Relevance of Laser Flare Photometry in Retinal Pathologies

Abstract

Laser flare photometry provides a non-invasive and objective measurement of the Tyndall effect in the anterior chamber. The laser flare value (measured in photon number per millisecond [pc/ms]) thus quantifies the extent of disruption to the blood-aqueous barrier and can be used in clinical applications to monitor uveitis therapy or to measure the postoperative degree of inflammation. Standardised performance must be observed during measurement. Publications of the last 35 years on laser flare photometry deal not only with the measurement procedure but also with its use in clinical practice for different ophthalmological pathologies. Likewise, various influencing factors have already been investigated and described that must be considered when measuring and evaluating laser flare values. The focus of this article is the relevance of laser flare photometry in retinal pathologies. In recently published studies, the level of objective tyndallometry in primary rhegmatogenous retinal detachment is shown to depend on lens status, symptom duration, and extent of retinal detachment. The greater is the area of the retina affected, the greater the disruption of the blood-aqueous barrier appears to be. Elevated laser flare values have also been considered as a predictor for the development of proliferative vitreoretinopathy (PVR). However, based on current knowledge, this assumption must be put into perspective. According to current data, objective tyndallometry can be used to monitor the progression of intraocular inflammation and to quantify the blood-aqueous barrier, and the values correlate with the extent and anatomical features, as well as the symptom duration in retinal detachment. Many influencing factors have already been identified. But further evaluation is desirable and needed. It is still unclear whether laser flare values can be used in the future as a predictor for sequelae such as PVR development.

Key words

laser flare photometry - Tyndall effect - inflammation - proliferative vitreoretinopathy - retinal detachment

