Habitual higher order aberrations affect Landolt but not Vernier acuity.

To assess whether the eye's optical imperfections are relevant for hyperacute vision, we measured ocular wave aberrations, visual hyperacuity, and acuity thresholds in 31 eyes of young adults. Although there was a significant positive correlation between the subjects' performance in Vernier- and Landolt-optotype acuity tasks, we found clear differences in how far both acuity measures correlate with the eyes' optics. Landolt acuity thresholds were significantly better in eyes with low higher order aberrations and high visual Strehl ratios (r2 = 0.22, p = 0.009), and significantly positively correlated with axial length (r2 = 0.15, p = 0.03). A retinal image quality metric, calculated as two-dimensional correlation between perfect and actual retinal image, was also correlated with Landolt acuity thresholds (r2 = 0.27, p = 0.003). No such correlations were found with Vernier acuity performance (r2 < 0.03, p > 0.3). Based on these results, hyperacuity thresholds are, contrary to resolution acuity, not affected by higher order aberrations of the eye.

Corneal endothelial cell loss after Baerveldt glaucoma drainage device implantation in the anterior chamber.

PURPOSE: To investigate central and peripheral corneal endothelial cell density (ECD) in relation to Baerveldt (BV) glaucoma drainage device (GDD) tube corneal (TC) distance. METHODS: Prospective study of all patients scheduled for glaucoma tube surgery with 36 months follow-up. A BV GDD was inserted into the anterior chamber (AC). Anterior segment optical coherence tomography (AS-OCT) scans were made to determine the TC distance. Central and peripheral ECD was measured, preoperatively and at 3, 6, 12, 24 and 36 months postoperatively. RESULTS: Fifty-three eyes were included [primary open-angle glaucoma, (n = 13); secondary glaucoma, (n = 30); and primary angle-closure glaucoma, (n = 10)]. Central ECD significantly decreased during follow-up, with a mean decrease of 4.54% per year (p < 0.001), and 6.57% in the peripheral quadrant closest to the BV GDD tube (PQC, p < 0.001). In the PQC, a yearly decrease of 1.57% was shown after transiridial tube placement versus 7.43% after placement 'free' into the AC (p = 0.006). Endothelial cell (EC) loss was related to TC distance (mean 1.69 mm), with a central loss of 6.20% and 7.25% in the PQC per year with shorter TC distances, versus a central loss of 4.11% and 5.77% in the PQC per year with longer TC distances (outside mean ± 2SD, p < 0.001). A difference in EC loss by glaucoma subtype was not identified. CONCLUSION: The TC distance is of significant influence on corneal ECD, a shorter TC distance causing more severe EC loss, especially in the PQC. Transiridial placement of the BV GDD tube seems safer than placement 'free' into the AC.

Phakic intraocular lens: Two-year results and comparison of endothelial cell loss with iris-fixated intraocular lenses.

PURPOSE: To evaluate the efficacy, safety, and stability of a foldable angle-supported Acrysof Cachet phakic intraocular lens (pIOL) to correct moderate to high myopia and compare endothelial cell loss after iris-fixated Artisan and Artiflex pIOL implantation. SETTING: University Eye Clinic Maastricht, the Netherlands. DESIGN: Retrospective observational study. METHODS: Foldable angle-supported pIOL implantation for myopia ranging from -6.0 to -16.5 diopters (D) was done. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent (SE), and adverse events were documented preoperatively and 6 months and 1 and 2 years postoperatively. Endothelial cell loss after implantation of the foldable angle-supported pIOL and iris-fixated pIOLs was compared 6 months and 1 and 2 years postoperatively. RESULTS: There were 158 eyes. The UDVA was equal to or more than 20/25 in 95% of eyes at 1 and 2 years postoperatively. The mean SE was -0.17 D ± 0.43 (SD) 2 years postoperatively. One patient developed pupil ovalization, resulting in explantation of the pIOL from both eyes. Acute endothelial cell loss in the foldable angle-supported pIOL group was -3.2% ± 0.7%, significantly higher than after iris-fixated pIOL implantation. Chronic endothelial cell loss from 6 to 24 months after surgery was -3.8% ± 0.7%. At the 2-year follow-up, the chronic endothelial cell loss in the foldable angle-supported pIOL group was not different than with iris-fixated pIOLs (P > .05). CONCLUSIONS: The foldable angle-supported pIOL effectively corrected moderate to high myopia. However, acute surgical endothelial cell loss was significantly higher than with iris-fixated pIOLs. FINANCIAL DISCLOSURE: Dr. Nuijts is a consultant to Alcon Laboratories, Inc., Théa Pharma GmbH, and ASICO LLC; he has received study grants from Acufocus, Inc., Alcon Laboratories, Inc., Carl Zeiss Meditec AG, Ophtec BV, and Physiol S.A. No other author has a financial or proprietary interest in any material or method mentioned.

