Normal Ocular Protrusion Values in South Indian Population and Effect of Age, Gender and Refractive Status on Ocular Protrusion

Figures & data

Table 1 Descriptive Data of Absolute and Relative Ocular Protrusion and Refractive Error Values in South Indian Population

Age	Mean Age ± Std. Dev (Years)	No. of Subjects	Mean Absolute Ocular Protrusion ± Std. Dev	95% CI	Range of Absolute Ocular Protrusion (mm)	Mean ± Std. Dev Refractive Error (DSE)	Mean Relative Ocular Protrusion
1–10	8.31 ± 1.27	93	12.73 ± 1.21 (OD)	12.48–12.98	11–17	−0.31 ± 0.93 (OD)	0.58 ± 0.50
			12.30 ± 1.10 (OS)	12.07–12.53	10–16	−0.39 ± 1.05 (OS)
11–20	13.69 ± 2.80	55	14.8 ± 1.25 (OD)	14.46–15.14	12–19	−0.42 ± 1.29 (OD)	0.51 ± 0.50
			14.40 ± 1.33 (OS)	14.04–14.76	12–18	−0.37 ± 1.05 (OS)
21–30	25.35 ± 2.80	71	15.79 ± 1.31 (OD)	15.48–16.10	12–18	−1.13 ± 1.50 (OD)	0.54 ± 0.51
			15.54 ± 1.41 (OS)	15.20–15.87	12–18	−1.24 ± 1.27 (OS)
31–40	35.35 ± 2.73	49	15.77 ± 1.36 (OD)	15.39–16.17	14−19	−0.57 ± 1.46 (OD)	0.51 ± 0.51
			15.43 ± 1.35 (OS)	15.04–15.82	13–19	−0.64 ± 1.35 (OS)
41–50	44.74 ± 2.63	31	15.87 ± 1.28 (OD)	15.40–16.34	13–18	0.23 ± 1.60 (OD)	0.48 ± 0.51
			15.58 ± 1.41 (OS)	15.06–16.10	13–18	0.02 ± 1.58 (OS)
51–60	55.39 ± 2.84	46	15.00 ± 1.03 (OD)	14.69–15.31	13–17	0.10 ± 1.80 (OD)	0.50 ± 0.51
			14.59 ± 1.02 (OS)	14.28–14.89	13–16	0.29 ± 1.63 (OS)
61–70	64.76 ± 2.60	42	14.36 ± 0.88 (OD)	14.08–14.63	13–16	0.21 ± 1.71 (OD)	0.52 ± 0.51
			14.07 ± 0.95 (OS)	13.78–14.37	12–16	0.23 ± 1.45 (OS)
Total	30.27 ± 19.76	387	14.67 ± 1.70 (OD)	14.50–14.84	11–19	−0.41 ± 1.48 (OD)	0.53 ± 0.50
			14.32 ± 1.75 (OS)	14.14–14.49	10–19	−0.34 ± 1.35 (OS)

Note: Bold numbers represent the mean data of total sample.

Abbreviations: Std. Dev, standard deviation; CI, confidence interval; DSE, diopters spherical equivalent.

Figure 1 Box plots of mean right absolute ocular protrusion in different age groups. The thick solid line in the box shows the median of the ocular protrusion. The error bars represent 5th percentile and 95th percentile values.

Figure 2 Quadratic function (thick curve, middle) is showing the absolute right eye (OD) absolute ocular protrusion values as a function of age. The equation shown in the box is the quadratic equations of the fit. Thin curves (above and below the thick curve) show 95% confidence intervals of individuals at a given age.

Table 2 Descriptive Data of Right Eye Mean Refractive Error and Right Eye Mean Absolute Ocular Protrusion Values Among Myopic, Emmetropic and Hyperopic Subjects in South Indian Population

Type of Ref. Error	Number of Eyes (OD)	OD_Ref. Error ± Std. Dev (DSE)	Mean Absolute Ocular Protrusion ± Std. Dev (mm)	p-value
Myopia	155	− 1.83 ± 0.92	14.83 ± 1.67	0.221
Emmetropia	153	− 0.08 ± 0.33	14.49 ± 1.78
Hyperopia	79	1.61 ± 0.65	14.68 ± 1.54

Abbreviations: Ref. error, refractive error; Std. Dev, standard deviation; DSE, diopters spherical equivalent.

Figure 3 Scatter plots showing the correlation between (A) magnitude of absolute myopia and absolute ocular protrusion; (B) magnitude of hyperopia and absolute ocular protrusion. Note that DSE on X-axis of both plots stands for diopter spherical equivalent.