Rashad Mohammad A
Ophthalmology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Clin Ophthalmol. 2012;6:885-94. doi: 10.2147/OPTH.S31086. Epub 2012 Jun 14.
This study aimed to evaluate the effectiveness of phototherapeutic keratectomy (PTK) as an alternative treatment to keratoplasty using the Pentacam to assess depth of dense opacities.
PTK was performed in eleven eyes of ten patients with superficial corneal opacities after assessment by Scheimpflug images of the Pentacam for central corneal thickness (CCT) and opacity level and depth.
The best-corrected spectacle visual acuity (BCSVA) significantly improved. The preoperative mean logMAR was 0.85 (0.14 decimal equivalent, 6/42 Snellen's equivalent), and the final postoperative mean logMAR was 0.58 (0.26 decimal equivalent, 6/23 Snellen's equivalent). The mean preoperative CCT was 465.64 ± 71.94 μm. The mean programmed ablation depth was 142.09 ± 47.58 μm. The programmed ablation depth was correlated to mean logMAR early (1 month) and not correlated later (6 months). None of the eyes lost lines of BCSVA or developed serious complications, such as keratectasia, delayed epithelialization, or corneal melting.
Corneal scars extending beyond the anterior one-fifth of the cornea can be treated safely and effectively by PTK due to the smoothing effect, with reduction of the cylinder rather than complete opacity removal. This can decrease the need for keratoplasty.
本研究旨在评估光治疗性角膜切削术(PTK)作为角膜移植替代治疗方法的有效性,使用Pentacam评估致密混浊的深度。
对10例患有浅表角膜混浊的患者的11只眼进行PTK,术前通过Pentacam的Scheimpflug图像评估中央角膜厚度(CCT)、混浊程度和深度。
最佳矫正视力(BCSVA)显著提高。术前平均logMAR为0.85(小数等效值0.14,相当于Snellen视力表的6/42),术后最终平均logMAR为0.58(小数等效值0.26,相当于Snellen视力表的6/23)。术前平均CCT为465.64±71.94μm。平均预设消融深度为142.09±47.58μm。预设消融深度与早期(1个月)平均logMAR相关,与后期(6个月)无关。所有眼睛均未丧失BCSVA行数,也未出现严重并发症,如角膜扩张、上皮化延迟或角膜溶解。
由于具有平滑作用,角膜前1/5以外延伸的角膜瘢痕可通过PTK安全有效地治疗,可减少散光而非完全清除混浊。这可减少角膜移植的需求。