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

2007年7月30日 星期一

Optic nerve hypoplasia

成因:

原因不明,可能與媽媽使用藥物(phenytoin, quinine, LSD, alcohol…)或DM mother, 等有關。可能是第13週出現ganglion cell degeneration有關。

表現: double ring sign (一圈yellow-white ring,外面再一圈pigment)

單側:伴 strabismus
雙側:伴 nystagmus

性別平均表現。(♀ = ♂)


相關疾病:
* de Morsier syndrome (septo-optic dysplasia)會有Optic nerve hypoplasia
* Optic nerve hypoplasia是Paradoxical pupillary phenomenon的成因之一
* fetal alcohol syndrome會有Optic nerve hypoplasia
* Optic nerve hypoplasia應安排MRI(尤其雙側更與CNS異常有關)
1. hydrocephalus
2. hydronenecephaly
3. ant. visual pathway tumor

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)

Botox

Botulinum toxin type A

由 C. Botulinum取得 (肉毒桿菌素)

作用: block neuromuscular condution(bind to receptor on presynapse motor nerve terminal, and inhibit the release of acetylcholine release,是間接作用,非直接作用喔!)

* 最初用來治療blepharospasm, hemifacial spasm
* FDA在2002也aprove for cosmetic use用來除皺紋
* Acute spastic ectropion可用Botox治療


適合打botox的情形

1. post-op small residual angle strabismus有效(特別好!術後2-8週打)
2. small to moderate angle exotropia or esotropia
3. acute paralytic strabismus(如CN6 palsy)避免antagonist contracture(打在同側antagonist: MR)
=> 然而,對於單或雙側的traumatic sixth nerve palsy無效。
4. cyclic esotropia
5. 可治療active phase的thyroid ophthalmopathy
6. inflamed prephthisial eye (不適合手術者)

* 打入muscle後,2-4天後開始作用
* 眼外肌約作用5-8週(1~2個月)
=> 可能產生permanent improvement for ocular alignment
* orbicularis muscle大約作用3個月

不適合的情形(botox無效,或需要多次給予):

1. A,V pattern
2. DVD
3. oblique muscle
4. chronic paralytic strabismus (antagonist已contracture)
5. congenital nystagmus


Side effect of BOTOX injection

* Botox injection最常出現的complication: temporary ptosis (考!)

( 3週至3月,小孩25%, 大人16%,小孩比較容易)
=> 也可利用來故意造成tarsorrhaphy的效果,可治療一些corneal epithelial defect

* 第二常見: vertical strabismus 17%
* 其它少見的complication: globe rupture, retrobulbar hemorrhage …

Ectropion VS Entropion

Ectropion (外翻)

* Down syndrome會有cicatricial ectropion (考試喜歡寫entropion讓你挑錯。另外要注意Down syndrome是esotropia,不是exotropia;horizontal nystagmus,不是vertical nystagmus;是myopia而非hyperopia)
* Blepharophimosis有lateral lower eyelid ectropion secondary to ant. lamellar deficiency. (考試喜歡寫entropion讓你挑錯)

* anophthalmic ectropion–loosening lower eyelid
=> prothesis太重,太大或frequency removal所致

* ectropion可造成exposure keratitis



entropion的分類:
 congenital(horizontal laxity)
 involutional
 acute spastic cicatricial(orbicularis spasm造成)
 Cicatricial(Vertical tarsoconjunctival contracture)

* cicatricial entropion ( secondary to post. lamellar scarring)
* 結膜結痂(conjunctival scarring) → 屬cicatricial

* Involutional entropion的成因
1. Horizontal eyelid laxity
2. lid retractor鬆弛
3. 年紀造成enophthalmos

* trichiasis有inturning of lashes
* Trachoma → cicatricial entropion

* Steven-Johnson syndrome → ectropion及entropion都可能


Lid correction for entropion(重要!常考!)
=> Weis, Quickert suture, no FTSG.
常用於cicatrical entropion及厲害的involutional entropion

Repair of retractor–Weis repair
 lower eyelid retractor advancement
 lateral canthal tightening
 taping of the eyelid
 mucous membrane grafting to the posterior eyelid

Temporizing measures – 用Quickact suture(high recurrent rate)
 Horizontal eyelid tightening –lateral tarsal strip
 整層切開,再作eyelid margin rotation



治療方式比較:

* Lid correction for entropion: Weis, Quickert suture

* repair for cicatricial ectropion:skin grafting

* Repair of lower eyelid retractor can be used in entropion and ectropion.


