Pop M, Aras M
Michel Pop Clinics, Montreal, Canada.
Ophthalmology. 1996 Nov;103(11):1979-84. doi: 10.1016/s0161-6420(96)30399-0.
Ninety eyes were retreated to correct myopic regression, with or without corneal haze, after primary photorefractive keratectomy (PRK); astigmatism ranging from -0.50 to -3 diopters (D) was present in 43 eyes.
The sphere (mean +/- standard deviation) was -2.82 +/- 1.74 D before repeat surgery. At 6 months, the mean was +0.30 D; at 1 year, it was -0.17 D. Patients were divided into two groups: group 1 included 56 eyes with little or no haze (< or = 1). The mean sphere value for this group was -2.13 D before retreatment; at 1 year, it was -0.20 +/- 0.76 D. At 6 months, 84% of sphere values were within +/- 1 D of the intended correction, with a mean haze value of less than 0.5, similar to that before repeat surgery; there was a mean gain of 0.25 Snellen line of best-corrected visual acuity. Astigmatism equal or greater than -0.5 D was present in 34 eyes (mean, -1.17 +/- 0.55 D). At 6 months, astigmatism was reduced to -0.45 +/- 0.48 D. The second group included 34 eyes with corneal haze greater than 1 (mean, 2.7). The mean sphere value was -3.95 D before photorefractive keratectomy and -0.12 +/- 1.48 D 1 year after treatment. Fifty percent of the mean sphere values were within +/- 1 D at 6 months, with a mean haze value of 1. The gain in mean best-corrected visual acuity was 1.3 Snellen lines. The mean astigmatism in nine eyes was -1.75 +/- 0.75 D before photorefractive keratectomy and -0.72 +/- 0.78 D 6 months after treatment.
There is a significant difference in the outcome predictability between the two groups. A second photorefractive keratectomy can be done 6 months after the primary treatment in patients with regression with or without trace haze. This group has a High predictability in achieving a good correction, with a low complication rate. When haze is present, retreatments are less predictable with 40% of patients overcorrected. Generally, however, these eyes have a statistically significant decrease in haze (Student's t test; P < 0.01) and an improvement in best-corrected visual acuity.
对90只眼睛进行再次手术，以矫正初次准分子激光原位角膜磨镶术（PRK）后出现的近视回退，无论有无角膜混浊；43只眼睛存在-0.50至-3屈光度（D）的散光。
再次手术前球镜度数（平均值±标准差）为-2.82±1.74D。6个月时，平均值为+0.30D；1年时，为-0.17D。患者分为两组：第1组包括56只角膜混浊很少或无混浊（≤1）的眼睛。该组再次治疗前球镜度数平均值为-2.13D；1年时，为-0.20±0.76D。6个月时，84%的球镜度数在预期矫正值的±1D范围内，平均混浊度值小于0.5，与再次手术前相似；最佳矫正视力平均提高了0.25行Snellen视力表。34只眼睛存在等于或大于-0.5D的散光（平均值，-1.17±0.55D）。6个月时，散光降至-0.45±0.48D。第2组包括34只角膜混浊度大于1（平均值，2.7）的眼睛。准分子激光原位角膜磨镶术前球镜度数平均值为-3.95D，治疗后1年为-0.12±1.48D。6个月时，50%的球镜度数平均值在±1D范围内，平均混浊度值为1。最佳矫正视力平均提高了1.3行Snellen视力表。9只眼睛的平均散光在准分子激光原位角膜磨镶术前为-1.75±0.75D，治疗后6个月为-0.72±0.78D。
两组在结果可预测性方面存在显著差异。对于有或无轻微混浊的近视回退患者，可在初次治疗6个月后进行二次准分子激光原位角膜磨镶术。该组在实现良好矫正方面具有较高的可预测性，并发症发生率低。当存在混浊时，再次手术的可预测性较差，40%的患者出现过矫。然而，总体而言，这些眼睛的混浊度在统计学上有显著降低（Student t检验；P<0.01），最佳矫正视力有所改善。
