Immunoglobulin E in aqueous humour.

The level of immunoglobulin E (IgE) was determined in the aqueous humour (AH) and serum by particle counting immunoassay (limit of sensitivity: 0.2 IU ml-1). This level in the AH was below 0.75 IU ml-1 in case of senile cataract (n = 22) and ranged from this assumed normal value to 550 IU ml-1 in case of uveitis (n = 37), Fuchs' cyclitis (n = 11), intraocular tumour (n = 7) and perforating ocular injury (n = 6). To know whether the IgE increase was related to a possible local production the AH/serum concentration ratio for IgE was calculated and divided by that for albumin. Values higher than 0.60 were considered as suggestive of a local synthesis and were observed in 31 of the 37 samples examined.