Abstract
Purpose: :
Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited disease characterized by seizures, mental retardation, and hamartomas involving multiple organ systems. In this study, the occurance rate and detailed features of retinal astrocytic hamartoma (AH) are described. Additionally, the presence and severity of systemic disease involvement is reported.
Methods: :
132 patients enrolled in the Cleveland Clinic TSC program were prospectively evaluated. A total of 99 patients had definite TSC (1998 Tuberous Sclerosis Alliance Revised Diagnostic Criteria) and were included in statistical analysis. Complete ocular examination, systemic associations (neurologic, dermatologic, renal, pulmonary, and cardiac), and genetic testing were analyzed.
Results: :
The study population included 49 males and 50 females with an average age at TSC diagnosis of 9 years (range: birth - 53 years). Ocular examination was completed in 81% of patients (n = 80) at an average age of 15 years (range: birth - 53 years). Retinal AH was detected in 36% patients (n = 29). Lesions were bilateral in 45% (n = 13) and multiple in 38% (n = 11) of these cases. In patients with multiple AH, an average of 4 (range: 2 - 7) lesions were observed. Average lesion size was 1.0 disc diameter (range: 0.5 - 2.5 disc diameters). The most common location was along the arcades (41%) followed by the retinal periphery (31%) and adjacent to the optic nerve (27%). In nearly all cases of AH, best corrected visual acuity was normal (average visual acuity = 0.12 logMAR; corresponding to approximately 20/25 Snellen). Genetic testing for TSC 1 and TSC 2 mutations was performed in 45% (n = 13) of patients with AH. Of these, 92% (n=12) had mutations. TSC 2 mutations were observed 3 times more frequently in patients with AH compared to TSC 1 mutations. A history of seizures was reported in 83% (n = 82) of patients. A variable degree of cognitive impairment, ranging from mild developmental delay to severe mental retardation, was present in 61% (n = 60) of patients. The most commonly observed major diagnostic criteria were: cortical tubers in 87% (n = 86), more than 3 hypomelanotic macules in 75% (n = 74), subependymal nodules in 71% (n = 70), and facial angiofibromas in 61% (n = 60) of patients.
Conclusions: :
Retinal AH is observed in about one third of patients with definite TSC. These lesions rarely cause visual disability. Patients with AH are more likely to have TSC 2 mutations.