敬請指教

本人才疏學淺,懇請諸位先進前輩不吝指正。歡迎光臨:空中視力保健室
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2009年8月5日 星期三

胚胎

網膜虹睫表神經; 外肌外鞏血內皮。
水晶表角結膜淚; 其它都在神經脊。


七言絕句: 好詩!




外胚層 (Ectoderm)

表面外胚層 (Surface ectoderm)
Lens
Corneal epithelium
Cojunctiva
lacrimal glands cells


視經外胚層 (Neuroectoderm )

optic nerve
Retina (RPE and neurosensory retina)
ciliary epithelium (pigmented and nonpigmented)
Iris muscle : sphincter and dilator
Iris epithelium

神經外胚層–由後往前:
optic nerve→retina→ciliary epithelium→iris muscle+epithelium


神經脊( Neural crest)

sclera(teporal之外的大部份)
choroid
stroma of iris
corneal stroma+endothelium
trabecular meshwork
Ciliary muscle

=> cornea,iris,choroid,stroma都在neural crest!


* 中胚層 (Mesoderm)
構成:
眼外肌的muscle fiber (sheath與tendon屬於neural crest)
sclera的temporal portion (sclera的其它部份由neural crest構成)
眼部血管的endothelial lining


器官整理:
* cornea
epithelium – surface ectoderm
stroma and endothelium – neurocrest

* sclera
temporal portion–mesoderm
其它部份–neural crest

* optic nerve:neuroectoderm

* extraocular muscle
belly – mesoderm
tendon and sheath – neural crest


Uvea

* Iris
 Iris muscle (dilator/sphincter)/epithelium – neuroectoderm
 Iris stroma–neural crest

* Choroid – neural crest

* Ciliary muscle – neural crest
 Melanocyte – neural crest
 Trabecular meshwork – Neural crest

* Lens – surface ectoderm


* vitreous–mesoderm + surface ectoderm + neuroectoderm (只差沒有neural crest→因為vitreous沒有 stroma)
* Retina–neuroectoderm
* RPE–neuroectoderm


Anterior chambers 的形成是經由Neural crest cells migrate分化而來
第1波:形成corneal endothelium(1內)
第2波:形成iris, 部份papillary membrane(2彩)
第3波:形成Keratocytes(3角)

口訣: 跳土風舞:「前一二三…向內踩腳」… 1內,2彩,3角


lens embryology:

22天–optic primordium
25天–optic vesicle
27天–lens plate
29天–lens pit
33天–lens vesicle且同時optic vesicle →2 layered optic cup
40天–來至後方的cells elongated→primary lens fiber(embryonic nucleus)→7週至8個月→來至equator的epithelium分化成secondary lens fiber→fetus nucleus

suture–由於lens由外向內分泌fiber,當前後cells相會時,則形成suture,在8週時可見到前有正立Y,後有倒Y結構(前正後倒)

Tunical vasculosa lentis – 分成:
Ant. vascular capsule
 來自long ciliary a.
 形成pupillary strand
 Capsulopupillary portion
Post. vascular capsule
 來自hyaloid a.
 形成Mittendorf dot

zonular fiber在3個月大時由ciliary epithelium來
congenital aphakia – 分primary (根本沒發育)及secondary(發育後又absorb掉)


* Mesenchymal structures of the head, including the eye, are all derived from "a combination of neural crest cells and mesoderm"

* The mesoderm gives rise to all vascular endothelia, all extraocular muscles, and temporal sclera

2009年5月30日 星期六

分類就是學問–Collagen type

Collagen目前有19種,以下略述容易被提及的重點

Type 1 collagen
=> 屬fibril-forming, 組成多數的connective tisse
=> corneal stroma的主要成份 (佔70%的wet weight of corneal stroma)
=> scleral stroma的主要成份

Type 3 collagen
=> corneal stroma及scleral stroma也有
=> 與corneal wound healing有重要關聯

Type 4 collagen
=> 所有的basement membrane都屬之
=> 例如 : Descemet's membrane主要成份就是type 4 collagen
=> 而Bowman's layer不是BM,所以不屬之。(AAO Sec.8第一題)


依器官整理:

Cornea: Type 1,3,5,6,7,12,14
=> Descemet's membrane: type 4,8
=> corneal epithelium的anchoring fibril: type 7
=> Bowman's layer 由 type 1,5,6 collagen 組成

Sclera: Type 1,3 …

Vitreous: Type 2,5,9,11
=> type 2構成主要的fibril
=> type 9構成surface的fibril

結論: 分類就是學問,背不起分類,人生就是黑白的 …



例題1: Vitreous裡主要的collagen不包含何者 ?
a. type 1 collagen
b. type 2 collagen
c. type 5 collagen
d. type 9 collagen
答: a

例題2:下列何者以type 4 collagen為主要成份之一?
a. Vitreous
b. External limiting membrane
c. Bowmann's layer
d. Descemet membrane
答: d.