重點整理:

Down syndrome和blepharophimosis是ECtroion!

Trachoma和Trichiasis是ENtropion

Steven-Johnson syndrome兩種都可能。

Eyelid malignancy

Basal cell carcinoma

* 是最常見的眼瞼惡性腫瘤 (佔95%)
* Slow growth,好發於下眼瞼 (上眼瞼最常見的malignancy仍然是BCC)
* 好發在六七十歲的老人(平均67歲),但有5-15%在20-40歲之間。

* Risk factors
 Smoking, excessive sun exposure
 blond hair, Celtic ancestry, blue iris (不是brown iris→AAO習題)

* S/S of eyelid BCC
Painless nodule, shiny and waxy, indurated, firm and immobile, pearly, rolled border, and with fine (small) telangiectatic vessels on the surface.(不會是clear cystic)

分類:
 Nodule type(常見)
 Morpheaform(較aggrassive)

治療:

以外科手術治療之復發率最低!故外科切除是Tx首選。
若BCC長在medial canthal region,則不能採用radiation或cryotherapy

手術:Mohs’ micrographic surgery

Mohs’ micrographic surgery
用於deep infiltrative morpheaform medial canthal tumor
可保留最多healthy tissue及確定tumor完整切除


Squamous cell carcinoma (SCC)

好犯 lower eyelid
 為BCC發生率的1/40,也是用Mohs’ micrographic surgery


Sebaceous carcinoma
 來自meibomian gland或zeiss gland (所以在upper lid比較多)
 好犯 upper eyelid,較好發於女性(女多於男),大於50歲
 然而,在upper eyelid的malignancy中,仍然以BCC最多!
 用 oil red o 及 sudan black 染細胞內的 lipid。

 細胞有 pagetoid intraepidermal involve的特性(skin spread)
 有pagetoid者要用cryotherapy,不可用radiation(無效!)
 看起來像chalazion,但loss of eyelash及meibomian surface destruction為其特徵
 常被誤認為chronic conjunctivitis ~(考!)
 預後比 BCC , SCC 還要差


malignant melanoma
 佔5% skin cancer, 但eyelid則 < 1%

分類 (前兩者皆有vertical invasive growth)
 Lentigo maligna melanoma (常見)
 Nodular melanoma (常見)
 Superficial spreading melanoma
 Acrolentignous melanoma
 Tumor厚度
 > 1.5mm會有metastasis的機會
 < 0.75mm則五年存活率98%
 若 > 4mm 則五年存活率剩50%
 Cutaneous melanoma不可使用cryotherapy(無效!) …
 雖然conjunctival melanoma使用cryothearpy有效呢!

飛車戰神–CAR and MAR

CAR : Cancer-associated retinopathy

tumor分泌recoverin蛋白質攻擊photoreceptor引起。
small-cell lung cancer引起的為最多
colon adenocarcinoma少被報告
早期眼底看起來normal
血管會比較細

CAR會侵犯視網膜的cone和rod細胞 (CAR,有C:cone,R: rod,都會)


MAR: melanoma-associated retinopathy

只攻擊rod (MAR,只有R,於是攻擊Rod)
ERG會呈現negative wave


整理:

* CAR, MAR皆屬於Type 3 hypersensitivity (口訣: 車神開Mazda 3)
* CAR會攻擊cone, rod; MAR只攻擊Rod (口訣:字母裡有什麼就攻擊什麼)


補充:

ERG會呈現negative wave者:

CSNB
X-linked Retinoschisis (XLRS)
Goldman-Farve syndrome (enhanced s-cone/blue-cone syndrome)
MAR → 表上沒有列出來

Eyelid Repair Procedures

下眼瞼重建手術

Small defect ( < 33%)
=> 外眥切開術(canthotomy)後,再直接縫合

Moderate defect (33~50%)
=> semicircular rotation (可至50% defect)

Large defect ( > 50%)

