Aqueous Flare Values Research Articles

Quantifizierung von Störungen der Blut-Kammerwasser-Schranke bei Retinopathia pigmentosa - Erste Ergebnisse

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. 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. 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). 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.

Quantitative Assessment of the Blood-aqueous Barrier in Human Eyes With Malignant or Benign Uveal Tumors

We assessed alterations of the blood-aqueous barrier in 43 eyes with malignant melanoma (31 choroidal and 12 ciliary body), 40 eyes with benign uveal tumors, and 199-age matched normal control eyes. Aqueous flare was quantified with the laser flare-cell meter and correlated with clinical and histopathologic findings. Aqueous flare (photon counts/ms) was significantly higher in melanoma eyes (20.91 +/- 12.40) than in eyes with benign tumors (4.26 +/- 1.55) (P < .0001) and normal control eyes (3.99 +/- 1.14) (P < .0001). In melanoma eyes, clinical and histologic findings associated with significantly increased aqueous flare values were as follows: tumor height, serous retinal detachment, tumor necrosis, lymphocytic tumor infiltration, and tumor hemorrhage. Development and growth of uveal melanomas are accompanied by marked alterations of the blood-aqueous barrier. The noninvasive laser flare-cell meter may give useful additional information about malignant and benign uveal tumors.

Aqueous Flare Following Penetrating Keratoplasty and in Corneal Graft Rejection

Corneal allograft rejection is a major complication of penetrating keratoplasty (PK). We used the laser flare-cell meter that allows, for the first time, non-invasive quantification of aqueous flare in vivo to analyze alterations of the blood-aqueous barrier following uncomplicated PK and in acute corneal graft rejection. Examination with the laser flare-cell meter was performed in 67 eyes of 62 patients (mean +/- SD age, 46.2 +/- 15.1 years) 12.8 +/- 13.2 months (range, 5 days to 60 months) after uncomplicated PK, in 82 normal control eyes of 82 age-and gender-matched patients (mean age, 49.0 +/- 17.1 years) and in 10 eyes of 10 patients (mean age, 51.6 +/- 15.1 years) with acute diffuse endothelial corneal graft rejection in nonherpetic eyes 15.1 +/- 12.9 months after PK. Compared with the normal unoperated control group (4.43 +/- 1.13 photon counts/ms), aqueous flare was significantly increased during the first 2 weeks following uncomplicated PK (14.73 +/- 8.30 photon counts/ms; P < .0001) but returned to normal levels more than 6 weeks after surgery (4.48 +/- 1.55 photon counts/ms; P > .1). In acute corneal graft rejection, aqueous flare values (17.10 +/- 6.05 photon counts/ms) increased to significantly higher levels than in eyes following uncomplicated PK and in the normal control group (P < .0001), but decreased significantly 9.5 +/- 3.3 days after treatment with systemic and topical corticosteroids (5.78 +/- 2.16; P < .0005). Application of the laser flare-cell meter appears promising for following up patients after PK and for detecting early corneal allograft rejection.

Tyndallometrie zur Überwachung der Therapie bei Sympathischer Ophthalmie

The Laser Flare-Cell Meter allows noninvasive quantitative measurement of aqueous flare in human eyes. In this study we analysed changes of aqueous flare in eyes with sympathetic ophthalmia under immunosuppressive treatment. Two men (54- and 59-year-old) with sympathetic ophthalmia (histological examination of the enucleated eyes confirmed the clinical diagnosis) were examined regularly with the Laser Flare-Cell Meter (Kowa). According to the flare values the dose of immunosuppressive treatment with cyclosporin A and prednisolone was gradually titrated. Under immunosuppressive treatment flare values of patient 1 normalized within 21 months. The dose of immunosuppressive treatment was carefully reduced according to flare values. Patient 2 showed very high flare values before treatment, which decreased to flare values of 20 flare counts/ms within 5 months of treatment with cyclosporin A and prednisolone. Both patients stopped immunosuppressive treatment because of systemic side-effects. Thereafter flare values increased acutely and a recurrence of sympathetic ophthalmia was observed in both patients. Under renewed immunosuppressive treatment aqueous flare values decreased again. Measurement of aqueous flare with the LFCM appears to be an effective tool for follow-up examinations, and especially for titrating of immunosuppressive treatment in eyes with manifest sympathetic ophthalmia.

Correlation between tyndallometry with the "laser flare cell meter" in vivo and biochemical protein determination in human aqueous humor

The laser flare-cell meter allows noninvasive measurement of aqueous flare in humans. In vitro studies have shown good correlations between flare values and albumin concentrations. In this study, we compared aqueous flare values and aqueous protein concentrations in living human eyes. We measured aqueous flare and the total aqueous protein concentration in 52 eyes of 52 patients (age 58.4 +/- 18.8 years) that underwent cataract extraction (22 eyes) or trabeculectomy (30 eyes). Before surgery, aqueous flare was determined with the laser flare-cell meter (Kowa FC-1000). During surgery, 50 microliters of primary aqueous humor was aspired, and total aqueous protein concentration was performed using a modified Pierce-BCA assay. Linear regression analysis was calculated. There was a high correlation between aqueous flare values and total aqueous protein concentration (y = 0.52x + 0.15, r = 0.98, p < 0.00001). This correlation was observed both in eyes with and without cataract. Our results indicate that aqueous flare values as determined with the laser flare-cell meter reflect the true aqueous protein concentration quite accurately. Lens opacities appear not to significantly alter the results of aqueous flare measurements. As expected by theoretical assumptions, flare measurements overestimate aqueous protein concentrations in eyes with severely impaired blood-aqueous barriers because, according to Rayleigh's law, larger protein molecules cause more light scattering. However, transformation and expression of flare values as "albumin concentration equivalents" according to in vitro-calibration may still be useful, especially if the results of different instruments are to be compared.(ABSTRACT TRUNCATED AT 250 WORDS)

Source of aqueous humor hydrogen peroxide

Purpose: To quantify intraocular inflammation after phacoemulsification with implantation of an accommodative posterior chamber intraocular lens (IOL).Setting: Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany.Methods: Twenty cataractous eyes of 20 patients without preexisting blood-aqueous barrier (BAB) deficiencies or previous intraocular surgery were included in this study. The mean age of the patients was 64.6 years ± 16.0 (SD). A single surgeon performed phacoemulsification through a superior sclerocorneal tunnel incision and implantation of a 1CU IOL (HumanOptics AG) though a 3.2 mm incision. The haptics of the single-piece acrylic 1CU lens are designed for anterior optic movement following ciliary muscle contraction. The postoperative treatment was standardized. Postoperative BAB breakdown was quantified by laser flare photometry (FC-1000, Kowa) at 1 day, 1 and 4 weeks, and 3 and 6 months.Results: The mean aqueous flare was 6.3 photons/ms ± 3.0 (SD) (range 4.0 to 12.2 photons/ms) 1 day postoperatively, with 64% of patients having normal aqueous flare values (<8.0 photons/ms). One week after surgery, the mean aqueous flare was 5.3 ± 2.8 photons/ms (range 2.0 to 10.5 photons/ms). Four weeks postoperatively, aqueous flare was normal in all patients and remained stable below the normal limit for up to 6 months (mean 3.3 ± 1.2 months; range 2.0 to 5.4 months). The number of aqueous cells did not increase at any follow-up and was normal in all eyes. No postoperative complications such as fibrin formation, synechias, macrophages on the IOL optic, or endophthalmitis were observed.Conclusions: Phacoemulsification with implantation of the 1CU accommodative IOL led to minimal and short-lasting BAB alteration. No signs of persistent inflammation or pigment dispersion were detected.