Table 3.

Results of Linear Mixed Models Assessing Factors Associated With Geometric Perfusion Deficits in Superficial and Deep Capillary Plexuses

	GPD-SCP					GPD-DCP
Fixed Effects	Estimate	SE	df	T Value	P Value	Estimate	SE	df	T Value	P Value
(Intercept)	7.059	3.152	189.1	2.239	0.027*	3.511	1.754	184.2	2.001	0.047*
Time (linear)	0.679	0.352	381.5	1.930	0.054	0.193	0.218	421.5	0.888	0.375
Time (quadratic)	−0.171	0.363	377.8	−0.471	0.638	0.054	0.225	416.4	0.239	0.811
DR severity = Referable	4.607	0.822	240.2	5.604	<0.001 *	2.652	0.432	251.8	6.141	<0.001 *
Age	−0.050	0.034	184.2	−1.480	0.141	−0.024	0.019	177.4	−1.248	0.214
Sex	1.095	0.821	184.8	1.333	0.184	0.434	0.458	178.3	0.947	0.345
DM duration	0.134	0.034	211.3	3.934	<0.001 *	0.038	0.019	203.4	2.010	0.046 *
HbA1c	−0.193	0.357	203.8	−0.542	0.588	−0.291	0.198	198.9	−1.473	0.142
Hypertension	2.064	0.920	184.9	2.244	0.026 *	1.706	0.512	178.7	3.331	0.001 *
Time (linear) × referable	0.286	0.432	384.3	0.663	0.508	0.222	0.267	424.1	0.829	0.408
Time (quadratic) × referable	0.508	0.458	379.2	1.108	0.269	−0.253	0.284	418.2	−0.893	0.372

df, degrees of freedom; DM, diabetes mellitus; DR, diabetic retinopathy; GPD-DCP, geometric perfusion deficits in deep capillary plexus; GPD-SCP, geometric perfusion deficits in superficial capillary plexus; SE, standard errors.

Linear mixed models were used. Time, DR severity, age, sex, DM duration, HbA1c, and hypertension were adjusted. To account for intra-patient and intra-eye correlations, both patient and eye (nested within patient) were modeled as random effects. The model included both linear and quadratic terms of time to account for potential nonlinear changes over 1 year.

^*P < 0.05.

The P values in bold represent statistical significance.