Prognostic indicators and outcome measures for surgical removal of symptomatic nonadvanced cataract

Should We Perform Early Cataract Surgery? A Patient Reported Outcome Study

Purpose

Current guidance states that access to cataract surgery should not be restricted by visual acuity (VA); nevertheless, 6/12 is used as a cut-off criterion in some health institutions. This study aims to determine the benefits of performing cataract surgery in patients with VA of 6/9 or better in both eyes; determine whether these benefits change over time; and compare the benefit observed between early first eye and second eye surgery.

Patients and Methods

Fifty adults with VA at least 6/9 in the worst eye and no ocular comorbidity were recruited. The Visual Function Index (VF-14) and Impact of Visual Impairment (IVI) questionnaires were conducted pre-operatively, 4 months post-operatively, and 12 months post-operatively. The t-test or a non-parametric equivalent was used to compare averages between groups.

Results

The mean change in VF-14 from baseline to 4 months was 16.43 (95% CI 12.49–20.50, p < 0.001) and the median change in IVI was 6.5 (IQR 9.75, p < 0.001). There was no significant difference between 4-month and 12-month follow-up (p > 0.05). There was no significant difference in the change in visual function between the first and second eye surgery (p > 0.05).

Conclusion

This study provides evidence that visual function improves after cataract surgery in patients with pre-operative VA of 6/9 or better. The improvement observed was clinically significant and unchanged a year after surgery. Visual function improved after second eye as much as after first eye surgery. Assessing patient reported visual function may give a more realistic indication of the benefit of early cataract surgery than relying on VA alone.

Predicting changes in cataract surgery health outcomes using a cataract surgery appropriateness and prioritization instrument

Objective

Determine whether items in a cataract surgery appropriateness and prioritization questionnaire can predict change in best corrected visual acuity (BCVA) and health related quality of life (HRQOL) following cataract surgery.

Methods

313 patients with a cataract in Ontario, Canada were recruited to participate. BCVA was measured using the Snellen chart. HRQOL was measured using a generic instrument (EQ5D), a visual functioning instrument (Catquest-9SF), and an appropriateness and prioritization instrument (17 items). Outcomes were measured preoperatively and 3–6 months postoperatively. Descriptive statistics were used to describe demographics and outcomes. For each appropriateness and prioritization questionnaire item, a one-way ANOVA was used to compare group means of the change in BCVA, EQ5D, and Catquest-9SF.

Results

Participants had a mean age of 69 years and were 56% female. BCVA improved in 81%, EQ5D in 49.6%, and Catquest-9SF score in 84% of patients. Improvement in both BCVA and Catquest-9SF scores were found in 68.5% of patients. The ANOVA showed a statistically significant association between a change in BCVA and the ability to participate in social life, and a statistically significant association between a change in Catquest-9SF and glare, extent of impairment in visual function, safety and injury concerns, ability to work and care for dependents, ability to take care of local errands, ability to assist others and ability to participate in social life.

Conclusions

Almost all patients had improved BCVA and/or visual functioning after surgery. Seven variables from the cataract appropriateness and prioritization instrument were found to be predictors of improvement in Catquest-9SF measuring visual functioning.

Trail Making Test performance contributes to subjective judgment of visual efficiency in older adults

Introduction. The determinant factors that influence self-reported quality of vision have yet to be fully elucidated. This study evaluated a range of contextual information, established psychophysical tests, and in particular, a series of cognitive tests as potentially novel determinant factors.

Materials & Methods. Community dwelling adults (aged 50+) recruited to Wave 1 of The Irish Longitudinal Study on Ageing, excluding those registered blind, participated in this study (N = 5,021). Self-reports of vision were analysed in relation to visual acuity and contrast sensitivity, ocular pathology, visual (Choice Response Time task; Trail Making Test) and global cognition. Contextual factors such as having visited an optometrist and wearing glasses were also considered. Ordinal logistic regression was used to determine univariate and multivariate associations.

Results and Discussion. Poor Trail Making Test performance (Odds ratio, OR = 1.36), visual acuity (OR = 1.72) and ocular pathology (OR = 2.25) were determinant factors for poor versus excellent vision in self-reports. Education, wealth, age, depressive symptoms and general cognitive fitness also contributed to determining self-reported vision.

Conclusions. Trail Making Test contribution to self-reports may capture higher level visual processing and should be considered when using self-reports to assess vision and its role in cognitive and functional health.

The clinical effectiveness and cost-effectiveness of second-eye cataract surgery: a systematic review and economic evaluation

BACKGROUND

Elective cataract surgery is the most commonly performed surgical procedure in the NHS. In bilateral cataracts, the eye with greatest vision impairment from cataract is operated on first. First-eye surgery can improve vision and quality of life. However, it is unclear whether or not cataract surgery on the second eye provides enough incremental benefit to be considered clinically effective and cost-effective.

