White-to-white measurement inaccurate in deep anterior chambers

This prospective study found that the traditional white-to-white technique for estimating ciliary sulcus diameter is inadequate and cannot predict sulcus sizes when the anterior chambers are deep.

The authors used ultrasound biomicroscopy to measure ciliary sulcus diameters in 111 highly myopic eyes of 72 volunteers. They used the IOLMaster to measure central anterior chamber depth and white-to-white diameter.

They found a statistically significant correlation between white-to-white diameters and horizontal sulcus diameters when the anterior chamber depth was less than 3.4 mm. However, when the anterior chamber depth was greater than 3.4 mm, horizontal sulcus  and white-to-white diameters were not correlated.