Figure 2
From: Brittle cornea syndrome: recognition, molecular diagnosis and management
Investigations in BCS. (a) Ocular optical coherence tomography (OCT) and pachymetry of a 32 year old patient with homozygous mutation in PRDM5 (deletion of exons 11–16; IV:4 of family BCS-001, Burkitt Wright et al. [3]). Note extreme thinning, particularly of the central cornea (300 μm) but even the maximum thickness at the periphery is only 330–380 μm. (b) Ocular OCT and pachymetry of a 31 year old patient with heterozygous mutation in PRDM5 (IV:8, BCS-001). Note only mild corneal thinning on OCT, with mean CCT measurement of 480 μm, increasing to 580–620 μm at the periphery. (c) Ocular OCT and pachymetry of a normal eye for comparison with a) and b), showing CCT of 580 μm and peripheral thickness of 650–750 μm. (d) Tympanogram of BCS patient (IV:4, BCS-001): a Type Ad curve is observed, demonstrating normal middle ear pressure but hypercompliance of the tympanic membrane. The volume by which the eardrum is displaced when a pulse of pressure is delivered to it is represented by the curve (~3.5 cm3), whilst the marker on the left demonstrates the degree of compliance observed (~1 cm3) for a normal tympanic membrane.