What to know
The Vision and Eye Health Surveillance System (VEHSS) uses diagnosis codes to identify diagnosed vision disorders in administrative claims and IRIS Registry electronic medical record data.
Overview
Diagnosed vision disorders include the following categories:
- Diagnosed refractive error
- Diagnosed vision loss and blindness
- Diagnosed visual disturbances
Diagnosed vision disorders are identified based on the presence of International Classification of Diseases (ICD)-9 and ICD-10 codes in patient claims or electronic health record (EHR) systems. Patients with one or more diagnosis codes associated with a VEHSS subgroup are assigned to that subgroup. Diagnosis codes may be primary or secondary and may be present for one eye, both eyes, or an unspecified eye. Only one instance of a diagnosis code is required for assignment to a subgroup. Subgroups are not mutually exclusive; a patient may be included in one or more subgroups. A patient assigned to any subgroup is counted only once for the category total.
Diagnosis codes in claims data are intended for billing purposes. Codes may not be present in cases where diagnosis codes are not required to justify payment. Diagnosed prevalence will not identify any undiagnosed conditions, will not include patients not covered by the insurer, and will not identify prevalence among patients without a visit in the calendar year of data.
The data sources available for all vision disorder categories include Medicare (default), IRIS Registry, Medicaid, Managed Vision Care, and MarketScan commercial insurance claims. Additional data source information is linked further below.
Diagnosed refractive error
VEHSS reports the annual prevalence of diagnosed disorders of refraction and accommodation, including the following 5 subgroups. Subgroups are not mutually exclusive.
Subgroup
Indicated conditions
All refraction and accommodation disorders
Category total – includes any clinical stage below.
Myopia
Myopia includes diagnosis codes indicating myopia.
Hypermetropia
Hypermetropia includes diagnosis codes indicating hypermetropia.
Astigmatism
Astigmatism includes diagnosis codes indicating regular, irregular, or unspecified astigmatism.
Presbyopia
Presbyopia includes diagnosis codes indicating presbyopia.
Other disorder of refraction and accommodation
Other disorder of refraction and accommodation includes diagnosis codes indicating anisometropia and aniseikonia, disorders of accommodation, internal ophthalmoplegia, paresis of accommodation, or spasm of accommodation.
Explore data in the VEHSS application
Diagnosed vision loss and blindness
VEHSS reports the annual prevalence of diagnosed blindness and low vision including the following 6 subgroups. Subgroups are not mutually exclusive.
Subgroup
Indicated conditions
All blindness and low vision
Category total – includes any clinical stage below.
Blindness, one eye, low vision other eye
Blindness, one eye, low vision other eye, includes diagnosis codes indicating blindness in one eye, low vision in the other eye.
Blindness, both eyes, including legal blindness
Blindness, both eyes, including legal blindness, includes diagnosis codes indicating blindness in both eyes, legal blindness, or cortical blindness.
Low vision or blindness, one eye
Low vision or blindness in one eye includes diagnosis codes indicating low vision or blindness in one eye, and no indication of blindness or low vision in the other eye.
Low vision, both eyes
Low vision, both eyes, includes diagnosis codes indicating low vision in both eyes.
Unqualified impairment, both eyes
Unqualified vision loss, both eyes, includes a diagnosis code indicating unqualified visual loss in both eyes.
Unqualified vision loss in one eye or unspecified visual loss
Unqualified vision loss in one eye or unspecified vision loss includes diagnosis codes indicating unqualified vision loss in one eye, unspecified visual loss, or problems with sight.
Explore data in the VEHSS application
Diagnosed visual disturbances
VEHSS reports the annual prevalence of diagnosed other visual disturbances including the following 4 subgroups. Subgroups are not mutually exclusive.
Subgroups
Indicated conditions
Any diagnosed visual disturbances
Category total – includes any clinical stage below.
Visual field defect
Visual field defect includes diagnosis codes indicating defects of the visual field, including scotoma, sector or arcuate defects, localized visual field defects, homonymous bilateral field defects, or contraction of the visual field.
Color blindness
Color blindness includes diagnosis codes indicating color vision deficiencies.
Night blindness
Night blindness includes diagnosis codes indicating night blindness, abnormal dark adaptation, and glare sensitivity.
Other/unspecified visual disturbances
Other/unspecified visual disturbances include other disturbances or defects of sight including subjective visual disturbances, diplopia, other and unspecified disorders of binocular vision, and vision sensitivity deficiencies.
Explore data in the VEHSS application
Limitations
Users should exercise caution when interpreting diagnosed vision disorders because these codes represent only service utilization or medical encounters that were coded with these diagnostic codes. A validation study conducted by VEHSS among patients at a university ophthalmology clinic found that diagnosis codes for diagnosed blindness and low vision have very low sensitivity (0.02) and very high specificity (0.83) for detecting best corrected visual acuity loss of 20/40 or worse in the better-seeing eye. Diagnosed legal US blindness had a sensitivity of 0.04 and specificity of 1.0 for detecting best corrected visual acuity loss of 20/200 or worse. Diagnosed prevalence of blindness or low vision may be expected to substantially underrepresent the actual prevalence of blindness or low vision.