[Quantification of disorders of the blood-aqueous humor barrier in retinitis pigmentosa--initial results].

BACKGROUND

Clinical findings in patients with retinitis pigmentosa (RP) frequently include cystoid macular edema (CME) and vitreous pigment dusting (VPD) indicating alterations of the blood-ocular barriers. It was the aim of this study to determine whether alterations of the blood-aqueous barrier (BAB) are present in RP.

PATIENTS AND METHODS

Aqueous flare was quantitatively determined in 56 eyes of 29 patients (mean age 36.4 +/- 11.2 years) with RP using the noninvasive laser flare-cell photometer (Kowa FC-1000, Tokyo, Japan). All RP patients had common forms of RP with markedly reduced or nondetectable ERG. The presence of CME and VPD was determined semiquantitatively by biomicroscopy. Fifty-eight eyes of 58 normal controls (mean age 38.2 +/- 8.5 y.) were also examined.

RESULTS

Aqueous-flare values were significantly higher in RP eyes (mean 9.65 +/- 3.24 photon counts/ms, range 4.0-18.1) than in the normal control eyes (mean 3.89 +/- 1.05, range 1.9-6.0, p < 0.0001, Mann-Whytney test). Forty-eight of the 56 RP eyes (86%) showed increased flare values (> 6.0 photon counts/ms). RP eyes with moderate to marked CME (n = 11) had significantly higher flare values (mean 14.66 +/- 1.92) than RP eyes without or with only questionable CME (8.52 +/- 2.18, p < 0.0001), and RP eyes with moderate to marked VPD (n = 17) had significantly higher (12.05 +/- 2.84) flare values than RP eyes without or with only minimal VPD (8.74 +/- 2.22, p < 0.0005).

CONCLUSIONS

Our findings show that the majority of patients with RP have alterations of the BAB with consecutively increased aqueous protein concentrations. The impairment of the BAB appears to be associated with CME and VPD. Measurement of aqueous flare in RP allows quantification of the impairment of the BAB and may be helpful in the future in choosing and monitoring patients with RP and CMP for possible antiinflammatory or antiedematous therapeutic measures.