OBJECTIVE

To conduct a systematic review of clinical effectiveness and analysis of cost-effectiveness of second-eye cataract surgery in England and Wales, based on an economic model informed by systematic reviews of cost-effectiveness and quality of life.

DATA SOURCES

Twelve electronic bibliographic databases, including MEDLINE, EMBASE, Web of Science, The Cochrane Library and the Centre for Reviews and Dissemination databases were searched from database inception to April 2013, with searches updated in July 2013. Reference lists of relevant publications were also checked and experts consulted.

REVIEW METHODS

Two reviewers independently screened references, extracted and checked data from the included studies and appraised their risk of bias. Based on the review of cost-effectiveness, a de novo economic model was developed to estimate the cost-effectiveness of second-eye surgery in bilateral cataract patients. The model is based on changes in quality of life following second-eye surgery and includes post-surgical complications.

RESULTS

Three randomised controlled trials (RCTs) of clinical effectiveness, three studies of cost-effectiveness and 10 studies of health-related quality of life (HRQoL) met the inclusion criteria for the systematic reviews and, where possible, were used to inform the economic analysis. Heterogeneity of studies precluded meta-analyses, and instead data were synthesised narratively. The RCTs assessed visual acuity, contrast sensitivity, stereopsis and several measures of HRQoL. Improvements in binocular visual acuity and contrast sensitivity were small and unlikely to be of clinical significance, but stereopsis was improved to a clinically meaningful extent following second-eye surgery. Studies did not provide evidence that second-eye surgery significantly affected HRQoL, apart from an improvement in the mental health component of HRQoL in one RCT. In the model, second-eye surgery generated 0.68 incremental quality-adjusted life-years with an incremental cost-effectiveness ratio of £1964. Model results were most sensitive to changes in the utility gain associated with second-eye surgery, but otherwise robust to changes in parameter values. The probability that second-eye surgery is cost-effective at willingness-to-pay thresholds of £10,000 and £20,000 is 100%.

LIMITATIONS

Clinical effectiveness studies were all conducted more than 9 years ago. Patients had good vision pre surgery which may not represent all patients eligible for second-eye surgery. For some vision-related patient-reported outcomes and HRQoL measures, thresholds for determining important clinical effects are either unclear or have not been determined.

CONCLUSIONS

Second-eye cataract surgery is generally cost-effective based on the best available data and under most assumptions. However, more up-to-date data are needed. A well-conducted RCT that reflects current populations and enables the estimation of health state utility values would be appropriate. Guidance is required on which vision-related, patient-reported outcomes are suitable for assessing effects of cataract surgery in the NHS and how these measures should be interpreted clinically.

STUDY REGISTRATION

This project is registered as PROSPERO CRD42013004211.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme.

Sustained supplementation and monitored response with differing carotenoid formulations in early age-related macular degeneration

Purpose

To compare the impact of sustained supplementation using different macular carotenoid formulations on macular pigment (MP) and visual function in early age-related macular degeneration (AMD).

Patients and methods

Sixty-seven subjects with early AMD were randomly assigned to: Group 1 (20 mg per day lutein (L), 0.86 mg per day zeaxanthin (Z); Ultra Lutein), Group 2 (10 mg per day meso-zeaxanthin (MZ), 10 mg per day L, 2 mg per day Z; Macushield; Macuhealth), Group 3 (17 mg per day MZ, 3 mg per day L, 2 mg per day Z). MP was measured using customised heterochromatic flicker photometry and visual function was assessed by measuring contrast sensitivity (CS) and best-corrected visual acuity (BCVA). AMD was graded using the Wisconsin Age-Related Maculopathy Grading System (AREDS 11-step severity scale).

Results

At 3 years, a significant increase in MP from baseline was observed in all groups at each eccentricity (P<0.05), except at 1.75° in Group 1 (P=0.160). Between 24 and 36 months, significant increases in MP at each eccentricity were seen in Group 3 (P<0.05 for all), and at 0.50° in Group 2 (P<0.05), whereas no significant increases were seen in Group 1 (P>0.05 for all). At 36 months, compared with baseline, the following significant improvements (P<0.05) in CS were observed: Group 2—1.2, 6, and 9.6 cycles per degree (c.p.d.); Group 1—15.15 c.p.d.; and Group 3—6, 9.6, and 15.15 c.p.d. No significant changes in BCVA, or progression to advanced AMD, were observed.

Conclusion

In early AMD, MP can be augmented with a variety of supplements, although the inclusion of MZ may confer benefits in terms of panprofile augmentation and in terms of CS enhancement.

Determinants of patient satisfaction and function related to vision following cataract surgery in eyes with no visually consequential ocular co-morbidity

PURPOSE

To investigate subjectively reported outcomes following cataract surgery and the relationships between such outcomes in the context of falling thresholds for cataract surgery.