* Hughes procedure (tarsoconjunctval flap from upper eyelid + skin graft) 最為理想
=> 若skin graft由它處取得,則叫modified Hughes procedure
=> modified Hughes procedure 需要蓋住pupil數週,屬Sharing-lid,應避免用於7歲以下小朋友,怕造成amblyopia

其它可修補更大範圍lid defect的procedre
* Cutler-Beard procedure (Full-thickness lower eyelid advancement)
* Tenzel semicircular rotation
=> 上兩種容易有round canthus的結果,應該不若Hughes procedure理想。


上瞼修補比下瞼修補更複雜,更難!

large upper eyelid defect:Cutler-Beard procedure

Honda CRV喔! CRVO

CRVO多單側

病理: 主要在lamina cribrosa堵塞


CRVO分類

1. Ischemic (non-perfused)
範圍較大(>10DD), hemorrhagic
marked venous dilation
很多cotton wool spots
FAG: 可見很多nonperfusion area
視力很差(<10% VA達20/400)
60%有iris neovascularation
90%>50 years

2. Nonischemic (perfused)
Venous stasis, retinopathy
Dot and flame shape hemorrhage, macular edema, 有或無mild disc edema
FAG: circulating prolong (有血流,但不通暢)
Anterior segment: NV很少見於non-ischemic CRVO

* 若有RAPD則表示可能為ischemic type
* ERG若bright flash: dark adapted ratio的降低可顯示ischemic type


risk factor for CRVO
1. Hypertension,
2. DM (比較:DM不是BRVO的risk factor)
3. POAG (glaucoma也BRVO的risk factor)
=> CRVO也是glaucoma的重要risk factor。


Hyperviscosity retinopathy和CRVO很像,但前者雙側發作,後者多單側


Treatment for CRVO

不建議用systemic anticoagulant
* Grid laser對年輕人的macular edema可能可以改善視力

* Radial optic neurotomy (RON)
=> 「arteriovenous crossing sheathotomy」用在BRVO,而非CRVO,勿混淆!

* 打tPA或TA
(以上療效皆未獲證實。)


一般預防性用PRP並不會降低iris NV的發生率

∴CVOS主張等早期的iris NV出現時再做(重要!)但若病患不太會回來follow up,還是可以先打PRP。

Refractive surgery的光學範圍



CK(China老K黨):欺侮尚欺侮 → 75-3-75
LTK(love to kiss):親我啊我要 → 75-25-1

Intracorneal ring : 「白鈴一三近,散光壹點零」
=> 近視 -1.0~ -3.0, 散光限制到 1.0

注意: FDA說PRK不可用來correct mixed astigmatism。

BRVO

* 最常發生於AV crossing, 可能發現hemorrhage, edema, cotton wool spots
* 常60 yrs以後發生,好發superotemporal (63%)
* risk factor for BRVO
hypertension
CV disease
BMI↑
Glaucoma
(DM不是BRVO的risk factor喔! 考試很愛考!)


Prognosis: 要看Parafoveal capillary的完整性

Extensive retina ischemia ( >5 disc diameter) 有40%產生NV,其中60%若不做PRP則會產生preretinal bleeding
 整體而言,50-60%視力≧20/40


photocoagulation用於BRVO兩種情形 (考!)
1. chronic macular edema (>3個月) (視力在 20/40 – 20/200 之間)
2. post. segment NV

iris NV於BRVO發生率只有 1%


BVOS證實:laser對有下列三條件的BRVO患者有助益
1. foveal vascularity完整
2. macular edema
3. 視力在20/40-20/200者 (0.1-0.5)

TA對於CRVO或CRVO的macular edema都有助益


BVOS主張:
1. 對於extensive ischemia ( >5DD) 者做laser可降低NV產生由22% 降為 12%
2. 對已有NV者可降低VH由60% -> 30% (降低一半!)

