病例9　20岁男性，主诉双眼近视散光进行性加重半年，左眼视力下降显著且戴镜矫正不佳

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

见图1-13。See Fig. 1-13.

鉴别诊断

Differential Diagnosis

◎ 圆锥角膜：双眼先后发病的非炎症性、进展性、局部扩张性角膜病变，以中央或旁中央角膜基质变薄、圆锥形突起、产生不规则散光和形成瘢痕为特征，伴双眼矫正视力的进行性下降。常于青春期发病，40岁左右逐渐趋于稳定。揉眼会使其加重。

◎ 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.

◎ 透明边缘性角膜变性：罕见，多表现为双眼下方边缘角膜进行性变薄，距角膜缘1~2mm，变薄区角膜透明，无血管，没有脂质沉着，不伴Fleischer环和Vogt线。

◎ 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：罕见，先天性，非进展性，常表现为双眼全角膜的变薄和扩张。

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

病史询问

Asking History

◎ 询问近视和散光的发病年龄；屈光不正每年的进展情况。

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

◎ 是否经常揉眼，是否有过敏性结膜炎如VKC等；是否有接触镜配戴史及角膜屈光手术史。

◎ 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、外伤、先天性及全身性疾病史（如成骨不全、结缔组织疾病、唐氏综合征、Ehlers-Danlos综合征及马方综合征等）。

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

检查

Examination

◎ 视力、显然验光，双眼不对称的近视、散光的增加及矫正视力下降。

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

◎ 圆锥角膜的早期体征包括：不对称的屈光不正合并高度或进行性加重的散光。角膜曲率计显示高度或不规则散光。检影表现为“剪刀影”反射。角膜曲率值或角膜地形图表现为下方变陡、轴向扭曲或曲率增加。角膜变薄，下方尤著。角膜变薄最重的区域与曲率变陡或突出的区域相对应。当手电从颞侧照射时，在鼻侧角膜上出现Rizutti征或锥形反射。Fleischer环是一种铁质沉积，常出现在圆锥基底部周围的上皮内，呈棕色，用钴蓝光更易观察。Vogt线为大体垂直平行排列在基质内的细条纹，通常会随着施加在眼球上的压力而消失，而去除压力时又会重新出现。

◎ 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.

◎ 圆锥角膜的晚期体征包括：Munson征，即向下凝视时下睑突出。表层瘢痕。Descemet膜破裂急性水肿，是指后弹力层破裂导致水分进入基质，出现严重的角膜增厚、视力下降和疼痛。急性水肿消退后基质瘢痕形成，在某些情况下可能通过改变角膜曲率和减少不规则散光反而使视力得到改善。

◎ 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.

◎ 角膜地形图检查（尤其眼前节分析仪如Penta cam）：可帮助早期诊断。双眼角膜地形图不对称，厚度不对称以及高度图不对称有助诊断。中央一定区域角膜曲率升高（轻度<48D、中度48~54D、重度>54D）和不规则散光，基质变薄（图 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).

诊断

Diagnosis

圆锥角膜（表1-1）。

Keratoconus (Table.1-1).

治疗

Management

◎ 早期的角膜全面检查、诊断和治疗最重要。

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

◎ 早期患者可以通过框架镜或软性角膜接触镜矫正视力。

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

◎ 如发展到中、重期可配戴RGP硬性角膜接触镜来矫正较高度和不规则散光。RGP不稳定或不能耐受者可以配戴巩膜镜。

◎ 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.

◎ 角膜胶原交联术可帮助延缓圆锥角膜的进展。

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

◎ 不能耐受RGP或晚期患者可以通过手术改善视力，包括深板层角膜移植术、穿透性角膜移植术、角膜表层镜片术和角膜基质环植入术等。

◎ 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.

◎ 对出现急性角膜水肿患者的治疗包括对疼痛和水肿的急症处理。通常给予睫状肌麻痹剂、5%氯化钠软膏(Muro)，局部使用降眼压药物来降低眼压或可使用眼压贴。在移除眼压贴后，患者可能仍需要持续使用氯化钠滴剂或软膏数周至数月，直到积液吸收。一般1~2个月角膜基质水肿会慢慢吸收，局部角膜形成瘢痕。一般形成瘢痕的圆锥角膜不会再进展。若瘢痕不在光学中心区，可配戴RGP继续提高视力；若瘢痕居中且面积较大，可行角膜移植手术。

◎ 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.

患者教育和预后

Patient Education & Prognosis

◎ 绝大多数患者硬性角膜接触镜效果良好。但患者需要适应，少数患者不能耐受。医生耐心讲解，增强其信心非常必要。

◎ 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.

◎ 晚期患者需要手术治疗，排斥率相对较低，预后较好。

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

◎ 建议患者避免剧烈的揉眼或外伤。患者通常在3~6个月的基础上，监测角膜变薄和变陡的进展，以及由此引起的视力变化，并重新评估角膜胶原交联术的必要以及角膜接触镜的适配和护理。急性角膜水肿的患者在积液吸收之前需要更密切的随访。

◎ 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.