PURPOSE: To evaluate the gonioscopic signs indicative of underdevelopm
ent of the iridocorneal angle and thereby obtain a correct diagnosis o
f goniodysgenetic glaucoma. METHODS: We examined morphologically the i
ridocorneal angle of 28 enucleated human eyes, including those from pr
emature infants as well as from older subjects. The ratio of the cilia
ry body band width to the width of the posterior limbus (the distance
between the termination of Descemet's membrane and the iris root), ter
med the theoretic C/L ratio, was calculated by drawing on light microg
raphs. Data were compared for three age groups: premature infants, chi
ldren, and subjects older than 9 years. We also examined clinically th
e appearance of the ciliary body band on gonioscopy in 135 eyes of 69
younger patients having primary glaucoma with open iridocorneal angles
and in 94 eyes of 47 age-matched control subjects. RESULTS: The theor
etic C/L ratio +/-SD was 1.4% +/- 2.7% in premature infants, 24.0% +/-
5.4% in children, and 36.7% +/- 8.0% in the older subjects. There was
a statistically significant difference between each of the three grou
ps (between premature infants and children, P <.001; between children
and older subjects, P <.005; between premature infants and older subje
cts, P < .001). On gonioscopy, 105 of 135 glaucomatous eyes (77.8%) an
d 13 of 94 control eyes (13.8%) showed either an invisible or very nar
row ciliary body band (P <.0001). CONCLUSION: The ciliary body band se
en on gonioscopy provides an indicator of the development of the irido
corneal angle. An invisible or very narrow ciliary body band represent
s an underdevelopment of the angle.