Rubella

German measle

single-strand RNA Togavirus

分為acquired及congenital(infant with maternal rubella syndrome。

acquired form比較少見,以keratoconjunctivitis, iritis等為主。

congenital form比較多,媽媽在懷孕「第一個」Trimester得到rubella。


眼部表現:

1. fundus change : 從 salt-and-pepper 到 較嚴重的 pseudo-retinitis pigmentosa都有。 (post. pole是主要影響處)
2. Nuclear Cataract (Morgagnian cataract) 15%
3. microphthalmos → glaucoma 10%

4. ant. sengment inflammation with iris atrophy
5. vitritis (很少會影響fundus檢查),有時會有ERD。
6. strabismus

系統相關: cardiac defect等。

* 病毒在出生後「三個月內」都活在lens裡面,在cataract手術後可分離出live virus particle(成人就無法找到live virus particle)。

* 開完cataract surgery,容易引起嚴重的inflammation,甚至形成membrane,需要用topical steroids and mydriatics來治療。

眼壓論高低–IOP

「IOP value」之分佈

Normal range: 10~22mmHg
Mean value: 16±3 mmHg, 非高斯分布(重要!)
Fluctuation 為2-6mmHg, 若fluctuation > 10mmHg, 可能為glaucoma

* high IOP是glaucoma最重要的「risk factor」之一。


IOP之決定因子

房水分泌房率
aqueous flow resistence (特別是juxtacanalicular meshwork)
長期使用corticosteroids
episcleral venous pressure (EVP):正常值在8-10mmHg
=> C-C fistula造成proptosis,可能有neurological sign,會造成EVP升高
=> Sturge-Weber會增加EVP
=> faical cutaneous aniomas (如nevus flammeus)會增加EVP
=> dilation of episcleral vessels會增加EVP
=> thyroid ophthalmopathy會增加EVP

★ foreshortening of the conjunctival fornices→「不會增加EVP」
(參考AAO sec. 10習題13)


不同量眼壓的姿勢: 躺著量 > 站著量 (背!很容易記錯)
早上的眼壓比下午還高

RD後眼壓通常會降5mmHg以上。


Applanation reading:

眼膜厚的眼壓「量測值」會比較高。
眼膜薄的眼壓「量測值」會比較低。

開過LASIK眼壓「量測值」會降。
corneal edema會使眼壓「量測值」下降。

dye太多會高估眼壓
dye太少會低估眼壓

scleral rigidity也會影響iOP的量測。


誰會降低我的眼壓? ↓

喝酒、大麻、海洛英、全身麻醉、懷孕、長期運動
Metabolic/respiratory acidosis(背)


誰會升高我的眼壓? ↑

安非他命、ketamine、succinylcholine、體溫升高
Corticosteroid會升眼壓。
大量喝水、喝茶會增加眼壓。
憋氣、打領帶、長處暗室、哭泣,會增加眼壓。


一般的uveitis初期會使眼壓下降。
特別會造成高眼壓的uveitis:HSV, Posner-Schlosemann, toxoplasmosis


LASIK與IOP之間的關聯

* 在suction過程中,IOP可瞬間高達65mmHg以上
* ocular hypertension不構成LASIK之contraindication
* 有顯著optic nerve cupping, VF loss, VA loss者,不適合做LASIK
* 不應以術後眼壓來決定是否使用降眼壓藥。若懷疑高眼壓者,應於術前先用適合降眼壓劑。

Acanthamoeba keratitis

Acanthamoeba(Portozoa)
 Dormant cyst
 Trohozoite (有感染性)

染色:可用calcofluor white(cyst) => green ; 或 acridine orange (both) => orange

agar: nonnutrient agar with (killed, not alive) E. coli overlay,
 blood agar, buffered charcoal-yeast extract agar


70%與contact lens有關 (自製saline、用tap water清洗CL…)

* 症狀:劇痛!(與角膜外觀不成正比的表現,考試重點)、diffuse SPK
* 由central infiltration開始 後來才進展到paracentral cornea ring infiltration

* enlarged corneal nerve (radial perineuritis!重要!)
* 除了Acanthamoeba,在MEN2b及leprosy會看到enlarged corneal nerves


病原分離: 早期用scraping, 晚期用lamellar cornea biopsy

治療時程:
epithelial stage: 2~4個月
stromal stage: 6~12個月

Tx: (下面的藥台灣幾乎都缺,也全都沒有衛署字號,要從國外訂貨,一週後才到貨)
 diamidine: propamidine hexamide
 Biquanide:polyhexamethyene biquanide chlorhexidine (PHMB)
 Imidazole:miconazole clotrimazole, ketoconazole, itraconazole,
 aminoglycoside:neomycine paromycin


做PK,要等disease-free 3~6月才做。

易牙居聚餐 (ERG)

a wave → 由photoreceptors產生 (negative wave)
b wave → 由muller cell及bipolar cell產生 (positive wave)
C wave => 刺激後2-4秒由RPE產生

* Dark adapted test ( scotopic ERG)
=> Cone-rod break 在5-10分鐘!

