病例9　20歲男性，主訴雙眼近視散光進行性加重半年，左眼視力下降顯著且戴鏡矯正不佳

CASE 9　A 20-year-old male complained of progressive aggravation of myopia and astigmatism for half a year in both eyes, and the visual acuity of left eye decreased signif icantly which could not be corrected with glasses

見圖1-13。See Fig. 1-13.

鑒別診斷

Differential Diagnosis

◎ 圓錐角膜：雙眼先后發病的非炎癥性、進展性、局部擴張性角膜病變，以中央或旁中央角膜基質變薄、圓錐形突起、產生不規則散光和形成瘢痕為特征，伴雙眼矯正視力的進行性下降。常于青春期發病，40歲左右逐漸趨于穩定。揉眼會使其加重。

◎ Keratoconus: it is a non-inf lammatory progressive keratop athy occurs successively in both eyes with local expansion of the cornea, which characterized by thinning of central or paracentral corneal stroma, conical protrusion, irregular astigmatism and scar formation, and accompanied by progressive decline of binocular corrected vision. It often starts in adolescence and tends to be stable around the age of 40. Rubbing eye make it worse.

◎ 透明邊緣性角膜變性：罕見，多表現為雙眼下方邊緣角膜進行性變薄，距角膜緣1~2mm，變薄區角膜透明，無血管，沒有脂質沉著，不伴Fleischer環和Vogt線。

◎ Pellucid marginal degeneration: rare, mostly manife sted as progressive corneal thinning in the inferior periphery of both eyes, 1 to 2 mm from the limbus. The thinning area of cornea is transparent and avascular. The lipoid deposition, Fleischer’s ring and Vogt’s striae are absent.

◎ 球形角膜：罕見，先天性，非進展性，常表現為雙眼全角膜的變薄和擴張。

◎ Keratoglobus: rare, congenital, nonprogressive, often characterized by thinning and ectasia of the entire cornea of both eyes.

病史詢問

Asking History

◎ 詢問近視和散光的發病年齡；屈光不正每年的進展情況。

◎ Ask the onset of myopia and astigmatism, annual progr ess in refractive error.

◎ 是否經常揉眼，是否有過敏性結膜炎如VKC等；是否有接觸鏡配戴史及角膜屈光手術史。

◎ Whether there is history of persistent eye rubbing, allergic conjunctivitis (such as VKC), contact lens wearing, corneal refractive surgery.

◎ 是否有其他眼病、外傷、先天性及全身性疾病史（如成骨不全、結締組織疾病、唐氏綜合征、Ehlers-Danlos綜合征及馬方綜合征等）。

◎ History of other eye diseases, trauma, congenital and systemic diseases (such as osteogenesis imperfecta,connective tissue disease, Down, Ehlers-Danlos and Marfan syndromes).

檢查

Examination

◎ 視力、顯然驗光，雙眼不對稱的近視、散光的增加及矯正視力下降。

◎ Visual acuity and manifest refractive correction: Note if there is asymmetric myopia between 2 eyes, increase of astigmatism and decrease of corrected vision.

◎ 圓錐角膜的早期體征包括：不對稱的屈光不正合并高度或進行性加重的散光。角膜曲率計顯示高度或不規則散光。檢影表現為“剪刀影”反射。角膜曲率值或角膜地形圖表現為下方變陡、軸向扭曲或曲率增加。角膜變薄，下方尤著。角膜變薄最重的區域與曲率變陡或突出的區域相對應。當手電從顳側照射時，在鼻側角膜上出現Rizutti征或錐形反射。Fleischer環是一種鐵質沉積，常出現在圓錐基底部周圍的上皮內，呈棕色，用鈷藍光更易觀察。Vogt線為大體垂直平行排列在基質內的細條紋，通常會隨著施加在眼球上的壓力而消失，而去除壓力時又會重新出現。

◎ Early signs of keratoconus include: Asymmetric refrac tive error with high or progressive astigmatism. Keratome try showing high astigmatism and irregularity (axis that do not add to 180 degrees). Scissoring of the red ref lex on ophthalmoscopy or retinoscopy. Inferior steepening,skewed axis, or elevated keratometry values on K reading and computerized corneal topography. Corneal thinning,especially in inferior cornea. Maximum corneal thinning corresponds to the site of maximum steepening or prominence. Rizutti’s sign or a conical ref lection on nasal cornea when a penlight is shone from the temporal side.Fleischer’s ring, an iron deposit often presents within the epithelium around the base of the cone. It is brown in color and best visualized with a cobalt blue f ilter. Vogt’s striae,f ine, roughly vertically parallel striations in the stroma. These generally disappear with f irm pressure applied over the eyeball and reappear when pressure is discontinued.

