Clinicopathological correlation of congenital corneal opacification using ultrasound biomicroscopy

Abstract

Aim: To investigate the correlation between clinical, high frequency ultrasound biomicroscopy (UBM) and, where possible, histological findings in cases of congenital corneal opacification presenting to the departments of ophthalmology, Great Ormond Street Hospital for Children, London, and the Hospital for Sick Children, Toronto, Canada. Method: 22 eyes of 13 children (age range 3-225 days) with congenitally opaque corneas were examined. UBM was performed using the ultrasound biomicroscope (Allergan-Humphrey). All eyes underwent penetrating keratoplasties (PKP) except five. The host corneas were all sent for histological examination.Results: The final diagnosis in our series was Peters' anomaly in nine cases (70%), corneal dystrophy in two cases (15%), and sclerocornea in two cases (15%). The UBM findings changed the clinical diagnosis in five cases (38%). In these five cases histology was available in four and confirmed the UBM diagnosis in each case. In no case of the 13 where histology was available did it contradict the UBM findings. In two cases a hypoechoic region in the anterior stroma was seen on UBM which correlated histologically with absent Bowman's layer and oedema. In two cases UBM revealed aniridia and in one, congenital aphakia, which was not apparent clinically. Conclusion: UBM examination is not only very useful in evaluating the clinical diagnosis in congenital corneal opacification, it also acts as a preoperative guide in cases undergoing PKP by detecting keratolenticular and iridocorneal adhesions and other ocular abnormalities such as aniridia and congenital aphakia. In all cases where PKP was performed the UBM diagnosis was confirmed histologically. The clinical diagnosis was incorrect in five cases. This has important implications in studies of phenotype/genotype correlation of congenital corneal opacification.

Anterior segment imaging in pediatric ophthalmology

“…14 In congenital corneal opacities such as Peters anomaly, sclerocornea, and limbal dermoids, the extent of the iris and lens involvement and adhesion to the cornea can guide surgery and determine prognosis preoperatively ( Figure 1). 15,16 In the examples shown in Figure 1, the need for lensectomy and vitrectomy can be predicted and planned prior to surgery. Discussion to proceed with surgery and prognosis can be appropriately discussed with the family based on the degree of dysgenesis identified on UBM.…”

Congenital corneal opacities – a surgical approach to nomenclature and classification

“…The advent of these has helped define phenotype much more precisely. 3 It is with this added knowledge that it may be more rational to consider CCO as being primary or secondary with a separate category of kerato-irido-lenticular dysgenesis (KILD).…”

“…Total sclerocornea may be better classified in some cases as a form of keratolenticular dysgenesis, 3 due to lens/iris disruption ( Figure 7) or failure of lens to separate from the cornea.…”

“…37 Previously, we have shown that CCO may be associated with aniridia. 3 Aniridia can also of course be associated with anterior polar or pyramidal cataracts which can cause keratolenticular adhesions with often discrete focal CCO. Whether the CCO seen with aniridia 38 is due to a mechanical fault or developmental is difficult to be certain about.…”

“…40,41 We have previously described a case of unilateral CCO where the 'good' eye had clear evidence of ARA and the affected eye had evidence of Axenfeld anomaly on HFU. 3 Again the poor prognosticators in such cases are uncontrolled glaucoma.…”