* ERG對refractive error不sensitive(除非high myopia)
* 老人跟newborn的ERG signal較低
* 任何年齡都可以做ERG,就連可愛的小寶寶也不用上全麻上陣哩!(強押硬上…)
* Pupil size會影響ERG結果(進去的光量小則signal小)
* Rod比Cone對光還要敏感1000倍 (才有辦法夜視啊!)

* Multifocal ERG →測cone (macula) function
* Pattern ERG → 測ganglion cell layer功能,以偵測early glaucoma
* ERG可評估chronic ischemic vascular disease – b wave, flicker response,通常amplitude會降低且會delay(如CRVO)


* Ocular Ischemic syndrome–ERG顯示 a wave、b wave↓ ∵內外retina皆ischemia
* APMPPE –EOG↓,ERG↓
* Serpiginous–EOG↓,ERG↓
* MEWDS––EOG↓,ERG↓
* Birdshopt–ERG↓
* MCP–ERG ↓or↑
* acute zonal occult outer retinopathy (AZOOR)–ERG↓

* Achromatopsia ( monochromats ): ERG缺cone response,但Rod response正常
* Albinisum: normal cone response in ERG
* CSNB: loss of the rod b-wave and netative-type ERG
* fundus albipunctus –normal ERG

* RP–ERG乃診斷RP最重要且可靠的工具!
=> loss or marked reduction of rod and cone
=> a,b wave皆下降 (下降,而不是negative)

* sectorial RP–只有在某個sector有,雙眼對稱
=> 不會出現reduced and delayed coned b-wave
=> 因為只有sectorial,不足以構成ERG change (seems normal ERG)

* Leber congenital amaurosis => ERG自出生幾乎detect不到

* Cone dystrophy–photopic ERG detect不到而rod ERG正常或接近正常

* Best disease (Vitelliform macular dystrophy)=> normal ERG, abnormal EOG

* Adult-onset vitelliform lesion→EOG正常

* familial drusen→normal ERG及EOG

* pattern dystrophy–mild EOG reduced (∵RPE disorder),normal ERG

* choroideremia–ERG早期異常,但到mid-life則消失
=> Carrier ERG正常,視力正常,有些peripheral RPE change

* Regional and central choroidal dystrophy→normal ERG及EOG

* X-lined Retinoschisis (XLRS)
=> ERG, a wave正常,b wave減弱
=> 最為constant的diagnostic feature
=> 整體而言,ERG呈negative waveform

* Goldman-Farve syndrome(enhanced S-cone syndrome)
=> ERG呈negative waveform



negative ERG

發生在a-wave增強或b-wave減弱的情形。

1. CSNB
2. Goldmann-Farve syndrome (enhanced S-cone syndrome)
3. X-linked Retinoschisis (XLRS)
4. MAR
5. Duchenne muscular dystrophy (DMD)
6. systemic malignant melanoma



例題1: 下列何者不會發現abnormal ERG?
a. Serpiginous
b. sectorial RP
c. Leber congenital amaurosis
d. CRVO
答: b

例題2: 下列何者不會發現ERG呈negative waveform?
a. CSNB
b. Goldmann-Farve syndrome (enhanced S-cone syndrome)
c. X-linked Retinoschisis (XLRS)
d. retinitis pigmentosa
答: d

例題4: 下列何者會出現正常的ERG及subnormal EOG?
a. retinitis pigmentosa
b. Best disease
c. pattern dystrophies
d. Adult-onset vitelliform lesion
答: b,c


ERG的是是非非:

(X) 小寶寶做ERG要上全麻
(X) ERG主要是測macular function
(X) sectorial RP會出現marked reduced ERG waveform
(X) pupil size不影響ERG的結果
(X) Albinisum會出現abnormal cone response in ERG
(O) ERG乃診斷RP最重要且可靠的工具!
(O) pattern dystrophy會有normal ERG
(O) Leber congenital amaurosis自出生幾乎detect不到ERG
(O) Multifocal ERG主要是測cone (macula) function
(O) White dot syndrome中,OHS及PIC的ERG及EOG通常正常

LHON

Leber Heritery Optic Neuritis

* 10-30歲年輕男性較易受影響 (80~90%)
* 10~20%的病患會有partial recovery of VA
* 法裔加拿大人(French Canadian)好發(其partial recovery of VA比例比較高)
* Acute , severe, painless visual loss (早期為單眼)
* 早期出現RAPD,然隨對側惡化,RAPD表現亦隨之減少


典型眼底表現:

* Hyperemia and elevation of the optic disc and thickening of the peripapillary retina (pseudoedema)
* Peripapillary telangiectasia
* Tortuosity of the medium-sized retinal arterioles


* Fundus finding可在視力惡化之前發現
 然而,亦有四成的病人在視力惡化之時沒有眼底異常
* FAG不會有leakage! ~必考
* 一旦第一眼出現問題之後,第二眼會在數週至數月之後,開始發病,極少數的病例會將此間隔拉長,最高達8年之久!
* 第二眼發病後,第一眼慢慢會變得atrophic,且Peripapillary telangiectasia消失。


眼科理學檢查發現
* 視力減退
* color vision loss
* VF: cecocentral scotoma(重要!)


mitochondrially inherited

=> 屬於missense及nonsense mutation的分類 (重要!)
=> 由媽媽的卵子傳給後代,男人的精子不會傳LHON(因為mitochondria在卵子的cytoplasm內)
=> All offspring of a female carrier are either affected or carriers.
=> 奇怪的是,女生幾乎不會發病(infrequenty develop visual symptoms),原因不清楚(可能是男生的問題DNA在細胞內比例比女生高,所以容易發病)


one of three pathogenic mitochondrial DNA (mtDNA) point mutations.

These mutations affect nucleotide positions 11778, 3460 and 14484 of the oxidative phosphorylation chain in mitochondria.

尤其影響高耗能的組織(optic nerve)

degeneration of retinal ganglion cells (RGCs) and their axons that leads to an acute or subacute loss of central vision.

其中有14484的病人,似乎比較有機會spontaneous改善中心視力 (考!14484 prognosis比11778的好。)


Family history不容易取得,也可能無FH (de novo mutation)
治療:目前無有效方法,corticosteroids無效!(考!)

Corneal dystrophy集中評比



沈澱物的口訣:

Micky Mouse Go Home to Los Angles

M → M : macular distrophy → MPS
G → H : granular dystrophy → Hyaline
L → A : Lattice dystrophy → Amyloid

請參考染色故事書


Stromal corneal dystrophy

Granular dystrophy
 AD遺傳
 最常見的stromal dystrophy
 Mason stain (+)
 分類
 type 1 : Groenouw dystrophy,最常見
 type 2:20幾歲出現,不常見erosion,視力佳
 type 3:位置很表淺,infant就出現erosion
 很像RBCD,且mutation也是BIGH3


Lattice dystrophy
 除了typeⅢ為AR之外,多數皆屬AD遺傳
 BIGH3 gene mutation (Lattice type 2 dystrophy與BIGH3無關)
 角膜有澱粉質(Amyloid)沈積
 PK之後recurrence的機會最高!

分類:

* Type I又稱為Biber-Haab-Dimmer Syndrome
=> 沉積為Type AA amyloid
=> 沒有全身性之amyloid沉積

* Type II 又稱為 Meretoja Syndrome
=> 常有facial mask、Blepharochalasis
=> 常有全身性之amyloid沉積
=> 會有orbital, EOM及orbital infiltratoin
=> 角膜Lattice line 較少,且在週邊位置
=> 與BIGH3無關

