Contrast Sensitivity Testing in Age-Related Macular Degeneration Using Motion Diamond Stimulus

Figures & data

Table 1 Patient Demographics and Baseline Characteristics

		AMD Group (n=20)	Control Group (n=10)	P-value
Age (years)
Mean (SD)		74.35 (9.03 yrs.)	65.3 yrs. (4.1 yrs.)	0.0056*
Median (IQR)		75.5 (13.5 yrs.)	64.5 yrs. (1.75 yrs.)
Gender, n (%)				0.1444
Male		7 (35%)	1(10%)
Female		13 (65%)	9 (90%)
Race, n (%)				0.007*
White		19 (95%)	4 (40%)
Black/African American		0	3 (30%)
Hispanic		0	1 (10%)
Other		1 (5%)	2 (2%)
BMI				0.0722
Mean (SD)		26.40 (3.52)	29.097 (4.13)
Smoking Status, n (%)				0.1957
Former or current smoker		11 (55%)	3 (30%)
Diabetes (n, %)		4 (20%)	2 (20%)	1.0000
Hypertension (n, %)		11 (55%)	6 (60%)	0.7945
Hyperlipidemia (n, %)		11 (55%)	3 (30%)	0.1957
VFQ-25 mean score (SD)		92.69 (5.59)	87.7 (9.5)	0.0797

Notes: All data are presented as the number of patients (n) out of the cohort for both AMD and control groups. *Indicates a p-value <0.05 in comparing the AMD group to controls.

Abbreviations: IQR, interquartile range; BMI, body-mass index.

Table 2 Ocular Comparison of eAMD and Dry AMD Eyes Between Initial Presentation and MDS Study Visit

	eAMD Eyes (n = 20)			Dry AMD Eyes (n = 20)			Control eyes (n = 20)
Months since 1st visit
Mean (SD)	40 mo. (36)			40 mo. (36)			N/a
	First visit	MDS date	P-value	First visit	MDS date	P-value	MDS date
Mean logMAR BCVA (SD)	0.258(0.22)	0.115(0.11)	0.013*	0.114(0.15)	0.063(0.097)	0.210	0.028 (0.060)
Imaging Data
CFT (µm), mean (SD)	347 (85)	282 (34)	0.003*	291 (41)	291 (37)	1.000	N/a
Intraretinal fluid (n, %)	1 (5%)	0		0	0		N/a
Subretinal fluid (n, %)	19 (95%)	6 (30%)		0	0		N/a
PED (n, %)	17 (85%)	14 (70%)		5 (25%)	5 (255)		N/a
Drusen (n, %)	20 (100%)	20 (100%)		20 (100%)	20 (100%)		N/a
Atrophy (n, %)	1 (5%)	1 (5%)		0	1 (5%)		N/a
Pigment (n, %)	0	4 (20%)		1 (5%)	2 (10%)		N/a
SHRM (n, %)	10 (50%)	0		0	0		N/a
Cataract (n, %)**			0.162			0.526
Clear lens	9 (47.4)	13 (65)		8 (42.1)	11 (55)		11 (55)
Trace nuclear sclerosis	2 (10.5)	4 (20)		3 (15.8)	4 (20)		5 (25)
1–2+	8 (42.1)	3 (15)		8 (42.1)	5 (25)		4 (20)
Pseudophakic (n, %)**	7 (36.8)	13 (65)	0.079	6 (31.5)	11 (55)	0.140	1 (5)
IOP (mmHg), mean (SD)	14.95 (2.0)	15.9 (2.9)	0.235	15.1 (2.5)	16.55 (2.7)	0.086	16.1 (3.09)

Notes: Data are presented as the number of eyes (n) out of the cohort of 20 for each group, followed by a percent unless otherwise indicated. The first visit indicates the time of treatment (first anti-VEGF injection) of the eAMD eye only; the contralateral eye was imaged at this time but received no treatment. *Indicates a p-value of <0.05 when comparing the mean difference between the first injection date and MDS date for the marked parameters; **cataract status data was missing from the EHR for one study patient during his or her initial visit.

