Nassaralla B A, Garbus J, McDonnell P J
Doheny Eye Institute, Los Angeles, Calif 90033, USA.
J Refract Surg. 1996 Nov-Dec;12(7):795-800. doi: 10.3928/1081-597X-19961101-12.
The capability of the 193-nm excimer laser to ablate the cornea and to remove opacities and various other corneal diseases in a procedure called phototherapeutic keratectomy (PTK) has been demonstrated. In this study we evaluated the long-term results of PTK for treatment of granular and lattice corneal dystrophies.
Four eyes with granular or lattice corneal dystrophy were treated with a mean follow-up of 47.8 months (range, 36 to 58 months). Focal ablations of the central cornea with an ablation zone of 5.5 to 6.0 mm were performed. Ablation depth was 110 microns in three eyes and 140 microns in one eye.
Removal of corneal opacities allowed for improvement in corrected visual acuity in all patients. Mean corneal thickness in the area of pathology decreased from 0.583 mm before surgery to 0.449 mm after surgery. Spherical equivalent of the manifest refraction measurements increased by a mean of +5.09 D. There were no major complications, but all patients developed slight haze. There was a hyperopic shift in three eyes.
Our long-term results suggest that PTK is a safe and effective alternative to penetrating and lamellar keratoplasty in patients with granular or lattice corneal dystrophies.
193纳米准分子激光在一种称为光治疗性角膜切削术（PTK）的手术中，具有消融角膜、清除混浊物及治疗各种其他角膜疾病的能力已得到证实。在本研究中，我们评估了PTK治疗颗粒状和格子状角膜营养不良的长期效果。
对4只患有颗粒状或格子状角膜营养不良的眼睛进行治疗，平均随访47.8个月（范围36至58个月）。对中央角膜进行局部消融，消融区为5.5至6.0毫米。3只眼睛的消融深度为110微米，1只眼睛为140微米。
所有患者角膜混浊物的清除均使矫正视力得到改善。病变区域的平均角膜厚度从手术前的0.583毫米降至手术后的0.449毫米。明显验光测量的等效球镜度平均增加了+5.09 D。无重大并发症，但所有患者均出现轻微角膜混浊。3只眼睛出现远视漂移。
我们的长期结果表明，对于颗粒状或格子状角膜营养不良患者，PTK是穿透性和板层角膜移植术的一种安全有效的替代方法。
