Purpose: To evaluate the gonioscopic signs indicative of underdevelopment of the iridocorneal angle and thereby obtain a correct diagnosis of goniodysgenetic glaucoma.
Methods: We examined morphologically the iridocorneal angle of 28 enucleated human eyes, including those from premature infants as well as from older subjects. The ratio of the ciliary body band width to the width of the posterior limbus (the distance between the termination of Descemet's membrane and the iris root), termed the theoretic C/L ratio, was calculated by drawing on light micrographs. Data were compared for three age groups: premature infants, children, and subjects older than 9 years. We also examined clinically the 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 theoretic 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 groups (between premature infants and children, P < .001; between children and older subjects, P < .005; between premature infants and older subjects, P < .001). On gonioscopy, 105 of 135 glaucomatous eyes (77.8%) and 13 of 94 control eyes (13.8%) showed either an invisible or very narrow ciliary body band (P < .0001).
Conclusion: The ciliary body band seen on gonioscopy provides an indicator of the development of the iridocorneal angle. An invisible or very narrow ciliary body band represents an underdevelopment of the angle.