I-choroid iyona yecala le-vascular yelihlo elilele phakathi kwe- retina kunye ne-sclera. I-choroid ixakeke kwinqanaba elingaphantsi kwe-0.2 mm kwaye lincinci ukuya kwi-0.1 mm kwinxalenye yeliso. Iqulethe ii-cells ze-epithelial ze-retinal ezifakwe kwi-retinal kwaye zinika oksijini kunye nokondla kwi-retina yangaphandle. I-choroid ifom i-tract ephethe iris iris kunye ne-body ciliary.
I-choroid yenziwe ngamacandelo amane ahlukeneyo:
- Uluhlu lweHolerer
- Uluhlu lweSttler (imitha yegazi ephakathi)
- I-Choriocapillaris (i-capillaries)
- Umlenze weBruch. (i-membrane engxenyeni yangaphakathi ye-choroid.)
I-melanin i-colored pigment e-dark color in the choroid ithatha ukukhanya kunye nemida ebonakalayo ngaphakathi kweso elingahlambulula umbono. I-melanin icingelwa ukuba ikhusele imitya yegazi ye-choroidal ngokubhekiselele kwisicatshulwa sokukhanya. I-pigment ye-choroidal yintoni ebangela ukuba "amehlo abomvu" xa imifanekiso ekhanyayo ithathwa.
Kwaziwa njenge: choroidea; yengubo echotshozayo
Ngaphandle kokubonelela ngokubonelela nge-oksijeni kunye negazi kwi-retina, ukuhamba kwegazi ye-choroidal kunokupholisa nokufudumala i-retina. I-choroid ibuye neeseli ezikhupha izinto ezicingelwa ukuba zibandakanyeke ekukhuleni kwe-sclera. I-choroid inokuguqula ubukhulu kwaye ezi tshintsho zingenza i-retina phambili kwaye ibuyele emuva, ibuyise i-photoreceptors kwisigxina sokugxila.
Oku akuvelisi umphumo omkhulu wokubaluleka kodwa kubaluleke kakhulu ekukhuleni kwamehlo xa umntwana.
Amehlo akho nombono omuhle uthembele ekunikezeni igazi okwaneleyo ukusebenza. Ngoko ke, i-choroid kufuneka ihlale isempilweni kunokwenzeka ngamaxesha onke. Xa indawo yeso libandakanya i-choroid isulelwe naluphi na uhlobo, i-nerula ne-optic i-nertic ingabandezeleka.
Xa i-macula kunye ne-optic i-nertic iyancipha okanye ichaphazeleke kakubi, umphumo uvame ukuhla kakhulu kwimbono kwaye ngezinye izihlandlo. Ukongeza, ezinye ezininzi izifo ezinzulu zingenzeka ngenxa yesifo.
Izifo kunye neengxaki zeCroroid
- Inqaba ye-choroidal isifo esiqhekezayo kwisithuba esingaphezulu kwe-choroid okanye kwi-choroid ebangelwa ukugqitywa kweempahla ze-choroidal. Nangona oko kwenzeka ngokukhawuleza, kubaluleke kakhulu. Ngokuqhelekileyo kubakho ngenxa yesifo sengqondo ngexesha lokuhlinzwa kweso. Ingxowankulu ye-choroidal inokuvelisa iimpawu ezinzulu. Unyango luqukethe i-headical steroid yehla, i- cycloplegic iliso lehla, kunye noxinzelelo lwamehlo ukuhla kwehla.
- Ukuqhekeka kwe-Choroidal kukugqitywa ngokupheleleyo kwi-choroid, i-membrane ye-Bruch kunye ne-retinal pigment epithelium eyenzeka ngenxa yokukhathazeka kwamehlo enjenge-hit fist. Ngelishwa, ininzi ye-choroidal rupture ibandakanya i-retina, ebizwa ngokuba yi-macula. I-macula ivumela ukuba sibe nomgangatho ophezulu, umbono ophakathi. Ukulimala kukukhokelela ekulahlekelweni kwama-photoreceptors kwi-macula kunye nokulahlekelwa kombono ophakathi. Ukuba ukuphuka akukho kwi-macula, umbono ophakathi ugcinwa.
- I-neroid ye-neroid iyimqoqo yeeseli ezi-pigmented okanye ezingenayo i-pigmented kwi-choroid, i-laycular layer phantsi kwe-retina. Uninzi lwe-choroidal nevi kuphela kufuneka lubekwe iliso. Ugqirha lakho kwamehlo liza kufotola indawo yenkxalabo kwaye uyihlolisise rhoqo. Uninzi alufunanga naluphina unyango. Ukuba i- choroidal nevus ine-pigmentation ye-orange, ibonakala iphakanyisiwe, okanye ifakwe ngendlela engavamile, inokwenzeka ukuba ingaba yi-melanoma ye-choroidal embi. Kule meko, kufuneka unyango olunonya.
I-dystrophies ye-Choroidal yiqela lezifo ezizuze njengefa ezichaphazela i-choroid. I-Choroideremia, i-Gyrate i-atrophy, i-dystrophy e-Central yooystroystyphytic, i-atrophy ye-choroidal eyahlukileyo kunye ne-pigmented retinochoroidal atrophy yimizekelo ye-dystrophies ye-choroidal. Ukulahleka kombono ophezulu kunokwenzeka kwezinye zee dystrophies.
I-Chorioretinitis yisona sifo esiqhelekileyo esihlasela i-choroidea. Olu hlobo lokuvuvukala luvame ukuvelisa amabala amnyama athambileyo kunye nombono onqabileyo. Abantwana abancinci kunye nalabo bantu balwa ne-Herpes Simplex Virus badla ngokuchaphazeleka kwesi sifo. I-antibiotics kunye ne-corticosteroids zisetyenziselwa ukuphumelela ukulwa ne-chorioretinitis.