality of the eye by means of the double-pass technique. METHODS Measurements of 6 healthy subjects were obtained in 5 visits over 1 week, at baseline and after sleeping with 4 different CLs of +0.50 D, +2.00 D, +5.00 D and +8.00 D (Acuvue2), randomly fitted on 4 different days. The control eye wore no CL. Corneal pachymetry and optical quality of the eye (OQAS, Visiometrics) were measured once at baseline and at three interval times in the follow-up visits: immediately after CL removal, and 1 and 2 h after CL removal. Optical quality was evaluated by means of the Strehl ratio and OQAS values at 100%, 20% and 9% contrasts. Intraocular scattering was evaluated with the objective scatter index (OSI). RESULTS Mean overnight swelling was 5.98 ± 4.29% in CL-eyes versus 0.30 ± 0.78% in control eyes (p < 0.01). Corneal swelling was maximal immediately after CL removal and decreased with time (p < 0.01). A significant worsening in all optical quality parameters and a significant increase of the OSI were found in eyes with corneal swelling (p < 0.05). Two hours after CL removal there were no statistically significant differences (p > 0.05) between CL-eyes and control eyes in any of the measured parameters. CONCLUSIONS Corneal swelling has a significant impact on the optical quality of the eye and on intraocular scattering as assessed with the double-pass technique.

Relationship between Corneal Biomechanical Properties and Optic Nerve Head Changes after Deep Sclerectomy

Purpose To evaluate corneal biomechanical properties and optic nerve head (ONH) changes following deep sclerectomy (DS) and the relation to each other. Methods Forty-nine eyes with primary open-angle glaucoma that underwent DS were studied. Corneal biomechanical properties were assessed using the Ocular Response Analyzer and the ONH was evaluated by Spectralis optical coherence tomography with enhanced depth imaging technology before surgery and 3 months postoperatively. Changes in corneal hysteresis (CH), corneal resistance factor (CRF), optic nerve cupping, prelaminar tissue thickness, and lamina cribrosa depth and thickness were registered. A correlation matrix and multiple linear regression models were used to determine predictors of ONH changes. Results At 3 months after surgery, mean corneal compensated intraocular pressure (IOPcc) significantly decreased by 27.9% (p<00.001) and mean Goldmann-correlated IOP (IOPg) decreased by 30.52% (p<00.001). Mean CH increased and CRF decreased by 18.4% and 10.1%, respectively (p<00.001). There was a significant reversal of ONH cupping mainly due to a prelaminar tissue thickening (p<00.001). Significant associations were found between ONH cupping reversal and prelaminar tissue thickening with preoperative IOPcc (p = 0.046), IOPg (p = 0.02), and CRF (p = 0.002) and with changes in IOP, CH, and CRF (p<00.001, p = 0.004, p = 0.018, respectively) after surgery. Conclusions Corneal hysteresis increased and CRF decreased significantly 3 months after DS. Corneal resistance factor was the single largest preoperative factor influencing cupping reversal changes. Despite the influence of preoperative variables, postoperative IOP reduction was the only independent factor influencing changes observed in the ONH after surgery.

Advantages, limitations, and diagnostic accuracy of photoscreeners in early detection of Amblyopia: a review

Amblyopia detection is important to ensure proper visual development and avoid permanent decrease of visual acuity. This condition does not produce symptoms, so it is difficult to diagnose if a vision problem actually exists. However, because amblyopia treatment is limited by age, early diagnosis is of paramount relevance. Traditional vision screening (conducted in <3 years) is related with difficulty in getting cooperation from a subject to conduct the eye exam, so accurate objective methods to improve amblyopia detection are necessary. Handheld devices used for photoscreening or autorefraction could offer advantages to improve amblyopia screening because they reduce exploration time to just few seconds, no subject collaboration is needed, and they provide objective information. The purpose of this review is to summarize the main functions and clinical applicability of commercially available devices for early detection of amblyopia and to describe their differences, advantages, and limitations. Although the studies reviewed are heterogeneous (due to wide differences in referral criteria, use of different risk factors, different types of samples studied, etc), these devices provide objective measures in a quick and objective way with a simple outcome report: retest, pass, or refer. However, due to major limitations, these devices are not recommended, and their use in clinical practice is limited.

Repeatability and agreement of ARK-30 autorefraction after cataract surgery

Background:  To evaluate the intra‐test variability of ARK‐30 handheld autorefractor and the agreement with subjective refraction and retinoscopy after uneventful cataract surgery.

Ocular tolerance of a new multipurpose solution specifically formulated for daily wear of silicone hydrogel contact lenses

PURPOSE To evaluate the safety, physiological performance, and effect on ocular tissues of a new multipurpose disinfecting solution (MPDS) specifically formulated for use with silicone hydrogel (SH) contact lenses (CL). METHODS Two MPDS [solution A (Solo-care Aqua(®), Ciba-Vision) and solution B (Hidro Health(®), Disop)] were randomly assigned and prescribed in a clinical trial in a crossover clinical trial (Registered #293/07/EC; Spanish National Health Department). Only lotrafilcon B CL daily wearers were included. After each solution was used, a masked investigator assessed the slit-lamp findings (SL9, Topcon Inc.), lens deposits, and wettability according to the Guidance for clinical investigation (ISO 11980). CL daily wearing time (hours per day and days per week) were recorded. RESULTS Fifty-four daily wearers were included. Average CL wear time was 8.3 ± 2.3 (CI95% 7.9-8.7) hours per day (8.5 ± 2.7 at baseline visit, 8.2 ± 1.9 with solution A, and 8.4 ± 2.2 with solution B). The average number of days per week of CL wear was 5.9 ± 1.3 (CI95% 5.6-6.1) (5.4 ± 1.6 at baseline visit, 6.1 ± 0.9 with solution A, and 6.0 ± 1.1 with solution B). Non-adverse slit-lamp findings were recorded (higher than 2 points). No statistical difference (P>0.05 Friedman test) in CL wearing time, number of days of CL wears and slit-lamp findings were found between the two solutions. CONCLUSIONS This clinical trial shows that the new formulation of Hidro Health(®) MPDS is safe when used for the care of daily-wear lotrafilcon B CL. This new solution has no clinical significance on ocular tissues, according to the Guidance for clinical investigation (ISO 11980).