Corneal myxoma associated with keratoconus and Down's syndrome

PURPOSE: Primary myxoma of the cornea is extremely rare. Until now, only four primary corneal myxomas were reported in the literature, whereas secondary involvement of the cornea by conjunctival and limbal tumors is much more common. METHODS: We report an additional case in a 26-year-old woman with keratoconus and Down's syndrome. Excision of the corneal mass was performed by penetrating keratoplasty. Histochemical, immunohistochemistry, and ultrastructural studies were used to obtain a definitive diagnosis. RESULTS: The tumor exhibited the characteristic histologic features of myxoma. The tumor cells showed immunoreactivity for vimentin but not for S-100 protein, epithelial membrane antigen, CAM 5.2, HHF-35, or muscle-specific actin. Ultrastructural features were fibroblast-like or stellate cells with cytoplasm containing abundant, rough reticulum and dilated cisternae. No recurrence was observed 36 months after penetrating keratoplasty. CONCLUSION: This is only the fifth report of such an occurrence. Although the coexistence of myxoma in Down's syndrome with keratoconus is described here for the first time, the differential diagnosis of apparently evident acute hydrops on clinical inspection should not rule out the possibility of a corneal myxoma. Histologic analysis should therefore be performed.     

Primary corneal myxoma

PURPOSE: To present the clinical and histopathological characteristics of a corneal myxoma. METHODS: A 36-year-old, white woman presented with blurred vision and a whitish opacity on the left cornea. Clinical examination revealed a whitish, non-tender, 5 x 9 mm superficial tumour on the cornea. The tumour was excised and examined microscopically. RESULTS: The tumour was composed of spindle-shaped cells in a myxomatous ground substance. Immunohistochemically, the tumour cells were positive for vimentin, muscle-specific antigen and smooth muscle antigen. The tumour was classified as a myxoma of the cornea. The origin of the tumour is discussed. CONCLUSION: This is the second reported case of a corneal myxoma without prior corneal disease.     

准分子激光治疗性角膜切削术治疗角膜弥漫性火药伤

目的:探讨准分子激光治疗性角膜切削术在角膜浅层弥漫性火药伤中的应用,为角膜弥漫性火药伤提供一种新的有效的治疗方法。方法:收集1999年12月至2003年12月期间在我院就诊的25例(39只眼)角膜浅层弥漫性火药伤患者,采用准分子激光治疗性角膜切削术进行异物清除。术后观察视力、角膜上皮恢复时间、眼压、远视状态和Haze等状况。结果:该手术与常规手术相比,缩短了手术时间,一只眼激光手术过程在10min以内。一次手术即可完成绝大部分的异物剔除,手术损伤小,一般在1周内角膜上皮可以完全恢复。术后在角膜光学区基本不残留角膜斑翳,术后视力显著提高。术后10d平均视力为0.6。术后患者轻度远视38例,中度远视1例。该手术产生的并发症在术中和术后也能得到良好的控制,安全性和预测性较高。结论:准分子激光治疗性角膜切削术在角膜浅层弥漫性火药伤中是一种方便、效果好、费用低廉并值得推广的治疗方法。     

Kornealer Tumor nach Vorderkammerlinsenimplantation bei Marfan-Syndrom

A 57-year-old male patient with Marfan syndrome presented at our clinic with a whitish gelatinous corneal tumour in the right eye. The initial examination revealed pronounced corneal oedema, bullous keratopathy, as well as an iris-fixed anterior chamber lens implanted 7?years previously. After the tumour was removed, the anterior chamber lens was explanted and keratoplasty was explanted and a two stage keratoplasty was performed. Histological analysis of the tumour and the cornea revealed vimentin and a number of smooth muscle actin (SMA)-positive tumour cells. The cornea below the tumour displayed a partially absent Bowman's layer and extensive pannus tissue. The characteristics of the corneal tumour and the subjacent cornea as described above are typical of secondary corneal myxoma. The influence of Marfan syndrome, a systemic connective tissue disorder present in the patient, on the etiopathogenesis of the corneal myxoma could not be fully determined.     

