Biochemical investigation of the subretinal fluid.

Abstract

In the study of the pathogenesis of detachment of the retina an important place is occupied by biochemical research on the subretinal fluid (SRF).According to current theories of pathogenesis, tears are considered to be the main factor in the development of retinal detachment. The Using the same method, Chignell, Carruthers, andRahi (I97i) have demonstrated that the subretinal fluid tends to become more like normal serum the greater the duration of the detachment. However, one of the fractions which is always present in normal serum (IgM) was not found in any of the cases studied, even those of long duration in which repeated operations had been carried out. The authors believed that this indicated that the capillary endothelium and Bruch's membrane were of limited permeability even in such cases, since in no instance did the subretinal fluid have the protein characteristics of a true exudate.Using the same method for their immunochemical studies of the vitreous body in human beings and cattle, Cooper, Halbert, and Manski (I963) found large amounts of serum protein. They also found tissue antigens in the human vitreous body that were unconnected with serum. This suggested that the soluble vitreous body antigens are not entirely derived from blood plasma. Analysis of the subretinal fluid of patients with idiopathic detachment revealed the presence of vitreous body components. The authors believed that, if normal human vitreous body contained a large amount of serum protein, the presence of such protein in the subretinal fluid did not indicate that it came from blood, while on the other hand discovery of specific vitreous body protein in the subretinal fluid showed that the vitreous body had something to do with the formation of the fluid. Thus the vitreous body is a component of the subretinal fluid and therefore plays a significant role in the formation and development of idiopathic retinal detachment.Studies of other components in the SRF have been few. Information on the content of mucopolysaccharides (glucosamine glucans) in the SRF is limited.

Experimental Retinal Detachment

“…Eyes with a large retinal hole ( \ m=ge\ 1 with RD was 0.06, whereas in human studies, ratios exceeding 1.0 have been encountered.12 This may be due to differences in duration of the detach-ment, the level of vitreous protein, the degree of RPE integrity or transport rate, or retinal hole size. In fellow eyes with vitrectomy alone, mean aqueous and vitreous protein concentrations were 0.28 and 0.23 mg/mL, respectively.…”

Elevated serum sialic acid in idiopathic acute iridocyclitis

“…Sialic acid is one of the major carbohydrates in the glycoproteins and glycolipids of the cellular membranes (Onat et al 1990). Sialic acid has been found in the eye in such places as the trabecular meshwork (Tripathi et al 1987), lens (Tao & Lee 1986), retina (Cohen & Nir 1984), subretinal fluid (Akhmeteli et al 1975), and retinal pigment epithelium (Mclaughlin & Boykins 1987). Rabbit studies demonstrated that the levels of protein, seromucoid, and sialic acid in the aqueous humor correlate with the severity of experimentally induced iridocyclitis (Gieldanowski 1976(Gieldanowski ,1977Szary 1977).…”

Ocular Fluid Ferning Test and Fractals

“…Things appear to be different for SRF crystals. Some researchers suggested a possible correlation between mucopolysaccharide concentration and a surgical outcome [11,12], A previous research on a limited number of cases highlighted a relationship among an unfavourable surgical outcome, high muco polysaccharide concentration and type 3 crys tallization [13], Nevertheless, it is well known that the SRF ferning test is mainly influenced by protein level [14], Therefore, more extensive investigations are required in order to demonstrate the pos sible relationship between the SRF ferning test and a surgical outcome. If this hypothesis could be verified, fractal dimension analysis would become very useful for the determina tion of crystallization morphology, hence for surgical prognosis.…”