| BackgroundThe shape of eyes has always occupied a very important position in human facial aesthetics.The economic and social development promotes the improvement of people’s aesthetic consciousness,which makes the demand of eye plastic surgery increasing.Orbital septum(OS),as an important tissue structure in eyelid,plays an important role in protecting eyeball and isolating orbital inflammation.With the deepening and refinement of the anatomy and histology of eyelid,orbital septum has been widely concerned for its unique physiological function and has been used in a variety of eye plastic surgery,such as blepharoplasty,double eyelid plasty,double eyelid repair and eyelid reconstruction.At present,studies find that there are great differences in the anatomical structure,location and relationship of the orbital septum between the eastern and Western cadavers.However,most of the research objects are Caucasian,Korean and Japanese,while the related anatomical and histological studies of orbital septum in Han Chinese have not been clearly reported,which is still in blank.At the same time,due to the differences in eye anatomy between different ethnic groups,the conclusions of orbital septum research at this stage could not be fully applied to the Han population.Therefore,the purpose of this study is to use the eyelid specimens of the Han Chinese for anatomical observation and histological analysis of the orbital septum,in order to supplement the existing research on the orbital septum of the Han Chinese,and provide more accurate anatomical support for the clinical application of the orbital septum.At the same time,we also optimize the double eyelid plasty according to the relevant research results to improve the clinical treatment effect.Methods1.Anatomical observation of orbital septum in Han ChineseTwenty four eyes of 12 adult cadavers(8 fixed with formalin and 4 fresh)were studied by gross anatomy.The anatomical structure of orbital septum,including its origin and distribution in eyelid,was observed in layer by layer.Secondly,to explore the position relationship between the upper orbital septum and levator aponeurosis fusion(upper white line,UWL)relative to the meibomian,and measure the specific value,data analysis and statistics,and to explore the position relationship between the lower orbital septum and blepharofascia fusion(lower white line,LWL)relative to the meibomian,and measure the specific value,data analysis and statistics.2.Histological study of orbital septum in Han ChineseTwelve eyelids of six Chinese adult cadavers were dissected and sectioned.The relationship between the eyelid composition and the structure around the orbital septum was observed by HE staining.The relative position and stratification of the orbital septum,levator palmebrae superioris(LPS)and Capsulopalpebral fascia(CPF)were studied by Masson staining.Scanning electron microscopy(SEM)was used to examine the surface of orbital septum(OS1 for levator muscle aponeurosis and OS2 for orbital fat)and levator muscle aponeurosis(LPS1 for levator muscle aponeurosis and LPS2 for levator muscle aponeurosis and Mullerian muscle aponeurosis).At the same time,the samples were observed by transmission electron microscope(TEM)to analyze the differences of the ultrastructural composition of each tissue,and to determine whether the posterior wall of the superior orbital septum exists.Scanning electron microscopy(SEM)was used to examine the surface of the lower orbital septum(OS3 for orbital septum and OS4 for orbital fat)and the surface of the eyelid sac fascia(CPF1 for eyelid sac fascia and orbital fat)and the surface of the eyelid sac fascia(CPF2 for palpebral fascia-Müller’s muscle).At the same time,the samples were observed by transmission electron microscope to analyze the differences of the ultrastructural composition of each tissue,and to determine whether the posterior wall of the inferior orbital septum exists.3.Clinical application of orbital septum reset double eyelid method in Han ChineseFrom December 2018 to December 2020,94 Han Chinese female volunteers with single eyelid underwent double eyelid blepharoplasty in the Department of plastic surgery of the First Affiliated Hospital of Naval Medical University were included in this study.The study was carried out after informed consent was obtained and approved by the hospital ethics committee.After random grouping,the experimental group was treated with modified orbital septum reset double eyelid surgery according to the results of anatomy and histology,while the control group was treated with classic incision double eyelid surgery.Postoperative follow-up observation indexes:(1)at 7 days and 6months after operation,the beauty seeker scored the degree of eyelid edema,bruise and scar with visual analogue scale / score(VAS);(2)at 6 months after operation,the beauty seeker scored the degree of eyelid edema,bruise and scar with the Global Aesthetic Improvement Scale(GAIS),(3)six months after the operation,the patients were observed whether there was double eyelid asymmetry or "fleshy feeling".ResultsPart one:With the anatomical observation of orbital septum of cadaver specimens,we found that:(1)The orbital septum was a completely continuous translucent connective tissue membrane.The fibrous connective tissue membrane continues with the thickened periosteum around the orbital margin.The attachment of the orbital septum starts from the orbital margin below the superficial branch of the lateral canthus tendon.It went up along the inner layer of the superior orbital margin,and crossed the supraorbital notch and the superior oblique trochlear.Because of the neurovascular passage at the superior nasal orbital margin,the orbital septum leaved the orbital margin and lied at the upper part of the posterior lacrimal ridge.The inferior part of the superficial branch of the medial canthus ligament went down along the lacrimal bone,adhered to the front of the zygomatic bone several mm away from the orbital margin at the zygomaticomaxillary suture of the inferior orbital margin,and finally to the outer orbital margin of Whitnall lateral orbital tubercle.