Keratoplasty after mustard gas injury: clinical outcome and histology

PURPOSE: Ocular injury by mustard gas can lead to severe eye damage with a delayed course. We report the corneal histology and follow-up after keratoplasty in a patient with mustard gas injury. METHODS: The patient presented with recurrent painful corneal inflammation in both eyes not improving under local therapy. Visual acuity impaired to handmovements. A penetrating keratoplasty was performed on the left eye and afterwards an autorotation keratoplasty on the right eye with a later corneal graft. RESULTS: After the operation of the left eye the patient was immediately painfree and the visual acuity improved to 0,4. So far there have been no signs for transplant rejection or inflammation. Histology of the cornea revealed massive stromal necrosis, and signs of chronic inflammation. Despite denervation of the cornea after autorotation keratoplasty the right eye was still painful and became only painfree after corneal transplantation. CONCLUSION: There has been not much experience with corneal transplantation after mustard gas injury and there is a high risk for transplant rejection due to inflammation and vascularisation of the cornea. Successful and painfree healing with keratoplasty seems only possible after complete removal of the necrotic material.     

Corneal changes in spondyloepiphyseal dysplasia tarda

BACKGROUND: A new type of corneal opacity with prominent corneal nerve fibers as an ocular complication of spondyloepiphyseal dysplasia tarda (SEDT). CASE: A 58-year-old woman, diagnosed with SEDT at 5 years of age, underwent a complete ophthalmological examination. OBSERVATIONS: The patient had no complaints and no history of eye disease. No relatives were reported to have suffered from SEDT. Slit-lamp examination disclosed a diffuse opacity in the central cornea in both eyes, which was localized in the middle to deep stroma. Dot opacities in the central and paracentral cornea were located in the middle of the stroma in both eyes. Optically clear regions were observed in the peripheral cornea of both eyes. More interestingly, corneal nerve fibers were visible passing from the limbus to the central cornea in both eyes. RESULTS: The etiology of the corneal opacities of this patient with SEDT is unknown. However, collagen and proteoglycan abnormalities in the skin of patients with SEDT have been reported. Therefore, such abnormalities may also be present in the cornea and these alterations may lead to corneal complications.     

Phototherapeutic keratectomy in treating keratomycosis

PURPOSE: To evaluate the efficacy of using phototherapeutic keratectomy (PTK) in the treatment of superficial keratomycosis. METHODS: We studied 9 patients with superficial keratomycosis that had infiltrated less than half of the corneal thickness and responded poorly to topical antifungal therapy. Using a 193-nm excimer laser, we performed PTK to try to eradicate the infiltrates and facilitate antifungal therapy. We compared our study group findings with those of a control group made up of 31 cases of keratomycosis, also involving infiltration of less than half of the corneal thickness that had been treated with traditional surgical procedures and topical antifungal agents. RESULTS: Using PTK and short-term antifungal eyedrops, we were able to eradicate keratomycosis without recurrence in all 9 study patients. Much less time was needed to treat the PTK group (12.9 +/- 3.6 days) than the control group (40.8 +/- 26.4 days) (P <0.05). After PTK, the ablated area underwent rapid reepithelialization (average, 3.6 +/- 1.8 days). Final vision ranged from 20/200 to 20/20. The PTK group had an average visual improvement of 2.9 +/- 2.1 lines, which was significantly better than final improvement found in the control group (average, 0.6 +/- 1.7 lines) (P < 0.05). PTK complications included mild corneal haze, astigmatism, and thinning cornea. CONCLUSIONS: Because PTK can shorten treatment time, hasten reepithelialization, and restore reasonably good vision, it can be a valuable therapeutic alternative for superficial keratomycosis, especially in instances in which there is poor response to treatment by topical antifungal agents alone.     

