Table 1. Characteristics of study population (n = 183); Gender, mean, standard deviations (SD) and range for refractive errors in diopters (dpt) and nerve-head to fovea distance (NFD) measured from the rim and the center of the nerve-head in 183 right eyes (OD) and left eyes (OS) in mm.

Measurement	N	Gender m:f	Mean	SD	Range	≤−5dpt	>−5<0dpt	0dpt	>0<5dpt	≥5dpt
Refraction OD	183	90∶93	−0.12	1.6	−7.50–6.50	3	45	90	44	1
Refraction OS	183	90∶93	−0.11	1.6	−7.50–6.25	4	43	91	44	1
NFD Center of the nerve-head	N	Gender m:f	Mean	SD	Range
OD	183	90∶93	4.73	0.28	4.04–5.39
OS	183	90∶93	4.72	0.27	4.00–5.33
NFD Rim of the nerve-head	N	Gender m:f	Mean	SD	Range
OD	183	90∶93	3.87	0.27	3.17–4.48
OS	183	90∶93	3.86	0.27	3.08–4.48