Steven A. Koopmans

Quality of care from the perspective of the cataract patient: the reliability and validity of the QUOTE-Cataract

Background/aims: To assess reliability and validity of the QUOTE-cataract, a questionnaire that measures the quality of care from the perspective of cataract patients. Methods: The QUOTE-cataract was tested in a multicentre study among 540 cataract patients in three different hospitals. Reliability was represented by internal consistency (Cronbach’s α), and repeatability (intraclass correlation coefficient (ICC)). Validity was evaluated qualitatively and by factor analyses. Results: A strong internal consistency coefficient (0.89), and high repeatability (ICC = 0.76) demonstrated good reliability. Content validity was assured by involvement of patients in the development of the questionnaire. Factor analysis confirmed an underlying taxonomy of generic and disease specific items. Conclusion: The QUOTE-cataract has good reliability and provides a valid assessment of quality of care in cataract surgery.

Prevention of posterior capsular opacification

Posterior capsular opacification (PCO) is a common complication of cataract surgery. The development of PCO is due to a combination of the processes of proliferation, migration, and transdifferentiation of residual lens epithelial cells (LECs) on the lens capsule. In the past decades, various forms of PCO prevention have been examined, including adjustments of techniques and intraocular lens materials, pharmacological treatments, and prevention by interfering with biological processes in LECs. The only method so far that seems effective is the implantation of an intraocular lens with sharp edged optics to mechanically prevent PCO formation. In this review, current knowledge of the prevention of PCO will be described. We illustrate the biological pathways underlying PCO formation and the various approaches to interfere with the biological processes to prevent PCO. In this type of prevention, the use of nanotechnological advances can play a role.

Intraocular degradation behavior of crosslinked and linear poly(trimethylene carbonate) and poly(d,l-lactic acid)

The intraocular degradation behavior of poly(trimethylene carbonate) (PTMC) networks and poly(D,L-lactic acid) (PDLLA) networks and of linear high molecular weight PTMC and PDLLA was evaluated. PTMC is known to degrade by enzymatic surface erosion in vivo, whereas PDLLA degrades by hydrolytic bulk degradation. Rod shaped specimens were implanted in the vitreous of New Zealand white rabbits for 6 or 13 wk. All materials were well tolerated in the rabbit vitreous. The degradation of linear high molecular weight PTMC and PTMC networks was very slow and no significant mass loss was observed within 13 wk. Only some minor signs of macrophage mediated erosion were found. The fact that no significant enzymatic surface erosion occurs can be related to the avascularity of the vitreous and the limited number of cells it contains. PDLLA samples showed more evident signs of degradation. For linear PDLLA significant swelling and a large decrease in molecular weight in time was observed and PDLLA network implants started to lose mass within 13 wk. Of the tested materials, PDLLA networks seem to be most promising for long term degradation controlled intravitreal drug delivery since this material degrades without significant swelling. Furthermore the preparation method of these networks allows easy and efficient incorporation of drugs.

Clinical comparison of the optical performance of aspheric and spherical intraocular lenses

PURPOSE: To compare the optical performance of aspheric Tecnis ZA9003 and spherical Sensar AR40e intraocular lenses (IOLs). SETTING: Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. METHODS: An aspheric IOL was implanted in 1 eye and a spherical IOL in the other eye of patients with bilateral age‐related cataract. Contrast sensitivity was measured using 2 computerized tests (vertical sine‐modulated gratings and circular sine‐modulated patterns) with cycloplegia and a 5.0 mm artificial pupil under photopic conditions at optimum refractive correction and at several defocus levels. The depth of focus and the myopic shift (shift of optimum focus toward more myopic values at lower spatial frequencies) were determined. Higher‐order aberrations were assessed using a Hartmann‐Shack wavefront analyzer; straylight was measured with a straylight meter. RESULTS: In the 60 eyes evaluated, there were no statistically significant differences in contrast sensitivity measured at optimum focus, depth of focus, or straylight between the 2 IOLs. The mean spherical aberration was significantly lower with the aspheric IOL (−0.036 &mgr;m) than with the spherical IOL (0.064 &mgr;m) (P<.001) and the mean myopic shift, statistically significantly smaller (0.05 diopter [D] and −0.47 D, respectively) (P<.001). CONCLUSIONS: Eyes with the aspheric IOL had lower spherical aberration than eyes with the spherical IOL and, related to that, a smaller myopic shift. No significant differences were found between the 2 IOLs in contrast sensitivity measured at optimum focus, depth of focus, or straylight. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