Reproducibility of anterior chamber angle analyses with the swept-source optical coherence tomography in young, healthy Caucasians.

PURPOSE: To assess the reproducibility of iridocorneal angle (ICA) analysis in young, healthy Caucasian subjects using swept-source optical coherence tomography (SS-OCT) by determining variability and interobserver agreement between expert and nonexpert observers. METHODS: Thirty-one healthy volunteers (nonexperts) acquired three consecutive SS-OCT images of the right eyes of their peer nonexperts. Images were analyzed by 31 nonexperts and additionally by three experts, whereby the angle opening distance (AOD) and the trabecular iris space area (TISA) at 500 and 750 µm were calculated. A random intercept model was used to determine the amount of variation between observers. In addition, the intra-observer variability between nonexperts and experts was calculated by determining the coefficient of variation (CV). RESULTS: A significant difference was found in the expert analysis for the nasal and temporal angle in the AOD500 (P = 0.002), AOD750 (P < 0.01), and TISA750 (P < 0.01), and the values AOD500 (P = 0.025), AOD750 (P = 0.012), and TISA500 (P = 0.010) were significantly larger if nonexperts analyzed SS-OCT images. The CV was only significant larger for nonexperts for AOD500 (11.1% vs. 8.7%, P < 0.01). CONCLUSIONS: This study demonstrated high reproducibility of angle analysis in young, healthy Caucasian subjects using SS-OCT. Nevertheless, nonexperts obtained significant larger values compared with experts, implying that training is a necessary requirement before analyzing SS-OCT images in ophthalmic practice.

Baerveldt drainage tube motility in the anterior chamber.

PURPOSE: To investigate the stability in position of the Baerveldt glaucoma drainage tube over time and to study movement of the drainage tube in the anterior chamber (AC) under varying light conditions. METHODS: This prospective study included 70 eyes with implantation of a Baerveldt glaucoma drainage tube in the anterior chamber. Anterior segment optical coherence tomography (AS-OCT) images were made preoperatively to quantify AC depth. AS-OCT images were made twice under photopic and twice under scotopic conditions, in the angle parallel to the Baerveldt tube to quantify drainage tube position, at 3, 6, 12, and 24 months postoperatively. Tube-corneal (T-C) and tube-iris (T-I) distances were measured. Additionally, the central AC depth and the peripheral angle opening (AOD 500) were determined. Two subgroups were distinguished according to tube position: free in the AC (group 1, n = 48) and transiridal (group 2, n = 22). RESULTS: After 24 months of follow-up, the drainage tube was found to move statistically significantly closer (0.12 mm) to the corneal endothelium in group 1 (p<0.01). There was no statistically significant difference in T-C distance over time in group 2. The T-C distance did not differ under photopic versus scotopic circumstances (p = 0.32). In both groups, the T-I distance was larger under scotopic conditions, a result of pupil dilation. CONCLUSIONS: The Baerveldt glaucoma drainage tube remained in a stable position when a transiridal implantation was performed, whereas the tube moved closer to the endothelium when placed free into the AC. Transiridal implantation of the Baerveldt tube seems a safe alternative for tube implantation with respect to tube motility.

