Four Risk Factors for Severe Visual Loss in Diabetic The Third The Diabetic
Report
Retinopathy Study
From the Diabetic Research
Retinopathy
Retinopathy Study
Group
\s=b\The
Diabetic Retinopathy Study Research Group has so far identified four retinopathy factors that increase the two-year risk of developing severe visual loss. The risk grows as the number of risk factors increases. Eyes with three or more risk factors (eyes with "high-risk characteristics") are at a much higher risk than eyes with two or fewer factors. The DRS protocol was changed in 1976 to require consideration of treatment for these "high-risk" eyes.
(DRS)
(Arch Ophthalmol 97:654-655, 1979) mong the
retinopathy factors that have been investigated in the Diabetic Retinopathy Study (DRS) so far, four have been found to increase the two-year risk of developing severe visual loss, which is defined in the DRS as visual acuity less than 5/200 at two
or more
consecutively completed
visits scheduled at fourmonth intervals. The four factors are (1) presence of vitreous or preretinal hemorrhage, (2) presence of new vessels, (3) location of new vessels on or near the optic disc, and (4) severity of new vessels.
follow-up
Accepted
for publication Nov 21, 1978. list of investigators in the Diabetic Retinopathy Study Research Group, see references 1 and 2. Reprint requests to DRS Coordinating Center, Division of Clinical Investigation, Department of Social and Preventive Medicine, University of Maryland School of Medicine, 600 Wyndhurst Ave, Baltimore, MD 21210. For
a
No
Risk factors according to ten retinopathy groups. NVD indicates 1 disc diameter of optic disc.
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new
vessels
on or
within
new vessels, these doubtedly at higher
Two-Year Incidence of Severe Visual Loss by No. of Risk Factors
2-yr Incidence of Severe Visual Loss No. of in Untreated Eyes RiskFactors Rate, % Group SE, % 0 1 2 3 4
a
b, c d, e, g f, h, i i
3.6 6.7 8.5 26.7 36.9
1.3 2.1
1.7 2.5 4.2
The first two DRS reports'- classify results according to these risk factors into ten groups that range from group a ("eyes with no new vessels and without hemorrhage") to group j ("eyes with moderate or severe NVD with or without NVE with hemor¬ rhage"). The abbreviation NVD desig¬ nates new vessels on or within 1 disc diameter of the optic disc, and NVE denotes the new vessels "elsewhere," ie, more than 1 disc diameter from optic disc. In the Figure, the ten groups are characterized as to the presence or absence of each of the risk factors. Group a (Figure) has none of the factors, group j has all four factors, and the intermediate groups have either one, two, or three factors. Although groups a and b are without
eyes
are
un¬
risk of severe visual loss than eyes with ordinary background retinopathy because, for DRS eligibility, either severe nonproliferative retinopathy had to be pres¬ ent in both of the patient's eyes, or the fellow eye had to have new vessels. In counting risk factors, NVD are counted twice: once for new vessels and once for closeness to the disc. When NVD are present (groups g, h, i, and,;'), then the question about severi¬ ty (Figure) applies to NVD only (and not to NVE). This is because a
subgroup analysis (not presented)
indicates that in eyes with NVD, the presence of moderate or severe NVE does not further increase the risk of severe visual loss. In the Table, the two-year incidence rates of severe visual loss in untreated eyes from the Figure are grouped according to the number of risk factors. Three items are noteworthy: First, the risk of visual loss grows progressively as more risk factors are added. Second, the risk remains mod¬ erately low with two or fewer risk factors, but then jumps from 8.5% to 26.7% as the number of risk factors increases from two to three. Third, eyes that were previously described as having "high-risk characteristics"2 now can be seen to be those with three or more risk factors; it is for these
eyes, if
they
were as
that the DRS
yet untreated,
protocol was changed in 1976 to require consideration of treat¬ ment.' Ophthalmologists may find
useful the rule of thumb which says that eyes with three or more risk factors are at "high risk" of severe visual loss. The foregoing method of combining risk factors is one convenient way to define eyes (with diabetic retinopa¬ thy) that are at a high risk of severe visual loss. The four risk factors are not necessarily the most important ones, nor are they necessarily the only important ones. Eyes in the DRS are being examined in a multivariate analysis to determine the potential importance of a large number of risk factors in diabetic retinopathy, includ¬ ing the four described in this commu¬ nication. The Diabetic Retinopathy Study is supported contracts with the National Eye Institute, National Institutes of Health, and US Depart¬ ment of Health, Education, and Welfare.
by
References
Retinopathy Study Research Group: Preliminary report on effects of photocoagulation therapy. Am J Ophthalmol 81:383-396, 1. The Diabetic
1976. 2. The Diabetic
Retinopathy Study Research Group: Photocoagulation treatment of proliferative diabetic retinopathy: The second report of Diabetic Retinopathy Study findings. Ophthalmology 85:82-105, 1978.