* TypeIII
=> 屬AR遺傳!
=> 沉積為Type AP amyloid


Macular dystrophy
 屬AR遺傳! 16q22 mutation
 發病時間最年輕! (3-9歲即有症狀)
 PK後recurrence的機率最低。
 Involve peripheral cornea及corneal endothelium
 沈積物是glycosaminoglycan (GAGs)
 可用colloidal iron及Alcian blue染色
 macular spot不清楚,且stroma是diffuse cloudy,被involve的Descemet’s membrane及endothelium後可見到cornea guttata

分類
type 1 : 比較多的一型,無法合成keratan
type 2: 可合成keratan,但量只有正常的30%


Gelatinous droplike dystrophy (primary familial amyloidosis
 AR, Chromosome 1P
 有protruding, mulberrylike subepithelial deposits
 多是日本人,作PK後復發率很高


Schnyder crystalline dystrophy
 AD, 20~30歲診斷出來,有subepithelial corneal crystal, Ch2 1p36
 因為local corneal lipid代謝異常,聚集cholesterol及phospholipid
 Oil red O stain可能phospholipid染紅(考!)

依時間出現的症狀如下:
 central subepithelial crystal (50%病患會有)
 central corneal opacity
 Dense corneal arcus lipoids
 Midperipheral corneal opacification
 Decreased corneal sensation
 相關疾病: type Ⅱa, Ⅲ,Ⅳ hyperlipidemia及40%有hypercholesterolemia


Corneal Stromal Dystrophy綜合評比
Regraft的機率: Lattice > Granular > Macular (L>G>M, LGM, LG made )
發生年齡: Granular > Lattice > Macular


Fleck dystrophy
 非進展性,可以是單側,affect keratocyte深積兩種物質
 CAG–用Alcian blue, colloidal iron染
 Lipid–用sudan black B或oil red O來染
 沈積物遍及整個stroma, 但其它層未involve,對視力通常不影響(考)


Cetnral cloudy dystrophy of Francosis
 非進展性,不需要治療
 對視力不影響(考!)
 MPS沈澱


Fuchs endothelial dystrophy (~考!)
* 通常 > 50 歲女性多,在50歲以前很少有症狀
* 有cornea guttata,可見到beaten bronze
* Descemet’s membrane變厚,角膜內皮細胞變大
* collagen及extracellular matrix深積於Descemet membrane造成endothelial cell dysfunction
* PK效果很好!(重要,必考!)
在眼內手術前,若量到 endothelial count < 1000/mm2,或CCT > 0.65m 則要特別小心!

青光眼用藥整理

* Alphagan是α-2 selective agonist,會有follicular conjunctivitis的副作用,小孩子用可能會有EPS之CNS副作用。
* Alphagan號稱有neuroprotection的效果,機轉不明
* Alphagan與timolol有加成性

* Betoptic透過NMDA的機轉保護視神經

* Xalatan的side effect: hypertrichiasis, hyperpigmentation, CME
* Xalatan降眼壓的機制: increase uveoscleral outflow


timolol 0.5% 與 Xalatan(latanaprost) 的比較
=> Xalatan 的peak effect on IOP比TML來得大
=> Xalatan使用後的variations in IOP較小
=> Xalatan較不會引起cardiovascular complications
> Xalatan has comparable or superior efficacy if administered once daily, in the evening
=> Xalatan causes more red eye

Endophthalmitis–眼內炎

* endogenous endophthalmitis – 最常來自endocarditis, 及GI tract
* endogenous fungal endophthalmitis以candida最常見
* chronic postoperative endophthalmitis:最常見P. Acnes


* endogenous Yeast (Candida) endophthalmitis:常見於indwelling cathetics, chronic antibiotic users, abdomen surgery (IV營養)
 multiple subretinal infiltration => mushroom shaped
 IV amphotericin B穿透力不好,但fluconazole則很好,但systemic SE少


* 在liver transplant後最常見的endogenous endophthalmitis→Endogenous Mold (Aspergillus) endophthalmitis(重要!)
=> lesion比candida大且進展快
=> 用amphotericin B,持別有vitritis時


* post. traumatic endophthalmitis發生率為2-7%
=> Bacillus cerus佔25%致病菌(考!)
=> 其與soil-contaminated injury有關,對vancomycin及clidamycin會sensitive
=> risk可用primary wound closure及早期FB removal來降低


postoperative endophthalmitis可分為

* Acute onset: 在intraocular surgery 6周內
 致病菌
 coagulative negative staphylococcus
 S. aureus
 Staphylococcus
 G(-) organism
 Chronic onset:

* 距intraocular surgery >6周
 致病菌
 propionibacterion
 coagulase negative staphylococcus
 fungi
 Bleb-associated endophthalmitis

* Months or years after surgery
 致病菌
 Streptococcus
 hemophilus
 G(+) organism


Endophthalmitis associated with conjunctival filtering bleb

一旦blebitis → endothphalmitis,則用IVI做treatment
* 常見菌:streptococcus, hemophilus, 其毒性強,即使立即治療,prognosis也比acute endophthalmitis還要差!


IV及oral antibiotics對cataract術後發生的endophthlmitis無效。
但是IV antibiotics對bleb-related endophthalmitis有效!


intraocular surgery如何prevent endophthalmitis?

 術前用antibiotic drop及術中用infusion antibiotics
 尚未證明可prevent endophthalmitis
 β-iodine則證明可減少culture-proven endophthalmitis


術式的影響

* 開phaco時,clear cornea incision比limbal/scleral approach之endophthalmitis機會較大
* ECCE比於ICCE較少發生endophthalmitis
* 開刀拚時間快也不會降低endophthalmitis的發生機率(一切都是天命…)


若是P. acne所引起的endophthalmitis,最重要的是要把PCO membrane用YAG打掉!(AAO習題)


Endophthalmitis Vitrectomy Study (EVS)

IVI : (急性期幾乎都要來一針的啦)

 0.4mg/0.1ml Amikin
 1mg/0.1ml vancomycin
 conjunctival injection:
 25mg vancomycin
 100mg ceftazine
 6mg dexamesasone
 14mg/ml Amikin

視力LP以上,打IVI和做vitrectomy的visual prognosis沒有差別。
但視力在LP以下,則做過VT的病患visual prognosis會比單純IVI來得好。

culture結果:約7% culture positive
其中70%是coagulase(-) staphylococcus

最終視力:
 50% > 20/40 (0.5)
 74% > 20/100 (0.2)

Coats disease (Retinal telegiectasia)

* Coats disease是最像Retinoblastoma的疾病 (不是PHPV喔!)
* male predominance (85%男生)
* idiopathic (non-herediatry, 與systemic vascular disease無關)
* unilateral (單側)
* 表現: retinal telegiectasia,會有venous dilation, microaneurism等,在nasal periphery較明顯,會產生大量的SRF,也就是會有Exudative RD。

★注意: 雖然是retinal vascular的問題,卻幾乎不會發生retinal NV!(重要)


* 在4歲以下的男童比較嚴重,常有leukocoria,要D/D:
1. FEVR
2. ROP
3. facioscapulohumeal muscular dystrophy


治療:

* laser photocoagulation的選擇以「dye yellow」(577mm)最佳:因為需要讓hemoglobulin吸收能量才能封住aneurysm。不可以使用krypton或diode。
* cryotherapy
* RD surgery

Peripheral Retinal Degeneratin

可能會造成RD的Peripheral Retinal Degeneratin
* lattice degeneration (正常人6~10%發生率)
* vitreoretinal tufts
* meridional folds (好發在superonasal)
* enclosed ora bays
* peirpheral excavations

不容易造成RD的Peripheral Retinal Degeneratin
* cobblestone (Paving-stone) degeneration(inferonasal)
* RPE hypertrophy
* RPE hyperplasia
* peripheral cystoid degeneration


Typical peripheral cystoid degeneration (TPCD)
=> 20歲後產生,裂在Outer Plexiform Layer (OPL),比RPCD「多」
(口訣: T-OP → Teaching CR正在手術室OP。主任誇:開得真好,有空多來上刀吧…)

Reticular peripheral cystoid degeneration (RPCD)
=> 裂在Nerve Fiber Layer (NFL),較「少」發生
(口訣: R-NF … Resident-在手術房只會滴水 → No Function…主任說:肉腳!沒事少上來吧)

* Typical degenerative retinoschesis: 1%, 好發在inferotemporal,裂在OPL
reticular degenerative retinoschisis: 1.6%,裂在NFL,易造成bullous RD