Consensus on recording of gas permeable contact lens fit.

PURPOSE: To develop a new schematic scheme for efficiently recording the key parameters of gas permeable contact lens (GP) fits based on current consensus. METHODS: Over 100 established GP fitters and educators met to discuss the parameters proposed in educational material for evaluating GP fit and concluded on the key parameters that should be recorded. The accuracy and variability of evaluating the fluorescein pattern of GP fit was determined by having 35 experienced contact lens practitioners from across the world, grading 5 images of a range of fits and the topographer simulation of the same fits, in random, order using the proposed scheme. The accuracy of the grading was compared to objective image analysis of the fluorescein intensity of the same images. RESULTS: The key information to record to adequately describe the fit of an GP was agreed as: the manufacturer, brand and lens parameters; settling time; comfort on a 5 point scale; centration; movement on blink on a ±2 scale; and the Primary Fluorescein Pattern in the central, mid-peripheral and edge regions of the lens averaged along the horizontal and vertical lens axes, on a ±2 scale. On average 50-60% of practitioners selected the median grade when subjectively rating fluorescein intensity and this was correlated to objective quantification (r=0.602, p<0.001). Objective grading suggesting horizontal median fluorescein intensity was generally symmetrical, as was the vertical meridian, but this was not the case for subjective grading. Simulated fluorescein patterns were subjectively and objectively graded as being less intense than real photographs (p<0.01). CONCLUSION: GP fit recording can be standardised and simplified to enhance GP practice.

Comparability and repeatability of corneal astigmatism measurements using different measurement technologies.

PURPOSE: To determine the comparability and repeatability of corneal astigmatism measurements obtained with different devices and determine the interobserver variability of a new automated keratometer. SETTING: University Eye Clinic Maastricht, the Netherlands. DESIGN: Prospective cohort study. METHODS: The right eye of healthy subjects was examined with the following 6 devices: IOLMaster (automated keratometry), Lenstar (automated keratometry), SMI Reference Unit 3 (automated keratometry), Javal (manual keratometry), KR-1W (corneal topography), and Pentacam (Scheimpflug imaging). An experienced operator obtained 3 repeated measurements. An inexperienced operator obtained additional measurements with the SMI Reference Unit 3. Astigmatism vector analysis was used to determine the comparability, repeatability, and interobserver variability. RESULTS: Corneal astigmatism vectors measured by automated, manual, or simulated keratometry were comparable except for the Pentacam equivalent keratometry (K) (P<.001, repeated-measures analysis of variance [ANOVA]). The mean difference between the equivalent K and other K values was 0.18 to 0.29 diopter (D) (P<.05, Hotelling trace multivariate ANOVA). The mean differences between automated, manual, and simulated keratometry were small (≤0.12 D). The within-subject standard deviation ranged from 0.05 D @ 21 degrees (KR-1W) to 0.18 D @ 23 degrees (Lenstar). The SMI Reference Unit showed small mean differences and comparable repeatability between the experienced operator and the inexperienced operator. CONCLUSIONS: Vector analysis showed comparable corneal astigmatism measurements using automated, manual, and simulated keratometry. Pentacam equivalent K values were not comparable with those of the other keratometers. The repeatability of astigmatism magnitudes was acceptable; however, the repeatability of astigmatism meridians was moderate. The SMI Reference Unit showed good interobserver variability.

Detection of Raman spectra in ocular drugs for potential in vivo application of Raman spectroscopy.

