OAR 436-035-0260
Visual Loss
(1)
Visual loss due to a work-related illness or injury is rated for central visual acuity, integrity of the peripheral visual fields, and ocular motility. For ocular disturbances that cause visual impairment that is not reflected in visual acuity, visual fields or ocular motility refer to section (5) of this rule. Visual loss is measured with best correction, using the lenses recommended by the worker’s physician. For lacrimal system disturbances refer to OAR 436-035-0440 (Integument and Lacrimal System).(2)
Ratings for loss in central visual acuity are calculated for each eye as follows:(a)
Reports for central visual acuity must be for distance and near acuity.(b)
The ratings for loss of distance acuity are as follows, reported in standard increments of Snellen notation for English and Metric 6: [Ratings not included. See ED. NOTE.](c)
The ratings for loss of near acuity are as follows: reported in standard increments of Snellen 14⁄14 notation, Revised Jaeger Standard, or American Point-type notation: [Ratings not included. See ED. NOTE.](d)
Once the ratings for near and distance acuity are found, add them and divide by two. The value which results is the rating for lost central visual acuity.(e)
If a lens has been removed and a prosthetic lens implanted, an additional 25%, is to be combined (not added) with the percent loss for central visual acuity to determine total central visual acuity, as shown in table (g).(f)
If a lens has been removed and there is no prosthetic lens implanted, an additional 50% is to be combined (not added) with the percent loss for central visual acuity to determine total central visual acuity, as shown in table (g).(g)
The table below may be substituted for combining central visual acuity and the loss of a lens for a total central visual acuity. The table displays the percent loss of central vision for the range of near and distance acuity combined with lens removal for a total central visual acuity. The upper figure is to be used when the lens is present (as found in (d)), the middle figure is to be used when the lens is absent and a prosthetic lens has been implanted (as found in (e)), and the lower figure is to be used when the lens is absent with no implant (as found in (f)). If near acuity is reported in Revised Jaeger Standard or American Point-type, convert these findings to Near Snellen for rating purposes under (2)(c) of this rule when using this table.(3)
Ratings for loss of visual field are based upon the results of field measurements of each eye separately using the Goldmann perimeter with a III/4e stimulus. The results may be scored in either one of the two following methods:(a)
Using the monocular Esterman Grid, count all the printed dots outside or falling on the line marking the extent of the visual field. The number of dots counted is the percentage of visual field loss; or(b)
A perimetric chart may be used which indicates the extent of retained vision for each of the eight standard 45° meridians out to 90°. The directions and normal extent of each meridian are as follows: [Ratings not included. See ED. NOTE.](A)
Record the extent of retained peripheral visual field along each of the eight meridians. Add (do not combine) these eight figures. Find the corresponding percentage for the total retained degrees by use of the table below.(B)
For loss of a quarter or half field, first find half the sum of the normal extent of the two boundary meridians. Then add to this figure the extent of each meridian included within the retained field. This results in a figure which may be applied in the chart below.(C)
Visual field loss due to scotoma in areas other than the central visual field is rated by adding the degrees lost within the scotoma along affected meridians and subtracting that amount from the retained peripheral field. That figure is then applied to the chart below.(4)
Ratings for ocular motility impairment resulting in binocular diplopia are determined as follows:(a)
Determine the single highest value of loss for diplopia noted on each of the standard 45° meridians as listed in the following table.(b)
Add the values obtained for each meridian to obtain the total impairment for loss of ocular motility. A total of 100% or more is rated as 100% of the eye. As an example: Diplopia on looking horizontally off center from 30 degrees in a left direction is valued at 10%. Diplopia in the same eye when looking horizontally off center from 21 to 30 degrees in a right direction is valued at 20%. The impairments for diplopia in both ranges are added, so the impairment rating would be 10% plus 20% resulting in a total loss of ocular motility of 30%.(5)
To the extent that stereopsis (depth perception), glare disturbances or monocular diplopia causes visual impairment are not reflected in visual acuity, visual field or ocular motility, the losses for visual acuity, visual fields or ocular motility will be combined with an additional 5% when in the opinion of the physician the impairment is moderate, 10% if the impairment is severe.(6)
The total rating for monocular loss is found by combining (not adding) the ratings for loss of central vision, loss of visual field, and loss of ocular motility and loss for other conditions specified in section (5) of this rule.(7)
The total rating for binocular loss is figured as follows:(a)
Find the percent of monocular loss for each eye.(b)
Multiply the percent of loss in the better eye by three.(c)
Add to that result the percent of loss in the other eye.(d)
Divide this sum by four. The result is the total percentage of binocular loss.(e)
This method is expressed by the formula(8)
Use the method (monocular or binocular) which results in the greater impairment rating.(9)
Enucleation of an eye is rated at 100% of an eye.
Source:
Rule 436-035-0260 — Visual Loss, https://secure.sos.state.or.us/oard/view.action?ruleNumber=436-035-0260.