Effects Of 3D Facial Anatomical Structure Characteristics On Average Face Of Asians And Caucasians On Ocular Ultraviolet Exposure

Objective:Cataracts constitute a global disease that affects quality of life and is a common and significant cause of visual impairment and blindness worldwide?Epidemiological evidence indicates that the age-standardized disability-adjusted life years?DALYs?rate of cataract vision loss is highest in Southeast Asia,whose population is predominantly of Asian descent,followed by the Eastern Med iterranean,Africa,and Western Pacific,and is the lowest in the United States and Europe,which are inhabited predominantly by Caucasians.Meanwhile,the prevalence of cataracts is higher in Asians than in Caucasians and other races.The eyes are known to be one of the main target organs for ultraviolet exposure,and ultraviolet light is one of the important environmental risk factors leading to age-related cataracts.There are many factors that affect the intensity of ocular UV exposure,such as latitude,altitude,solar elevation angle?SEA?,and background reflectivity.In addition,facial anatomy is also one of the factors that affect the intensity of ocular UV exposure.The 1902 edition of the Encyclopedia Britannica states that in Caucasoid,"brow-ridges are strongly developed",whereas in Mongoloids,"prominent brow-ridges"are usually absent.These types of differences in facial morphology result in differences in the superciliary arch and glabella between Asians and Caucasians.Some studies have shown that nose,facial and vault shapes may have been driven by local adaptation to climate in some ways,and large masticatory components and a pronounced glabellar region and supraorbital ridge,which are found in Fuegian and south continental Patagonian samples but not in Asians.Ambient light exposure levels affect the visual system changes of birds and primates.This effect is equally applicable in humans.Due to the different levels of ambient light exposure in different areas,the eye size of different populations and the latitude of the living area have positive relationship.In this study,we speculate that compared with Asians and other races,the characteristics of the superciliary arch and glabella in Caucasians may block more ocular UV exposure.This explanation may be another reason for the difference in the level of ocular UV exposure intensity between Caucasians and other races,in addition to differences in environmental UV exposure intensity levels.When standing,the human is in the natural head position?NHP?,and the line of sight is horizontal.While the human is walking,the head is tilted downward and the line of sight direction is at a downward angle of 15°with the horizontal direction.The difference in the position of the head is bound to affect the ocular optical angle of incidence,which in turn affects the ocular UV exposure intensity.In summary,this study constructs a 3D optical model of Asians and Europeans,create the concept of 3D MOOAI?Three-Dimensions Maximum Ocular Optical Angle of Incidence?,explores the effects of facial anatomy on ocular UV exposure of Asian and European by UV monitoring and computer simulation,and providing a new basis for improving the perception of ocular UV exposure in age-related cataracts.Methods:1.We chose the 3D facial models with typical average facial features of Asians and Europeans provided by FaceGen Modeller software to represent Asians and Caucasians,respectively.And then we used 3D printing technology to print the Asian and European facial anatomy models and placed them on the previous manikins as 3D facial anatomy manikins for UV exposure monitoring.The monitoring location is a wide square located in Fuxin?42.00°N,121.69°E,46 m?and Shenyang?41.96°N,123.48°E,42 m?,Liaoning Province,China.The background was pavement,and the reflectivity was 0.08and 0.05 for the UVA and UVB bands.During data collection,the manikins were rotated clockwise at a constant speed?360°/min,equivalent to 6°/s?.The measurement interval was 15 min in Fuxin and 20 minutes in Shenyang.The data collected was calculated by the"AvaSoft 7.4 for USB2.0"software to obtain the UV intensity and the biologically effective UV exposure intensity(UVBE_cat).2.In this study,we used 3ds Max software to create the 3D MOOAI of the Asian and European manikins.And we imported the optical models into 3ds Max software[version 2017]to express the effect of anatomical structure on the light entering the eyes by rendering the resulting shadow.The daylight module was set up with the longitude and latitude according to the geographical location of Fuxin and Sanya,and the date and time of daylight module was the measuring time in Funxin and the summer solstice with a full SEA range in Sanya.The direct light,skylight diffuse scattering,and normal daylight rendering results of the Asian and the European manikins were output.The MATLAB 2018a software was used to calculate the grayscale value.Linear regression was used to analyze the relationship between the grayscale value,3D MOOAI,SEA and rotation angles.Results:1.The ocular UV exposure intensity of the Asian and European manikins for UVA and UVB bands showed a bimodal curve with time.When the SEA was approximately