PURPOSE: Raman spectroscopy holds potential for the assessment of intraocular pharmacokinetics. Raman spectra of ocular drugs were acquired, to determine the drug-specific Raman signature. The ability of the Raman technique to quantify drug concentrations was also investigated. METHODS: The experimental setup was based on a High Performance Raman Module 2500 Raman module, designed for 180° "backscatter" signal detection in the wavenumber range of 400-1,800 cm(-1). Excitation source was a diode laser emitting a beam with a wavelength of 785 nm and a power of 10 mW. Laser light was focused in the sample with a long-working-distance microscope objective (25×/0.50). Samples were measured in quartz cuvettes in 10 sequential measurements, with exposure time 30 s. The total number of measured drugs was 49. To determine whether signal intensity and drug concentration correlate, 2 drugs were diluted in water and measured with 120 s exposure time at different concentrations. RESULTS: An active ingredient-specific Raman signature was detected in 4 glaucoma drugs, 6 mydriatics, 5 antibiotics, 4 anesthetics, 3 anti-inflammatory drugs, 2 types of artificial tears, and 5 other drugs. In 20 drugs, no specific Raman signature was detected. Linear correlation of drug concentration with signal intensity was high (R(2)≥0.94). CONCLUSIONS: Using low laser powers, Raman signatures for 29 commonly used ocular drugs were detected. Correlation of drug concentration with signal intensity is high, which is essential for monitoring drug concentration in ocular media. The presented results encourage the use of Raman spectroscopy to acquire detailed information on the pharmacokinetics of these ocular drugs.

Dissatisfaction after implantation of multifocal intraocular lenses.

PURPOSE: To analyze the symptoms, etiology, and treatment of patient dissatisfaction after multifocal intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Maastricht University Medical Center, The Netherlands. DESIGN: Case series. METHODS: In this retrospective chart review, the main outcome measures were type of complaints, uncorrected and corrected distance visual acuities, uncorrected and distance-corrected near visual acuities, refractive state, pupil diameter and wavefront aberrometry measurements, and type of treatment. RESULTS: Seventy-six eyes of 49 patients were included. Blurred vision (with or without photic phenomenon) was reported in 72 eyes (94.7%) and photic phenomena (with or without blurred vision) in 29 eyes (38.2%). Both symptoms were present in 25 eyes (32.9%). Residual ametropia and astigmatism, posterior capsule opacification, and a large pupil were the 3 most significant etiologies. Sixty-four eyes (84.2%) were amenable to therapy, with refractive surgery, spectacles, and laser capsulotomy the most frequent treatment modalities. Intraocular lens exchange was performed in 3 cases (4.0%). CONCLUSION: The cause of dissatisfaction after implantation of a multifocal IOL can be identified and effective treatment measures taken in most cases.

Reproducibility of anterior chamber angle measurements with anterior segment optical coherence tomography.

PURPOSE: To study the reproducibility and variability of iridocorneal angle (ICA) measurements by using anterior segment optical coherence tomography (AS-OCT) by expert and nonexpert observers. METHODS: Twenty-three healthy volunteers (nonexperts with a basic knowledge of ophthalmology) acquired five consecutive AS-OCT images in the enhanced anterior segment single mode in the 180° to 0° meridian of the right eyes of their peers. Two experts and the 23 nonexperts analyzed the images. The ICA software tool was used to determine the angle opening distance (AOD) and the trabecular iris surface area (TISA) at 500 and 750 µm. A random intercept model was fitted to evaluate the variability of acquiring an image. For both the experts and the nonexperts, inter- and intraobserver variability of analyzing an AS-OCT image was determined with the coefficient of variation (CV). Reproducibility was qualified by using the intraclass correlation coefficient (ICC). RESULTS: There was no statistically significant difference in the variability of acquiring an image. The range of intraobserver variability in image analysis was from 9.4% to 12.5% in the experts and from 4.2% to 17.4% in the nonexperts. Interobserver variability was 10.7% in the experts and 10.2% in the nonexperts. The reproducibility was high, 0.875 and 0.942 in the experts and 0.906 in the nonexperts. CONCLUSIONS: The overall reproducibility of the ICA measurements with the AS-OCT is good in open angles. Inter- and intraobserver variability showed similar mean values of reproducibility between the experts and nonexperts. The wide range of intraobserver variation in the nonexperts suggests that this group should undergo extensive instruction before routinely analyzing AS-OCT images.

Evaluation of the comparability and repeatability of four wavefront aberrometers.