治疗性准分子激光角膜切削术及其进展

应用激光切削角膜表浅病变组织，即治疗性准分子激光角膜切削术（PTK）治疗角膜病已开展了20余年，近年来发展迅速，技术日趋完善，适应证得到拓展并且有严格的规范，安全性高。PTK已用于大泡性角膜病变、角膜的隆起性病损、角膜浅表炎症性病变、遗传性角膜营养不良性病变、翼状胬肉以及一些儿童浅表性角膜病变的治疗，PTK与其他疗法的联合应用在治疗角膜病变中也发挥着较好的治疗作用。此外PTK治疗浅表性角膜病变的安全性较好，不良反应小，可延迟或替代角膜移植术，具有较好的应用前景。就PTK在眼科临床应用中的注意事项、效果、安全性、并发症、适应证等研究进展进行综述。     

Histological study of gelatinous drop-like dystrophy following excimer laser phototherapeutic keratectomy

PURPOSE: Investigation of effects of excimer laser phototherapeutic keratectomy (PTK) on gelatinous drop-like dystrophy. OBJECT AND METHODS: The patient was a 28-year-old woman with gelatinous drop-like dystrophy. She had a history of penetrating keratoplasty and underwent PTK for recurrent lesions by spot mode several times. Finally her sight deteriorated and she underwent lamellar keratoplasty. We divided the corneal specimen into 2 halves, the non-ablated area and the ablated area. The corneal specimens were investigated histologically. RESULTS: Light microscopy showed a decrease in thickness of the epithelial layer, absence of Bowman's layer, and amyloid positive materials at the subepithelial layer in both areas. Electronmicroscopy showed irregularly arranged amyloid fibrils in the subepithelial layer of the non-ablated area. In the ablated area, two different types of amyloid fibrils were identified. In the middle and deep stromal layer, the collagen lamellar structure was intact and keratocytes were normal in both areas. CONCLUSIONS: In the subepithelial layer, two different types of amyloid fibrils were identified in the ablated area. These findings might show that the original disease was affected by excimer laser ablation. In the middle and deep stromal layer, collagen lamellar structure was intact and keratocytes were normal in both areas. These findings suggest that PTK has less effect on the tissue beneath the ablated area, indicating that PTK is a useful and safe technique to remove corneal opacities.     

A case of recurrent corneal erosion caused by self-inflicted injury]

A 20-year-old female developed periodically recurrent corneal erosion in a 10mm diameter area of the central cornea. Since the episodes of corneal erosion occurred suddenly in the early morning every 6-7 days and since medical treatments could not prevent recurrence, we suspected that the corneal erosion was due to self-inflicted injury such as mechanical damage and/or topical application of toxic drugs. Psychological tests also indicated that the patient had a tendency towards hysteria. The corneal erosion has not recurred since we completely protected both her eyes at night. These findings strongly suggested that the cause of this corneal erosion was due to self-inflicted injury.     

Treatment of an 8-mm Myxoma Using Acellular Corneal Tissue

A myxoma is a benign tumor found in the heart and in various soft tissues; however, a corneal myxoma is rare. A mucinous mass of unknown etiology was observed on the left cornea of a 32-year-old male patient. We performed deep anterior lamellar keratoplasty using acellular corneal tissue and concurrent amniotic membrane transplantation. Hematoxylin and eosin staining revealed vacuolation of the parenchyma and myxoid change in the corneal tissue that occurred in the anterior half of the corneal parenchyma. We identified a myxoid stroma by Alcian blue staining and observed collagen fibers with denatured stroma by Masson trichrome staining. The patient''s visual acuity improved from light perception to 20 / 200, and the intraocular pressure remained within the normal range for one year after surgery. The transplanted cornea survived successfully with well-maintained transparency, and recurrence was not observed one year after surgery.     

Biomechanical response of the cornea to phototherapeutic keratectomy when treated as a fluid-filled porous material

PURPOSE: Surgical effect on corneal deformation has been traditionally analyzed based on the solid material assumption. We examine the validity of this assumption by treating the cornea as a fluid-filled porous material and separately modeling the solid and fluid constituents inside the cornea. In particular, the internal sub-atmospheric fluid pressure is treated as an important part of the mechanical loading in addition to the intraocular pressure. METHODS: Finite element simulations of phototherapeutic keratectomy (PTK) were conducted with the cornea treated as a fluid-filled porous material, and through-the-thickness difference in swelling phenomena was taken into account. The results were compared with the same PTK simulations based on the solid material assumption of the cornea. RESULTS: The PTK simulation results based on the fluid-filled porous material assumption demonstrated a significantly higher amount of unintended hyperopic shift compared to the results based on the traditional solid material assumption. The proposed approach qualitatively matched experimental observations. CONCLUSIONS: The internal sub-atmospheric pressure significantly influenced corneal deformation. The simulation results based on the fluid-filled porous material assumption raise serious questions regarding the validity of existing models in corneal surgery, where the effect of the internal sub-atmospheric pressure on corneal deformations is neglected.     