例題3:vitreous中哪一類的collagen為最主要成份?
a. Type 1 collagen
b. Type 2 collagen
c. Type 7 collagen
d. Type 9 collagen
答: b.

2007年8月10日 星期五

基礎眼科學重點備忘筆記

6. left occipital lobe的post. aspect被傷到,可能產生congruous right upper quadrant anoptic VF defect,也就是在右眼的外上(upper temporal in r't eye)、左眼的內上(nasal upper in l't eye)

7. 影響CN3的aneurysm在哪最多?
答: Post. communicating artery與internal carotid artery之間
(口訣: PCICA → 電腦裡的IC是A等的…)

8.larimal nerve (CN5-1的分支),帶著post-ganglionic parasympathetic fibers支配lacimal glands,掌管lacrimation

9. CN V-1,V-2, 3,4,6 皆通過cavernous sinus
=> CN V-3(mandibular br.)不通過cavernous sinus。

10. de Morsier syndrome會有bilateral optic nerve hypoplasiade
=> 另外還有absence of the septum pellucidum

11. oculodermal melanocytosis (nevus of Ota)
=> unilateral
=> uveal tract可能有hyperpigmentation
=> glaucoma的可能
=> malignant melanoma的可能

12. PAX gene掌管身體胚胎發育的協調

13. anti-oncogen p53的描述
=> it prevents cells from proliferating if their DNA is irreparably damaged.
=> p53就像「防火牆」,萬一出問題,就得停止災情擴大。

15. retinoblastoma中,只有5~10%會有family history。
=> retinoblastom與13q14 deletion syndrome有關
=> 遺傳型是AD

16. 「傳子也傳女,女傳子不傳,子顯女不顯,問君是何病?」
答: 庶乎「粒線體遺傳」之德 …

17. tear film裡富含什麼Ig?
答: IgA (情人眼裡出IgA…)

18. blue cones吸收440nm的光

21. pilocarpine的作用
=> induce myopia
=> induce accommodation
=> central AC shallowing
=> reduce night vision (pupil變小,光圈小,則夜照差)

22. pilocarpine是direct-acting cholinergic agent
=> echothiophate iodide是cholinsterase inhibitor

23. cocaine的機轉: blocks re-uptake of norepinephrine
=> 可用於Horner syndrome之診斷(若點了pupil不大,就是有Horner syndrome)

24. Dapiprazole hydrochloride (Rev-Eyes)是什麼的解藥?
=> phenylephrine (Neo-Synephrine) → Rev配Neo,倒回去就是新的…絕配!

25. CAI的副作用:metabolic acidosis (不是alkalosis)
=> 另一個副作用應該是hypokalemia(不是hyperkalemia)

27. antiviral: vitroptic, vidarabine, acyclovir
(抗病毒藥的命名有個特色:藥名幾乎都會有個V…)

29. rhodopsin的mutation與何有關?
=> retinitis pigmentosa

32. linkage analysis是決定allele之間相近度的一種方法。

36. CN4在muscle cone外,retroblbar最難打到她!

37. optic nerve從optic canal進入眼窩,不跟別人擠SOF…

38. 四條直肌之中,MR的insertion離limbus最近

39. fetal alcohol syndrome沒有microspherophakia
=> 但有microphthalmos,Peters anomaly, narrow forehead and small nose

40. neurocristopathy沒有突變的型式(mutation)
=> 因為…忍者龜才會突變。
=> migration(遷), induction(引), regression(退), differentiation(分)
=> neurocristopathy四招: 遷、引、退、分。就是不變 …

41. post. emryotoxon, peter anomaly, Axenfeld-Rieger syndrome, post. keratoconus皆屬於congenital AC anomaly
=> iris coloboma不屬於congenital AC anomaly

