Assessment of Hereditary Retinal Degeneration in the English Springer Spaniel Dog and Disease Relationship to an RPGRIP1 Mutation

Table 3

ERG amplitude and implicit time for normal and affected ESS dogs in the masked study. Median, 5th and 95th percentiles are given for ERG a- and b-wave amplitudes (a) in microvolts and in (b) for implicit times in milliseconds, for normal and affected ESS dogs. Scotopic ERGs consisted of scotopic low-intensity responses (S: 0.01 cd·s/m²), which were elicited 4, 8, 12, 16, and 20 minutes after dark adaptation designated: S1, S2, S3, S4, and S5, scotopic standard intensity responses, Ssd: 3 cd·s/m², and scotopic higher intensity responses, Sh: 10 cd·s/m². Photopic ERGs consisted of a photopic single flash response: Psd, and 30 Hz flicker responses: Pfl, using 3 cd·s/m² for both, after at least 10 minutes of light adaptation using 30 cd/m² of background light.

(a)

Response	Wave	Normal			Affected
		Median	5th	95th	Median	5th	95th
S1	b	29.8	16.7	53.1	20.4	15.0	34.0
S2	b	61.6	40.2	101.3	37.7	35.4	45.0
S3	b	98.4	73.9	116.3	52.1	39.4	61.2
S4	b	122.8	78.8	146.4	56.2	50.9	71.2
S5	b	137.3	86.5	185.0	75.0	53.4	85.8
Ssd	a	128.1	102.1	181.9	29.0	16.9	64.9
	b	196.5	138.7	261.6	146.5	72.5	186.0
Sh	a	162.3	137.4	236.8	38.1	23.5	86.9
	b	240.5	171.7	307.7	169.4	77.6	230.8
Psd	a	8.3	3.9	11.5	3.0	2.5	3.6
	b	30.8	13.8	35.0	15.4	6.6	24.9
Pfl	b	34.1	15.4	47.5	15.0	6.9	22.6

(b)

Response	Wave	Normal			Affected
		Median	5th	95th	Median	5th	95th
S1	b	63.5	57.2	87.1	81.0	65.7	87.7
S2	b	75.8	69.2	92.4	84.5	78.5	91.7
S3	b	78.7	75.0	92.3	81.4	76.9	89.8
S4	b	82.3	73.6	95.3	80.3	76.3	96.0
S5	b	80.6	74.8	94.9	86.2	77.3	94.3
Ssd	a	14.3	12.5	15.4	13.5	12.3	15.7
	b	32.7	31.3	59.5	196.5	138.7	261.6
Sh	a	12.6	11.3	13.7	13.3	10.1	15.0
	b	46.9	32.6	52.4	240.5	171.7	307.7
Psd	a	10.6	10.0	12.0	10.0	9.0	12.8
	b	21.6	20.0	23.5	30.8	13.8	35.0
Pfl	b	21.5	20.4	24.8	34.1	15.4	47.5