OCTA on the density of optic nerve microvessels in myopic population with ocular hypertension.

OBJECTIVE: To measure functional, structural, and blood flow parameters of the optic disk in myopic patients with ocular hypertension (OHT) and myopic patients using optical coherence tomography angiography (OCTA), this study aims to investigate the variability of each parameter between the two groups, and to analyze the correlation between the RNFL thickness and blood flow parameters, as well as the diagnostic value of these blood flow parameters for myopic patients with OHT. METHODS: This was a cross-sectional study. Myopic adults who were attending the Eye Center of Jinan Second People's Hospital between December 2020 and January 2022, and who had a confirmed diagnosis of OHT, were enrolled. This cohort constituted the myopic group. In these subjects, retinal nerve fiber layer (RNFL) thickness and blood flow parameters within the superficial optic disk 6 × 6 mm area were measured using OCTA. The optic disk blood flow parameters included radial peripapillary capillaries (RPC) perfusion density (PD) in nasal, temporal, superior, and inferior sectors. Visual field assessments were conducted using a Humphrey visual field meter to obtain the visual field index (VFI) and pattern standard deviation (PSD). SPSS 22.0 statistical software was utilized to determine if statistical differences existed between the parameters of the two groups and to analyze the correlation between blood flow parameters and RNFL thickness. Additionally, the area under the subject's operating characteristic curve (AUROC) was used to assess the diagnostic value of blood flow parameters for myopic patients with OHT. RESULTS: There was no statistical difference in PSD and VFI in the OHT group compared with the myopic group (P = 0.351, 0.242). The RNFL thickness was (103.64 ± 8.13) µm and (97.56 ± 12.94) µm in the myopic and OHT groups, respectively. There was no statistical difference in RNFL thickness between the OHT and myopic group (P = 0.052). The PD of radial peripapillary capillaries (RPC) in nasal, temporal, superior, and inferior sectors showed an overall decreasing trend between the myopic and OHT groups, but there was a statistical difference only in the temporal sector (P = 0.008). Correlation analysis of blood flow parameters and structural parameters showed that the PD in the temporal sector and RNFL thickness were not correlated (P = 0.263). By plotting the AUROC of blood flow parameter, it was found that OCTA had good value in diagnosing myopic patients with OHT, and the PD of the temporal sector had higher diagnostic value for differentiating the OHT group from myopic group (AUROC = 0.718, P = 0.008) CONCLUSIONS: Compared with the myopic group, blood flow parameters decreased in the OHT group, while structural and functional parameters did not change significantly, suggesting that blood flow damage may have occurred earlier in myopic patients with OHT, by the correlation analysis between structural and blood flow parameters. OCTA has good diagnostic value for myopic patients with OHT.

The Efficacy of Simultaneous Injection of Dexamethasone Implant and Ranibizumab Into Vitreous Cavity on Macular Edema Secondary to Central Retinal Vein Occlusion.

The purpose of this study was to determine the safety and effectiveness of simultaneous vitreous injection of dexamethasone implant and ranibizumab on macular edema secondary to central retinal vein occlusion (CRVO). We conducted a 6-month retrospective self-control study. Twenty-five patients diagnosed with macular edema secondary to CRVO were enrolled in this study. The patients received intravitreal injection of dexamethasone implant and ranibizumab. The changes in best corrected visual acuity (BCVA), central retinal thickness (CRT) and interocular pressure (IOP) before and at 2w, 1, 2, 3, 4, 5, 6 m after injection were recorded and compared. The adverse reactions in eyes and whole body were observed. The BCVA of all patients at 2 w (61.8 ± 5.42), 1 m (68.68 ± 5.23), 2 m (70.8 ± 5.8), 3 m (68.44 ± 5.61), 4 m (65.76 ± 5.76), 5 m (67.08 ± 5.57), and 6 m (70.12 ± 5.46) after surgery were significantly higher than that before surgery (52.2 ± 5.06,p < 0.01), and CRT of all patients at 2w (393.36 ± 52.66 um), 1 m (334.52 ± 32.95 um), 2 m (298.800 ± 29.97 um), 3 m (309.080 ± 28.78 um), 4 m (345.48 ± 39.81 um), 5 m (349.080 ± 29.88 um), and 6 m (309.76 ± 30.41 um) after surgery were significantly reduced than that before surgery (583.76 ± 121.09 um, p < 0.01). Macular edema recurred in an average of 4.44 ± 0.51 months after treatment, and those patients received combined treatment again. During follow-up, the most common adverse reactions were subconjunctival hemorrhage and increased intraocular pressure, with the incidence of 22% (11/50) and 18% (9/50) respectively. In all cases, the increased intraocular pressure could be controlled by a single intraocular pressure reducing drug. No patient needed to receive anti-glaucoma surgery. The overall incidence of lens opacity was 4% (2/50). After the first injection, no case showed lens opacity. After re-injection, 2 patients (2 eyes) (8%) developed lens opacity. None of the patients showed serious ocular adverse reactions or systemic complications such as vitreous hemorrhage, retinal detachment, endophthalmitis, uveitis or ocular toxicity. The simultaneous vitreous injection of dexamethasone implant and ranibizumab can significantly improve the visual acuity and anatomical prognosis in macular edema secondary to central retinal vein occlusion (CRVO-ME) patients, exhibiting good safety and effectiveness.