Abstract
Purpose: :
To evaluate the prevalence of goniodysgenesis among juvenile onset primary open angle glaucoma (JOAG) patients and to correlate these with single nucleotide polymorhisms (SNP)/mutations in the CYP1B1 gene.
Methods: :
Gonio photographs of 80 unrelated JOAG patients were analysed. JOAG patients were diagnosed as those presenting with open angle glaucoma between 10-40years of age with IOP >22mmHg and glaucomatous optic atrophy in both eyes after excluding all secondary causes of glaucoma .The coding sequences of CYP1B1 were amplified from the genomic DNA followed by direct sequencing (forward and reverse) among the JOAG patients and 100 ethnically matched controls.
Results: :
The mean age of patients was 25.4 ±8.7 yrs. 53(66%) patients had developmental angle anomalies that included high iris insertion, prominent iris processes or a featureless angle giving the appearance of a membrane. We observed SNP’s in 42 patients. These included both heterozygous and homozygous SNP’s at c.142 C>G(R48G), c 355G>T(A199S) and at c.685G>A(E229K) of exon 2. Polymorphisms were found in 21 out of 53 patients with goniodysgenesis while they were also found in 21 of 27 patients who had no apparent goniodysgeneisis ( p=0.9).
Conclusions: :
Two thirds of the patients with juvenile onset primary glaucoma had some form of goniodysgenesis in this cohort. A large proportion of patients had CYP1B1 SNP’s. Single nucleotide polymorphisms at CYP1B1 locus alone are not related to the goniodysgenesis seen among JOAG patients.
Keywords: genetics • trabecular meshwork • gene screening