7.1 T MRI to Assess the Anterior Segment of the Eye

PURPOSE Visualization of the anterior segment and biometric evaluation of the entire crystalline lens pose significant challenges for imaging techniques because of tissue-induced distortion artifacts. The present study was conducted to demonstrate the advantages of high-resolution magnetic resonance imaging (micro-MRI) for visualizing the anterior segment. METHODS High-resolution MR ocular images were acquired on an ultra-high-field MR unit using a two-channel coil with four coil elements and T(2)-weighted turbo spin echo sequences ex vivo in pig, rabbit, monkey, and human donor eyes and in vivo in rabbits. Tissue heating, reproducibility, and signal-to-noise ratio were investigated in vivo. Monkey eye lens thickness (LT) was also measured using A-scan ultrasonography (US). RESULTS Anterior segment details of phakic eyes were obtained ex vivo (pig, rabbit, monkey, and human donor eyes) with pixel matrix size 512 × 512 (in-plane resolution 80 × 80 μm) and in vivo (rabbit eyes) with pixel matrix size 320 × 320 (in-plane resolution 125 × 125 μm). Complete quantification of lens dimensions as they correlate with the sulcus-sulcus and angle-angle plane can be performed. In LT determinations in monkey eyes, no significant difference was detected between micro-MRI and A-scan US (P > 0.05, Mann-Whitney U test). Biometric analysis of one pseudophakic monkey eye confirmed the absence of relevant distortion artifacts. CONCLUSIONS Micro-MRI allows ex vivo and in vivo visualization and quantification of the spatial arrangement of the anterior eye segment. Imaging of the retroiridian region, including the entire crystalline lens, overcomes a number of major limitations in the quantitative evaluation of the anterior segment.

Relation between injected volume and optical parameters in refilled isolated porcine lenses

Purpose:  This study was performed to elucidate the correlation between added lens refill material and enhanced lens power as well as the correlation between lens refilling volume and accommodative amplitude as determined by equatorial stretching of ex vivo refilled pigs’ lenses.

Quality of care from the perspective of the cataract patient: QUOTE Cataract Questionnaire.

Purpose: To examine the potential of a questionnaire (QUOTE Cataract) to measure quality of care from the perspective of cataract patients in quality‐assurance or improvement programs. Setting: Department of Ophthalmology, University Hospital Maastricht, Maastricht, University Hospital Groningen, Groningen, and Rotterdam Eye Hospital, Rotterdam, The Netherlands. Methods: Cataract patients (N = 540) who had cataract surgery 2 to 8 months previously rated 31 quality‐of‐care aspects in terms of importance (range 0, not important, to 10, extremely important) and performance (0 = yes, 1 = no). An arithmetic combination of the 2 parameters was used to generate quality‐impact factors (Q) (range 0, best quality of care, to 10, this aspect needs improvement according to every respondent). The goal was to identify bottlenecks in the quality of care. Results: Patients scored aspects concerning patient education as the most important quality aspects. The top 3 quality‐impact factors were to inform patients what to do in emergency situations (Q = 3.39), inform patients about the risks of treatment (Q = 3.00), and minimize the number of ophthalmologists to 1 per patient (Q = 2.79). Conclusion: The QUOTE Cataract Questionnaire effectively measured quality of care in cataract surgery patients in different hospital settings and provided practical information for quality‐assurance programs.