准分子激光治疗性角膜切削术治疗角膜浅层病变的实验和临床研究

目的：观察准分子激光治疗性膜切削术（photo-therapeutic keratectomy,PTK)后兔角膜组织的修复情况,探讨PTK的临床疗效,适应证和治疗参数。方法：（1）实验组采用8．17％硫酸烧灼法制作兔角膜浅层瘢痕模型,2周后行PTK;于术后不同时间进行角膜活体共焦显微镜,神经染色,光镜和透射电镜检查,并与对照组进行比较。（2）根据临床治疗组26例（30只眼）角膜浅层病变患者的病变种类,分别行去除上皮和非去除上皮PTK。观察术后不同时间患者的视力,屈光状态和角膜曲率变化情况,以及角膜雾状混浊（haze)的程度,随访时间6个月。结果：（1）实验组兔角膜切削区PTK术后早期多形 性粒细胞和巨噬细胞浸润。浅基质成纤维细胞增生活跃,新生胶原纤维排列紊乱,疏松;术后6个月趋于正常,组织修复稳定。（2）临床治疗组PTK术后6个月最佳矫正视力与术前比较,21只眼提高,5只眼不变,4只眼下降;其中PTK治疗角膜营养不良和角膜带状变性的效果最佳;术后6个月haze 0级23只眼,0．5级5只眼,1级2只眼,平均远视移动度数＋1．52D。结论：兔角膜PTK术后6个月组织修复趋于稳定;临床PTK治疗角膜浅层病变患者,方法简便,安全,有效,其中以治疗角膜营养不良和角膜带状变性的效果最佳,采用PTK治疗的角膜病变以不超过角膜前1／3厚度为宜。     

Corneal myxoma

BACKGROUND: Myxomas are rare benign tumors that can be found most frequently in the heart. We report the clinical and histological findings in a very rare case of corneal myxoma, which is only the sixth case in the literature. CASE: A whitish elevated tumor of the anterior cornea developed in the left eye cornea of a 46-year-old man 2 years after luxation of the patient's lens into the anterior chamber and subsequent endothelial decompensation. The tumor covered the entire surface of the cornea except for the outer limbal periphery at Schwalbe's line. OBSERVATIONS: Histologically, the hypocellular tumor was characterized by scattered spindle- and stellate-shaped cells with wavy, randomly oriented collagen fibers in a myxomatous ground substance staining positively for acid mucopolysaccharides. Bowman's layer was absent. Immunohistochemically, the tumor cells were positive for vimentin. Ultrastructurally, the tumor cells had features characteristic of keratocytes with no basement membrane, much rough endoplasmic reticulum and vacuoles containing mucoid-like material. CONCLUSIONS: The ultrastructural observations support the hypothesis of a cellular origin of the myxoma from keratocytes. The tumor growth was most probably stimulated by chronic endothelial failure and bullous keratopathy.     

Early pellucid marginal corneal degeneration: case reports of two refractive surgery candidates.

PURPOSE: To report two refractive surgery candidates who demonstrated early corneal topographic findings of pellucid marginal degeneration. METHODS: Case reports. RESULTS: Two candidate patients for corneal laser surgery were examined. The patients had normal examinations, including normal slit lamp biomicroscopy results and corrected visual acuity that was 20/20 or better in each eye. The corneal topography in one eye of patient I and both eyes of patient 2 was characterized by the presence of irregular astigmatism and inferior corneal steepening with a pattern consistent with pellucid marginal degeneration. Marked asymmetry between the eyes was noted. The inferior cornea was thinner than the central cornea in both eyes of each patient. CONCLUSION: Patients with early corneal ectasia often present as refractive surgery candidates with normal corrected visual acuity and normal pachymetry of the central cornea. Corneal topography and regional pachymetry measurements can be used to identify these patients. Patients with pellucid marginal degeneration are not good candidates for refractive surgery because of the potential for poor outcomes and the possibility that iatrogenic thinning of the cornea could lead to progression of the disease.     