PURPOSE: To compare total ocular aberrations and corneal aberrations identified with four different aberrometers and to determine the repeatability and interobserver variability. METHODS: In this prospective comparative study, 23 healthy subjects underwent bilateral examination with four aberrometers: the Irx3 (Hartmann-Shack; Imagine Eyes, Orsay, France), Keratron (Hartmann-Shack; Optikon, Rome Italy), iTrace (ray-tracing; Tracey Technologies, Houston, TX), and OPD-Scan (Automated Retinoscopy; Nidek, Gamagori, Japan). Six images per eye were obtained. Second-, third- and fourth-order spherical aberrations were exported for 5.0-mm pupils. RESULTS: Significant differences in measurements were found for several total ocular aberrations (defocus [2,0], astigmatism [2,2], trefoil [3,-3], trefoil [3,3], and spherical aberration [4,0]) and corneal aberrations (defocus [2,0] and astigmatism [2,2]). The Irx3 showed the highest repeatability in measuring total ocular aberrations, followed by the Keratron, OPD-Scan, and iTrace. The repeatability of the corneal aberration measurements was highest for the iTrace, followed by the Keratron and OPD-Scan. The OPD-Scan showed a lower interobserver variability, compared with the Irx3, Keratron, and iTrace. CONCLUSIONS: Total ocular and corneal aberrations are not comparable when measured with different aberrometers. Hartmann-Shack aberrometers showed the best repeatability for total ocular aberrations and iTrace for corneal aberrations. It would be worthwhile in the future to evaluate aberrometers in patients with more aberrant eyes.

Visual outcome and patient satisfaction after multifocal intraocular lens implantation: aspheric versus spherical design.

PURPOSE: To evaluate visual outcomes and patient satisfaction after implantation of an aspheric apodized diffractive intraocular lens (IOL) or a spherical apodized diffractive IOL in cataract surgery. SETTING: Maastricht University Medical Center, The Netherlands. DESIGN: Nonrandomized clinical trial. METHODS: This prospective nonrandomized study with a 6-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL and a spherical AcrySof ReSTOR SN60D3 IOL. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuities, straylight levels, incidence of glare and halos, and contrast sensitivity levels. RESULTS: The mean UDVA was 0.14 ± 0.15 logMAR in the aspheric group (47 eyes) and 0.14 logMAR ± 0.17 (SD) in the spherical group (45 eyes) and the mean CDVA, -0.01 ± 0.06 logMAR and 0.02 ± 0.10 logMAR, respectively. The mean UNVA was Jaeger (J) 1 in 83.0% of patients in the aspheric group and 55.5% of patients in the spherical IOL group (P = .003). The DCNVA was J1 in 95.7% and 71.1%, respectively (P = .001). There were no significant differences between the 2 groups in contrast sensitivity levels, intraocular straylight levels, incidence of night-vision symptoms, or subjective rating of vision. CONCLUSIONS: Patients with the aspheric multifocal IOL had significantly better near vision than patients with the multifocal spherical IOL. The UDVA, CDVA, intraocular straylight, night-vision symptoms, and contrast sensitivity were similar between the 2 groups.

Value of optical coherence tomography for anterior segment surgery.

UNLABELLED: Anterior segment optical coherence tomography (AS-OCT) is an important new noncontact imaging technology that uses a 1310 nm super luminescent diode. It can be used to assess anterior chamber biometry, corneal thickness, lens thickness, and angle configuration; to visualize pathological processes; to evaluate postsurgical anatomy and posttraumatic eyes; and to image phakic intraocular lenses and intracorneal ring segments. Because it is a noncontact technique, it can also be used intraoperatively, which could be useful during trabeculectomy and after deep anterior lamellar keratoplasty to detect abnormalities in the cornea and interface. A disadvantage of AS-OCT is its inability to penetrate the iris pigment epithelium, which makes it impossible to evaluate the structures behind the iris. The most frequently used devices are time-domain AS-OCT, but new Fourier-domain OCT devices, which have faster image acquisition and higher resolution, are currently under investigation. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of central corneal thickness and anterior chamber depth measurements using three imaging technologies in normal eyes and after phakic intraocular lens implantation.

