Preliminary Observation Of Visual Impairment Related To Vacuolar Sella

Object:The term "empty sella(ES)" was first proposed by Busch in 1951 at autopsy studies to refer to the finding the defects of the diaphragm sellae,flattening of the pituitary gland,and the empty sella was full of cerebrospinal fluid(CSF)[1]Empty sella syndrome is an anatomical and clinical entity composed of intrasellar reposition of the CSF and compression of the pituitary tissue.Two types of empty sella should be distinguished.Primary empty sella(PES)is unrelated to any known previous pathogenesis.There has been several hypotheses of the pathogenesis of PES,such as congenital deficiency of diaphragmatic sellae,immunoreaction,multiple pregnancies,pituitary apoplexy,long-term effects of cerebrospinal fluid(CSF)[2l SESS is usually due to surgery or radiotherapy[3].Clinical manifestations of ESS mainly include headache,visual impairment(hypopsia,visual field defects,papilloedema and optic atrophy),CSF leak and endocrine function disturbances,obesity and hypertension[4].The empty sella is mainly diagnosed by magnetic resonance imaging(MRI).It was reported that second surgical exploration of SESS usually confirmed downward herniation of the optic nerves and chiasm into an enlarged sella due to traction by tethering scar tissue[5].That might be one of the pathogeneses of SESS visual function impairment.The object of our study is:1.Observation of PESS and SESS visual function impairment;2.Study the relevance of ES optic chiasma downward herniation and visual function impairment;3.Study the pathogenesis of the ES visual function impairment.Methods:During the past 6 months,we recruited 28 ESS patients in Peking Union Medical College Hospital.The control group had 24 ES patients without visual impairment,and the case group had 4 ES patients with visual impairment(2 PESS and 2 SESS).Diagnosis was made by MRI(including sagittal and coronal weighted T1 enhanced images and coronal T2 images).Diagnostic criteria:1.empty sella is defined as partial or total when less or more than 50%of the sella is filled with CSF respectively;2.the gland thickness being<2 mm;3.pituitary stalk was or not compressed or displaced;4.excluding pituitary atrophy or developing pituitary gland.Exclusion criteria:1.SESS patients that went through 2 or more than 2 sella turcica surgeries;2.patients had other severe endocrine diseases;3.other ophthalmic comorbidity that might affect vision function,such as cataracts,glaucoma,and retinopathy;4.refractive error?±3.Results:Among all 28 patients,male/female=9/19,and the mean age is 57.0±19.8.Among ESS patients with visual impairment,SESS(with history of sella turcica surgery)accounts for 50%,and PESS also accounts for 50%.In the ES control group,SESS accounts for 37.5%,and PESS accounts for 62.5%.OR=1.67.P>0.05.But chiasma downward herniation could be observed among patients with visual function impairment on their MRI images.Conclusion:There might be no significant correlation between history of sella turcica surgery or radiotherapy and visual function impairment among ES patients,but the impairment might has correlation with chiasma downward herniation.And visual impairment might depend on the severity of chiasma herniation.