42. oculocutaneous albinisum包括
=> iris transilluminatino
=> tyrosinase positive
=> tyrosinase negative
=> skinhypopigmentation
=> nystagmus (有原因的,不是隨隨便便不明不白的哩!)
★ oculocutaneous albinism乃因缺乏fundus pigmentation造成的sensory defect nystagmu,故非idiopathic。

43. neural crest的三波發育 (土風舞口訣: 一二三、內踩腳)
=> 第一波: corneal endothelium (內:endothelium)
=> 第二波: iris stroma (彩:iris)
=> 第三波: corneal stroma (角:keratocyte)
★ ciliary epithelium是neuroectoderm的結果…不屬neural crest。

44. cyclosporin可減少KCS的不適症狀,但無法幫忙增加淚水 (只能助產,不能幫客戶懷孕…)

45. AREDS說:moderate to advanced AMD患者吃了「黃斑部營養套餐」,就會減緩視力惡化喔!。
=> mild或healthy的人吃了無效!

46. AREDS建議moderate to advanced AMD患者可以每天起床後大喊一聲旺旺,然後開始享用「黃斑部營養套餐」:
=> Antioxidants: vit. C, 500mg Vit. E 400IU, beta carotene 15mg
=> minerals: zinc 80mg(zinc oxide), copper 2mg(cupric oxide)
喔,菜單裡「沒有Vit. A」,喜歡這一味的只好自己買紅蘿蔔回家煮了。

47. ε-crystallin是eyzyme lactate dehydrogenase
=> 一串字寫了6個"e",就是提示我們要選ε

48. LASIK術後靠著endothelial pump抓住corneal flap

49. 可影響藥物穿透角膜的因素
=> 濃度、pH值、載體、離子型皆可影響
★ 藥量無影響! (不是點愈多就進去愈多 … )

50. 眼藥水若提高lipid solubility,則容易穿透角膜
=> solution的穿透力比ointment好(所以PK後的用藥以frequent topical為主)

51. Timolol 0.5%有多少minigram
=> 0.25mg … -_-||

52. smoker若用beta carotene可能會引起lung cancer

53. 散瞳劑疊疊樂之 duration 集中評比:
atropine > scopolamine > homatropine > cyclopentolate > tropicamide
=> 記得scopolamine第二,tropicamide最短效,cyclopentolate第二短
=> 有 -ine 結尾的因為比較IN,所以可以high比較久

2007年8月8日 星期三

Chromosome地址造冊

Ch. 1
* Stargardt disease, AR, Chromosome 1
* Gelatinous droplike dystrophy (primary familial amyloidosis)AR, Chromosome 1P
* GLC1A, 1q23 for Juvenile Glaucoma

Ch. 2
* AR form的pediatric glaucoma, chromosome 2
* Alport syndrome, X-linked為主或AR(10%), Mutation在collagen gene在X chromosome或chromosome 2而影響basement membrane

Ch. 3
* von Hippel-Lindau disease,位在 chromosome 3
* Dominant optic atrophy–AD, 位在 chromosome 3

Ch. 4
* Bietti crystalline corneoretinal dystrophy, AR, Chromosome 4q
* Wolf-Hirschhorn syndrome, 4p
* Rieger syndrome–4q25

Ch. 6
* HLA gene在Chromosome 6上
* North Carolina macular dystrophy, chromosome 6

Ch. 9
* Tuberous sclerosis (Bourneville syndrome), AD, chromosome 9
* familial dysantonomia (Riley-Day syndrome), AR,Chromosome 9q

Ch. 10
* Gyrate atrophy, AR, Chromosome 10, ornithine aminotransferase mutation (OAT)

Ch. 11
* Aniridia,PAX6 gene在chromosome 11p13 , AD
* Best vitelliform dystrophy, AD,VMD2 gene (bestrophin)→Ch.11
* FEVR, AD最多(82%), FEVR 1 gene 在chromosome 11
* Ataxia-telangiectasia(Louis-Bar syndrome), AR,AT gene在chromosome 11

Ch. 13
* Retinoblastoma 13q
* Wilson disease, AR, chromosome 13q14.3
* Trisomy 13, Edward sydnrome

Ch. 15
* Marfan syndrome, AD, chromosome 15q21.1 (fibrillin gene)

Ch. 17
* Cystinosis (cysteine代謝異常),Chromosome 17p13
* Central areolar choroidal dystrophy, chromosome 17
* Neurofibromatosis-1,AD , chromosome 17 (NF-2在ch.22)