BACKGROUND: The repeatability and interchangeability of imaging devices measuring central corneal thickness (CCT) and anterior chamber depth (ACD) are important in the assessment of patients considering refractive surgery. The purpose of this study was to investigate the agreement of CCT and ACD measurements using three imaging technologies in healthy eyes and in eyes after phakic intraocular lens implantation (pIOL). METHODS: In this comparative study, CCT and ACD were measured using anterior segment optical coherence tomography (AS-OCT), Orbscan II, and Pentacam in 33 healthy volunteers (66 eyes) and 22 patients (42 eyes) after pIOL implantation. Intraobserver repeatability was evaluated for all three devices in the healthy volunteer group. RESULTS: Pairwise comparison of CCT measurements showed significant differences between all devices (P < 0.001), except for the AS-OCT and Orbscan II in the healthy volunteer group (P = 0.422) and the Orbscan II and Pentacam in the pIOL group (P = 0.214). ACD measurements demonstrated significant differences between all pairwise comparisons in both groups (P < or = 0.001). Intraobserver reliability was high for CCT and ACD measurements in the healthy volunteer group, with coefficients of variation ranging from 0.6% to 1.2% and 0.4% to 0.5% respectively. CONCLUSIONS: CCT and ACD measurements using AS-OCT, Orbscan II, and Pentacam demonstrated high intraobserver reliability. However, these devices should not be used interchangeably for measurements of CCT and ACD in healthy subject and patients after pIOL implantation.

Prevalence of habitual refractive errors and anisometropia among Dutch schoolchildren and hospital employees.

PURPOSE: Refractive error (RE) is suggested to cause not only visual impairment, but also functional problems such as aspecific health complaints and lower levels of school achievement. During the last few decades the prevalence of myopia has increased worldwide, especially in Asia. We investigated the prevalence of habitual RE and anisometropia in a Dutch population of children and employees. METHODS: In a cross-sectional study, RE in both eyes of 520 children (aged 11-13 years) and 444 hospital employees (aged 17-60 years) were measured using an autorefractometer. The measurements were performed without using a cycloplegium. Pearson's correlation coefficient (r) was used to analyse correlations between the right and left eyes. Chi-square tests were used to test the differences between subgroups according to gender and age. RESULTS: In schoolchildren 28% of right eyes were myopic (> 0.50 D) and 8% hyperopic (> 0.50 D). Pearson's r between right and left eyes for spherical equivalent power (SEP) was 0.93. The mean cylinder deviation in right eyes was 0.26 D (range 0.00-4.50 D). Anisometropia > 1.00 D was present in 4.6% of children; 22% of children were not optimally (> 0.50 D) corrected. In hospital employees, 30% of right eyes were myopic (> 0.50 D) and 10% hyperopic (> 0.50 D). Pearson's r between right and left eyes for SEP was 0.53. The mean cylinder deviation in right eyes was 0.35 D (range 0.00-5.75 D). Anisometropia > 1.00 D was present in 25% of employees. Anisometropia was more frequently present in employees aged 40-60 years, than in those aged 17-39 years (30% versus 18%; p = 0.02, Cramer's V = 0.15). CONCLUSIONS: Refractive errors are common in children aged 11-13 years and in working adults aged 17-60 years. Distributions of sphere and cylinder deviations are similar for Dutch schoolchildren and hospital employees. Surprisingly, anisometropia proved to be more prevalent with age. In children many eyes are not optimally corrected. Increased attention should be paid to uncorrected and miscorrected REs.

Iris-fixated anterior chamber phakic intraocular lens for myopia moves posteriorly with mydriasis.

