The Study On The Relationship Between Color Deficiency And Changes Of Macular Retinal And The Severity Of Parkinson Disease

Background: Parkinson disease(PD)is a common neurodegenerative disease in the elderly people.The clinical manifestations include abundant motor and non-motor symptoms.The prominent non-motor symptoms include affective disorder,cognitive disorder,sleep disorder,hyposmia,decreased autonomic nervous function and visual impairment.Due to the close relationship with the quality of daily life of PD patients,Visual dysfunction,as one of the non-motor symptoms of PD,has gradually become a new hotspot in recent years.And it may be expected to become a biological marker for early diagnosis of PD,just like the olfactory disorder.In the field of visual function detection,optical coherence tomography(OCT)is a common non-invasive retinal imaging technology,which has been applied to the study of PD retina for more than 10 years.Many related studies have found that thinning of macular retinal thickness can be used as a biomarker for early diagnosis of PD.Munsell's chess is a more accurate method of color perception test.Many studies by it have found that the color perception disorder in PD patients is gradually aggravated with the progress of the disease.The purpose of this study was to explore the differences and characteristics of color perception and macular thickness between PD patients and healthy controls,the correlation between color perception and macular thickness and the severity of disease,and the relationship between color perception and macular thickness.Method : 30 PD patients in Dalian Friendship Hospital were enrolled as case group,and 30 age-matched and sex-matched healthy people as controls.All the participants underwent neuroophthalmological examinations,including visual acuity,slit lamp microscopy and fundus examination,Mini-Mental State Examination(MMSE),TOPCON CT-80 to measure intraocular pressure,and OCT scanner to scan maculararea under "Macular Cube 512 x 128" mode to obtain macular retinal thickness(the thickness of center area,the thickness of the four quadrants of 3mm circle and 6mm circle,the average thickness of macular cube).The inner and outer rings are divided into four quadrants each: superior,inferior,nasal,and temporal.All participants were tested for binocular and monocular color perception with Munsell's chess.PD severity was assessed by the Unified Parkinson Disease Rating Scale(UPDRS)Part III motor assessment and HY(Hoehn and Yahr)scale.In this study,the eyes of PD patients with severe limb symptoms were defined as the ipsilateral eye subgroup,and the eyes of the opposite side were defined as the contralateral eye subgroup.And they were compared with the randomly selected eyes of all healthy controls.All data were analyzed by SPSS22 software.The differences(retinal thickness and color vision in macular area)between patients and healthy controls were compared using student t test.Statistical descriptions were made by(mean ±standard deviation).And the correlation between variables was examined by Pearson's test.Values of p < 0.05 indicated statistically significant differences.Result : The mean age of PD patients was 69.6±9.4 years,and age-matched healthy was 70.5±6.5 years.There was no significant difference between the two groups(p >0.05).The mean disease duration was 3.6± 4.3 years,the UPDRSIII score was22.8±8.8,and the HY scale was 1.8±0.8.patients with PD showed significantly thinner in foveal retinal(p=0.001),four quadrants of inner rings(superior(p=0.001),inferior(p=0.001),nasal(p=0.001),temporal(p=0.001))four quadrants of outer rings(superior(p=0.001),inferior(p=0.006),nasal(p=0.001)),and mean retinal thickness of macular volume(p=0.001)in the ipsilateral eye subgroup.what's more,patients with PD showed significantly thinner in foveal retinal(p=0.001),four quadrants of inner rings(superior(p=0.001),inferior(p=0.001),nasal(p=0.001),temporal(p=0.001))four quadrants of outer rings(superior(p=0.001),inferior(p=0.001),nasal(p=0.001)),temporal(p=0.037)and mean retinal thickness of macular volume(p=0.001)in contralateral eye subgroup.Patients with PD showed significantly Color discrimination including binocular color vision(p = 0.001),ipsilateral eye subgroup(p = 0.001),contralateral eye subgroup(p = 0.002).The color discrimination ability of the case group was worse than which of the control group,but there was no significant difference.Highly significant inverse correlation between the nasal quadrant of inner rings and mean retinal thickness of macular volume and the HYscale were observed in the PD patients' ipsilateral eyes,respectively(r=-0.676p=0.001),(r=-0.416 p=0.022).Highly significant inverse correlation between temporal quadrant of rings and inferior quadrant outer of rings,and mean retinal thickness of macular volumea and HY scale in the contralateral eyes,respectively(r=-0.528p=0.003),(r=-0.361 p=0.050),(r=-0.370 p=0.044).Highly significant inverse correlation between mean retinal thickness of macular volumea and the nasal quadrant of inner rings and UPDRSIII score in the ipsilateral eyes,respectively,(r=-0.394 p=0.031),(r=-0.361 p=0.050).Highly significant inverse correlation between the temporal quadrant of outer rings and mean retinal thickness of macular volume and UPDRSIII scores in the contralateral eye respectively,(r=-0.446p=0.014),(r=-0.365 p=0.047).The total error scores(TES)of color perception,regardless of the binocular,ipsilateral and contralateral eye have highly significant positive correlation with HY scale respectively(r = 0.752 p= 0.001),(r = 0.663 p =0.001)(r = 0.592 p = 0.001).The total error scores of color perception,regardless of the binocular,ipsilateral and contralateral eye have highly significant positive correlation with UPDRSIII score(r = 0.469 p = 0.009),(r = 0.441 p = 0.015)(r =0.461 p = 0.010).whereas,we didn't detect any correlation between the thickness of macular retina and TES,regardless of the ipsilateral and contralateral eyes.Conclusion: In this study,there is a reduction of macular retina thickness and poor color discrimination in PD patients.With the progress of the disease,the thickness of macular retina became thinner and thinner,and the color perception became worse and worse.However,there is no significant correlation between color vision and macular thickness.OCT and Munsell,alone or in Combination,as two effective,non-invasive,cheap and available examinations,can be helpful to the diagnosis and differential diagnosis of PD,the understanding of the severity of PD and evaluate the efficacy of drugs.