Abbreviations: BCVA, best corrected visual acuity; CFT, central foveal thickness; PED, pigment epithelial detachment; SHRM, subretinal hyperreflective material; IOP, intraocular pressure.

Table 3 ANOVA Analysis of MDS & Pelli-Robson Outputs Comparing eAMD, Dry AMD, and Controls

		df	SS	MS	F	p
α-value at edge-width 3	Between groups	2	0.0013	0.0006	0.23787	0.78908
	Within groups	57	0.1556	0.0027
α-value at edge-width 6	Between groups	2	0.0048	0.0024	1.00966	0.370765
	Within groups	57	0.135	0.0024
β-value at edge-width 3	Between groups	2	0.0163	0.0081	2.1442	0.126518
	Within groups	57	0.2165	0.0038
β-value at edge-width 6	Between groups	2	0.0319	0.016	3.73171	0.02999*
	Within groups	57	0.2439	0.0043
Pelli-Robson threshold	Between groups	2	0.2048	0.1024	6.8702	0.00212*
	Within groups	57	0.8494	0.0149

Notes: One-way ANOVA analysis of MDS and Pelli-Robson outputs comparing the 3 eye groups: eAMD, dry AMD, and controls. *Represents a p-value <0.05.

Figure 1 Comparison of average contrast sensitivity thresholds (y-axis) as a function of contrast modulation ratio (x-axis) for all three groups of eyes: exudative age-related macular degeneration (eAMD), dry AMD, and controls. Threshold values are plotted in a logarithmic fashion and inversely on the y-axis. ie, performance decreases at increased contrast modulation ratios. The dots represent four contrast modulation ratios. The best-fit lines represented are exponentially fitted regressions using Excel’s GROWTH function.

Table 4 Contrast Sensitivity Parameters for MDS and Pelli-Robson for eAMD, Dry AMD, and Control Cohorts

	eAMD	Dry AMD	Control
MDS edge-width 3
α (mean, sd)	0.0337 (0.0578)	0.0247 (0.0298)	0.02312 (0.063)
β (mean, sd)	0.0687 (0.0434)	0.0849 (0.0601)	0.1088 (0.076)
MDS edge-width 6
α (mean, sd)	0.0163 (0.0140)	0.0264 (0.0809)	0.00459 (0.066)
β (mean, sd)	0.0722 (0.0645)	0.0937 (0.0660)	0.12818 (0.066)
Pelli-Robson, log CS
Mean (SD)	1.4325 (0.1139)	1.515 (0.1077)	1.575 (0.142)

Notes: Quantitative data from the MDS and Pelli-Robson tests. α represents the threshold level, and β represents the slope of the threshold.

Table 5 Tukey HSD Post-Hoc Analysis Among eAMD, Dry AMD, and Controls

	(I) Cohort	(J) Cohort	(I-J) Q-Statistic	P-value
α-value at edge-width 3	eAMD	Dry AMD	0.7673	0.8345
	eAMD	Control	0.9052	0.7791
	Dry AMD	Control	0.1380	0.8999
α-value at edge-width 6	eAMD	Dry AMD	0.9293	0.7694
	eAMD	Control	1.0784	0.7096
	Dry AMD	Control	2.0078	0.3382
β-value at edge-width 3	eAMD	Dry AMD	1.1713	0.6723
	eAMD	Control	2.9102	0.10799
	Dry AMD	Control	1.7389	0.4427
β-value at edge-width 6	eAMD	Dry AMD	1.4699	0.55248
	eAMD	Control	3.8293	0.0238*
	Dry AMD	Control	2.3593	0.22640
Pelli-Robson threshold	eAMD	Dry AMD	3.0224	0.0913
	eAMD	Control	5.2206	0.00143*
	Dry AMD	Control	2.1981	0.2741

Notes: Tukey HSD Post-hoc analysis comparing each of the 3 eye groups: eAMD, dry AMD, and controls, separately. *Represents a p-value <0.05.