The Clinical Study Of Spherical Aberration Compensated Laser Ablation For Presbyopia

Objective To investigate the effectivity, safety, predictability and stability of spherical aberration compensated laser oblation for presbyopia. Methods24presbyopes who underwent excimer laser oblation (21myopes,3hyperopes; laser in situ keratomileusis (LASIK) for23eyes of13patients, laser subepithelial keratomileusis (LASEK) for19eyes of11patients) during2005to2008in EENT Hospital of Fudan University were included in our research and their distant corrected near visual acuity was lower than J5. The patients in the experimental group were all female and their mean age was47.09years old. Their preoperative spherical equivalent (SE) was-2.98DS.12patients (5males,7females) in the control group were matched with experimental group in age, SE, ADD value and the time of operation. Their mean age were48.33years old and their mean SE was-5.20DS. For the experimental group, the intended postoperative SE was-0.25DS for the dominant eye and-0.50DS for the non-dominant eye. For the control group, it was-0.25DS for the dominant eye and-1.00DS for the non-dominant eye. The non-dominant eye of the experimental group underwent compensated ablation directed by shotfile protocol. The postoperative outcomes were observed, which contained the refractive error, corrected distant visual acuity (CDVA), uncorrected distant visual acuity(UDVA), uncorrected near visual acuity (UNVA),distant corrected near visual acuity, binocular UDVA and UNVA, contrast sensitivity (CS). WFA-1000aberration analyzer was applied to measure the early and long-term spherical aberration (SA)(Z(4,0))value.The curvature of the front cornea was measured by Pentacam. The mean K value in the radius of2mm(K2mm) and4mm (K4mm) was calculated. The consecutive change of AK(change of K value) was analyzed according to the change of ΔK2(K value of corneal apex-K2mm), ΔK4(K2mm-K4mm). The time of the last visit was4.5years postoperatively. SPSS13.0software was applied to analyze the data. It was statistical significance when P<0.05. Results According to the non-dominant eye of the experimental group, the mean UNVA (LogMAR) was0.203months postoperatively,and0.404.5years postoperatively which declined2lines (p=0.019). The4.5-year postoperative UNVA of the non-dominant eye of the experimental group was1line better than the dominant eye (p=0.041) and no difference of distant corrected near visual acuity was found (p=0.368). There was no difference of postoperative UDVA of the non-dominant eye of the experimental group between3months and4.5years (p=0.298); the UDVA increased6.5lines4.5years postoperatively compared with the preoperative UDVA (p=0.007) and not different from the UDVA of the dominant eye4.5years postoperatively (p=0.166).4.5years postoperatively, the binocular UDVA was-0.03 for the experimental group and0.01for the control group; the binocular UNVA was0.38for the experimental group and0.30for the control group; there was no difference of binocular UDVA and UNVA between the two groups (p=0.096,p=0.054). The4.5-year postoperative UDVA of the non-dominant eye of the experimental group declined0.6lines compared with preoperative CDVA (p=0.009), and no one declined exceed2lines; postoperative CDVA was not different from the preoperative (p=1.000). The difference between6-month postoperative CS and preoperative CS was insignificant (p>0.05,n=9); The4.5-year postoperative CS (no glare) increased in the size of1.6°and0.7°(p=0.025,p=0.046,n=12) and glare CS increased in the size of1.0°(p=0.042,n=11). The intended SE of the non-dominant eye of the experimental group was-0.50DS and the4.5-year postoperative SE was-0.53DS which was not different from the preoperative (p=0.268). The postoperative ADD of the experimental group was not different from the preoperative ADD (p=0.862), and the ADD increased postoperatively according to the control group (p=0.012), and the experimental group had lower ADD value compared with the control group (p=0.041). In the experimental group, SA of the non-dominant eye was-0.190μm preoperatively and-0.045μm6months postoperatively, and the difference was significant (p=0.022,n=8). While4.5years postoperatively, the SA of the non-dominant eye was-0.143μm and not different from the preoperative, and more positive than the dominant eye (p=0.002,n=11).The early outcomes of SA of the non-dominant eye was more positive than preoperative.The positive value decreased while the negative value increased gradually. The ΔK2of the non-dominant eye of the experimental group was-0.022D preoperatively and0.303D4.5years postoperatively, and the difference was statistical significant (p=0.005,n=9); the preoperative ΔK4was0.066D and0.362D4.5years postoperatively, and the difference was statistical significant(p=0.010,n=9). Postoperatively, ΔK2and ΔK4increased dramatically in early time while decreased in long term. ΔK4changed greatly.Conclusion The spherical aberration compensated laser oblation for presbyopia was safe, effect in short time and had good predictability. The long-term effectivity and stability needed further study with a lager sample.