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1.  Asymmetry in Keratoconus and Vision-Related Quality of Life 
Cornea  2013;32(3):267-272.
Purpose
To examine the relation of increased ocular asymmetry over time on vision-related quality of life in keratoconus.
Methods
Subjects were in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study and had complete data on a least one scale of the NEI VFQ and examination data at baseline and at least one follow-up visit. Three measures of disease asymmetry (visual acuity, corneal curvature, and refractive error) and better eye status were assessed. Multilevel models were fit to the data.
Results
Analyses were completed using 961 subjects. Six scales on the NEI VFQ had adequate variability to model (distance activity, driving, mental health, near activity, ocular pain, and role difficulties). Refractive error changes were not associated with statistically significant quality of life differences. Except for ocular pain, statistically significant, but not clinically meaningful, differences were found for visual acuity changes and corneal curvature changes. For a 0.1-unit logMAR visual acuity change, the quality of life scales decreased between 0.20 and 0.99 units. For a 1.00-D steepening of corneal curvature these decreases were on the order of 0.20 to 0.59 units. Changes related to asymmetry were small as well: decreases on the order of 0.20 to 0.38 units.
Conclusions
Increasing ocular asymmetry and decreases in visual acuity and corneal steepening in the better eye were associated with decreasing vision-related quality of life, though the magnitudes of the changes were not clinically meaningful. Of these two disease status indicators, the vision in the better eye had greater effect on vision-related quality of life.
doi:10.1097/ICO.0b013e31825697c4
PMCID: PMC3482277  PMID: 22825402
Keratoconus; quality of life; longitudinal
2.  Longitudinal Trends in Resource Utilization in an Incident Cohort of Open Angle Glaucoma Patients 
American journal of ophthalmology  2012;154(3):452-459.e2.
Purpose
To characterize the costs of caring for patients with open-angle glaucoma (OAG) in the United States (US) over time and to identify factors that influence these costs.
Design
Longitudinal cohort study.
Methods
Claims data from 19,927 newly-diagnosed OAG patients enrolled in a large US managed care network were reviewed to identify glaucoma-related charges for all incident OAG patients from 2001–2009. Average glaucoma-related charges for enrollees with OAG were characterized in six month blocks from the date of initial OAG diagnosis through the following 5 years. Factors associated with being an enrollee in the costliest 5% for glaucoma-related charges (accruing ≥$5810 in charges in the first 2 years) were identified using logistic regression.
Results
The costliest 5% of enrollees were responsible for $10,202,871 (24%) of all glaucoma-related charges. By comparison, those whose costs fell within the lower 50% of the cost distribution collectively amassed only $7,986,582 (19%) of all glaucoma-related charges. A spike in glaucoma-related charges occurred in the 6 month period around the time of OAG diagnosis, stabilized by 1 year following diagnosis, and remained relatively constant over time. Risk factors associated with being in the costliest 5% for glaucoma-related care included younger age, Northeastern US state residence, undergoing cataract surgery, and possessing ocular co-morbidities.(p<0.006 for all comparisons).
Conclusions
A small subset of enrollees account for a large proportion of all glaucoma-related charges. Understanding the characteristics of these individuals and finding ways to reduce disease burden and costs associated with their care can result in substantial cost savings.
doi:10.1016/j.ajo.2012.03.032
PMCID: PMC3422396  PMID: 22789564
3.  The Development of a Decision Analytic Model of Changes in Mean Deviation in People with Glaucoma: The COA Model 
Ophthalmology  2012;119(7):1367-1374.
Purpose
To create and validate a statistical model predicting progression of primary open angle glaucoma (POAG) assessed by loss of visual field as measured in mean deviation (MD) using three landmark studies of glaucoma progression and treatment.
Design
A Markov decision analytic model using patient level data described longitudinal MD changes over seven years.
Participants
Patient level data from the Collaborative Initial Glaucoma Treatment Study (CIGTS, n=607), the Ocular Hypertension Treatment Study (OHTS, n=148, only those who developed POAG in the first five years of OHTS) and Advanced Glaucoma Intervention Study (AGIS, n=591), the COA model.