PURPOSE: To elucidate the physiological characteristics of eyes implanted with iris-fixated anterior chamber phakic intraocular lenses (pIOLs), which are increasingly being used for the correction of higher myopic and hyperopic refractive errors. METHODS: In a case series of 20 patients (39 eyes), the position of the pIOL to the natural lens and the cornea was evaluated under photopic (135 lux) and low mesopic (< 1 lux) circumstances with anterior segment optical coherence tomography. RESULTS: The distance between the pIOL and the natural lens decreased, and congruently, the distance from the pIOL to the corneal endothelium increased under low mesopic circumstances. CONCLUSIONS: The distance between the pIOL and the corneal endothelium increases when the pupil dilates under dark circumstances, contributing to the already excellent safety data available on pIOL implantation.

Evaluation of signs and symptoms in 3- and 9-o'clock staining.

PURPOSE: This study evaluates the relationship between bulbar hyperemia, conjunctival staining, lens comfort and 3- and 9-o'clock corneal staining in rigid gas permeable (GP) contact lens wear. METHODS: The study involved 55 GP contact lens wearers (with and without 3- and 9-o'clock staining) and 26 non-lens wearers. Corneal staining was graded based on a specially designed image grading scale developed at the University of Maastricht. The Efron grading scale was used to grade bulbar hyperemia and conjunctival staining. Ocular comfort and lens comfort were analyzed using a visual analogue scale (VAS) and a questionnaire to differentiate symptomatic from asymptomatic subjects. RESULTS: Bulbar hyperemia showed a significant but low correlation with corneal staining, and eyes with conjunctival staining showed more corneal staining than eyes without conjunctival staining. No correlation was found between staining in the nasal and temporal regions of the cornea in subjects with substantial 3- and 9-o'clock staining. No correlation was found between VAS comfort scores and corneal staining. In those subjects with substantial 3- and 9-o'clock staining, symptomatic subjects showed more corneal staining than asymptomatic subjects. CONCLUSIONS: Practitioners are advised to evaluate both the nasal and temporal regions of the cornea when assessing 3- and 9-o'clock staining, and they should be hesitant to rely on the amount of bulbar hyperemia for the prediction of the severity of 3- and 9-o'clock staining. Assessment of conjunctival staining could potentially be a useful tool in clinical practice to identify patients at risk of developing 3- and 9-o'clock staining. The lack of correlation between corneal staining and lens comfort stresses the need for regular contact lens check-ups in GP lens wearers. It appears that the simple registration of the presence or absence of ocular symptoms is a better predictor of 3- and 9-o'clock staining than using VAS comfort scores.

Influence of anterior chamber morphometrics on endothelial cell changes after phakic intraocular lens implantation.

PURPOSE: To analyze the position of iris-fixated phakic intraocular lenses (pIOLs) using anterior segment optical coherence tomography (AS-OCT) and evaluate the effect of anterior chamber morphometrics on endothelial cell changes. SETTING: Department of Ophthalmology, Academic Hospital Maastricht, The Netherlands. METHODS: In this cross-sectional study, AS-OCT was used to measure the distances from the center and the edges of the pIOL to the corneal endothelium in 242 eyes with various models of myopic pIOLs. Endothelial cell measurements were performed preoperatively and at each follow-up examination. RESULTS: The mean follow-up was 34.1 months+/-24.7 (SD) (range 3 months to 7 years). The mean distance between the edge of the pIOL and the endothelium was 1.37+/-0.22 mm. Although this distance was smaller than the safety value of 1.50 mm in 68.6% of the eyes, no eye developed corneal decompensation. There was a significant endothelial cell density (ECD) loss of 1.28%+/-8.46%, 3.25%+/-8.24%, and 5.02%+/-10.40% at 2 years, 5 years, and 7 years, respectively. Linear mixed-model analysis predicted a yearly ECD loss of 0.98% for a mean edge distance of 1.37 mm, 0.15% for an edge distance of 1.59 mm (mean plus 1 SD), and 1.80% for an edge distance of 1.15 mm (mean minus 1 SD). CONCLUSIONS: A shorter distance between the edge of the pIOL and the endothelium was significantly associated with higher ECD loss. For safety reasons, the postoperative examination should include long-term evaluation of the anterior chamber morphometrics in addition to ECD counts.

