IRIS® Registry

IRIS® Registry at a Glance

Iris Registry
IRIS Registry
Data Type Health registry compiled from participating ophthalmology practices’ electronic medical records systems
Sample Convenience sample consisting of patients visiting IRIS-participating ophthalmology practices
VEHSS Topics Included Service Utilization
Medical Diagnoses
Vision Exam Measures
Years Analyzed 2016
Approximate Size 17 million patients in 2016, approximately half of all ophthalmology practices
sample data map

IRIS® Registry

Compiled by the American Academy of Ophthalmology (AAO), IRIS® Registry (Intelligent Research In Sight) is the nation’s first comprehensive eye disease clinical registry. The IRIS® Registry enables ophthalmologists to use clinical data to improve care delivery and patient outcomes and help practices meet requirements of the federal Physician Quality Reporting System (PQRS). The IRIS® Registry uses methods compliant with the Health Insurance Portability and Accountability Act of 1996 (HIPAA) to collect data from patient records directly from practices’ individual electronic medical record (EMR) systems. These EMR systems periodically report health record data based on the IRIS® Registry data fields on a nightly or weekly basis. The system tracks diagnosed disorders based on ICD-9/ICD-10 codes and also includes procedures and visual acuity measures and other clinical data documented in the medical record. In 2016 there were 2,888 practices with a total of 11,374 ophthalmologists, optometrists, and other providers contracted with the IRIS® Registry.

IRIS® Registry coverage began in 2013, but sample size has increased over time. As of January 1, 2018, IRIS® Registry contained more than 44.23 million patients and 182 million encounters. In 2016, the IRIS® Registry collected data from a convenience sample of more than 50% of ophthalmologists nationally. AAO estimates that as of 2017, more than 84% of ophthalmologists in the United States were participating in the IRIS® Registry.

The main advantages of IRIS® Registry are its wide coverage and availability of diagnostic test results such as acuity values. However, IRIS® Registry is a convenience sample of ophthalmology practices, and cannot by itself produce national prevalence estimates.  IRIS® Registry is also a new data system and has not been externally evaluated for data completeness, reliability, or validity. The IRIS® Registry team provided summary-level frequencies and prevalence values to the VEHSS system and has not granted access to person-level data. This limits the ability of the VEHSS team to assess the quality of IRIS® Registry data.

Analysis Overview

For the VEHSS project, AAO analyzed IRIS® Registry data to estimate the prevalence rate of specific diagnoses, the rate of clinical procedures, and the prevalence rate of visual acuity values when reported, as observed over a single year of observations in the 2016 IRIS® Registry data. AAO analyzed the 2016 IRIS® Registry and supplied de-identified summary reports of frequencies and rates, summarized by state and by age group, race/ethnicity, sex, and insurer.

NORC further analyzed the summary data files, mapping outcomes to VEHSS-defined categories, calculating confidence intervals, and cleaning data. Results were further suppressed if the numerator was <3 and the denominator was less than 30, or the numerator was ≥3 and the denominator was ≤30.

A detailed description of the analytical steps is described in the report “VEHSS Claims & Registry Data Analysis Plan Cdc-pdf[PDF – 579 KB]External.” Full analysis documentation is included in the “VEHSS IRIS® Registry Data Report Cdc-pdf[PDF – 1.5 MB]External.”

Data Indicators and Case Definitions

IRIS® estimates include data indicators representing three topics of the overall VEHSS project:

  • Vision Exam Measures–best-corrected acuity measures.
  • Medical Diagnoses–medical conditions defined by ICD-10 code and classified into 17 main categories and 79 subgroups, as described in the report “VEHSS ICD9 and ICD10 Diagnosis Categories Report.”
  • Service Utilization–medical procedures and encounters as defined by CPT code and service date were reported by AAO, but are not included in our initial analyses nor this report because of the lack of a suitable denominator.

Vision Exam Measures

Vision exam measures currently include best-corrected visual acuity. In our initial analyses, acuity is defined categorically and patients are divided into eight subgroups using acuity values contained in the IRIS® data (Table 1).

Table 1. Visual Function Topic Variables

Best-corrected Visual acuity

Visual Function Topic Variables
Category Subgroup
Normal vision
Any vision loss (≤20/32 in better eye)
US blind (≤20/200 in better eye)
WHO blind (≤20/400 in better eye)
Monocular vision loss (≤20/70 in one eye with normal vision in the other)
Missing acuity (patient has no valid acuity measure)

Acuity measures are based on each patient’s last visual acuity observation in 2016, using their best-corrected acuity in the better-seeing eye. The prevalence rate of patients who exhibit moderate impairment in one eye with normal vision in the other are reported as having monocular vision loss.
Approximately 16% of IRIS® Registry’s current patients have no acuity values. It is unclear whether these missing values result from lack of measurement by the practice, data quality issues, or both. We anticipate that completeness of the patient acuity measures will increase over time. Additionally, IRIS® Registry does not currently have a high proportion of presenting visual acuity, uncorrected acuity, or other visual measures. AAO suggests that the recording and reporting to IRIS® Registry of such vision values was still subject to uncertainty, but that coverage was expected to improve over time. We will continue to investigate the option of including such measures in future analyses.

