Bruch’s membrane opening minimum rim width and peripapillary retinal nerve fibre layer thickness measurement in myopic eyes with glaucoma

Introduction: Optic nerve head imaging in myopic eyes with glaucoma is challenging due to atypical myopic optic disc morphology. Peripapillary retinal nerve fibre layer (pRNFL) and Bruch’s membrane opening-minimum rim width (BMO-MRW) utilize different anatomical reference points to measure the retinal nerve fibre layer. Purpose: To evaluate the diagnostic agreement between BMO-MRW and pRNFL in glaucomatous eyes with varying degrees of myopia. Design: Prospective observational study. Methods: Forty-three eyes diagnosed as primary open-angle glaucoma, normal-tension glaucoma, and primary angle-closure glaucoma with varying degrees of myopia were included in the study. Geometric measurement of the neuroretinal rim tissue was conducted with spectral domain optical coherence tomography (SD-OCT) usingtwo different parameters: BMO-MRW and pRNFL. The classification of scan quality and diagnostic agreement between both methods were compared using an exact McNemar’s test. The association between the summary classifications of quality scans with myopic degree was assessed with Fisher’s exact test. Results: BMO-MRW had a higher percentage of good quality image scans compared to pRNFL (p = 0.004). BMO-MRW was capable of obtaining equally good quality scans for glaucomatous eyes with various myopic degrees, whereas pRNFL demonstrated a significant statistical difference between mild, moderate, and high myopia(p = 0.001). pRNFL was difficult to identify in highly myopic eyes. By excluding poor quality scans, the diagnostic agreement between both modalities was 48.4% (p = 0.002). The observed agreement was higher in low myopia (66.7%), followed by moderate myopia (28.6%) and high myopia (16.7%). Conclusion: Compared to pRNFL, BMO-MRW is a better diagnostic imaging modality in glaucoma, especially for eyes with high myopia. Scan quality must be considered when interpreting OCT result in daily clinical practice to yield more accurate and reliable results.

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Influence of uveitis on Bruch’s membrane opening minimum rim width and retinal nerve fibre layer thickness measurements

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2018-313016 ◽

2018 ◽

Vol 103 (10) ◽

pp. 1413-1417 ◽

Cited By ~ 3

Author(s):

Matthias F Kriegel ◽

Arnd Heiligenhaus ◽

Carsten Heinz

Keyword(s):

Layer Thickness ◽

Nerve Fibre ◽

Retinal Nerve Fibre Layer ◽

Bruch's Membrane ◽

Bruch’S Membrane ◽

Fibre Layer ◽

Bruch’S Membrane Opening ◽

Nerve Fibre Layer ◽

Active Inflammation ◽

The Impact

Background/aimsTo assess the impact of papillary leakage and active inflammation on optical coherence tomography (OCT)-based retinal nerve fibre layer thickness (RNFLT) and Bruch’s membrane opening minimum rim width (BMO-MRW) measurements in uveitic eyes with and without secondary glaucoma.MethodsProspective, single-centre analysis of patients with uveitis. All patients included received a fluorescein angiography examination and an OCT scan measuring the BMO-MRW and the RNFLT in three concentric peripapillary ring scans.ResultsOverall, 95 eyes of 56 patients were enrolled. Papillary leakage and active inflammation were present in 39 (41%) and 57 (60%) eyes, respectively. Twenty-one eyes were classified as glaucomatous; 10 of those glaucomatous eyes showed papillary leakage. Both BMO-MRW and RNFLT measurements were significantly increased in eyes with papillary leakage (BMO-MRW: p=0.0001; RNFLT: first to third ring (p<0.0001)). Active inflammation led to a significantly thickened RNFLT (first ring: p=0.0026; second ring: p=0.0009; third ring: p=0.0002) while only a trend towards increased values could be observed in the BMO-MRW measurements (p=0.3063). Glaucomatous eyes with papillary leakage demonstrated significantly higher values on both BMO-MRW and RNFLT measurements than glaucomatous eyes without leakage (BMO-MRW: p=0.0159; RNFLT: first ring: p=0.0062; second ring: p=0.0037; third ring: p=0.0197). No significant difference could be observed between glaucomatous eyes with leakage and non-glaucomatous eyes without leakage (BMO-MRW: p=0.4132; RNFLT: first ring: p=0.5412; second ring: p=0.3208; third ring: p=0.1164).ConclusionsThe OCT scanning parameters BMO-MRW and RNFLT were significantly influenced by papillary leakage in uveitic eyes with and without glaucoma. RNFLT values were also significantly increased while active inflammation was present. In patients with uveitis, these OCT-based imaging tools should be interpreted with caution, especially in those with papillary leakage or active inflammation.

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