The least severe form of papillorenal disease shown in the eye is the exiting of blood vessels from the periphery that do not disturb the shape of the eye. Other eye malformations include scleral staphyloma, which is the bulging of the eye wall. There can also be retinal thinning and myopia. Additionally, there can be an optic nerve cyst, which is dilation of the optic nerve posterior to the globe; which most likely results from incomplete regression of the primordial optic stalk and the filling of this area with fluid. Retinal coloboma is also common, which is characterized by the absence of retinal tissue in the nasal ventral portion of the retina. However, this is an extremely rare finding. Molecular genetic testing
Sequence analysis shows that Pax2 is the only known gene associated with the disease. Mutations in Pax2 have been identified in half of renal coloboma syndrome victims. Treatment
Management of the disease should be focused on preventing end-stage kidney disease (ESKD) and/or vision loss. The treatment of hypertension may also preserve renal function. Renal replacement therapy is recommended, and vision experts may provide assistance to adapt to continued vision loss. Kidney transplant is also an option. Treatment plans seem to be limited, as there is a large focus on the prevention of papillorenal syndrome and its implications. People with congenital optic nerve abnormalities should seek ophthalmologists regularly and use protective lenses. If abnormalities are present, a follow up with a nephrologist should be achieved to monitor renal function and blood pressure.
Papillorenal syndrome is an autosomal dominant genetic disorder marked by underdevelopment (hypoplasia) of the kidney and colobomas of the optic nerve. Presentation
Ocular
Ocular disc dysplasia is the most notable ocular defect of the disease. An abnormal development in the optic stalk causes optic disc dysplasia, which is caused by a mutation in the Pax2 gene. The nerve head typically resembles the morning glory disc anomaly, but has also been described as a coloboma. A coloboma is the failure to close the choroid fissure, which is the opening from the ventral side of the retina in the optic stalk. Despite the similarities with coloboma and morning glory anomaly, significant differences exist such that optic disc dysplasia cannot be classified as either one entity. Optic disc dysplasia is noted by an ill-defined inferior excavation, convoluted origin of the superior retinal vessels, excessive number of vessels, infrapapillary pigmentary disturbance, and slight band of retinal elevation adjacent to the disk. Some patients have normal or near normal vision, but others have visual impairment associated with the disease, though it is not certain if this is due only to the dysplastic optic nerves, or a possible contribution from macular and retinal malformations. The retinal vessels are abnormal or absent, in some cases having small vessels exiting the periphery of the disc. There is a great deal of clinical variability. Kidney
The most common malformation in patients with the syndrome is kidney hypodysplasia, which are small and underdeveloped kidneys, often leading to end-stage renal disease (ESRD).