Methods
We developed a Markov model with transition matrices stratified by current MD, age, race and intraocular pressure categories and used a microsimulation approach to estimate change in MD over seven years. Internal validation compared model prediction for seven years to actual MD for COA participants. External validation used a cohort of glaucoma patients drawn from university clinical practices.
Main Outcome Measures
Change in visual field as measured in MD in decibels (dB).
Results
Regressing the actual MD against the predicted produced an R2 of 0.68 for the right eye and 0.63 for the left. The model predicted ending MD for right eyes of 65% of participants and for 63% of left eyes within 3 dB of actual results at seven years. In external validation the model had an R2 of 0.79 in the right eye and 0.77 in the left at five years.
Conclusion
The COA model is a validated tool for clinicians, patients and health policy makers seeking to understand longitudinal changes in mean deviation in people with glaucoma..
doi:10.1016/j.ophtha.2012.01.054
PMCID: PMC3389134  PMID: 22537616
4.  Pharmacogenetics of Complement Factor H (Y402H) and treatment of exudative age-related macular degeneration with ranibizumab 
Aims
To determine whether complement factor H (CFH) genotypes have a pharmacogenetic effect on the treatment of exudative age-related macular degeneration (AMD) with ranibizumab.
Methods
A retrospective study of 156 patients with exudative AMD treated with intravitreal ranibizumab monotherapy was conducted. AMD phenotypes were characterized by clinical examination, visual acuity, fundus photography, fluorescein angiography, and injection timing. Patients received intravitreal ranibizumab injections as part of routine ophthalmologic care and were followed for a minimum of nine months. Each patient was genotyped for the single nucleotide polymorphism rs1061170 (Y402H) in the CFH gene.
Results
Baseline lesion size and angiographic type, as well as mean visual acuities at baseline, 6 months, and 9 months were similar among the three CFH genotypes. Over 9 months, patients with both risk alleles received approximately one more injection (p = 0.09). In a recurrent event analysis, patients homozygous for the CFH Y402H risk allele had a 37% significantly higher risk of requiring additional ranibizumab injections (p = 0.04)
Conclusions
In our cohort, response to treatment of AMD with ranibizumab differed according to CFH genotype, suggesting that determining patients' CFH genotype may be helpful in the future in tailoring treatment for exudative AMD with intravitreal ranibizumab.
doi:10.1136/bjo.2008.150995
PMCID: PMC3490485  PMID: 19091853
Complement Factor H; Ranibizumab; Age-Related Macular Degeneration; Pharmacogenetics
5.  Demonstration of an online tool to assist managed care formulary evidence-based decision making: meta-analysis of topical prostaglandin analog efficacy 
Background
The purpose of this paper was to demonstrate the use of an online service for conducting a systematic review and meta-analysis of the efficacy of topical prostaglandin analogs in reducing intraocular pressure (IOP) in glaucoma and ocular hypertension.
Methods
An online service provider (Doctor Evidence) reviewed and extracted data from the peer-reviewed literature through September 2009. Randomized controlled studies of at least three months’ duration assessing at least two prostaglandin analogs in patients with primary open-angle glaucoma, ocular hypertension, or normal-tension glaucoma were included. The primary endpoint was mean IOP. Summary estimates were created using random-effects models. The Q Chi-square test was used to assess statistical heterogeneity.
Results
Sixteen studies satisfied the inclusion criteria and were analyzed. On average, greater IOP-lowering was seen with bimatoprost relative to latanoprost (1 mmHg, P = 0.025) and travoprost (0.8 mmHg, P = 0.033) based on mean IOP after 12–26 weeks of treatment. No statistical difference was observed in IOP-lowering between latanoprost and travoprost (P = 0.841). Findings were similar to previously published meta-analyses of topical prostaglandin analogs.
Conclusion
Systematic reviews relying on meta-analytic techniques to create summary statistics are considered to be the “gold standard” for synthesizing evidence to support clinical decision-making. However, the process is time-consuming, labor-intensive, and outside the capability of most formulary managers. We have demonstrated the effectiveness of a commercial service that facilitates the process of conducting such reviews.
doi:10.2147/TCRM.S20495
PMCID: PMC3150474  PMID: 21845051
evidence-based medicine; meta-analysis; review; systematic; prostaglandin analogs; glaucoma
6.  Changes in the Quality of Life of People with Keratoconus 
American journal of ophthalmology  2008;145(4):611-617.
