Because certain aspects of the lamina cribrosa may be associated with an increased risk of glaucoma progression, researchers recently set out to take a closer look at the structure in patients with and without retinal nerve fiber layer (RNFL) thinning. Using optical coherence tomography (OCT) to image the structure and compare it between study subjects, they discovered lamina cribrosa defects are an independent risk factor for RNFL thinning. In addition, glaucoma progression may correspond topographically to the defect location, the said in the study.
The California-based team of researchers conducted the longitudinal cohort study at a tertiary glaucoma center and recruited 43 patients (51 eyes) with lamina cribrosa defects and 68 patients (83 eyes) without defects. The patients were followed for an average of three and a half years. They used swept-source OCT to image lamina cribrosa defects and spectral-domain OCT to document RNFL thickness every six months.
The results show the mean rate of global RNFL loss in eyes with lamina cribrosa defects was two-fold faster than that in eyes without defects. In addition, the rate of RNFL thinning was faster in the defect sectors than in unaffected sectors. The only factor associated with a faster rate of RNFL loss in eyes with defects was thinner corneal thickness, the researchers wrote in the study.
“In the management of open-angle glaucoma, [lamina cribrosa] findings may inform the likelihood and rate of glaucoma progression,” the study concludes.
|Moghimi S, Zangwill LM, Manalastas PIC, et al. Association between lamina cribrosa defects and progressive retinal nerve fiber layer loss in glaucoma. JAMA Ophthalmol. February 7, 2019. [Epub ahead of print].|