Laboratory Studies
Laboratory methods of diagnosing primary congenital glaucoma include the following:
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Hybridization analysis using hybridization of a mutant nucleic acid probe to the CYP1B1 gene
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Direct mutation analysis by restriction digest
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Sequencing of the CYP1B1 gene
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Hybridization of an allele-specific oligonucleotide with amplified genomic DNA
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Identification of the presence of mutant proteins encoded by the CYP1B1 gene
Imaging Studies
High-resolution anterior segment optical coherence tomography
Other Tests
Examination under anesthesia can supply important information about the childhood patient.
In addition to tonometry, corneal measurements, gonioscopy, and ophthalmoscopy should be performed in the operating room and carefully documented.
Intraocular pressures recorded under general anesthesia are usually lower than those obtained in the office because of the effects of the anesthetic agents. In unilateral cases, asymmetry of otherwise normal intraocular pressures may be diagnostic, along with other signs, such as corneal diameter.
If available in the operating room, pachymetry to quantify corneal edema and A-scan ultrasound to determine axial distention often are useful. [2] Photography of the optic nerves is advised. Portable, handheld SD-OCT scanners allow for imaging of retinal nerve fiber layers. Microscope integratede OCT systems may also be used to determine ganglion cell and nerve fiber layer thicknesses and segmental changes.
Multiple examinations may be needed before a definitive diagnosis can be made.
