title: Longitudinal Changes in Retinal Nerve Fiber Layer Thickness after Intravitreal Anti-vascular Endothelial Growth Factor Therapy.
abstract: OBJECTIVE
  To 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.
  
  
  METHODS
  Twenty 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.
  
  
  RESULTS
  The 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.
  
  
  CONCLUSIONS
  Repeat 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.
authors.affiliation: Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Korea.; Research Institute for Medical Science, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Jo
authors.affiliation: Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Woo-Jin
authors.initials: WJ
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Il-Hwan
authors.initials: IH
authors.lastname: Shin
authors.affiliation: Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Korea.; Research Institute for Medical Science, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Jung-Yeul
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000368:Aged; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure; D058449:Intravitreal Injections; D008297:Male; D009412:Nerve Fibers / Q000473:pathology*; D011446:Prospective Studies; D000069579:Ranibizumab / Q000627:therapeutic use*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D057135:Wet Macular Degeneration / Q000188:drug therapy*
chemical_list: D020533:Angiogenesis Inhibitors; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000069579:Ranibizumab
keywords: Anti-vascular endothelial growth factor; Optical coherence tomography; Retinal nerve fiber layer