Publication History

Received: 29 October 2022

Accepted: 05 December 2022

Article published online:
04 April 2023

• References/Literatur

• 1 Sawa M, Tsurimaki Y, Tsuru T. et al. New quantitative method to determine protein concentration and cell number in aqueous in vivo. Jpn J Ophthalmol 1988; 32: 132-142
• 2 Schaub F, Fauser S, Kirchhof B. et al. [Laser flare photometry for identification of high-risk patients for proliferative vitreoretinopathy]. Ophthalmologe 2018; 115: 1079-1083
• 3 Sawa M. Laser flare-cell photometer: principle and significance in clinical and basic ophthalmology. Jpn J Ophthalmol 2017; 61: 21-42
• 4 Tugal-Tutkun I, Herbort CP. Laser flare photometry: a noninvasive, objective, and quantitative method to measure intraocular inflammation. Int Ophthalmol 2010; 30: 453-464
• 5 el-Harazi SM, Feldman RM, Chuang AZ. et al. Reproducibility of the laser flare meter and laser cell counter in assessing anterior chamber inflammation following cataract surgery. Ophthalmic Surg Lasers 1998; 29: 380-384
• 6 el-Maghraby A, Marzouki A, Matheen TM. et al. Reproducibility and validity of laser flare/cell meter measurements as an objective method of assessing intraocular inflammation. Arch Ophthalmol 1992; 110: 960-962
• 7 el-Maghraby A, Marzouki A, Matheen TM. et al. Reproducibility and validity of laser flare/cell meter measurements of intraocular inflammation. J Cataract Refract Surg 1993; 19: 52-55
• 8 Shah SM, Spalton DJ, Smith SE. Measurement of aqueous cells and flare in normal eyes. Br J Ophthalmol 1991; 75: 348-352
• 9 Oshika T, Nishi M, Mochizuki M. et al. Quantitative assessment of aqueous flare and cells in uveitis. Jpn J Ophthalmol 1989; 33: 279-287
• 10 Guex-Crosier Y, Pittet N, Herbort CP. Sensitivity of laser flare photometry to monitor inflammation in uveitis of the posterior segment. Ophthalmology 1995; 102: 613-621
• 11 Wakefield D, Herbort CP, Tugal-Tutkun I. et al. Controversies in ocular inflammation and immunology laser flare photometry. Ocul Immunol Inflamm 2010; 18: 334-340
• 12 Ladas JG, Wheeler NC, Morhun PJ. et al. Laser flare-cell photometry: methodology and clinical applications. Surv Ophthalmol 2005; 50: 27-47
• 13 Tappeiner C, Heiligenhaus A. Der Stellenwert von Laser Flare Messungen zur Verlaufsbeurteilung von Uveitiden. Klin Monbl Augenheilkd 2022;
• 14 Nguyen NX, Küchle M. Aqueous flare and cells in eyes with retinal vein occlusion–correlation with retinal fluorescein angiographic findings. Br J Ophthalmol 1993; 77: 280-283
• 15 Nguyen NX, Schönherr U, Küchle M. Aqueous flare and retinal capillary changes in eyes with diabetic retinopathy. Ophthalmologica 1995; 209: 145-148
• 16 Küchle M, Schönherr U, Nguyen NX. et al. Quantitative measurement of aqueous flare and aqueous “cells” in eyes with diabetic retinopathy. Ger J Ophthalmol 1992; 1: 164-169
• 17 Küchle M, Nguyen NX, Naumann GO. Quantitative assessment of the blood-aqueous barrier in human eyes with malignant or benign uveal tumors. Am J Ophthalmol 1994; 117: 521-528
• 18 Castella AP, Bercher L, Zografos L. et al. Study of the blood-aqueous barrier in choroidal melanoma. Br J Ophthalmol 1995; 79: 354-357
• 19 Hager A, Meissner F, Riechardt AI. et al. Breakdown of the blood-eye barrier in choroidal melanoma after proton beam radiotherapy. Graefes Arch Clin Exp Ophthalmol 2019; 257: 2323-2328
• 20 Kubota T, Motomatsu K, Sakamoto M. et al. Aqueous flare in eyes with senile disciform macular degeneration: correlation with clinical stage and area of neovascular membrane. Graefes Arch Clin Exp Ophthalmol 1996; 234: 285-287
• 21 Kubota T, Küchle M, Nguyen NX. Aqueous flare in eyes with age-related macular degeneration. Jpn J Ophthalmol 1994; 38: 67-70
• 22 Dolar-Szczasny J, Bucolo C, Zweifel S. et al. Evaluation of Aqueous Flare Intensity in Eyes Undergoing Intravitreal Bevacizumab Therapy to Treat Neovascular Age-Related Macular Degeneration. Front Pharmacol 2021; 12: 656774
• 23 Demirel S, Bilici S, Batıoğlu F. et al. Is There Any Difference between Ranibizumab and Aflibercept Injections in Terms of Inflammation Measured with Anterior Chamber Flare Levels in Age-Related Macular Degeneration Patients: A Comparative Study. Ophthalmic Res 2016; 56: 35-40
• 24 Pastor JC. Proliferative vitreoretinopathy: an overview. Surv Ophthalmol 1998; 43: 3-18
