Iqbal Mohammed, Hammour Abdallah, Elsayed Ahmed, Gad Ahmed
Department of Ophthalmology, Faculty of Medicine, Sohag University, Sohag, Egypt.
Department of Ophthalmology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
Med Hypothesis Discov Innov Ophthalmol. 2023 Dec 31;12(2):78-89. doi: 10.51329/mehdiophthal1473. eCollection 2023 Summer.
Keratoconus (KCN) is an ectatic disorder of the cornea characterized by stromal weakness and apical protrusion of the cornea, and is associated with a gradual and painless reduction in visual acuity. KCN in pediatric patients has certain important characteristics, such as a progressive and aggressive nature. We aimed to analyze the visual, refractive, and topographic outcomes of implanting a single 210° arc-length Keraring segment according to a novel, objective, Q value-based nomogram (Q-N) for the treatment of pediatric versus adult KCN.
This prospective, multicenter, non-randomized, open-label trial included 47 eyes of 47 patients who were allocated to one of two groups. The included 33 eyes of patients ≥ 18 years of age, whereas the included 14 eyes of patients aged 14 - 17 years. All patients underwent femtosecond laser-assisted implantation of a single 210° arc-length Keraring segment according to the Q-N and were followed up for 6 months. All eyes underwent visual acuity measurement, cycloplegic refraction, and corneal topography at baseline and 6 months after surgery.
The study groups were comparable in terms of sex proportions and KCN grades (both > 0.05). The adult group exhibited significant postoperative improvements in mean uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), sphere, cylinder, spherical equivalent (SE), and Kmax (all < 0.001) with a mean change of -0.56 logarithm of the minimal angle of resolution (logMAR), - 0.40 logMAR, 3.07 diopters (D), 0.70 D, 3.42 D, and - 5.26 D, respectively. The pediatric group exhibited significant postoperative improvements in mean UDVA, CDVA, sphere, SE, and Kmax (all < 0.05) with a mean change of - 0.62 logMAR, - 0.34 logMAR, 3.18 D, 3.67 D, and - 5.37 D, respectively. There were no significant differences between the groups in terms of the mean change in visual, refractive, and topographic variables (all > 0.05). No postoperative complications were observed in either group.
Use of the objective Q-N was efficient in the treatment of pediatric KCN, with postoperative improvements in the mean visual, refractive, and topographic parameters, comparable to outcomes in adult keratoconus. Q-N achieved good corneal remodeling with subsequent improvements in visual, refractive, and topographic outcomes in both adult and pediatric patients with keratoconus. To verify our preliminary findings, we recommend further multicenter randomized clinical trials using the Q-N nomogram in a larger sample of pediatric patients with KCN as an adjunct treatment before or after CXL.
圆锥角膜（KCN）是一种角膜扩张性疾病，其特征为基质薄弱和角膜顶端突出，并伴有视力逐渐且无痛性下降。儿科患者的圆锥角膜具有某些重要特征，例如病情呈进行性且较为严重。我们旨在根据一种新颖、客观、基于Q值的列线图（Q-N），分析植入单个210°弧长的Keraring节段治疗儿科与成人圆锥角膜的视力、屈光和地形图结果。
这项前瞻性、多中心、非随机、开放标签试验纳入了47例患者的47只眼，这些患者被分配到两个组中的一组。成人组包括33例年龄≥18岁患者的眼睛，而儿科组包括14例年龄在14 - 17岁患者的眼睛。所有患者均根据Q-N接受飞秒激光辅助植入单个210°弧长的Keraring节段，并随访6个月。所有眼睛在基线和术后6个月均进行视力测量、睫状肌麻痹验光和角膜地形图检查。
研究组在性别比例和圆锥角膜分级方面具有可比性（均P>0.05）。成人组术后平均裸眼远视力（UDVA）、矫正远视力（CDVA）、球镜、柱镜、等效球镜（SE）和最大角膜曲率（Kmax）均有显著改善（均P<0.001），平均变化分别为-0.56最小分辨角对数（logMAR）、-0.40 logMAR、3.07屈光度（D）、0.70 D、3.42 D和-5.26 D。儿科组术后平均UDVA、CDVA、球镜、SE和Kmax也有显著改善（均P<0.05），平均变化分别为-0.62 logMAR、-0.34 logMAR、3.18 D、3.67 D和-5.37 D。两组在视力、屈光和地形图变量的平均变化方面无显著差异（均P>0.05）。两组均未观察到术后并发症。
使用客观的Q-N治疗儿科圆锥角膜有效，术后平均视力、屈光和地形图参数均有改善，与成人圆锥角膜的结果相当。Q-N在成人和儿科圆锥角膜患者中均实现了良好的角膜重塑，随后视力、屈光和地形图结果均得到改善。为验证我们的初步发现，我们建议在更大样本的儿科圆锥角膜患者中进一步开展多中心随机临床试验，将Q-N列线图作为角膜交联（CXL）之前或之后的辅助治疗方法。