Downloaded From: http://archopht.jamanetwork.com/ by a Michigan State University User on 06/14/2015
Report
Retinopathy Study
From the Diabetic Research
Retinopathy
Retinopathy Study
Group
\s=b\The
Diabetic Retinopathy Study Research Group has so far identified four retinopathy factors that increase the two-year risk of developing severe visual loss. The risk grows as the number of risk factors increases. Eyes with three or more risk factors (eyes with "high-risk characteristics") are at a much higher risk than eyes with two or fewer factors. The DRS protocol was changed in 1976 to require consideration of treatment for these "high-risk" eyes.
(DRS)
(Arch Ophthalmol 97:654-655, 1979) mong the
retinopathy factors that have been investigated in the Diabetic Retinopathy Study (DRS) so far, four have been found to increase the two-year risk of developing severe visual loss, which is defined in the DRS as visual acuity less than 5/200 at two
or more
consecutively completed
visits scheduled at fourmonth intervals. The four factors are (1) presence of vitreous or preretinal hemorrhage, (2) presence of new vessels, (3) location of new vessels on or near the optic disc, and (4) severity of new vessels.
follow-up
Accepted
for publication Nov 21, 1978. list of investigators in the Diabetic Retinopathy Study Research Group, see references 1 and 2. Reprint requests to DRS Coordinating Center, Division of Clinical Investigation, Department of Social and Preventive Medicine, University of Maryland School of Medicine, 600 Wyndhurst Ave, Baltimore, MD 21210. For
a
No
Risk factors according to ten retinopathy groups. NVD indicates 1 disc diameter of optic disc.
Downloaded From: http://archopht.jamanetwork.com/ by a Michigan State University User on 06/14/2015
new
vessels
on or
within
new vessels, these doubtedly at higher
Two-Year Incidence of Severe Visual Loss by No. of Risk Factors
2-yr Incidence of Severe Visual Loss No. of in Untreated Eyes RiskFactors Rate, % Group SE, % 0 1 2 3 4
a
b, c d, e, g f, h, i i
3.6 6.7 8.5 26.7 36.9
1.3 2.1
1.7 2.5 4.2
The first two DRS reports'- classify results according to these risk factors into ten groups that range from group a ("eyes with no new vessels and without hemorrhage") to group j ("eyes with moderate or severe NVD with or without NVE with hemor¬ rhage"). The abbreviation NVD desig¬ nates new vessels on or within 1 disc diameter of the optic disc, and NVE denotes the new vessels "elsewhere," ie, more than 1 disc diameter from optic disc. In the Figure, the ten groups are characterized as to the presence or absence of each of the risk factors. Group a (Figure) has none of the factors, group j has all four factors, and the intermediate groups have either one, two, or three factors. Although groups a and b are without
eyes
are
un¬
risk of severe visual loss than eyes with ordinary background retinopathy because, for DRS eligibility, either severe nonproliferative retinopathy had to be pres¬ ent in both of the patient's eyes, or the fellow eye had to have new vessels. In counting risk factors, NVD are counted twice: once for new vessels and once for closeness to the disc. When NVD are present (groups g, h, i, and,;'), then the question about severi¬ ty (Figure) applies to NVD only (and not to NVE). This is because a
subgroup analysis (not presented)
indicates that in eyes with NVD, the presence of moderate or severe NVE does not further increase the risk of severe visual loss. In the Table, the two-year incidence rates of severe visual loss in untreated eyes from the Figure are grouped according to the number of risk factors. Three items are noteworthy: First, the risk of visual loss grows progressively as more risk factors are added. Second, the risk remains mod¬ erately low with two or fewer risk factors, but then jumps from 8.5% to 26.7% as the number of risk factors increases from two to three. Third, eyes that were previously described as having "high-risk characteristics"2 now can be seen to be those with three or more risk factors; it is for these
eyes, if
they
were as
that the DRS
yet untreated,
protocol was changed in 1976 to require consideration of treat¬ ment.' Ophthalmologists may find
useful the rule of thumb which says that eyes with three or more risk factors are at "high risk" of severe visual loss. The foregoing method of combining risk factors is one convenient way to define eyes (with diabetic retinopa¬ thy) that are at a high risk of severe visual loss. The four risk factors are not necessarily the most important ones, nor are they necessarily the only important ones. Eyes in the DRS are being examined in a multivariate analysis to determine the potential importance of a large number of risk factors in diabetic retinopathy, includ¬ ing the four described in this commu¬ nication. The Diabetic Retinopathy Study is supported contracts with the National Eye Institute, National Institutes of Health, and US Depart¬ ment of Health, Education, and Welfare.
by
References
Retinopathy Study Research Group: Preliminary report on effects of photocoagulation therapy. Am J Ophthalmol 81:383-396, 1. The Diabetic
1976. 2. The Diabetic
Retinopathy Study Research Group: Photocoagulation treatment of proliferative diabetic retinopathy: The second report of Diabetic Retinopathy Study findings. Ophthalmology 85:82-105, 1978.
Downloaded From: http://archopht.jamanetwork.com/ by a Michigan State University User on 06/14/2015
