目的：采用角膜光密度定量评价散光经上皮准分子激光角膜切削术(TPRK)术后角膜上皮下混浊(haze)的临床特点。

方法：回顾性临床研究。连续性收集2022年10月至2024年12月在我院行TPRK的屈光不正(散光≥1.25 D)患者74例106眼，根据术后是否出现haze将其分为透明组(65眼)和haze组(41眼)，术前及术后复查均行Pentacam眼前节分析仪检查，记录术前及透明组术后1 mo、haze组术后haze程度最重时间点的角膜中央2 mm圆形、2-6 mm环形和6-10 mm环形各区域的角膜全层平均光密度，及散光轴(散光以负柱镜形式表示)和正交轴(与散光轴垂直的轴向)切面中央6 mm的角膜切面全层平均光密度，及haze组顺规散光患者散光轴鼻侧和颞侧2-6 mm区域内的角膜切面全层平均光密度，并计算术后较术前角膜光密度变化量。

结果：透明组和haze组间性别、年龄、等效球镜等基线资料均无差异(均P>0.05)； 角膜2-6 mm区域haze组角膜光密度变化量大于透明组(Z=-2.226，P=0.026)，中央2 mm及6-10 mm区域两组间角膜光密度变化量均无差异(均P>0.05)； 两组在正交轴角膜光密度变化量均无差异(均P>0.05)，而在散光轴haze组的角膜光密度变化量大于透明组(Z=-2.371，P=0.018)； haze组顺规散光患者术后颞侧角膜光密度大于鼻侧，且角膜光密度变化量亦大于鼻侧(Z=-4.288，P<0.001； Z=-4.043，P<0.001)。

结论：不同于近视和远视的球镜矫正，散光TPRK术后haze主要表现在散光轴的周边切削区，且顺规散光患者在散光轴的颞侧较鼻侧发生haze的几率更高或程度更重。

METHODS:In this retrospective clinical study, a total of 74 patients(106 eyes)with astigmatism ≥1.25 D who underwent TPRK in our hospital from October 2022 to December 2024 were continuously collected. All of the study subjects were divided into transparent group(65 eyes)and haze group(41 eyes)based on whether haze occurred after surgery. Pentacam examination was performed before and after surgery, and corneal densitometry was recorded at the time points of preoperation, 1 mo postoperation in the transparent group and the most severe haze degree in the haze group. The collected corneal densitometry included the average densitometry of the entire corneal layer in the central 2 mm, 2-6 mm, and 6-10 mm areas, as well as the average densitometry of the entire layer of the corneal section in the center 6 mm of the astigmatism axis(astigmatism expressed in negative cylindrical form)and orthogonal axis(the axis perpendicular to the astigmatism axis), and the average densitometry of the entire layer of the corneal section in the nasal and temporal 2-6 mm areas of the astigmatism axis in the haze group of patients with regular astigmatism. The change in corneal densitometry after surgery compared with that before surgery was calculated.

RESULTS:There was no statistically significant difference in baseline data such as gender, age, and spherical equivalent between the transparent group and the haze group(all P>0.05). The change in corneal densitometry in the 2-6 mm area of the haze group was greater than that in the transparent group(Z=-2.226, P=0.026), while there was no significant difference in the change of corneal densitometry in the central 2 mm and 6-10 mm areas between the two groups(both P>0.05). There was no significant difference in the change of corneal densitometry between the transparent group and haze group along the orthogonal axis(all P>0.05), while the change of corneal densitometry in the haze group along the astigmatism axis was greater than that in the transparent group(Z=-2.371, P=0.018). The temporal corneal densitometry of patients with regular astigmatism in the haze group after surgery was higher than that of the nasal side, and the change in corneal densitometry was also greater than that of the nasal side(Z=-4.288, P<0.001; Z=-4.043, P<0.001).

CONCLUSION:Unlike spherical correction for myopia and hyperopia, haze after TPRK for astigmatism was mainly manifested in the peripheral cutting area of the astigmatism axis, and patients with regular astigmatism had a higher probability or severity of haze on the temporal side of the astigmatism axis than on the nasal side.