below 30°,the difference value of the ocular UV exposure intensity between Asian and European manikin was relatively small;when the SEA was approximately in the range of 30°to 60°,the difference value was relatively large only when the rotation angle was approximately in the range of 282°-336°and 24°-72°;when the SEA was approximately in the range of 60°to 71.03°,the difference value was relatively large at the 150°rotation angle range facing the sun,and for the UVA and UVB bands,the ocular UV exposure intensity in the Asian manikin can be up to 1.87 and 1.47times of that in the European mainkin.2.For the UVA and UVB bands,when the SEA was above 60°,the UV_estimatedstimated exposure intensity can be up to 22%and 16%below the actual ambient UV exposure intensity.3.The UVBE_catat intensity of the Asian manikin was higher than that of the European manikin,and the difference value can be greater than59%of the European manikin.4.The MOOAI in horizontal plane of the Asian and European manikins were 168°and 156°,respectively;the 3D MOOAI of the two manikins were 118.93°and 97.56°,respectively;the average upper MOOAI of the two manikins were 60.16°and 44.85°,respectively;and the average lower MOOAI of the two manikins were 58.77°and 52.71°,respectively.5.When the SEA was below 30°,the grayscale value of the direct exposure in the Asian and the European manikins was similar;when the SEA was 30°to 60°,the range of rotation angles with different grayscale value between the Asian and European manikins were increased with the increasing of SEA.;when the SEA was 60°,the difference of the grayscale values between the two manikins increased sharply;when the SEA was in the range of 66°to78°,the grayscale value of the Asian manikin decreased gradually to the lowest value;when SEA was higher than 78°,the grayscale value of the direct exposure in the Asian and the European manikins was similar and kept in the lowest value.6.When SEA was below 60°,the grayscale value of the diffuse light of the two models is slightly higher than the gray value in the range of 96°to 264°when the rotation angle is in the range of 0°to 96°and 264°to 354°,and the difference value was decreased with the increasing SEAs;when the SEA was above 60°,the gray values of the diffuse light of the two manikins were almost unchanged.7.When SEA was below 60°,the R² values of the regression equations in the direct and diffuse exposure for the two manikins were greater than or equal to 0.90;when SEA was above 60°,the R² values of the regression equations in the diffuse exposure were slightly smaller.8.The ocular UV radiation exposure intensity of the Asian and European manikins with a head tilt angle of 15°was less than when the head tilt angle was 0°.In the UVA and UVB bands,when the head tilt angle was 0°and 15°,the ocular UV radiation exposure intensity of the European manikin decreased sharply at the SEA of 60°and 49°,respectively.At this time,the ocular UV radiation exposure intensity of the Asian manikin was still high.9.In the UVA and UVB bands,the difference value of ocular UV exposure intensity for the two manikins in the head tilt angle between 0°and 15°were higher at the rotation angle of150°toward the sun than that at the rotation angle of 210°against the sun.For the UVA band,the average difference of the Asian and European manikins in the head tilt angles of 0°can 1.49 times and 1.74 times higher than that at head tilt angles of 15°,respectively;and the values were 1.41 times and 1.51 times for the UVB band.For the UVA band,the average difference between the two manikins in the head tilt angles of 0°and 15°were 1.15 times and 1.34 times than the European manikin respectively;and the values were 1.19 times and 1.27 times for the UVB band.10.When the head tilt angle were 0°and 15°,the difference of grayscale value in the direct light exposure between the Asian and European manikins were large,and the gray value of the diffuse scattered light of the two manikins was almost the same.Conclusion:1.The risk of high ocular UV exposure is greater in the Asian manikin than in the European manikin.2.The differences in facial anatomy between the Asian and European manikins lead to the differences of 3D MOOAI,and 3D MOOAI can affect the ocular UV intensity of the two manikins.3.The differences in ocular UV exposure between the Asian and European manikins were mainly affected by direct light.When the SEA ranged from 60°to 78°,the difference in direct light exposure between the two manikins was greatest.4.When the head tilt angle is 0°,the ocular UV exposure intensity of the Asian and European manikins is higher than that at the head tilt angle of 15°.When the head tilt angle is 0°and 15°,the SEA which the ocular UV exposure of the European manikin decreased sharply was about 60°and 49°,respectively.5.For the UVA band,the average difference between the two manikins in the head tilt angles of 0°and15°were 1.15 times and 1.34 times than the European manikin respectively;and the values were 1.19 times and 1.27 times for the UVB band.6.The tilt angle of the head has a great influence on the direct light exposure of the Asian and European models,and has little effect on the diffuse scattered light exposure.