Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
Department of Ophthalmology, Ospedali Privati Forlì "Villa Igea," Forlì, Italy.
Cornea. 2021 Sep 1;40(9):1098-1103. doi: 10.1097/ICO.0000000000002609.
To evaluate the surgical and 3-year clinical outcomes of modified big-bubble 9-mm deep anterior lamellar keratoplasty (DALK) in eyes with previous ALK (ALK).
In this interventional case series, 21 consecutive eyes with unsatisfactory vision after ALK (superficial ALK n = 9; laser-assisted ALK n = 7; and epikeratophakia n = 5) underwent large-diameter (9-mm) DALK. The surgery involved deep trephination based on the anterior segment optical coherence tomography pachymetry measurement at 9-mm diameter, pneumatic dissection from the base of the trephination and limited stromal clearance of the optical zone (6 mm). Main outcome measures were success rates of pneumatic dissection, best spectacle-corrected visual acuity, and complication rates.
Pneumatic dissection with type 1 bubble formation succeeded in 19 (90%) eyes. In the 2 remaining cases, the 6-mm optical zone was cleared by manual dissection. Perforation occurred in one of the latter cases; no procedure was converted to penetrating keratoplasty. One month after complete suture removal, the preoperative mean best spectacle-corrected visual acuity (0.75 ± 0.23 logMAR) improved to 0.09 ± 0.10 logMAR (P < 0.001) and remained stable up to 3 years after surgery. At the final follow-up, refractive astigmatism was ≤4.5 and <6 D in 20 (95%) and 21 (100%) eyes, respectively. Stromal rejection was observed in 2 eyes (10%) and was treated successfully with steroids.
Even in eyes with previous ALK, pneumatic dissection can be achieved through a modified DALK technique with a low risk of complications and excellent visual and refractive outcomes.
评估改良大直径 9mm 深板层角膜移植术（DALK）治疗既往准分子激光角膜磨镶术（ALK）后患者的手术效果及 3 年临床疗效。
本研究为回顾性系列病例研究，21 例接受过 ALK（浅层 ALK9 例，准分子激光辅助 ALK7 例，角膜表层镜片术 5 例）但术后视力不佳的患者行大直径（9mm）DALK。手术采用基于 9mm 前节光学相干断层扫描测厚仪的深层环钻，行气动分离，光学区（6mm）行有限的基质松解。主要观察指标为气动分离成功率、最佳矫正视力和并发症发生率。
19 只眼（90%）行气动分离并形成 1 型气泡。另外 2 只眼通过手动分离完成 6mm 光学区松解。其中 1 只眼发生穿孔，未改行穿透性角膜移植术。术后 1 个月完全拆线时，术前平均最佳矫正视力（0.75±0.23logMAR）提高至 0.09±0.10logMAR（P<0.001），术后 3 年保持稳定。末次随访时，20 只眼（95%）的等效球镜屈光度为≤4.5D，21 只眼（100%）为<6D。2 只眼（10%）出现基质排斥反应，经皮质激素治疗后缓解。
即使在既往行 ALK 术的患者中，改良 DALK 技术也能安全有效地行气动分离，并发症风险低，视力和屈光效果良好。