Ch. 19
* Myotonic dystrophy, AD, chromosome 19

* Mucolipidosese–mucopolysaccharide Ⅳ (mapped to Chromosome 19p)

Ch.21
* Trosomy 21→Down syndrome

Ch.22
* Neurofibromatosis-2 (von Reclinghausen neurofibromatosis)
* Sorsby macular dystrophy, AD, TIMP3 gene (chromosome 22)

Sex chromosome
* Klinefelter syndrome (47XXY,男性多出一個X染色體)
* Turner syndrome(45X,女生少一個X)
* color vision– 正常x chromosome上有1個red gene及3個green gene

2007年8月7日 星期二

Trisomy

Trisomy 21 – Down syndrome

* 人類最常見的chromosal disorder
* 約有5%為translocation異常

眼表現:

* 合併keratoconus, cataract, myopia(不是hyperopia)
* upslant(mongoloid) palpebral fissure (不是downslant/anti-mongoloid
* Almond-shaped palpebral fissures
* strabismus,通常esotropia(不是exotropia)
* Brushfield's spot
* iris stromal hypoplasia
* optic atrophy
* prominent epicanthal folds
* blepharitis (chronic, cicatricial)


Trisomy 18 (Edwards syndrome)

* prominent epicanthal folds, ptosis
* blepharophimosis with small or oblique palpebral fissures
* thick lower lid
* hypertelorism (hypotelorism)
* hypoplastic supraorbital ridges
* congenital glaucoma
* conreal opacities
* microphthalmos
* iris and uveal colobomas



Trisomy 13 (Patau syndrome)

* hypotelorism (有時會是 hypertelorism)
* shallow supraorbital ridges
* absent eyebrow (眉毛不見了?小貓咪叨走了 …)
* epicanthal folds
* cyclopia (rarely)
* corneal couding
* introcular connective tissue, including cartilage
* 多半為microphthalmos, clinical anophthalmos (少見)
* PHPV
* catarct
* uveal coloboma
* retinal dysplasia
* optic nerve hypoplasia, atrophy, colobomas
* anterior "cleavage" syndrome

2007年8月3日 星期五

Aqueous humor整理

* Aqueous humor由non-pigmented epithelium of ciliary body分泌
=> 分泌速度: 2-3μl/min
=> 每分鐘有1%的房水量turnover

* 房水由Post. chamber→Anterior chamber,成份會隨之改變。

* Aqueous humor九成由trabeculum排出,一成由uveoscleral route排出。

* Aqueous humor供應cornea的90%的glucose

* 人類的aqueous humor與serum plasma成份比較:
1. aqueous humor中Vit. C (Ascorbic acid)濃度比serum plasma還高(高約二三十倍)
2. aqueous humor中chloride、sodium的成份比比serum plasma還高一些些。
2. aqueous humor的potassium與serum plasma一樣多
3. aqueous humor的glucose、HCO3比serum plasma低
4. aqueous humor中protein成份正常狀況下極低,只有plasma中的1/200~1/500。

2007年7月30日 星期一

Tearfilm

* cornea的oxygen supply來自precorneal tearfilm為主(其它少部份來自lid血管、aqueous humor)

* 淚液(tear film)中會出現的免疫球蛋白(immunoglobulin)
=> IgA, Secretory Iga(S-IgA)為主(由主淚腺及副淚腺分泌)。
=> 眼部發炎時,IgA及IgG都會提高
=> Vernal conjunctivitis時,IgE會飆高。

* Tear lysozyme可破壞bacteria cell wall, β-lysin可破壞bacteria的細胞膜,latoferrin可吸收游離鐵,抑制bacteria代謝

* Tear osmolarity在aqueous tear不足或MGD患者會升高
* tear中的potassium比serum plasma的濃度高出很多
* air-precorneal tearfilm負責最大部份的屈光度數


tear function assessment

tear breakup time
 > 10 sec 正常
 < 10 sec 異常
schirmer test
 > 10mm 正常
 < 10mm 異常
tear meniscus
 > 0.3mm 正常
 < 0.3mm 異常


* Tear break up – 跟 lipid layer相關
=> Meibomian gland dysfunction時會出現lipid tear deficiency
=> Rosacea 或 oral isobetinoin 都可能造成lipid layer異常

* Vit. A 乏是 mucin tear deficeicny 最常見的原因
=> 其它還有chemical burn, cicatricial pemphigois, Steven-Johnson syndrome, trachoma