Eyeblink frequency and type in relation to 3- and 9-o'clock staining and gas permeable contact lens variables.

PURPOSE: The primary goal of this study was to evaluate if there is a difference in frequency and in completeness of eyeblinks (type of eyeblink) in rigid gas permeable (GP) lens wearers experiencing 3- and 9-o'clock staining compared with GP lens wearers without substantial staining and nonlens wearers. METHODS: The study involved 26 nonlens wearers and 55 GP contact lens wearers, with and without 3- and 9-o'clock staining. Every eyeblink over a 5-min period was categorized as a complete eyeblink, incomplete eyeblink, or an eyeblink attempt. In addition, type of lens fit (interpalpebral vs. lid attachment), lens-to-cornea fit (flat vs. steep), spherical equivalent of the refraction, and corneal coverage (on-eye lens diameter) were analyzed. RESULTS: No difference in overall eyeblink frequency was found between nonlens wearers (group I, n = 26), GP lens wearers with less than grade 1 corneal staining (group II, n = 25) and GP lens wearers with grade 1 or more corneal staining (group III, n = 30). Fewer complete eyeblinks, more incomplete eyeblinks and more eyeblink attempts were seen in group III than in group I or II (p < 0.01, p = 0.03, p < 0.01, respectively). Fewer complete eyeblinks and more eyeblink attempts (p < 0.01 for both) were found in interpalpebral lens fits than in lid attachment fits. Fewer complete eyeblinks (p = 0.02) and more incomplete eyeblinks (p = 0.03) were found with lenses rated as large or optimal in size than with lenses rated as small. CONCLUSIONS: GP lens wearers experiencing 3- and 9-o'clock staining showed a different eyeblink frequency for individual types of eyeblinks, but not for overall eyeblinks. Fewer complete eyeblinks, more incomplete eyeblinks, and more eyeblink attempts were observed in GP wearers with 3- and 9-o'clock staining compared with wearers with minimal staining and nonwearers. In addition, some individual contact lens variables were associated with more incomplete eyeblinks.

Long-term follow-up of a multifocal apodized diffractive intraocular lens after cataract surgery.

PURPOSE: To report the long-term performance of the AcrySof ReSTOR SA60D3 intraocular lens (IOL) after cataract surgery. SETTING: University Hospital Maastricht, Maastricht, The Netherlands. METHODS: This prospective clinical trial comprised 44 eyes (22 consecutive patients) having cataract surgery with implantation of the ReSTOR IOL. Monocular and binocular uncorrected distance visual acuity, best corrected distance visual acuity, uncorrected near visual acuity, best distance-corrected near visual acuity, spectacle dependence, undesired visual symptoms, patient satisfaction, and incidence of posterior capsule opacification were analyzed 6 months and 3 years postoperatively. RESULTS: The mean uncorrected distance acuity (logMAR) was 0.046 +/- 0.099 at 6 months and 0.115 +/- 0.173 at 3 years and the mean best corrected distance acuity, -0.040 +/- 0.075 and -0.018 +/- 0.093, respectively. Binocular uncorrected and best-corrected near acuities (logMAR) were 0.009 +/- 0.029 at 6 months and 0.014 +/- 0.035 at 3 years. All patients achieved a binocular uncorrected and best distance-corrected near acuity of 20/25 or better at 6 months and 3 years. On a quality-of-life questionnaire, patients reported good distance, intermediate, and near acuity without complaints of severe glare or halos. Complete spectacle independence for distance and near acuity was achieved by 83.7% and 81.9% of patients, respectively, at 6 months and 85.0% and 75.0% of patients, respectively, at 3 years. Four eyes (9.1%) required neodymium:YAG capsulotomy. CONCLUSIONS: Cataract surgery with the AcrySof ReSTOR SA60D3 IOL provided good, stable distance and near visual acuities over a 3-year follow-up, leading to low spectacle independence and high patient satisfaction.