Altered Retinal And Pupillary Light Reaction And Clinical Significance In Patients With Vascular Cognitive Impairment And Dementia

Objective : This study used ophthalmic retinal correlation tests to examine changes in retinal thickness,blood flow,and retinal function in patients with vascular cognitive impairment and dementia(VCID)and whether these changes are associated with altered cognitive function.(VCID).Pupillary Light Reaction(PLR)is analysed for changes in the pupillary light reflex in patients with VCID,and the feasibility of PLR testing as an aid to the management of patients with VCID is explored.Method: In this study,using an observational cross-sectional study,30 patients(55 eyes)diagnosed with vascular cognitive impairment or dementia were recruited,excluding 7 patients(14 eyes)with cerebrovascular accidents with cognitive impairment Normal controls were ophthalmologically recruited normal volunteers matched for gender and age to the cognitive impairment group 31 volunteers(62 eyes)were recruited from the ophthalmology department.OCT(Optic Coherence Tomography)completes the measurement of structural parameters of the retina,including: the optic disc segment: Average Retinal Nerve Fiber Layer thickness(RNFL t-average),Inferior RNFLt,Superior RNFLt,Nasal RNFLt,and Temporal RNFLt.Inferior RNFLt,Superior RNFLt,Nasal RNFLt and Temporal RNFLt;Macula: Cube Volume(CV)and Macula Thickness(CT).OCTA(Optic Coherence Tomography Angiography)completes the assessment of retinal microvascular perfusion and measures: Superficial Retinal Capillary Plexus(SRCP)in the macula,Deep Retinal Capillary Plexus Vessel Density(VD)in the Superficial Retinal Capillary Plexus(SRCP),Deep Retinal Capillary Plexus(DRCP),Vessel Density(VD)in the Foveal Avasculae Zone(FAZ),VD in the Foveal Density-300 μm around the Foveal Avasculae Zone(FD-300),and VD in the Foveal Density-300.All subjects had a cranial MRI(within three months for the normal group)and the Simple Mental State Examination Scale(Mini-Mental State Examination(MMSE)and Montreal Cognitive Assessment(MoCA)cognitive function tests,as well as a detailed medical history and Best Corrected Visual Acuity(BCVA)examination,axonometry,and a cognitive examination.BCVA,axial measurements,Non-Contact Tonometer(NCT)measurements and Pupillary Light Reaction(PLR)parameters.The results are compared and analysed to evaluate the relationship between these changes and pathological changes and cognitive levels.Results:Comparison of quantitative parameters related to the OCT optic discA.Changes in the optic disc RNFLt and comparison between normal control and VCID groups: compared with normal control group,the VCID group showed a significant thinning in the optic disc Temporal RNFLt(P<0.05);the mean RNFLt,Superior RNFLt,Inferior RNFLt,Nasal RNFLt of the optic disc in the VCID group compared with normal control group The difference was not significant(P>0.05).B.Changes in optic disc RNFLt and comparison between the cerebrovascular accident control group excluding cognitive impairment(hereafter referred to as the stroke group)and the VCID group: compared with the stroke group,the VCID group had a significantly thinner optic disc Inferior RNFLt(P<0.05);the mean optic disc RNFLt(P=0.05),Superior RNFLt,and Nasal RNFLt in the VCID group compared with the stroke group.Temporal RNFLt,and Nasal RNFLt were not significantly different compared to each other(P>0.05).Comparison of quantitative parameters related to OCT maculaA.Changes in macular retinal thickness and comparison between normal control and VCID groups: compared to normal controls,the VCID group was significantly thinner(P<0.05),CV was significantly reduced(P<0.05)and GCL-IPL was significantly thinner(P<0.05)compared to the mean CT;macular central recess thickness,no significant difference(P>0.05).B.Changes in macular retinal thickness and comparison between the stroke and VCID groups: compared to the stroke group,there were no significant differences in mean CT,macular central recess thickness,CV,or GCL-IPL in the VCID group(P>0.05).Comparison of macular-related quantitative parameters in OCTAA.Changes and comparison of macular blood flow density(VD)in the normal control and VCID groups: compared with the normal control group,the macular SRCP VD was significantly lower in the VCID group(P<0.01)and the paracentral macular concave VD(FD-300)was significantly reduced(P<0.01);there was no statistical difference in macular DRCP VD and macular central concave nonperfused zone(FAZ)size(P> 0.05).B.Changes in macular VD in the stroke and VCID groups and comparison: the FAZ was significantly smaller in the VCID group compared with the stroke group(P<0.05);no significant differences in VD of SRCP,VD of DRCP,FD-300,results(P>0.05).Comparison of quantitative parameters related to OCTA optic discA.Change and comparison of VD of the peri-optic disc radiating capillaries(RPC)in the normal control and VCID groups: compared with the normal group,there was a significant reduction in the overall VD of the RPC in the VCID group(P<0.05).B.Changes in VD of RPC in the stroke and VCID groups and comparison: no statistically significant difference in results between the stroke and VCID groups(P>0.05).Comparison of PLR parameters: The difference in pupil change curve during the recovery period(3-4s)was significant(P<0.05)in the VCID group compared to the normal control group,with slower pupil recovery in the VCID compared to the normal control group.Comparison of cognitive scores with various incorporated indicators of macula and optic discThe MMSE was not significantly correlated with any of the included indicators of macula and optic disc(P>0.05);the total MoCA score was significantly and positively correlated with mean macular thickness(r=0.312,P=0.035)and macular volume(r=0.319,P=0.031),but not with any of the other indicators(P>0.05).Conclusions:1.patients with VCID may develop degenerative retinopathy with reduced VD around the optic disc,thinning of the retinal thickness in the macular region,reduced VD in the SRCP,smaller CV,reduced FD-300 flow density,and thinning of the GC-IPL thickness,with thinning of the RNFLt in patients with VCID first appearing in the temporal quadrant around the optic papilla.2.The reduced FAZ in the macula and the thinning of the RNFLt below the optic disc in patients with VCID compared to those with cerebrovascular accidents may indicate an increased risk of cognitive impairment and may be used as an ophthalmic biomarker to screen or monitor people with a high prevalence of cognitive impairment after stroke.3.MMSE did not have a strong statistical correlation with the reference biomarkers selected for this study,and the question of retinal biomarkers to detect altered cognitive impairment remains to be tested.MoCA was positively correlated with mean macular thickness and macular volume,which may suggest a strong correlation between mean macular thickness and macular volume and cognitive impairment in VCID.4.Pupil light retraction is slower in patients with VCID compared to normal controls and PLR may be a new route to assist in the diagnosis of VCID.5.Early preventive,therapeutic monitoring of VCID may be possible with non-invasive,simple and effective methods such as OCT,OCTA,PLR measurements;OCT,OCT may provide additional useful predictive biomarkers of conversion to VCID in people with a high incidence of stroke.