◎ 圓錐角膜的晚期體征包括：Munson征，即向下凝視時下瞼突出。表層瘢痕。Descemet膜破裂急性水腫，是指后彈力層破裂導致水分進入基質，出現嚴重的角膜增厚、視力下降和疼痛。急性水腫消退后基質瘢痕形成，在某些情況下可能通過改變角膜曲率和減少不規則散光反而使視力得到改善。

◎ Later signs of keratoconus include: Munson’s sign, a protrusion of the lower eyelid in downgaze. Superf icial scarring. Breaks in Descemet’s membrane acute hydrops,a condition where a break in Descemet’s membrane allows aqueous into the stoma causing severe corneal thickening,decreased vision and pain. Stromal scarring after resolution of acute hydrops, which paradoxically may improve vision in some cases by changing corneal curvature and reducing the irregular astigmatism.

◎ 角膜地形圖檢查（尤其眼前節分析儀如Penta cam）：可幫助早期診斷。雙眼角膜地形圖不對稱，厚度不對稱以及高度圖不對稱有助診斷。中央一定區域角膜曲率升高（輕度<48D、中度48~54D、重度>54D）和不規則散光，基質變薄（圖 1-14）。

◎ Corneal topography examination (especially the anterior segment analyzers such as Pentacam): is helpful for early diagnosis. The asymmetry of corneal topography, thickness and height is helpful for diagnosis. Corneal curvature increased (mild<48D, moderate 48 to 54D, severe>54D),irregular astigmatism in a specif ic central area, and thinning of stroma (Fig. 1-14).

診斷

Diagnosis

圓錐角膜（表1-1）。

Keratoconus (Table.1-1).

治療

Management

◎ 早期的角膜全面檢查、診斷和治療最重要。

◎ Early comprehensive examination of cornea, diagnosis and treatment are critical.

◎ 早期患者可以通過框架鏡或軟性角膜接觸鏡矯正視力。

◎ Patients in the early stage can be corrected by glasses or soft contact lens.

◎ 如發展到中、重期可配戴RGP硬性角膜接觸鏡來矯正較高度和不規則散光。RGP不穩定或不能耐受者可以配戴鞏膜鏡。

◎ If it develops to middle and advanced stages, RGP contact lens is suitable for correcting irregular or high astigmatism. Scleral contact lens is an option for those who cannot wear or tolerate RPG stably.

◎ 角膜膠原交聯術可幫助延緩圓錐角膜的進展。

◎ Corneal collagen cross-linking is helpful for slowing the progress of keratoconus.

◎ 不能耐受RGP或晚期患者可以通過手術改善視力，包括深板層角膜移植術、穿透性角膜移植術、角膜表層鏡片術和角膜基質環植入術等。

◎ Vision of patients who are intolerable to RPG or in advanced stages can be improved by surgery, including deep anterior lamellar keratoplasty, penetrating keratoplasty,epikeratoplasty, intracorneal ring segment implantation, etc.

◎ 對出現急性角膜水腫患者的治療包括對疼痛和水腫的急癥處理。通常給予睫狀肌麻痹劑、5%氯化鈉軟膏(Muro)，局部使用降眼壓藥物來降低眼壓或可使用眼壓貼。在移除眼壓貼后，患者可能仍需要持續使用氯化鈉滴劑或軟膏數周至數月，直到積液吸收。一般1~2個月角膜基質水腫會慢慢吸收，局部角膜形成瘢痕。一般形成瘢痕的圓錐角膜不會再進展。若瘢痕不在光學中心區，可配戴RGP繼續提高視力；若瘢痕居中且面積較大，可行角膜移植手術。

◎ Medical therapy for patients who have an episode of corneal hydrops involves acute management of the pain and swelling.Patients are usually given a cycloplegic agent, sodium chloride(Muro) 5% ointment, topical IOP-lowering drugs to reduce intraocular pressure and may be offered a pressure patch.After the pressure patch is removed patients may still need to continue sodium chloride drops or ointment for several weeks to months until the episode of hydrops has resolved.Generally, corneal stroma edema will be absorbed slowly with scar formation in local cornea in 1 to 2 months. If the scar is not in the optical center, RGP can be chosen to improve vision, while corneal transplantation can be considered if the scar is in the center with a large area.

患者教育和預后

Patient Education & Prognosis

◎ 絕大多數患者硬性角膜接觸鏡效果良好。但患者需要適應，少數患者不能耐受。醫生耐心講解，增強其信心非常必要。

◎ Most patients can be corrected well by RPG, although it needs an adaptive process and a few patients cannot tolerate it. It is necessary for doctors to explain patiently and enhance their conf idence.

◎ 晚期患者需要手術治療，排斥率相對較低，預后較好。

◎ Surgical treatment is needed in advanced cases. The rejection rate is relatively low and the prognosis is usually optimistic.

◎ 建議患者避免劇烈的揉眼或外傷。患者通常在3~6個月的基礎上，監測角膜變薄和變陡的進展，以及由此引起的視力變化，并重新評估角膜膠原交聯術的必要以及角膜接觸鏡的適配和護理。急性角膜水腫的患者在積液吸收之前需要更密切的隨訪。

◎ Patients are advised to avoid vigorous eye rubbing or trauma. Patients are usually followed on a 3 to 6 months basis to monitor the progression of the corneal thinning, steepening, the resultant visual changes, and to reevaluate the need for cross linking and contact lens f it and care. Patients with hydrops are seen more frequently until it resolves.