Central visual fields were investigated by automated static perimetry
in a group of healthy myopic individuals with peripapillary crescents
and tigroid fundus changes only. Results were compared with 'emmetropi
c' and 'myopic subjects without crescents' control groups. The sample
comprised 122 young, healthy volunteers between the ages of 18.5 and 3
5.4 years, free from any ocular or systemic disease, with refractive e
rrors ranging from +4.00 D to - 25.75 D. Central visual fields were ex
amined using programs 30-2 and 30-1 of the Humphrey Field Analyzer (HF
A), which in combination yield a test point resolution of 4.2 degrees
within the central 30 degrees. Visual field analysis showed a decline
in the differential light sensitivity in myopes with peripapillary cha
nges only, compared with the control groups. These field changes becam
e more pronounced as the degree of myopia, axial length and area of th
e peripapillary crescent increased. Results suggest that the sensitivi
ty decline of the central field occurs in subjects with axial lengths
above 26 mm and more than 5 D of myopia. Knowledge of the likely field
defects encountered in myopia will assist practitioners to distinguis
h between physiological and pathological fields in myopes.