PAX

PAX gene mutation屬於Transcription factor mutation

PAX2 mutation → optic nerve coloboma, renal hypoplasia

PAX3 mutation → Waardenburg syndrome with dystopia conthorum

PAX6 mutation → aniridia, peter anomaly , autosomal dominant keratitis, dominant foveal hypoplasia

* aniridia通常伴隨cataract and glaucoma

* 注意:幾乎所有的aniridia都由PAX mutation而來,但仍有一些partial aniridia是來自AR的Gillepre syndrome

* WAGR : Wilm's tumor, Aniridia, Genitoruinary anomaly, Mental retard (位置在11p13產生gene deletion)

2007年7月27日 星期五

Pigmented VS non-pigmented



ciliary body在stroma下有兩層epithelium

外層(靠近stroma,近AC): pigmented epithelium
內層(靠近aqueous方向,近PC): non-pigmented epithelium

blood-aqueous barrier: 在non-pigmentary epithelium的apices間有tight junction形成。

DM retinopathy : lacy vacuolization of pigmented epithelium of iris(重要!)

medulloepithelioma(diktyoma)起源於ciliary body的non-pigmentary epithelium

房水的分泌:與non-pigmentary epithelium上有Na+K+ pump相關。

Carbonic anhydrase II receptor在 pigmented / non-pigmented epithelium上都有。

2007年7月24日 星期二

遺傳型整理

通論及法則:

結構性疾病中AD比較多一些。
代謝病中大部份都是AR。
AR疾病可能會比較嚴重,若出現基因異型體的AR,通常沒有症狀。
Mitochondrial遺傳和X-link很像,但mitochondrial只能由母親傳下一代。

Oncogene,及Supressor Gene引起的疾病通常都是AD (如Retinoblastoma)
=> 例外: Ataxic-telangiectasia (AT)偏偏給人家是AR,所以考試就很愛考!

整體而言,AD的疾病比較多,但AR比較會被考,這一切的一切,使得猜題變得很有深度與難度,需要無比的勇氣與絕佳的手感方可達成任務!


Corneal dystrophy

macular dystrophy:AR (重要!)
lattice dystrophy:AD (but lattice typeⅢ為AR)
granular dystrophy:AD
Schnyder dystrophy:AD
Gelatinous droplike dystrophy:AR (少見,應該不會考吧)

CHED-1:AD
CHED-2:AR (口訣: 2→R)


Phakomatoses
* Louis-Bar Syndrome(ataxia-telangiectasia):AR (重要!)
* Tuberous sclerosis:AD
* Neurofibromatosis:AD
* Sturge-Weber Syndrome:sporadic (不是AD也不是AR,無inheritanc pattern)

Alzheiber disease(AD):AD (口訣:AD剛好是AD)


Retinoblastoma若為遺傳:AD
Myotonic dystrophy: AD
Marfan syndrome:AD

Xeroderma pigmentosa: AR (很愛考!)


代謝疾病(AR較多)
Mucopolysaccharidosese大部份都是AR
例外:Fabry disease及Hunter為(XR)
Wilson disease(chromosome 13q14.3):AR
Ehlers-Danlos syndrome (AR)
xeroderma pigmentosum – AR
Glalactosemia(AR)


FEVR: AD
Ichthyosis:AD
blepharophimosis:AD (很喜歡故意寫成AR騙人!口訣:眼瞼「包皮」症→D)


Adult的POAG→AD
infantile glaucoma→AR


Mitochondria disease
* LHON (missense and nonsense mutations)
* MELAS syndrome
* CPEO

HLA

animal的WBC表面有glycoprotein叫MHC
而人類叫HLA (human leukocyte antigen)
有六種:
class Ⅰ:HLA-A,B,C
class Ⅱ:HLA-DR,DP,DQ

HLA gene在Chromosome 6



HLA B27

比例:

正常population: 5%
A.S→HLA-B27(+) 佔 90%
Reiter syndrome 85~95%
Anterior uveitis→在台灣, HLA-B27(+) 佔 70%
Inflammatory bowel disease→ HLA-B27(+) 不到50%
IBD+scarolitis: 20%


Behcet disease→HLA B51


Sarcoidosis→HLA B8,B13


SO, VKH→HLA DR4
JRA→HLA DR4,Dw2


Birdshot → HLA A29


retinal vasculitis→HLA B44


MS, OHS→ HLA B7, DR2


intermediate uvetiis→HLA B8,B51