The automated measurement repeatability for GC-IPL thickness was significantly lower in patients with age-related macular degeneration with out of normal CMT range. The effect of changes in macular morphology should be considered when analyzing GC-IPL thicknesses in a variety of ocular diseases.

PurposeTo determine the effects of intravitreal anti-vascular endothelial growth factor (VEGF) on thickness of the retinal nerve fiber layer (RNFL) in patients with age-related macular degeneration.MethodsTwenty eyes of 20 patients diagnosed with age-related macular degeneration who underwent intravitreal anti-VEGF injection were studied. Postinjection RNFL thickness was measured using optical coherence tomography. Average thickness, four-quadrant RNFL thicknesses, and intraocular pressure (IOP) in affected eyes were measured before and 6 and 12 months after anti-VEGF injection for comparison. RNFL thickness and IOP in affected and normal fellow eyes were also compared. Given that macular lesions can affect RNFL thickness, the changes in thickness were evaluated by dividing the 12 clock-hour RNFL into the pathologic areas adjacent to the lesion and the non-pathologic area.ResultsThe mean clock-hour segment in the pathologic area was 4.8 hours. A significantly thicker RNFL was exhibited in temporal quadrants and pathologic areas (p = 0.043 and 0.048, respectively) in affected eyes before injection compared to the baseline RNFL thickness in normal eyes. No significant differences were found in RNFL thickness or IOP between affected and normal eyes after injection. The changes over time in the temporal and pathologic areas were statistically significant at 6 and 12 months after injection compared to baseline data (p < 0.05). No significant differences were displayed in RNFL thickness in the other three quadrants or in non-pathologic areas in either affected or normal eyes. Sequential changes in RNFL thickness in affected eyes were not significant.ConclusionsRepeat intravitreal anti-VEGF treatment did not have a significant effect on RNFL thickness. RNFL thickness significantly decreased with time in the pathologic areas and in the temporal segment adjacent to exudative macular lesions. The reduction in RNFL thickness was most likely associated with changes in the macular lesion rather than with anti-VEGF injection.

The impact of changes associated with shifting of the measurement center should be taken into consideration when measuring GCIPL thickness in patients with retinal diseases, glaucoma, or neuro-ophthalmological conditions.

PurposeTo evaluate the effect of spectral domain‐optical coherence tomography (SD‐OCT) measurement center shift on the measurement of macular thickness.MethodsProspective observational case series. A total of 60 normal eyes of 60 subjects included in the study. SD‐OCT macular scanning (macular cube 512 × 128 scan) was performed twice by an experienced examiner. The average retinal thicknesses of the nine macular sectors as defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) were recorded. Each coefficient of repeatability was calculated for the macular thickness measurements of the ETDRS subfields. Thereafter, the measurement center was manually decentered to a seven scan point, each from the central fovea in steps of 58.7 μm horizontally and 47.2 μm vertically. At each shift point, the change in the macular thickness was compared.ResultsWhen the displacement distance between the measurement center point and the foveal center was within 117.4 μm horizontally and 141.6 μm vertically, the macular thickness measurements did not show any significant differences. However, if the offset of the EDTRS grid center from the anatomic fovea exceeded, we noted that the thickness at the fovea increased and the opposite‐direction region at the inner circle was significantly thinner than the displaced point.ConclusionsThe effect of measurement center shift needs to be considered when analyzing the macular thickness measurements in various ophthalmologic diseases.