Abstract
Purpose:
To investigate the quantifiable difference in retinal nerve fiber layer (RNFL) thickness in both the superior and inferior domains of the optic nerve between glaucomatous eyes and glaucoma suspect eyes using Optical Coherence Tomography (OCT) data.
Methods:
This was a retrospective chart review of 236 eyes of 236 patients with established diagnosis of glaucoma (Group 1) and 134 eyes of 134 patients diagnosed as glaucoma suspect (Group 2). For both study groups the variables collected included age, sex, race, visual acuity (VA), intraocular pressure (IOP), cup-to-disc (CD) ratio, VF mean deviation (MD), pattern standard deviation (PSD), and OCT parameters including RNFL thickness in each quadrant, cup area and rim area. Exclusion criteria included age > 75 years old and date of service between VF and OCT testing > 3 months. 84% of the patients had stringent reliability indices using the 10% cutoff rates for false-negative and false-positive responses, as well as fixation losses. Paired and unpaired t-test, Chi-square test were used to analyze data.
Results:
In our study, 88% of patients were African American, 9% Caucasian, and 3% identified as other. There was a statistically significant difference between Group 1 and Group 2 in terms of age (70±15 vs 63±13, p<.0001), CD ratio (.69±.12 vs .60±.17, p<.0001), medications (1.8±1.2 vs .2±.5, p<.0001), VF MD (-11.2±9.6 vs -4.3±5.6, p<.0001), VF PSD (5.2±3.4 vs 3.1±2.9, p<.0001), and logmar visual acuity (.40±.61 vs .15±.24, p<.0001), respectively. There was no difference in gender or IOP (16.0±5.6 vs 16.5±3.6, p=.35). However, there was a significant difference between Group 1 and Group 2 with respect to superior NFL (80.5±25.9 vs 108.5±22.9, p<.0001 ) and inferior NFL (84.3±39.8 vs 117.4±22.6, p<.0001), respectively.
Conclusions:
There was a statistically significant difference in both superior and inferior RFNL between glaucoma and glaucoma suspect eyes. We propose that the use of RNFL thickness, especially the superior and inferior quadrants, be a potential tool incorporated into the screening, evaluation and staging of disease states in glaucoma as well as glaucoma suspect patients.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
550 imaging/image analysis: clinical •
610 nerve fiber layer