Abstract:

Objective

To observe the changes of retinal thickness and blood flow in cataract patients with hypertension after phacoemulsification by optical coherence tomography（OCT）and optical coherence tomography angiography（OCTA）.

Methods

A total of 58 patients（66 eyes）diagnosed with age-related cataracts and scheduled for phacoemulsification and intraocular lens implantation at the First Medical Center of PLA General Hospital from April 2023 to July 2024 were enrolled.Patients were divided into two groups based on a confirmed diagnosis of hypertension or a history of taking antihypertensive medication：the hypertension group（30 patients，33 eyes）and the non-hypertension group（28 patients，33 eyes）.The Cirrus 5000-HD OCT（produced by Carl Zeiss Meditec）was used to scan and obtain images of the macular retina thickness.Using the AngioPlex 3mm×3mm imaging mode to scan and obtain central macular thickness（CMT），superficial vascular plexus（SVP），and vascular perfusion density（PD）images of the macula fovea.Age，axial length，systolic blood pressure，intraocular pressure（IOP），and bestcorrected visual acuity（BCVA）were analyzed for normality using the Shapiro-Wilk test.Data that followed a normal distribution were represented as±s，while data that did not follow a normal distribution were represented as the median and interquartile range［M（Q25，Q75）］.Two-factor repeated measures ANOVA was used for intra-group and inter-group analysis，and the Bonferroni correction method was applied for simple effect analysis.Qualitative data such as gender and eye type were expressed as rates and analyzed using the chi-square test.

Results

The PD values of the central area of the macula，inner layer of the macula，intact area of the macula，central area of the optic disc，inner layer of the optic disc，and intact area of the optic disc in the hypertensive group at 1 day，7 days，and 30 days after surgery were 0.12±0.06，0.13±0.05，0.16±0.14，0.33±0.05，0.44±0.57，0.35±0.04，0.31±0.05，0.33±0.06，0.33±0.04，0.21±0.10，0.21±0.11，0.22±0.09，0.37±0.04，0.38±0.04，0.38±0.04，0.35±0.04，0.36±0.04，and 0.36±0.04，respectively.0.04，with no statistically significant differences（F＝2.061，1.072，1.601，0.947，1.559，1.158；P＞0.05）.The PD of the central macular area，inner macular area，and intact macular area at different time points after surgery in the non hypertensive group were 0.10±0.04，0.12±0.05，0.12±0.05，0.33±0.05，0.36±0.04，0.34±0.05，0.30±0.05，0.33±0.04，and 0.31±0.05，respectively，and the differences were statistically significant（F＝3.084，4.462，3.705；P＜0.05）.The CMT values at 1 day，7 days，and 30 days postoperatively for the hypertension group were（242.61±19.78）μm，（246.27±22.02）μm，and（261.27±24.64）μm，respectively.For the non-hypertension group，the CMT values at the same time points were（233.39±21.93）μm，（235.27±22.90）μm，and（244.21±26.27）μm，respectively.Comparison of CMT between the two groups at each postoperative time point showed a statistically significant difference（F _{betweengroups}＝5.13，P＜0.05）.Within-group comparisons also showed statistically significant differences（F _withingroup＝81.251，P＜0.05）.The interaction effect was also statistically significant（F _interaction ＝5.599，P＜0.05）.At 30 days postoperatively，the CMT in the hypertension group was significantly larger than that in the non-hypertension group，with a statistically significant difference（t＝2.721，P＜0.05）.The BCVA values at 1 day，7 days，and 30 days postoperatively for the hypertension group were（0.08±0.10）logMAR，（0.05±0.07）logMAR，and（0.02±0.05）logMAR，respectively.For the nonhypertension group，the BCVA values at the same time points were（0.05±0.05）logMAR，（0.01±0.03）logMAR，and（0.02±0.06）logMAR，respectively.The BCVA between the two groups at each postoperative time point had a statistically significant difference（F _{betweengroups}＝5.216，P＜0.05）.Withingroup comparisons also showed statistically significant differences（F _withingroup ＝10.796，P＜0.05）.However，the interaction effect was not statistically significant（F _interaction＝2.953，P＞0.05）.At 1 day postoperatively，the BCVA in the hypertension group was lower than that in the non-hypertension group，with a statistically significant difference（t＝2.065，P＜0.05）.Similarly，at 7 days postoperatively，the BCVA in the hypertension group was lower than that in the non-hypertension group，with a statistically significant difference（t＝2.804，P＜0.05）.The IOP values at 1 day，7 days，and 30 days postoperatively for the hypertension group were（14.77±3.34）mmHg，（13.07±2.71）mmHg，and（12.07±2.34）mmHg，respectively，with statistically significant differences（F＝18.426，P＜0.05）.The IOP at 7 days and 30 days postoperatively was lower compared to 1 day postoperatively，with statistically significant differences（t＝-3.619，-5.162；P＜0.05）.Additionally，the IOPat 30 days postoperatively was lower compared to 7 days，with a statistically significant difference（t＝-2.979，P＜0.05）.

Conclusions

The thickness of the macular fovea is significantly thicker in hypertensive patients than in non-hypertensive patients1 month after phacoemulsification，which may increase the risk of cystoid macular edema.Within one month after surgery，the blood flow perfusion in the macular and optic disc regions did not change significantly in hypertensive patients，and IOP showed a stable downward trend.Although there was a slight delay in the recovery of BCVA in hypertensive patients，their visual acuity recovery was not significantly affected by the end of the first month postoperatively.

Key words: Cataract, Hypertension, Phacoemulsification, Optical coherence tomography, Optical coherence tomography angiography