Consanguinity and severity of primary congenital glaucoma

To evaluate the severity of primary congenital glaucoma (PCG) among children born of consanguineous marriage.

In this case-control study, the medical records of unrelated consanguineous patients and unrelated nonconsanguineous (control) PCG patients seen at a single tertiary eye care facility were retrospectively reviewed. Those with a minimum of 5 years' follow-up were included. Data collected included age at presentation, corneal diameter, axial length, corneal haze at presentation and its persistence after surgery, need for repeat surgery, and final visual acuity.

A total of 130 PCG patients were included: 30 patients born of consanguineous marriage and 100 nonconsanguineous control patients. The median age of presentation for consanguineous cases was 3 months (range, 1-36) compared with 10 months (range, 2-24) for nonconsanguineous cases (P < 0.001). Mean corneal diameter for consanguineous cases was 13 ± 0.82 mm and for nonconsanguineous cases was 12.41mm ± 1.18 mm (P = 0.002). Consanguineous cases also had a significantly higher prevalence of corneal haze persisting after surgery (P < 0.001) and need for repeat IOP-lowering surgery (P = 0.039). The consanguineous group had 44 eyes (73%) with severe PCG compared with 69 (34.5%) in the nonconsanguineous group (P < 0.001).

In this study cohort, children with PCG born of consanguineous parents were more severely affected at presentation compared with children born of nonconsanguineous parents; they also had poorer outcomes with IOP-lowering surgery independent of severity at presentation. It is however possible that a founder effect with consanguinity over multiple generations could account for our observations.