(2)The orbital septum was fused with the levator aponeurosis at the upper edge of the upper meibomian plate.The standard deviation of the distance between the highest fusion point and the meibomian plate was 11.2 ± 0.8mm.The standard deviation of the distance between the lowest fusion point and the lower meibomian plate was 9.7 ± 1.1mm.The fusion part of upper and lower eyelids overlaps with the edge of meibomian,forming an oval like structure.Part two:(1)The orbital septum of the upper eyelid was divided into two layers,covering the orbital fat from the periosteal thickening area and extending to the meibomian plate.At first,the inner and outer layers of the orbital septum were close.At the lowest part of the orbital fat,the anterior layer of the orbital septum was separated from the posterior layer.The anterior layer was fused with the levator aponeurosis and continues to extend forward.After the inner layer was reflexed,it extended along the surface of the levator aponeurosis There were no obvious muscle cells in the orbital septum,and muscle structure could be seen in the levator aponeurosis.The closer to the levator muscle,the higher the muscle content.The orbital septum of the lower eyelid was also divided into two layers.In the process of extending the lower eyelid margin,the inner layer of the anterior wall of the orbital septum folded back around the orbital fat to form the posterior wall of the orbital septum.(2)The results showed that: 1.The surface of OS1,OS2,LPS1 and LPS2 were mainly composed of collagen fibers and fibroblasts.Under the same visual field standard,the content of collagen fibers: LPS2 > OS1 > OS2 ≈ LPS1;under the same visual field standard,the content of fibroblasts: LPS2 > OS1 > OS2 ≈ LPS1;under the same visual field standard,the content of collagen fibers: LPS2 > OS1 > OS2 ≈ LPS1;under the same visual field standard,the content of fibroblasts: LPS2 > OS1 > OS2 ≈ LPS1;Under the same visual field standard,the uniformity of collagen fiber thickness was: LPS2 >OS1 > OS2 ≈ LPS1;under the same visual field standard,the uniformity of fibroblast arrangement was: LPS2 > OS1 > OS2 ≈ LPS1.That was to say,OS2 and LPS1 had the same surface structure and characteristics,meanwhile,OS2 and LPS1 were the same tissue,both of them were orbital septum tissue,while OS1 was different from OS2 and LPS1,which proves that the orbital septum was stratified.We infered that the orbital septum was divided into two layers(anterior layer and posterior layer),and there was a retroflexion part of the posterior layer of the orbital septum.The surface structure of LPS1 and LPS2 was quite different,and OS1,OS2 and LPS1 all contain telocytes,while LPS2 contain no.The posterior wall of the orbital septum was located on the surface of the levator aponeurosis and did not fuse with the levator aponeurosis.The results showed that the surface of OS3,OS4,CPF1 and CPF2 were mainly composed of collagen fibers and fibroblasts.Under the same visual field standard,the content of collagen fibers:CPF2 > OS3 > OS4 ≈ CPF1;under the same visual field standard,the content of fibroblasts: CPF2 > CPF3 > OS4 ≈ CPF1;under the same visual field standard,the thickness uniformity of collagen fibers: CPF2 > OS3 > OS4 ≈ CPF1;under the same visual field standard,the arrangement uniformity of fibroblasts: CPF2 > OS3 >OS4≈CPF1.Similar to the upper eyelid,the posterior wall of the orbital septum of the lower eyelid existed and did not fuse with the palpebral sac fascia.(3)There were many trojan cells in OS1,OS2 and CPF1 tissues under transmission electron microscope,and the structure was clear and distinguishable.There were no typical Trojan cells in CPF2 tissues.Part three:By comparing the data of 7 days after surgery and 6 months of follow-up,there were significant differences in VAS scores of edema,bruise and scar degree between the two groups(P < 0.05);the GAIS score of the experimental group was better than that of the control group,and the differences between the two groups were statistically significant(P < 0.05).The proportion of asymmetry in the experimental group was higher than that in the control group,while the proportion of double eyelid "fleshy feeling" was less than that in the control group,the difference was statistically significant(P < 0.05).Conclusions1.The orbital septum of Han Chinese was a continuous fibrous connective tissue membrane from arcuate margin to meibomian margin.In the process of extending to meibomian plate,the superior and inferior orbital septum fused with levator aponeurosis and palpebral sac fascia respectively.This study provided more complete information about the anatomical characteristics of orbital septum in Han Chinese,which would help surgeons to better understand the appearance and internal structure of the orbit,so as to evaluate the preoperative eyelid characteristics of Han Chinese more accurately and individually,and to carry out better surgical intervention.2.There were two layers of orbital septum,the anterior layer of anterior wall and the posterior layer of anterior wall.There were posterior walls in the upper and lower eyelid orbital septum(that was,the orbital septum reflexes near the tarsal plate).The structure and cell composition of the anterior and posterior layers of the orbital septum were consistent with those of the posterior wall,and telocytes were found.This conclusion could better guide the improvement of eyelid related surgical approach and operation method,and the orbital septum contained telocytes,which was expected to carry out the research on eyelid repair mechanism in the future.3.Orbital septum reset double eyelid method was based on the anatomical characteristics of orbital septum and the dynamic relationship with levator aponeurosis and orbicularis oculi muscle.Compared with traditional operation,the double eyelid was more natural and has less postoperative complications,which had certain clinical application value. |
PDF Full Text Request