Protocol
Project Title: A retrospective analysis of the association between the use of simvastatin and the
development of cataracts.
Cataracts are a major cause of reversible blindness in the United States. Current literature regarding the
association between statin use and the development of cataracts is controversial and inconclusive. The
population in the United States is aging and the demand for cataract prevention will continue to increase.
The purpose of this project is to determine the association between statin use and the development of
cataracts.
We will perform a case-control retrospective chart review patients (approximately n=300) , aged 40 to 79
years, diagnosed with incident cataracts, between January 1, 2008 and October 31, 2012 at Altru Health
Systems, Grand Forks,ND. Institutional Review Boards will be obtained from Altru Health System
and and the University of North Dakota.
Cases will be defined as patients between 40 and 79 years old diagnosed with an incident cataract using the
following ICD-9 codes:
ICD 9 Codes
Nonsensile Cataract NOS
Anterior Subcapsular
Posterior Subcapsular
Cortical Cataract
Nuclear Cataract
Nonsensile Cataract NEC
Senile Cataract NOS
Incipient Cataract
Anterior Subcapsular Senile Cataract
Posterior Subcapsular Senile Cataract
Cortical Senile Cataract
Senile Nuclear Cataract
Mature Cataract
Hypermature Cataract
Senile Cataract NEC
Cataracta Complicata NOS
Cataract in Inflammatory Disease
Cataract with Neovascularization
Cataract with Degenerative Disease
Tetanic Cataract
Myotonic Cataract
Cataract with Syndrome NEC
Toxic Cataract
Cataract with Radiation
After-Cataract NOS
After-Cataract NEC
After-Cataract Obscuring Vision
Cataract NEC
Cataract NOS
366.00
366.01
366.02
366.03
366.04
366.09
366.10
366.12
366.13
366.14
366.15
366.16
366.17
366.18
366.19
366.30
366.32
366.33
366.34
366.42
366.43
366.44
366.45
366.46
366.50
366.52
366.53
366.80
366.90
Congenital Cataract NOS
Capsular Cataract
Cortical/Zonular Cataract
Nuclear Cataract
Congenital Total/Subtotal Cataract
Congenital Cataract/Lens Anomaly NEC
Cataract Extraction Status
743.30
743.31
743.32
743.33
743.34
743.39
v45.61
Excluded from the study will be any patient with the following diagnoses and/or medications in their
medical history after the index date (incident cataract) and/or 3 years prior:: Diabetes Mellitus, Diabetic
Cataract 366.41, Myotonic Dystrophy, Atopic Dermatitis, Neurofibromatosis Type 2, Galactosemia,
Homocystinemia, Wilson’s Disease, Down’s Syndrome, Chronic Anterior Uveitis, Acute Angle Closure
Glaucoma, Steroid Use (Systemic, Topical), High Myopia, Hereditary fundus dystrophies (Retinitis
Pigmentosa, Leber, Gyrate, Atrophy, Erickler), Radiation, UVA/UVB light, Medications (psoralens,
antipsychotics [chlorpromatine], allopurinol, tamoxifen, amiodarone, tricyclic antidepressants, K-sparing
diuretics, thyroid hormone, tetracycline, suflamylonmephentine), trauma, congenital, s/p vitrectomy, s/p
glaucoma treatment. Also excluded will be anyone with the following diagnosis/ICD-9 prior to the index
date: cataract -366. x; corneal opacity and other disorders of cornea-371.x; Glaucoma – 365.x; Disorders of
iris and ciliary body - 364.x; Retinal detachments and defects – 361.x; Inflammation of eyelids – 373.x.
Controls will be randomly selected from patients (approx.. n=300) aged 40-79 years being seen for a
general physical exam (ICD-9: V70). Controls will be matched by gender and age (±2 years), as well as
calendar year of index year (cataract occurrence) of cases.
Data to be recorded will include: Age, gender, race, smoking history, coronary artery disease, metabolic
syndrome, statin use, statin type, lipid-lowering use, lipid-lowering type, steroid use, steroid type, HbA1c,
hypertension, type of cataract, lipid profile, comorbidities.
The software application SPSS 19.0 for Windows will used to analyze demographic and clinical
characteristics of patients. Frequencies and relative percentages will be computed for each
categorical variable. Chi-square tests or Fisher’s exact tests will be performed to determine which
categories were significantly different from one another, and t-test will be used to compare
continuous variables. All p-values will be two-sided, and p-value < 0.05 will be considered
significant. Missing data will be excluded from analysis.
Society would benefit from knowing whether or not the ubiquitous statin medications are associated
with an increased risk of developing cataracts in order to better manage healthcare.
For the purpose of this study, there will be no physical interaction between the principal
investigators and the patients whose charts are being reviewed. Furthermore, no procedures will be
performed nor will direct interaction occur with patients of this study. Data will be stored securely
on password-protected computers and files. The data file will not contain any identifying
information such as patients’ names or medical record numbers. Only those involved in the research
project will be able to access the data. Data will be stored in the Department of Family and
Community Medicine at the UND School of Medicine and Health Sciences for a period of six years
after analysis.