ABSTRACT
@#AIM: To study the effects of small-incision lenticule extraction(SMILE)and femtosecond laser-assisted excimer laser <i>in situ</i> keratomileusis(FS-LASIK)on early postoperative corneal higher order aberrations(HOAs)and visual quality in patients with high myopia. <p>METHODS:Totally 102 patients(204 eyes)with high myopia who underwent corneal refractive surgery between August 2018 and August 2020 in the hospital were selected as study subjects for the prospective study, and they were randomly divided into SMILE group(51 cases, 102 eyes)and FS-LASIK group(51 cases, 102 eyes). The postoperative visual acuity, corneal HOAs and objective visual quality were compared between the two groups, and the correlation between corneal HOAs and objective visual quality was analyzed. <p>RESULTS: At 1mo after surgery, the spherical equivalent degrees in SMILE group and FS-LASIK group were significantly reduced(<i>P</i><0.05), and there was no statistically significant difference in the proportion of patients with postoperative uncorrected visual acuity≥preoperative best corrected visual acuity between the two groups(95.1% <i>vs</i> 92.2%, <i>P</i>>0.05). The corneal HOAs in the two groups were significantly increased(<i>P</i><0.05), and the overall spherical aberration(SA), trefoil and higher HOAs in SMILE group were lower than those in FS-LASIK group(all <i>P</i><0.05). The objective scattering index(OSI)was significantly increased in the two groups while the MTF cutoff frequency(MTF<sub>cutoff</sub>), Strehl Ratio(SR)and contrast visual acuity(VA100%, VA20%, VA9%)were significantly decreased(all <i>P</i><0.05). The OSI of SMILE group was lower than that of FS-LASIK group while MTF<sub>cutoff</sub> and VA9% were higher than those of FS-LASIK group(all <i>P</i><0.05). The corneal HOAs in patients with high myopia were negatively correlated with MTF<sub>cutoff</sub> and were positively correlated with OSI(<i>P</i><0.05).<p>CONCLUSION:Both SMILE and FS-LASIK can effectively correct high myopia, and SMILE has a smaller increase in early postoperative corneal HOAs, and it is of great significance to relieve visual quality impairment.
ABSTRACT
AIM:To compare the changes of surgically induced corneal higher order aberrations after phacoemulsification with 2.8mm clear corneal incisions at different sites.METHODS:The clinical data of 100 cases (100 eyes) of patients with cataract treated by phacoemulsification with 2.8mm clear corneal incision in our hospital from March 2015 to April 2016 were analyzed retrospectively.According to the site of incision,they were divided into Group A (temporal clear corneal incision,n =55) and Group B (upper clear corneal incision,n=45).Changes of the best corrected visual acuity (BCVA),surgically induced astigmatism (SIA) and corneal topography were compared between the two groups before surgery,at 1d,1wk,1 and 3mo after surgery.The corneal wavefront aberrations were measured by wavefront aberration analyzer,and the changes of higher-order aberrations in corneal 6mm range were recorded.RESULTS:The BCVA of two groups decreased at 1d,1wk,1 and 3mo after surgery (P＜0.05),and the BCVA of Group A at 1d,1wk,and 1mo after surgery was lower than that of Group B (P＜0.05).SIA of the two groups decreased at 1wk,1 and 3mo after surgery (P＜0.05),and the SIA of Group A at different time points after surgery were lower than those of Group B (P＜0.05).The surface asymmetry index (SAI) and the surface rule index (SRI) of the two groups increased at 1 d after surgery,and were gradually decreased at 1wk,1 and 3mo after surgery.The SRI and SAI in Group A were lower than those in Group B at 1d and 1wk after surgery (P＜ 0.05).The total corneal higher-order aberrations (tHOAs) and four-order spherical aberration (SA)showed significant differences between the two groups at 3mo after surgery (P＜0.05).CONCLUSION:The application of 2.8mm temporal clear corneal incision in phacoemulsification can promote the recovery of visual acuity,reduce the effect of surgery on corneal shape,and reduce corneal higher-order aberrations.
