Association between laser flare photometry and symptom duration in primary rhegmatogenous retinal detachment.

PURPOSE: The purpose of this study was to investigate preoperative blood-ocular barrier disruption via laser flare photometry (LFP) in patients diagnosed with rhegmatogenous retinal detachment (RRD), and to analyse possible associations with symptom duration and anatomical parameters. METHODS: We retrospectively analysed consecutive patients presenting with RRD at a single centre between January 2016 and March 2020. LFP was performed in both eyes after pupillary dilatation prior to RRD surgery. Symptom duration, extent of retinal detachment, and lens status were assessed. For statistical analysis, we carried out the unequal variances t test and Welch's analysis of variance (ANOVA). RESULTS: We included 373 eyes of 373 patients (mean age 63.96 years ± 10.29; female:male ratio 1:1.8). LFP values quantified in photon count per millisecond (pc/ms) increased with longer symptom duration when comparing patients with a symptom duration of 0-3 days (n = 158; 9.25 ± 6.21 pc/ms) and ≥ 4 days (n = 215; 11.97 ± 11.58 pc/ms; p = 0.004). LFP values also rose with the number of retinal quadrants affected by RRD (1 quadrant, 6.82 ± 4.08 pc/ms; 2 quadrants, 10.08 ± 7.28 pc/ms; 3 quadrants, 12.79 ± 7.9 pc/ms; 4 quadrants, 31.57 ± 21.27 pc/ms; p < 0.001), macula off status (macula on, 8.89 ± 6.75 pc/ms; macula off, 12.65 ± 11.66 pc/ms; p < 0.001), and pseudophakic lens status (pseudophakia, 12.86 ± 9.52 pc/ms; phakia: 9.31 ± 9.67 pc/ms; p < 0.001). CONCLUSION: In RRD patients, blood-ocular barrier disruption quantified by LFP is associated with the duration of symptoms and the disease's anatomical extent. These results warrant further investigation of the potential clinical use of LFP in RRD.

Lens status and degree of lens opacity influence laser flare photometry (objective tyndallometry).

PURPOSE: Objective tyndallometry using laser flare photometry can be utilized e.g., in management of uveitis. Previous studies showed a significant difference in flare values between pseudophakic and phakic eyes. We investigate a potential association between the degree of lens opacification and flare value in a large cohort phakic eyes. METHODS: Retrospective, non-interventional single center study. Laser flare values of 460 healthy fellow eyes from two large cohorts (primary rhegmatogenous retinal detachment (RRD), macular holes (MH)) were correlated with lens status, degree of lens opacity, and age. RESULTS: Out of 460 patients (mean age 64.6 ± 11.2, 57% male) 30.4% were pseudophakic (70.2 ± 10.9) and 69.6% phakic, of which 47.8% showed a clear lens (57.3 ± 9.1), 43.2% an mild cataract (65.2 ± 9.0) and 9.0% a moderate cataract (73.5 ± 9.0).In pseudophakia, flare (8.14 ± 4.6 pc/ms) was significantly higher compared to phakia (6.4 ± 3.9 pc/ms; p < 0.001). In phakic eyes, flare values increased significantly with increasing lens opacity (clear lens 5.3 ± 2.8 pc/ms; mild cataract 7.0 ± 4.0 pc/ms; moderate cataract 9.5 ± 6.1 pc/ms; p < 0.001). In clear lenses and mild cataract, age correlated significantly with flare (two-sided, p < 0.001, clear lenses R = 0.3; mild cataract R = 0.4). In clear lenses, flare values increased with age by 0.09 per year, in mild cataract by 0.17 (regression coefficients). No significant correlation was found between age and flare value in moderate cataract and pseudophakic eyes. CONCLUSION: The level of objective tyndallometry seems to be dependent on lens status, degree of lens opacity and age. These factors should therefore be taken into account when interpreting laser flare values in the future.