Nancy Pittet

Use of Laser Flare Photometry to Assess and Monitor Inflammation in Uveitis

PURPOSE Laser flare photometry (LFP) is a new quantitative method for the evaluation of aqueous flare, making flare the only inflammatory parameter that can be evaluated precisely and objectively. The aim of this study was to characterize the inflammatory pattern of acute human leukocyte antigen-B27 (HLA-B27)-related anterior uveitis and to determine further clinical use and limitations of LFP in posterior inflammation. METHODS In the first part of the study, 78 episodes of HLA-B27-related acute anterior uveitis were analyzed to determine mean pretreatment (initial) flare, mean flare evolution, need for additional periocular steroids, and mean duration of an episode. In the second part of the study, the use of LFP was further tested in posterior inflammation, first by analyzing the predictive value of a subclinical LFP-detected flare increase for disease recrudescence in posterior scleritis, and then by exploring clinical applications for LFP in posterior uveitis, where LFP was essential either in the establishment of a diagnosis or in guiding therapeutic decisions. RESULTS Mean initial flare in HLA-B27-related acute anterior uveitis was 160 +/- 22 photons/msec, and mean duration of an episode was 18.5 +/- 15 days. A 50% and 90% flare reduction occurred after 2 and 8 days, respectively. In posterior scleritis, LFP was accurate in monitoring response to systemic steroid therapy and a small flare increase was predictive for disease recrudescence in five of six cases (predictive value 0.83, sensitivity 100%). In posterior uveitis, LFP was sensitive to monitor systemic treatments and to establish a diagnosis in unclear cases by measuring the effect of a selective therapy (therapeutic trial) on the flare level. CONCLUSION In acute anterior HLA-B27-associated uveitis, LFP represented a potential improvement in management by allowing precise adjustment of therapy. In uveitis of the posterior segment, our data confirm the validity of LFP to monitor response and adjust systemic therapy and to detect disease recurrence in patients with a sufficient pretreatment level of associated blood-aqueous barrier disruption (flare).

Dexamethasone versus diclofenac sodium eyedrops to treat inflammation after cataract surgery

Abstract We compared the postoperative anti‐inflammatory effect of diclofenac sodium 0.1 % and dexamethasone phosphate 0.1% in a prospective, randomized, doublemasked pilot study. Anterior chamber inflammation was evaluated by measuring aqueous flare and cells with a laser flare‐cell meter at one, three, 12, 30, and 60 days after cataract surgery. Flare values in the two groups did not significantly differ at any time, nor did aqueous cell counts at one, three, 12, and 60 days after surgery. At 30 days, however, cell count was significantly lower in the diclofenac group. Diclofenac sodium seems to be as potent as dexamethasone phosphate, as good an anti‐inflammatory agent, and may replace corticosteroid therapy after cataract surgery.

Sensitivity of Laser Flare Photometry to Monitor Inflammation in Uveitis of the Posterior Segment