Medical Diagnoses

Medical Diagnoses are reported based onusing the VEHSS-defined medical diagnosis categorization structure. As reported in the “VEHSS Diagnosis Code Categories and Crosswalk,” we identified all eye and vision related ICD10 diagnosis codes, and organized them into a 2-level categorization structure, including 17 Categories and 79 Subgroups, as listed in Table 2.

Medical Diagnosis Categories
Category Subgroup
Retinal Detachment and Defects
Diabetic Eye Diseases
Early/mild diabetic retinopathy
Moderate /severe non-proliferative diabetic retinopathy
Proliferative diabetic retinopathy
Diabetic macular edema (dme, csme)
Other/unspecified diabetes related eye conditions
Age-Related Macular Degeneration (AMD)
AMD, unspecified
Early AMD
Dry-form AMD
GA, modifier for Dry-form
Wet-form AMD
CNV, modifier for Wet-form
Other Retinal Disorders
Retina vascular disease, occlusive (arterial, venous)
Central retinal vein occlusion
Branch retinal vein occlusion
Central retinal arterial occlusion
Branch retinal artery occlusion
Retina vascular disease, non-occlusive
Macular edema (if not diabetic)
Hereditary chorioretinal dystrophy
Myopic degeneration
Other/unspecified retinal disorders
Open-angle glaucoma
Primary open-angle glaucoma
Low-tension glaucoma
 Glaucoma suspect
 Primary angle-closure glaucoma
 Narrow-angle glaucoma
 Congenital glaucoma
 Neovascular glaucoma
 Other/unspecified glaucoma
 Senile cataract
 Non-congenital cataract
 Congenital cataract
Posterior capsular opacity
Aphakia and other disorders of lens
Disorders of Refraction and Accommodation
Other disorder of refraction and accommodation
Blindness and Low Vision
Unqualified visual loss, both eyes
Unqualified vision loss in one eye, or unspecified visual loss
Vision impairment one eye
Moderate or severe vision impairment better eye; profound vision impairment of lesser eye
Moderate or severe vision impairment both eyes
Profound vision impairment, bilateral, or legal blindness
Strabismus and Amblyopia
Injury, Burns and Surgical Complications of the Eye
Surgical complication
Disorders of Optic Nerve and Visual Pathways
Optic nerve disorders
Visual pathway disorders
Other Visual Disturbances
Visual field defect
Color blindness
Night blindness
Other/unspecified visual disturbances
Infectious and Inflammatory Diseases
Infectious diseases
Eyelid infection and inflammation
Other inflammatory conditions
Lacrimal system and orbit inflammation
Orbital and External Disease
Congenital anomalies
Other/unspecified orbital or external disease
Lacrimal diseases
Eyelid disorders
Dry eye syndrome
Disorders of the globe
Cancer and Neoplasms of the Eye
Malignant neoplasm of the eye
Benign neoplasm of the eye
Cornea Disorders
Endothelial dystrophy (inc Fuchs)
Other corneal disorders
Other Eye Disorders

Denominators used to Calculate Prevalence Rates

The sample (denominator) of patients consists of the total number of current patients with an encounter with an IRIS-member provider during the year of observation.

Potential LImitations

This analysis is subject to a number of potential limitations. AAO reported summary outcome statistics using VEHSS-defined data indicators and case definitions for visual function, eye examinations, and medical diagnoses. Some of the possible limitations include the following:

  • VEHSS does not have access to patient-level data nor details on the process of mapping EMR data to IRIS® Registry. The quality of underlying EMR data, and the process of mapping EMR records to IRIS® Registry could not be validated by the VEHSS team.
  • IRIS® Registry data represents a convenience sample of current ophthalmology patients, and should not be considered representative of the general population. IRIS® Registry rates contained in this report are calculated on the basis of per 100 current ophthalmology patients, and are not representative of the overall population.
  • IRIS® Registry does not include all ophthalmology practices, and may be more likely to include practices who primarily serve Medicare patients because automated PQRS reporting is a motivating factor for providers to register with IRIS® Registry. The IRIS® Registry is a convenience sample and its representativeness of the population of all ophthalmology patients is still being studied.
  • IRIS® Registry only includes patients of ophthalmology practices. However, about 20% to 30% of providers in IRIS® Registry are optometrists who work for mixed-provider practices participating in IRIS® Registry.
  • IRIS® Registry includes services provided regardless of payer, but cannot identify the payer of specific procedures.
  • Eye-examination rates are not reported due to the lack of a suitable denominator.