ABSTRACT
PURPOSE: To compare the corneal first surface higher-order aberrations (HOAs) of normal subjects and patients with dry eye using KR-1W(R) (Topcon Corp., Tokyo, Japan) and Pentacam(R) HR (Oculus Inc., Dutenhofen, Germany). We analyzed the relationship between the aberrations and the diagnostic parameters of dry eye. METHODS: We evaluated anterior corneal HOAs in 71 normal eyes and 71 dry eyes using KR-1W(R) and Pentacam(R). Dry eye patients were examined for fluorescein staining, tear break-up time (TBUT), and Schirmer I test. Ocular Surface Disease Index (OSDI) was used for assessment of subjective symptoms in dry eye patients. RESULTS: HOAs measured by both instruments were greater in the dry eye group than in the control group, although HOAs using KR-1W(R) only achieved statistical significance. The anterior corneal HOAs measured by the 2 instruments were significantly correlated with superficial punctate keratitis. Moreover, TBUT and the Shirmer I test negatively correlated, and OSDI positively correlated, with anterior corneal HOAs. CONCLUSIONS: The HOAs in patients with dry eye were significantly different from controls and tended to increase with disease severity. KR-1W(R) might be more useful than Pentacam(R) to detect tear film instabilities.
Subject(s)
Humans , Fluorescein , Keratitis , TearsABSTRACT
PURPOSE: To compare the corneal higher-order aberrations (HOAs) of normal young subjects using Galilei(TM) G4 (Zeimer, Port, Switzerland) and Pentacam(R) (Oculus Inc., Wetzlar, Germany). METHODS: Corneal HOAs were measured using Galilei(TM) G4 and Pentacam(R) in 41 healthy individuals (41 eyes). Intraclass correlation coefficients (ICCs) were obtained to evaluate the repeatability of the 2 devices. Differences in HOAs between the 2 instruments were analyzed with a paired t-test and correlations evaluated. RESULTS: All ICCs measured using Galilei(TM) G4 and Pentacam(R) showed more than moderate repeatability (>0.81) except trefoil, tetrafoil, 4th and 5th HOAs. When comparing the measurements obtained with Galilei(TM) G4 and Pentacam(R), total HOAs, spherical aberration (SA), secondary astigmatism and 5th total HOAs were statistically significantly different between the 2 device (all p < or = 0.001). In addition, Galilei(TM) G4 and Pentacam(R) showed discrepancy among all corneal HOAs items. Although the total corneal HOAs and the SA were significantly correlated, other HOA measurements generally exhibited a low correlation. CONCLUSIONS: Corneal HOAs obtained by the 2 instruments cannot be used interchangeably due to their differences and discrepancy although corneal HOAs measured using Galilei(TM) G4 and Pentacam(R) showed relatively high repeatability.
Subject(s)
Astigmatism , LotusABSTRACT
PURPOSE: To compare surgically induced astigmatism (SIA) and some corneal higher order aberrations in patients who underwent microcoaxial cataract surgery (MCCS) or conventional cataract surgery. METHODS: A prospective randomized study included 60 eyes of 55 patients. Thirty eyes received MCCS using a 2.2mm clear corneal incision (group 1), and 30 eyes received conventional cataract surgery using a 2.8 mm clear corneal incision (group 2). SIA and corneal higher order aberrations were measured with a Keratometer (Humphrey, Zeiss) and i-Trace (Tracey Technologies) preoperatively, and at 1 and 3 months after cataract surgery. SIA was analyzed vectorially using the Alpins method. RESULTS: There was no significant difference in preoperative UCVA or BCVA between the two groups. At 1 month and 3 months after surgery, SIA in group 1 was less than that in group 2, but this difference was not significant. There was no statistically significant difference in postoperative change of corneal higher order aberrations in each group at 1 month or 3 months after surgery, and there was no statistically significant difference in corneal higher order aberrations between the two groups preoperatively, at 1 month, or 3 months after surgery. CONCLUSIONS: There was no significant difference in SIA and corneal higher order aberrations between the two groups.