a 32-year - old male patient was examined for vision loss and the presence of a mass in the left eye in december 2010 .
he had been examined at other hospitals for chronic open - angle glaucoma of the left eye that had persisted since 2006 .
small blisters of the cornea began to appear in october 2007 ; these blisters progressed gradually and eventually invaded the entire cornea . before the appearance of the lesion , no other treatments , such as
laser therapy or phototherapy had been applied , with the exception of eye drops ( alphagan - p ; allergan , irvine , ca , usa ) .
when the patient first visited our clinic , the visual acuity of his left eye was light perception , and the intraocular pressure ( iop ) measured by a tono - pen ( tono - pen aviva , reichert , ny , usa ) was 43 mmhg . upon , slit - lamp examination , a 8.7  7-mm gelatinous mass and blisters covering the entire cornea with new vessels at the 6 o'clock position were observed .
the entire corneal thickness was 1.39 mm , the depth of the degenerated lesion was 0.89 mm , and the residual corneal tissue was 0.50 mm , as measured by anterior optical tomography ( visante optical coherence tomography ; carl zeiss meditec , dublin , ca , usa ) ( fig .
the host cornea was trephinated to a level of 70% to 80% of its thickness using the 8.0-mm hessburg - barron disposable vacuum trephine ( katena instruments , denville , nj , usa ) .
a blunt spatula was used to separate the overlying corneal tissue along the plane of dissection . the anterior lamellar stroma ( about 80% in thickness )
the residual stroma was removed layer - by - layer with repeated dissections until descemet 's membrane was exposed .
the acellular corneal tissue , with a diameter of 8.5 mm , was sutured in place using 32 interrupted stitches of 10 - 0 nylon .
we performed permanent amniotic membrane grafting with a temporary amniotic membrane patch to minimize epithelization delay .
the temporary amniotic membrane and stitches were removed one week after the surgery , and the corneal epithelial defects remained one month after surgery .
iop remained within the normal range , and visual acuity increased to 20 / 200 .
the size of the lesion was 8.7  7 mm , and it consisted of gelatinous white tissue with an irregular surface . under the corneal epithelium ,
myxoid tissue was observed , with a severely vacuolar degenerated stroma beneath the myxoid tissue .
the myxoid tissue was positive on alcian blue staining ( ph 2.5 ) , and a few scattered fibroblasts were observed on hematoxylin and eosin ( h&e ) staining ( figs . 3 , 4 , and 5 ) .
the lesion appeared to be a loose , hypocellular , minimal collagen - depositional , glycosaminoglycan - rich myxoid mass in the subepithelial anterior stroma .
moreover , the central site of the lesion exhibited vacuolar change beneath the myxoid tissue ( fig .
the spindle cells were negative for amyloid ( congo red ) and the vacuoles were negative for chondrocytes ( toluidine blue ) .
myxomas are derived from abnormal fibroblasts that secrete excess mucopolysaccharides instead of producing mature collagen fibers .
corneal myxomas are considered to be a secondary reactive process , and the tumor cells have been suggested to derive from embryonic mesenchymal cells with a multipotential character .
a primary myxoma in the cornea is considered to be rare and a secondary corneal myxoma is a reactive process in someone who has had prior corneal disease or injury inducing chronic corneal edema .
corneal myxomas tend to form anteriorly beneath the epithelium and arise in previously inflamed or injured corneas .
generally , corneal myxomas show spindle - shaped cells within a loose stroma ( h&e ) , and the myxoid stroma stains strongly with alcian blue , indicating high glycosaminoglycan content .
clinically , the differential diagnoses considered were salzmann 's nodular degeneration , allergic hypertrophia , a foreign body reaction , pannus , corneal keloid , amyloid deposition , dermoid tumor , and corneal squamous cell carcinoma .
the patient in this study was being treated with alphagan - p for chronic open - angle glaucoma in a different hospital .
however , there have been no reports that factors , such as glaucoma or glaucomatous agents , induce secondary corneal myxoma . in this case , the myxoma is assumed to be a primary corneal myxoma , because the growing myxoma induced increased iop , and iop returned to the normal range when the myxoma was removed .
this case was similar to a corneal myxoma in the gross and pathological findings on h&e , alcian blue , and masson trichrome staining , but had a lower cell density than other myxomas reported to date .
moreover , the accompanying vacuolar changes in this case were different from those of past myxomas .
contact lens - induced epithelial microcysts or corneal pseudocysts have been previously reported [ 14 - 16 ] , but microcysts were limited in the epithelium and those previous cases differed from this case in the size and number of cysts .
contact lens - induced epithelial microcysts were induced by decreased aerobic metabolic activity due to chronic hypoxia in extended lens wear .
similarly , the vacuolar changes likely resulted from the accumulation of metabolites such as lactic acid in the stroma , because the air supply to the cornea was blocked for a long time by the gelatinous tissue .
however more research is necessary to identify the factors that can induce vacuolar changes in the corneal stroma .
dalk is used to remove pathological corneal stroma from descemet 's membrane and involves transplantation of the stroma from a donor 's cornea .
the advantage of this procedure is that it preserves the recipient 's corneal inner layer and reduces the occurrence of transplant rejection and failure .
recently , dalk using glycerol - preserved corneal tissue was reported to reduce allogeneic immune rejection . in this case , the patient 's descemet 's membrane was intact , but the size of the corneal lesion was 8 mm , which indicated a greater possibility of rejection and involvement of the deep stroma .
we used albumin - preserved acellular corneal tissue from which the cells were removed by gamma irradiation so that the graft was less likely to be rejected .
previous studies have shown that it can also inactivate prions while maintaining the integrity of human albumin , which may be a distinct advantage when compared with other forms of corneal storage available today [ 9,18 - 20 ] .
amniotic membrane is known to decrease surface inflammation and scarring in addition to facilitating epithelialization .
we performed amniotic membrane transplantation for the purpose of improving the microenvironment of limbal epithelial stem cells . in conclusion
, we experienced an 8-mm myxoma in the anterior half of the corneal stroma , accompanied by vacuolation , and we treated it via lamellar keratoplasty with acellular corneal tissue .
 a myxoma is a benign tumor found in the heart and in various soft tissues ; however , a corneal myxoma is rare . 
 a mucinous mass of unknown etiology was observed on the left cornea of a 32-year - old male patient . 
 we performed deep anterior lamellar keratoplasty using acellular corneal tissue and concurrent amniotic membrane transplantation . 
 hematoxylin and eosin staining revealed vacuolation of the parenchyma and myxoid change in the corneal tissue that occurred in the anterior half of the corneal parenchyma . 
 we identified a myxoid stroma by alcian blue staining and observed collagen fibers with denatured stroma by masson trichrome staining . 
 the patient 's visual acuity improved from light perception to 20 / 200 , and the intraocular pressure remained within the normal range for one year after surgery . 
 the transplanted cornea survived successfully with well - maintained transparency , and recurrence was not observed one year after surgery . 
Case Report
Discussion