Sustained moderate visual loss as a predictive end point for visual loss in non-proliferative diabetic retinopathy.
OBJECTIVE
In PKC-DRS2, the efficacy of the oral PKC-beta inhibitor, ruboxistaurin 32 mg/day, was measured by the primary end point of sustained moderate visual loss (SMVL: a > or = 15 letter decrease from baseline on the ETDRS (Early Treatment Diabetic Retinopathy Study) chart sustained at least for the last 6 months of study participation). We now evaluate whether SMVL is more accurate than moderate visual loss (MVL: a single occurrence of a decrease from baseline of > or = 15 ETDRS letters) for predicting future visual loss.


METHODS
Study eyes with moderately severe to very-severe non-proliferative diabetic retinopathy, best-corrected visual acuity of at least 45 letters on the ETDRS chart (approximately Snellen 20/125), and no prior pan retinal photocoagulation were evaluated in 506 patients (869 eyes) who completed 36 months of treatment.


RESULTS
Sixty-five percentage (26/40) of study eyes with the onset of SMVL within 24 months of enrolment still had SMVL at study completion (36 months). In comparison, only 24% (30/126) with MVL within 24 months had SMVL at study completion. Analyses based on data from 6, 12, and 18 months of treatment were similar.


CONCLUSIONS
SMVL is a more predictable measure of subsequent visual loss than is a single time point measure of MVL.
Girach
A
A
Department of Ophthalmology, Merck Research Laboratories, Hertfordshire, UK. aniz_girach@merck.com
Aiello
L P
LP
Milton
R C
RC
Davis
M D
MD
Danis
R P
RP
Zhi
X
X
Sheetz
M J
MJ
Vignati
L
L
D003930:Diabetic Retinopathy; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D008301:Maleimides / Q000627:therapeutic use*; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology*
D004791:Enzyme Inhibitors; D007211:Indoles; D008301:Maleimides; C099154:ruboxistaurin