¡¡¡¡DISCUSSION

¡¡¡¡The data demonstrate high correlation between the central cone function and the posterior pole AF of the fundus. Although the visual field may show concentric constriction obviously and even tubular visual field or b waves of FERG reduce, it is important to preserve remaining central vision at the endª²stage of RP.

¡¡¡¡Lipofuscin is derived from the shed and degraded photoreceptor outer segments and normally accumulates in the RPE with age [ 5,6 ]. An abnormal increase or depletion of lipofuscin manifests as high or low density areas respectively in fundus AF images. At the advanced stage of RP these changes may reveal the central cone function.

¡¡¡¡There were reports that some patients with genetically different forms of RP manifest a ring of high density AF representing abnormal parafoveal accumulation of lipofuscin which usually encircles preserved foveal areas [ 7,8 ]. However, Similar parafoveal rings have recently been documented in other retinal dystrophies. In this study it was found that soª²called "ring of high density AF" appear in the intact pattern sometimes and patients had a better visual acuity usually. At the endª²stage of classical RP it is difficult to see such changes in other patterns. The ring of high density AF might be seen easily at previous stages.

¡¡¡¡A pilot study demonstrated high correlation between the central vison and AF area but it associated with if the fovea is influenced. When the fovea is influenced though AF area is similar to that of intact pattern the visual acuity may be bad.

¡¡¡¡We emphasize the importance of protecting central vision due to the vision of solitary island pattern. In this case both the visual field and AF area were so bad but the central vision was often better. Although it can not be cured yet it should be tried to perform a protective treatment such as inhibiting apoptosis, improving blood supply and supplying nutrition of neurons etc.

¡¡¡¡The changes of AF image correlated with the central vision and different pattern of AF images showed different vision. It is not confirmed yet the order of their development but it may well be that intact pattern is early stage and central hypofluorescence pattern is late in their heuristic procedure.

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¡¡¡¡4 Henderson R, Lorenz B, Moore AT. Clinical and molecular genetic aspects of Leber¬ðs congenital amaurosis. In: Lorenz B (Eds) Essentials in ophthalmology. Springerª²Verlag, Berlin, pp 2006;133ª²155

¡¡¡¡5 Wing GL, Blanchard GC, Weiter JJ. The topography and age relationª²ship of lipofuscin concentration in the retinal pigment epithelium. Invest Ophthalmol Vis Sci 1978(7);17:601ª²607

¡¡¡¡6 Delori FC, Goger DG, Dorey CK. Ageª²related accumulation and spatial distribution of lipofuscin in RPE of normal subjects. Invest Ophthalmol Vis Sci 2001;42(8):1855ª²1866

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¡¡¡¡8 Popovic P, Jarcª²Vidmar M, Hawlina M. Abnormal fundus autofluorescence in relation to retinal function in patients with retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2005;243(10):1018ª²1027

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