Selected predictors of apoptosis in retinitis pigmentosa

The genetics of non syndromic retinitis pigmentosa [RP] is complex with numerous gene mutations. An attempt to overcome each individual mutation provides an overwhelming challenge. However targeting apoptosis which represents a final common pathway to photoreceptor cell death may provide a more practical approach. This study focused on some predictors of apoptosis in RP and their potential usefulness for patients' management and relatives' early diagnosis. Forty nine RP patients with thirty controls were evaluated genetically and ophthalmologicaly with assessment of plasma total nitrite and nitrate [as an index for nitric oxide], Plasma sFas as an index of apoptosis and plasma fatty acids levels. Autosomal recessive RP was the most common type of inheritance and the levels of plasma sFas and nitric oxide [NO] were significantly higher in retinitis pigmentosa compared to controls. Retinitis pigmentosa patients had significantly lower percentage of plasma omega3 fatty acids especially docosahexaenoic acid [DHA] relative to controls. sFas, NO, and DHA could differentiate between RP patients and control subjects with 100%, 100%, 97% sensitivity and 90%, 90%, 100% specificity respectively. sFas and nitric oxide levels were higher in cases of autosomal recessive [AR] type followed by X-linked, autosomal dominant, then simplex cases relative to the control group this may explain why AR and X-Linked forms are clinically more severe. In conclusion; diagnosis and treatment of RP could be aided by systemic markers or predictors of retinal degeneration. The consistent decrease in the plasma omega 3 fatty acids especially DHA, and increase sFas and nitric oxide levels may draw the attention upon the use of these markers as laboratory tests for relatives of affected patients who are at high risk for having retinitis pigmentosa. Also, omega 3 fatty acids in the form of DHA were recommended as possible supplements for the patients and their relatives

Taurine level and field changes in different hereditary types of retinitis pigmentosa

This study was performed to detect if there is a correlation between various hereditary subtypes, taurine level and field indices. This correlation may help in the accurate diagnosis and management of different hereditary subtypes of retinitis pigmentosa cases. The study included 28 patients with retinitis pigmentosa [16 males and 12 females] and 25 controls with matched age and sex distribution. All patients and controls were subjected to clinical evaluation that included personal and family history taking, informative pedigree construction and full clinical examination to exclude the associated genetic syndromes. Field changes were detected in both eyes of 22 RP patients using Humphrey field analyzer 640 utilizing the 24-2 program. All patients and ten of the controls were examined for plasma taurine level by amino acid analyzer [Lc 3000 Eppendorf Biotronik]. A statistical analysis was done using statistical package for social science [SPSS] program. The results showed that taurine level can help in the diagnosis of different hereditary subtypes of retinitis pigmentosa, especially simplex cases that has no definite inheritance. This will improve the genetic counseling for RP families. Taurine can also be considered as a marker for the degree of severity of visual field affection in retinitis pigmentosa cases