SETTING

Large, private, non-refractive cataract practice, Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland

METHODS

Pre-operative, intra-operative and post-operative data of 2552 eyes undergoing phacoemulsification and implantation of the Tecnis(R) ZCB00 1-piece intraocular lens (IOL) by a single surgeon between July 2009 and October 2013 was analysed. Patients without visually consequential ocular co-morbidity completed two validated questionnaires, designed to assess subjectively perceived visual functioning and identify symptoms of dysphotopsia following cataract surgery.

RESULTS

54.8 % of questionnaire respondents were entirely satisfied (satisfaction 10/10) post-operatively, with 83.7 % reporting satisfaction of ≥7/10. Satisfaction was positively associated with patient age and negatively associated with spectacle dependence, dysphotopsia, and function related to vision (NEI VF-11) score. The mean (±standard deviation[SD]) dysphotopsia score was 1.36 (±1.9; scale 0-10), with 40 % of respondents reporting no dysphotopsia symptoms and 9.8 % reporting clinically meaningful dysphotopsia. The mean (±SD) National Eye Institute visual function-11 (NEI VF-11) score was 0.33 (±0.53; scale 0-4) and reduced function related to vision was associated with increasing severity of dysphotopsia symptoms. When linear regression was applied, 17.5 % of the variation in functionality was attributable to symptoms of dysphotopsia.

CONCLUSION

Dysphotopsia is an important determinant of a patient having difficulty with vision-related tasks following cataract surgery, and patient satisfaction is positively associated with patient age and negatively associated with spectacle in dependence, dysphotopsia and function related to the vision (NEI VF-11) score.

Central Retinal Enrichment Supplementation Trials (CREST): design and methodology of the CREST randomized controlled trials

PURPOSE

The Central Retinal Enrichment Supplementation Trials (CREST) aim to investigate the potential impact of macular pigment (MP) enrichment, following supplementation with a formulation containing 10 mg lutein (L), 2 mg zeaxanthin (Z) and 10 mg meso-zeaxanthin (MZ), on visual function in normal subjects (Trial 1) and in subjects with early age-related macular degeneration (AMD; Trial 2).

METHODS

CREST is a single center, double-blind, randomized clinical trial. Trial 1 (12-month follow-up) subjects are randomly assigned to a formulation containing 10 mg L, 10 mg MZ and 2 mg Z (n = 60) or placebo (n = 60). Trial 2 (24-month follow-up) subjects are randomly assigned to a formulation containing 10 mg L, 10 mg MZ, 2 mg Z plus 500 mg vitamin C, 400 IU vitamin E, 25 mg zinc and 2 mg copper (Intervention A; n = 75) or 10 mg L and 2 mg Z plus 500 mg vitamin C, 400 IU vitamin E, 25 mg zinc and 2 mg copper (Intervention B; n = 75). Contrast sensitivity (CS) at 6 cycles per degree represents the primary outcome measure in each trial. Secondary outcomes include: CS at other spatial frequencies, MP, best-corrected visual acuity, glare disability, photostress recovery, light scatter, cognitive function, foveal architecture, serum carotenoid concentrations, and subjective visual function. For Trial 2, AMD morphology, reading speed and reading acuity are also being recorded.

CONCLUSIONS

CREST is the first study to investigate the impact of supplementation with all three macular carotenoids in the context of a large, double-blind, randomized clinical trial.

Objective assessment of crystalline lens opacity level by measuring ocular light scattering with a double-pass system

PURPOSE

To assess the crystalline lens opacity level by measuring ocular light scattering with a double-pass system.

DESIGN

Prospective, single-center, cross-sectional study.

METHODS

Two hundred fifty-three eyes of 135 patients referred for cataract evaluation were enrolled. Patients with corneal or retinal anomalies potentially impairing ocular transparency were excluded. Lens opacification was assessed by the Lens opacities classification system III. Optical Quality Analysis System (Visiometrics SL) measurements provided ocular Modulation Transfer Function cutoff frequency and Objective Scatter Index. Best-corrected visual acuity and Quality of Vision questionnaire scores (Rasch-scaled) were recorded. We analyzed correlations between visual acuity, type and severity of cataract, Optical Quality Analysis System measurements, and discomfort level in each group.

RESULTS

In patients with best-corrected visual acuity better than 20/32, we found correlations between Objective Scatter Index, Modulation Transfer Function, and visual acuity (r = 0.4, P < .0001). The Objective Scatter Index, Modulation Transfer Function, and visual acuity were correlated with each type of cataract. In patients with good visual acuity and moderate functional symptoms, the Objective Scatter Index values also were correlated to the severity of posterior subcapsular cataract (r = 0.4, P = .0006).

CONCLUSIONS

Patients with incipient cataract may report visual discomfort, despite minor lens opacity on slit-lamp examination, minor loss of best-corrected visual acuity, or both. The measurement of ocular scattering with the Optical Quality Analysis System device may be a useful tool in the preoperative evaluation of patients with early cataract.