• 25 Charteris DG. Proliferative vitreoretinopathy: revised concepts of pathogenesis and adjunctive treatment. Eye (Lond) 2020; 34: 241-245
• 26 Schröder S, Muether PS, Caramoy A. et al. Anterior chamber aqueous flare is a strong predictor for proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Retina 2012; 32: 38-42
• 27 Hoerster R, Hermann MM, Rosentreter A. et al. Profibrotic cytokines in aqueous humour correlate with aqueous flare in patients with rhegmatogenous retinal detachment. Br J Ophthalmol 2013; 97: 450-453
• 28 Conart JB, Kurun S, Ameloot F. et al. Validity of aqueous flare measurement in predicting proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Acta Ophthalmol 2017; 95: e278-e283
• 29 Mulder VC, Tode J, van Dijk EH. et al. Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Br J Ophthalmol 2017; 101: 1285-1289
• 30 Asaria RH, Kon CH, Bunce C. et al. Adjuvant 5-fluorouracil and heparin prevents proliferative vitreoretinopathy: Results from a randomized, double-blind, controlled clinical trial. Ophthalmology 2001; 108: 1179-1183
• 31 Wickham L, Bunce C, Wong D. et al. Randomized controlled trial of combined 5-Fluorouracil and low-molecular-weight heparin in the management of unselected rhegmatogenous retinal detachments undergoing primary vitrectomy. Ophthalmology 2007; 114: 698-704
• 32 Sundaram V, Barsam A, Virgili G. Intravitreal low molecular weight heparin and 5-Fluorouracil for the prevention of proliferative vitreoretinopathy following retinal reattachment surgery. Cochrane Database Syst Rev 2013; (01) CD006421
• 33 Asaria RH, Kon CH, Bunce C. et al. How to predict proliferative vitreoretinopathy: a prospective study. Ophthalmology 2001; 108: 1184-1186
• 34 Schaub F, Hoerster R, Schiller P. et al. Prophylactic intravitreal 5-fluorouracil and heparin to prevent proliferative vitreoretinopathy in high-risk patients with retinal detachment: study protocol for a randomized controlled trial. Trials 2018; 19: 384
• 35 Schaub F, Schiller P, Hoerster R. et al. Intravitreal 5-Fluorouracil and Heparin to Prevent Proliferative Vitreoretinopathy: Results from a Randomized Clinical Trial. Ophthalmology 2022; 129: 1129-1141
• 36 Machemer R, Aaberg TM, Freeman HM. et al. An updated classification of retinal detachment with proliferative vitreoretinopathy. Am J Ophthalmol 1991; 112: 159-165
• 37 Küchle M, Nguyen NX, Horn F. et al. Quantitative assessment of aqueous flare and aqueous ‘cells’ in pseudoexfoliation syndrome. Acta Ophthalmol 1992; 70: 201-208
• 38 Oshika T, Kato S, Sawa M. et al. Aqueous flare intensity and age. Jpn J Ophthalmol 1989; 33: 237-242
• 39 El-Harazi SM, Ruiz RS, Feldman RM. et al. Quantitative assessment of aqueous flare: the effect of age and pupillary dilation. Ophthalmic Surg Lasers 2002; 33: 379-382
• 40 Fearnley IR, Spalton DJ, Smith SE. Anterior segment fluorophotometry in acute anterior uveitis. Arch Ophthalmol 1987; 105: 1550-1555
• 41 Shah SM, Spalton DJ. Changes in anterior chamber flare and cells following cataract surgery. Br J Ophthalmol 1994; 78: 91-94
• 42 Liu Y, Luo L, He M. et al. Disorders of the blood-aqueous barrier after phacoemulsification in diabetic patients. Eye (Lond) 2004; 18: 900-904
• 43 Schoeneberger V, Eberhardt S, Menghesha L. et al. Association between blood-aqueous barrier disruption and extent of retinal detachment. Eur J Ophthalmol 2022;
• 44 Menghesha L, Schoeneberger V, Gerlach S. et al. Association between laser flare photometry and symptom duration in primary rhegmatogenous retinal detachment. Int Ophthalmol 2022;
• 45 Little B, Ambrose V. Blood-Aqueous barrier breakdown associated with rhegmatogenous retinal detachment. Eye (Lond) 1991; 5: 56-62
• 46 Yoshino Y, Ideta H, Nagasaki H. et al. Comparative study of clinical factors predisposing patients to proliferative vitreoretinopathy. Retina 1989; 9: 97-100
• 47 Schoeneberger V, Menghesha L, Gerlach S. et al. Lens status and degree of lens opacity influence laser flare photometry (objective tyndallometry). Eur J Ophthalmol 2022;
• 48 Schalnus RW, Ohrloff C, Magone T. [The aqueous humor-vitreous body barrier and the blood-aqueous humor barrier after YAG laser capsulotomy in capsular sac vs. ciliary sulcus fixation of the intraocular lens]. Ophthalmologe 1995; 92: 289-292