Relationship between contrast sensitivity and spherical aberration Comparison of 7 contrast sensitivity tests with natural and artificial pupils in healthy eyes

PURPOSE: To find a contrast sensitivity test that can be used clinically to evaluate interventions aimed at minimizing spherical aberration and determine the circumstances under which these tests should be performed. SETTING: Laboratory of Experimental Ophthalmology, University of Groningen, Groningen, The Netherlands. METHODS: Contrast sensitivity tests were performed using 2 experimental designs. Design 1 was with a natural pupil under mesopic and photopic conditions. Design 2 was with a 5.0 mm artificial pupil after cycloplegia under photopic conditions only. Two computerized tests (vertical sine‐modulated gratings [VSG] and Holladay circular sine‐modulated patterns [HACSS]) and 5 chart tests (Pelli‐Robson, acuity‐measuring letter charts at low contrast [2.5% and 10%], VectorVision, and edge contrast sensitivity) were used. Spherical aberration was assessed with a Hartmann‐Shack wavefront analyzer. RESULTS: Forty‐nine healthy subjects aged 20 to 35 years (n = 24) and 55 to 70 years (n = 25) participated. Design 2 showed a significant relationship between contrast sensitivity and spherical aberration with the HACSS at 3 cycles per degree (cpd) (P = .03) and 6 cpd (P = .01) and with the VSG at 6 cpd (P = .01). Design 1 yielded no significant relationships. CONCLUSIONS: Using an artificial pupil, a relationship between contrast sensitivity and spherical aberration was established with the VSG and HACSS tests but not with the chart tests. No test showed a relationship using natural pupils under either lighting condition. Chart tests are unsuitable for uncovering contrast sensitivity differences related to differences in spherical aberration, as typically found in healthy phakic eyes.

Shape of the anterior cornea : Comparison of height data from 4 corneal topographers

Purpose To compare the ability of clinical corneal topographers to describe the shape of the anterior cornea for optical modeling. Setting University Medical Center Groningen, Groningen, Netherlands. Design Cross‐sectional study. Methods The anterior corneal shape of healthy subjects was assessed with 4 topographers (Atlas Placido disk, Galilei dual Scheimpflug, Orbscan scanning slit, Pentacam single Scheimpflug). Exported height data were fit with Zernike polynomials. Mean values with the standard deviation, interdevice variability, and test–retest variability were determined for the defocus Z(2,0), astigmatism Z(2,−2) and Z(2,2), coma Z(3,−1) and Z(3,1), and spherical aberration Z(4,0) coefficients for 5.5 mm and 8.0 mm diameters. Results At 5.5 mm, the single Scheimpflug topographer showed the smallest coefficient of repeatability; 0.31 &mgr;m for Z(2,0); 0.40 and 0.34 &mgr;m for Z(2,−2) and Z(2,2), respectively; 0.15 and 0.11 &mgr;m for Z(3,−1) and Z(3,1), respectively; and 0.08 &mgr;m for Z(4,0); the other topographers showed up to 10 times larger coefficients of repeatability. The (unsigned) mean differences between the topographers were in the range of 0.20 to 1.21 &mgr;m for Z(2,0); 0.02 to 0.31 &mgr;m and 0.06 to 0.42 &mgr;m for Z(2,−2) and Z(2,2), respectively; 0.03 to 0.18 &mgr;m and 0.03 to 0.35 &mgr;m for Z(3,−1) and Z(3,1), respectively; and 0.00 to 0.14 &mgr;m for Z(4,0). The Placido‐disk topographer and single Scheimpflug topographer data corresponded best. Similar trends were found at 8.0 mm. Conclusion Test–retest variability hampered a detailed description of the anterior corneal shape at the level of individual subjects; interdevice variability compromises the exchangeability of the devices. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Barriers to and facilitators of sports participation in people with visual impairments

We examined barriers to and facilitators of sports participation in people with visual impairments. Participants registered at Royal Visio, Bartiméus, and the Eye Association were invited to complete a questionnaire (telephone or online). Six hundred forty-eight of the invited participants (13%) completed the questionnaire, and 63% of the respondents reported sports participation. Walking (43%), fitness (34%), and cycling (34%) were frequently mentioned sports. Costs, lack of peers/buddies, and visual impairment were negatively associated with sports participation, whereas higher education and computer (software) use were positively associated. The most important personal barrier was visual impairment; transport was the most important environmental barrier. Active participants also mentioned dependence on others as a personal barrier. The most important personal facilitators were health, fun, and social contacts; support from family was the most important environmental facilitator. To improve sports participation in people with visual impairments, the emphasis in a sports program should be on the positive aspects of sports, such as fun, health, and social contacts.