Asymmetry of Peak Thicknesses between the Superior and Inferior Retinal Nerve Fiber Layers for Early Glaucoma Detection: A Simple Screening Method

Abstract

PurposeTo assess whether the asymmetry in the peripapillary retinal nerve fiber layer (pRNFL) thickness between superior and inferior hemispheres on optical coherence tomography (OCT) is useful for early detection of glaucoma.Materials and MethodsThe patient population consisted of Training set (a total of 60 subjects with early glaucoma and 59 normal subjects) and Validation set (30 subjects with early glaucoma and 30 normal subjects). Two kinds of ratios were employed to measure the asymmetry between the superior and inferior pRNFL thickness using OCT. One was the ratio of the superior to inferior peak thicknesses (peak pRNFL thickness ratio; PTR), and the other was the ratio of the superior to inferior average thickness (average pRNFL thickness ratio; ATR). The diagnostic abilities of the PTR and ATR were compared to the color code classification in OCT. Using the optimal cut-off values of the PTR and ATR obtained from the Training set, the two ratios were independently validated for diagnostic capability.ResultsFor the Training set, the sensitivities/specificities of the PTR, ATR, quadrants color code classification, and clock-hour color code classification were 81.7%/93.2%, 71.7%/74.6%, 75.0%/93.2%, and 75.0%/79.7%, respectively. The PTR showed a better diagnostic performance for early glaucoma detection than the ATR and the clock-hour color code classification in terms of areas under the receiver operating characteristic curves (AUCs) (0.898, 0.765, and 0.773, respectively). For the Validation set, the PTR also showed the best sensitivity and AUC.ConclusionThe PTR is a simple method with considerable diagnostic ability for early glaucoma detection. It can, therefore, be widely used as a new screening method for early glaucoma.

Combining Optical Coherence Tomography and Fundus Photography to Improve Glaucoma Screening

“…Glaucoma specialists generally use the temporalsuperior-nasal-inferior-temporal map to compare the standard data of cpRNFL thickness with the measured cpRNFL thickness. Cases displaying the disappearance of the double hump pattern, a difference between left and right eye graphs, and an RNFL thickness outside the normal range were used to help diagnose glaucoma [32,33].…”

“…There are increasing reports on the accuracy of glaucoma diagnosis using OCT, with some reports demonstrating a sensitivity and specificity of approximately 89% and 95%, respectively [30]. In relation to the diagnosis, spectral domain optical coherence tomog-raphy (SD-OCT) is more useful than fundus photography [31][32][33][34][35][36][37][38][39][40][41][42]. In particular, OCT is an excellent auxiliary test for glaucoma diagnosis owing to its non-invasive nature and the rapid generation of accurate tomographic images of the retina and optic nerve head.…”

Development of a nomogram using fundus photography to predict glaucoma progression in patients showing disc hemorrhage

“…Fundus photography has been widely used in ophthalmology, including glaucoma assessments, because it is relatively inexpensive and easy to perform [13][14][15][16][17] . In addition, images can be saved and used for further clinical purposes at a later date, which is useful for monitoring disease progression.…”

Diagnostic Ability of Swept-Source and Spectral-Domain Optical Coherence Tomography for Glaucoma

“…Optical coherence tomography (OCT) is a well-known modality providing objective evaluation of structural alterations in the optic nerve head or macular area. 1 2 3 The development of OCT from time-domain OCT to spectral-domain OCT has increased the resolution and acquisition speed of OCT images, as well as the accuracy of glaucoma diagnosis. 4 5 Recently, swept-source OCT, a new OCT system with a novel light source and detector, has been introduced.…”