长期配戴角膜塑形镜对患者角膜和视觉质量的影响

目的:探讨长期配戴角膜塑形镜对角膜形态、角膜生物力学以及客观视觉质量的影响。方法:回顾性研究。收集2019-10/2020-12在我院配戴角膜塑形镜2a的近视患者33例60眼,其中男19例35眼,女14例25眼,平均年龄11.80±1.51岁,平均等效球镜为-3.25±0.69D。收集患者配戴前和配戴2a时的相关数据资料。利用Pentacam三维眼前节分析系统测量角膜最薄点中心3mm区域前后表面曲率半径(ARC和PRC)、角膜最薄点厚度(THP)、角膜扩张综合偏差分析指数(BADD)。Corvis ST生物力学分析仪测量非接触生物力学校正眼压(bIOP)、最大形变幅度(DA)、最大反向半径(HCR)、顶点和1mm间形变幅度比值(DR)、硬度参数(SPA1)、角膜生物力学参数(CBI)。运用Pentacam与Corvis ST联合诊断系统分析得出断层扫描生物力学指数(TBI)。OQAS-Ⅱ客观视觉质量分析系统测量调制传递函数截止频率(MTF cutoff)、斯特烈尔比(SR)、客观散射系数(OSI)以及OV值(OV100%、OV20%和OV9%)。对患者配戴角膜塑形镜前和连续配戴角膜塑形镜2a的上述各项参数进行比较。结果:配戴角膜塑形镜2a与配戴前相比ARC增高、THP降低、BADD增高,比较有差异(t=-9.38、2.85、-13.08,均P<0.05),PRC与配戴前相比无差异(t=-1.49,P>0.05);配戴角膜塑形镜2a与配戴前相比DA增高、HCR降低,比较有差异(t=-2.37、2.28,均P<0.05),bIOP、DR、SPA1、CBI、TBI分别与配戴前相比无差异(t=1.36、-1.87、1.27、-0.95、-1.49,均P>0.05);配戴角膜塑形镜2a SR较配戴前增高,OV20%和OV9%较配戴前均降低,比较有差异(t=-5.31、8.37、2.34,均P<0.05),MTF cutoff、OSI、OV100%与配戴前相比无差异(t=-1.57、-1.35、1.11,均P>0.05)。结论:长期配戴角膜塑形镜改变角膜前表面形态,对角膜生物力学无明显影响,患者日间客观视觉质量提高,而夜间视觉质量下降。

Effects of long-term wearing of orthokeratology lens on corneal and visual quality of patients

AIM: To investigate the effects of long-term orthokeratology lens wearing on corneal morphology, corneal biomechanics and objective visual quality.

METHODS: A retrospective study was conducted to collect 33 myopic patients(60 eyes), including 19 males(35 eyes)and 14 females(25 eyes), mean age 11.80±1.51 years old, with an average equivalent spherical lens of -3.25±0.69D, who had been wearing orthokeratology lens for 2a from October 2019 to December 2020 in our hospital. Relevant data were collected before wearing and 2a after wearing. The radius of curvature(ARC and PRC), the thickness of the thinnest cornea(THP)and the index of comprehensive deviation analysis of corneal dilation(BADD)were measured by Pentacam anterior segment analysis system. Corvis ST biomechanical analyzer measured non-contact biomechanical corrected intraocular pressure(blOP), maximum deformation amplitude(DA), maximum reverse radius(HCR), ratio of deformation amplitude between apex and 1mm(DR), hardness parameters(SPA1), and corneal biomechanical parameters(CBI). The biomechanical index(TBI)of CT scan was obtained by the combined diagnosis system of Pentacam and Corvis ST. OQAS-II objective visual quality analysis system measured modulation transfer function cutoff frequency(MTF cutoff), Stryl ratio(SR), objective scattering coefficient(OSI)and OV value(OV100%, OV20% and OV9%). The above parameters were compared before and continuously wearing orthokeratoscope for 2a.

RESULTS: After 2a of wearing orthokeratology, ARC increased, THP decreased, and BADD increased(t=-9.38, 2.85, -13.08; all P<0.05), while there was no significant difference between PRC and before wearing(t=1.49, P>0.05). DA increased and HCR decreased compared with before wearing orthokeratology lens(t=-2.37, 2.28; all P<0.05), but bIOP, DR, SPA1, CBI and TBI showed no difference(t=1.36, -1.87, 1.27, -0.95, -1.49; all P>0.05). SR was higher than before, OV20% and OV9% were lower than before(t=-5.31, 8.37, 2.34; all P<0.05), MTF cutoff, OSI and OV100% had no difference compared with before(t=-1.57, -1.35, 1.11; all P>0.05).

CONCLUSION: Long-term wearing of orthokeratology lens changed the morphology of the anterior corneal surface, but had no significant effect on the corneal biomechanics, and the objective visual quality of patients was improved during the day, but decreased at night.