PURPOSE Laser flare photometry is a new quantitative method for evaluating aqueous flare, making flare the only inflammatory parameter that can be evaluated precisely and objectively. The validity of the method already has been demonstrated in anterior segment inflammation. The aim of this study is to assess the validity and limitations of the method to quantify and monitor inflammation in uveitis with predominant involvement of the posterior segment. METHODS Five well-defined conditions with uveitis predominant in the posterior segment were analyzed in this study: Behçet uveitis, pars planitis, posterior sarcoidosis, posterior pole toxoplasmosis, and birdshot chorioretinopathy. (1) Mean initial (pretreatment) flare was determined; (2) in the patients needing systemic steroid therapy, introduction of therapy was correlated with evoluting laser flare photometry; and (3) in patients with quiescent disease, the predictive value of a defined subclinical photometry-detected flare rise for disease recrudescence was analyzed. RESULTS Initial pretreatment flare was 331.8 +/- 47.7 photon counts per millisecond (ph/msecond) (mean +/- standard error of the mean) for Behçet uveitis, 15.6 +/- 1.3 ph/msecond for pars planitis, 26.9 +/- 4.6 ph/msecond for posterior sarcoidosis, 7.5 +/- 1.0 ph/msecond for posterior pole toxoplasmosis, 5.8 +/- 0.7 ph/msecond for birdshot chorioretinopathy, and 4.7 +/- 0.1 ph/msecond for a group of 88 control eyes. A significant flare reduction after start of steroid therapy was seen in Behçet uveitis (78% reduction), sarcoidosis (44.8%), and pars planitis (51%), but not in toxoplasmosis or in birdshot. A small flare rise had a predictive value for disease recrudescence in 27/35 patients (predictive value, 0.77; sensitivity rate, 100%). The level of associated blood-aqueous barrier disruption for reliable follow-up of posterior uveitis was empirically determined to be 13 to 15 ph/msecond. CONCLUSION Laser flare photometry was found to be very sensitive to monitor inflammation in uveitis of the posterior segment as long as a sufficient level of associated blood-aqueous barrier disruption (flare) was present.

Aqueous humor analysis after Nd:YAG laser capsulotomy with the laser flare-cell meter.

ABSTRACT Using the laser flare‐cell meter (Kowa FC‐1000), we conducted a prospective study analyzing the effect of Nd:YAG posterior capsulotomy on the quantity of aqueous particles, aqueous flare, and intraocular pressure in 65 eyes (58 patients). Aqueous particles increased at six hours, followed by flare rise which was significant at 18 hours after capsulotomy. Only 22 eyes (34%) had a significant flare rise over prelaser values. Anti‐inflammatory therapy was necessary in only one patient. The mean intraocular pressure value did not rise significantly after capsulotomy. Acute intraocular hypertension (AIOHT) (> 7 mm Hg increase) occurred between three and six hours after laser therapy in 12 patients (19%), was related in time to particle rise, and always responded to a single dose of acetazolamide. Acute intraocular hypertension was strongly correlated with elevated aqueous particles (P < .0001) and somewhat correlated with flare rise (P <.036), but was not correlated with the intraocular lens position (bag or sulcus fixation). Our findings strongly suggest that trabecular meshwork clogging by debris generated by the cap‐sulotomy is the mechanism at the origin of AIOHT.

The effect of thalidomide and supidimide on endotoxin-induced uveitis in rats

Abstract• Background: Endotoxin-induced uveitis (EIU) is an animal model of ocular inflammation, produced by footpad injection of endotoxin (lipopolysaccharide, LPS) to mimic the human disease of acute anterior uveitis, that is useful for testing new anti-inflammatory therapy. The purpose of this study was to test the anti-inflammatory effect on EIU of thalidomide and one of its derivatives, supidimide.• Methods: EIU was produced in rats by hind footpad injection of LPS (100 μg/animal). Animals were killed 20 h after LPS injection. Inflammation was evaluated by anterior chamber determination of proteins and cells.• Results: A dosage of 400 mg/kg per day of thalidomide was efficient in reducing inflammation whether given in three doses (at − 24 h, − 4 h and + 4 h relative to LPS challenge = THAL-1; p < 0.001 for proteins and cells), in two doses (−4 h and +4 h = THAL-2; p < 0.001 for proteins, p < 0.012 for cells) or in one dose (at +4 h=late THAL; p < 0.001 for proteins, p≤0.02 for cells). A dosage of 300 mg/kg per day of thalidomide was still efficient (p≤0.023 for proteins, p≤0.06 for cells), but 150 mg/kg per day had no effect on inflammation. Supidimide (400 mg/kg per day) had some anti-inflammatory effect (p ≤ 0.053 for proteins, p < 0.06 for cells).• Conclusion: High-dose thalidomide had a potent anti-inflammatory effect in EIU, but lower doses were not sufficient to reduce inflammation. At similar high doses, supidimide had some effect on EIU but was less effective than thalidomide.