Purpose
The Collaborative Longitudinal Evaluation of Keratoconus Study (CLEK) has previously shown that people with keratoconus report significantly impaired vision-related quality of life (V-QoL) as measured on the National Eye Institute Visual Function Questionnaire (NEI-VFQ), similar to people who have severe macular degeneration. In this report we evaluate changes that occurred in V-QoL over 7 years of follow-up.
Design
Prospective cohort study of 1166 participants followed for 7 years.
Methods
We estimated change in quality of life by projecting the slope of a minimum of three reports on 11 scales of the NEI-VFQ. Correlation with clinical indicators was evaluated, and differences were assessed between those who had clinically significant changes in clinical factors and those who did not. Logistic regression was used to assess factors associated with a decline in 10 points or more in a scale score over 7 years.
Results
All scales showed modest decline except Ocular Pain and Mental Health. Baseline factors were not associated with longitudinal change in NEI-VFQ scores. A 10-letter decline in high-contrast binocular visual acuity and a 3.00 D increase in corneal curvature were associated with significantly larger declines in V-QoL. In multivariate analysis, these factors also were found to be associated with a 10-point decline in NEI-VFQ scale scores.
Conclusions
Keratoconus is associated with significantly impaired V-QoL that continues to decline over time. For a substantial plurality these declines are significant.
doi:10.1016/j.ajo.2007.11.017
PMCID: PMC2753249  PMID: 18226798
keratoconus; quality of life; NEI Visual Function Questionnaire; NEI-VFQ CLEK Study
7.  Lens fluorescence and accommodative amplitude in pre-presbyopic and presbyopic subjects 
Experimental eye research  2007;84(5):1013-1017.
Accommodative amplitude (AA; the difference, measured in diopters, between the near and far points of vision) declines steadily with age such that, by midlife, most individuals are unable to focus clearly on near objects and, thus, are said to be presbyopic. Conversely, intrinsic lens fluorescence (LF) increases steadily with age. Previous studies have suggested that AA and LF are negatively correlated, independent of age. Were this to be the case, it might suggest that the biochemical modifications underlying increased tissue fluorescence (for example, glycation of lens proteins) contribute to presbyopia. We used quantitative techniques to re-evaluate the relationship between AA and LF in 161 healthy volunteers aged between 25 and 70. Our data confirmed that AA decreases with age, becoming essentially zero by age 55, and LF increases with age. However, in marked contrast to previous reports, statistical analysis failed to detect any correlation between LF and AA independent of age. Thus, the biochemical processes responsible for increased LF observed in the aged lens are unlikely to contribute directly to presbyopia.
doi:10.1016/j.exer.2007.01.012
PMCID: PMC2682368  PMID: 17359974
8.  Clinical phenotypes associated with the Complement Factor H Y402H variant in age-related macular degeneration 
American journal of ophthalmology  2007;144(3):404-408.
Purpose
To determine whether the complement factor H (CFH) Y402H variant is associated with specific age-related macular degeneration (AMD) clinical phenotypes.
Design
Retrospective, case-control study.
Methods
188 Caucasian subjects with AMD and 189 control subjects were genotyped for the T-to-C polymorphism in exon-9 of the CFH gene by restriction-fragment length analysis and DNA sequencing using genomic DNA from mouthwash samples. AMD phenotypes were characterized by clinical examination, fundus photography, and fluorescein angiography.
Results
Heterozygosity for the at-risk genotype (TC) increased the likelihood for AMD 2.1-fold (95% CI 1.3–3.3) while homozygosity for the genotype (CC) increased the likelihood for AMD 6.5-fold (95% CI 3.4–12.5) in our population. The C allele was significantly associated with predominantly classic choroidal neovascularization (OR 2.01, 95% CI 1.34–3.30). Neovascular lesion size was similar among the three genotypes (p=0.67).
Conclusions
The Y402H CFH variant carried a significantly increased risk for developing AMD in our population. Genotype/phenotype correlations regarding choroidal neovascular lesion type were observed
doi:10.1016/j.ajo.2007.05.018
PMCID: PMC2140051  PMID: 17631852

Results 1-9 (9)