Avellino corneal dystrophy after LASIK

OBJECTIVE: To report cases of Avellino corneal dystrophy (ACD) exacerbated by LASIK for myopia. DESIGN: Retrospective, noncomparative, interventional case series and review of the literature. PARTICIPANTS: Seven patients. INTERVENTION: Six patients with exacerbation of granular corneal deposits after LASIK were examined for TGFBI mutations by polymerase chain reaction sequencing of DNA. One previously reported patient who was heterozygous for the ACD gene was followed up for 16 months after mechanical removal of granular deposits from the interface after LASIK. MAIN OUTCOME MEASURES: Slit-lamp examination, visual acuity, manifest refraction, and DNA sequencing analysis. RESULTS: All patients were heterozygous for the Avellino dystrophy gene. Corneal opacities appeared 12 months or more after LASIK. Best spectacle-corrected visual acuity decreased as the number and density of the opacities increased. One patient underwent mechanical removal of granules from the interface and had a severe recurrence within 16 months. Another patient had removal of the granules from the interface with PTK, followed by treatment with topical mitomycin C. In this patient, the cornea has remained relatively clear for 6 months. CONCLUSIONS: Laser in situ keratomileusis increases the deposition of visually significant corneal opacities and is contraindicated in patients with ACD. Mechanical removal of the material from the interface does not prevent further visually significant deposits. Mitomycin C treatment, in conjunction with surgical removal of opacities, may be an effective treatment.     

准分子激光PTK治疗复发性角膜上皮糜烂

目的:探讨准分子激光治疗性角膜切削术(excimer laser phototherapeutic keratectomy,PTK)治疗角膜上皮糜烂的方法和疗效。方法:选择9例11眼复发性角膜上皮糜烂(recurrent corneal erosiou)患者,行准分子激光治疗性角膜切削术(PTK),戴治疗性角膜接触镜5~7d,随访3mo~3a。结果:9例11眼中8例10眼一次性痊愈,1例1眼再次PTK治疗痊愈。结论:PTK是治疗复发性角膜上皮糜烂简便有效的方法。     

Bilateral eyelid myxomas in Carney''s complex.

A 21-year-old man with a history of an excised soft tissue mass of the groin and spotty cutaneous pigmentation underwent excision of nodules of the right lower and left upper eyelids. The patient subsequently had a cutaneous mass of the left ear removed. All excised lesions were classified as myxomas. A diagnosis of multiple myxoma, spotty pigmentation, and endocrine overactivity (Carney's) complex was made.     

Transparency, swelling and scarring in the corneal stroma

PURPOSE: This paper briefly reviews current explanations for corneal transparency and uses a well-developed model to try to explain the increased light scattering either accompanying corneal swelling or following phototherapeutic keratectomy (PTK). METHODS: The direct summation of fields (DSF) method was used to compute light transmission as a function of wavelength. The method requires input of a number of structural parameters. Some of these were obtained from electron micrographs and others were calculated from X-ray diffraction data. RESULTS: By swelling sections of stroma cut from different depths in the tissue, we have shown that fluid entering the cornea causes more swelling in the posterior lamellae than in the anterior lamellae. Furthermore, posterior lamellae can reach a higher final hydration than anterior lamellae. Collagen-free regions ('lakes') exist in corneas swollen in vitro and in Fuch's dystrophy corneas, many of which may be caused by the death of cells. The DSF method shows that local fibril disordering, increased refractive index mismatch, and increased corneal thickness together can account for a 20% increase in light scattering in a Fuch's dystrophy cornea at H=5.8 compared to the normal cornea. Additional scattering is probably caused by 'lakes'. The DSF method applied to PTK rabbit stroma with high levels of haze suggests that the newly deposited collagen is not the cause of the increased light scattering. CONCLUSIONS: Fluid is not uniformly distributed within the corneal stroma when the cornea swells. Increased hydration of posterior lamellae may be because of known differences in the glycosaminoglycans between the anterior and posterior stroma. Lamellar interweave in the anterior stroma probably limits the extent to which the constituent lamellae can swell. The DSF method can be used to account for increased light scattering in oedematous corneas but cannot account for haze following PTK.