Measurement of fornix depth and area: A novel method of determining the severity of fornix shortening

Purpose To measure the depth and area of the fornix in normal adults and patients with symblepharon. The fornix depth of normal eyes (n20) and patients with symblepharon (Stevens-Johnson syndrome, n4) was measured at six locations in each eye using non-invasive, dull-edged stainless steel metric scale. Before and after conjunctival reconstruction surgery, the depths of fornix were also measured by the same method. The overall area was assessed from those fornix depth at six points. The mean depths of the superior nasal and temporal, inferior nasal and temporal, fornices as well as mean depths of medial nasal and temporal canthi fornices in normal eyes were 14.1 ± 2.5, 14.1 ± 2.5, 10.0 ± 2.1, 10.4 ± 1.8, 3.0 ± 0.9, and 5.2 ± 1.2 mm, respectively. The mean overall area of the conjunctival fornix in normal subjects was 909.6 ± 162.2 mm 2. All these parameters were significantly lower in the eyes of patients. Both depth and area after surgery were significantly deeper and larger than before. This estimation may prove useful when evaluating the severity of symblepharon and determining the post-surgical prognosis.