Macular Ganglion Cell-Inner Plexiform Layer and Retinal Nerve Fiber Layer Thickness in Eyes With Primary Open-Angle Glaucoma Compared With Healthy Saudi Eyes: A Cross-Sectional Study

Macular ganglion cell complex parameters by optical coherence tomography in cases of multiple sclerosis without optic neuritis compared to healthy eyes

Purpose:

To compare different macular thickness parameters and peripapillary retinal nerve fiber layer (RNFL) thickness between recently diagnosed cases of multiple sclerosis (MS) without optic neuropathy (ON) and healthy individuals.

Methods:

This cross-sectional study was performed between June 2014 and June 2015. All subjects underwent ocular and retinal examination. Spectral domain optical coherence tomography (SD-OCT) was used to measure the thickness of different layers of the retina at macular and peripapillary regions and at different quadrants. Between groups comparison was performed with P < 0.05 indicating statistical significance.

Results:

There were 32 eyes in the MS group and 74 eyes in the control group. The MS group was significantly younger than the control group (P < 0.001). The mean ganglion cell complex (GCL++) thickness in superior macular area was 64.1 ± 8.9 μ in the MS group and 71.1 ± 5.9 μ in the control group. The thickness of the RNFL did not statistically differ in each of the quadrants between groups. Despite controlling for age, the macular thickness parameters were significantly thinner in eyes with MS compared to healthy eyes (P < 0.01).

Conclusion:

The macular ganglion cell complex (mGCC) parameters were significantly reduced in recently diagnosed cases of MS as compared to healthy individuals.

Assessing reproducibility and the effects of demographic variables on the normal macular layers using the Spectralis SD-OCT

Purpose

To quantify and view the possible influence of demographic variables on normal macular layers. Additionally, we wanted to assess the reproducibility using the Spectralis SD-OCT.

Methods

A Spectralis SD-OCT machine using a commercially available algorithm was used to scan 242 healthy subjects in an outpatient setting. We examined retinal thicknesses in seven layers: retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL) and retinal pigment epithelium (RPE). Combined retinal thicknesses were expressed as inner retinal layer (IRL), photoreceptor layer (PL) and total retinal thickness (TRT). Measurements were taken from each of the nine sectors defined by the Early Treatment Diabetic Retinopathy Study; the center was the fovea, the inner circle (IC) was 1–3 mm away, and the outer circle (OC) was 3–6 mm away.

Results

The TRT was thickest inferiorly in the IC, and superiorly in the OC. The RNFL (P=0.030), GCL (P=0.006), IPL (P=0.006), IRL (P=0.030), PL (P<0.001) and TRT (P=0.001) were found to be thicker in males. The GCL (r=0.078, P=0.001), IPL (r=0.079, P=0.001), IRL (r=0.072, P=0.002), PL (r=0.076, P=0.001) and TRT (r=0.090, P<0.001) were found to decrease with age. The INL (r=0.060, P=0.010), ONL (r=0.078, P=0.001), and RPE (r=0.066, P=0.004) were inversely related to axial length. Excellent reproducibility was observed in all layers.

Conclusion

Our study shows differences in various retinal layers according to age, gender, and axial length. Additionally, we demonstrate excellent reproducibility of this algorithm using the Spectralis SD-OCT.