Optical Coherence Tomography Angiography Characteristics of Radiation Optic Neuropathy
Condition: Optic Radiation Neuropathy Following Radiotherapy Procedure
MeSH terms: Optic Nerve Diseases
Study type: Observational

Summary: 
      Aim: To develop a suitable radiation optic neuropathy (RON) diagnostic model based on optical
      coherence tomography angiography (OCTA) and to reveal the correlation between endocrine and
      OCTA indexes in nasopharyngeal carcinoma (NPC) patients with radiation encephalopathy (RE).

      Methods: This retrospective cross-sectional study included 80 male NPC patients with RE
      following radiotherapy (40 non-RON and 40RON). Endocrine and OCTA indexes were collected. The
      macular and peripapillary vessel density (VD) were automatically analyzed using AngioVue 2.0
      of the RTVue XR Avanti device. The OCTA indexes were included in the multivariable binary
      logistic regression model between non-RON and RON. For all RE patients, a multiple linear
      regression was performed between each of the OCTA indexes and the endocrine indexes.
    

Detailed description: 
      Best corrected visual acuity (BCVA) and OCTA (Optovue, Inc., CA, USA) were performed in the
      RE patients. All examinations were performed by experienced ophthalmic examiners. AngioVue
      software 2.0 of the RTVue XR Avanti device (Optovue, Inc., CA, USA) was used to perform OCTA
      imaging. The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was applied
      to the scans. Images with a scan quality of not less than 6 were included, while images with
      obvious artifacts detected by a senior ophthalmologist were excluded. The vessel density (VD)
      and retinal thickness of the macular and optic nerve head (ONH) area were automatically
      analyzed in 6 × 6 mm angioretina mode and 4.5 × 4.5 mm angiodisc mode, respectively.

      The statistical analyzes were performed using SPSS 24.0 (SPSS Inc., IL, USA). Student's
      t-test was performed to compare normally distributed variables, while the Mann-Whitney test
      was performed to compare nonnormally distributed variables. Categorical variables were
      analyzed with the chi-squared test Statistical significance was set at p < 0.05. The major
      statistically significant OCTA variables were included in the multivariable binary logistic
      regression model between NRON and RON. Then, thereceiver operating characteristic (ROC) curve
      was generated according to the model, and the area under the curve (AUC), sensitivity (SE)
      and specificity (SP) were reported. In addition, for all RE patients, backward multiple
      linear regression was performed between each of the above OCTA variables and the
      statistically significant endocrine indexes.
    

Intervention name(s): head and neck radiation
Intervention type(s): Radiation
Intervention description(s): RON and non-RON: nasopharyngeal carcinoma patients recieved head and neck radiation; Normal: normal individuals.
Observational model: Case-Control
Time perspective: Retrospective
Sampling method: Probability Sample
Study population: 
        The diagnosis of RON was established according to the following criteria: (1) painless
        progressive sight loss, (2) abnormal VEP and VF defect, and/or (3) ophthalmoscopic evidence
        of blurring of the optic disc margins, dilation of retinal veins, hemorrhages, exudates,
        neovascularization or atrophic optic disc, and/or (4) impaired optic nerve based on MRI.