To evaluate the efficiency, predictability, and residual astigmatism between first- and second-generation keratorefractive lenticule extraction (KLEx) surgeries in a prominent astigmatism population. A retrospective cohort study was conducted, and individuals who underwent first- and second-generation KLEx surgeries were enrolled. A total of 31 and 35 eyes were categorized into first and second KLEx groups, respectively. Visual acuity, refraction, topographic parameters, and surgical indices were recorded. Independent t tests were used to compare the postoperative uncorrected distance visual acuity (UDVA), spherical equivalent (SE), and residual astigmatism between the two groups. The difference in UDVA was not significant three months after KLEx surgery (P = 0.509), and the SEs three months after surgery also presented similar values between the two groups (P = 0.552). The first KLEx group demonstrated greater residual astigmatism than did the second KLEx group throughout the three-month follow-up period (all P < 0.05). The values of surgically induced astigmatism (SIA), difference vector (DV), magnitude of error (ME) and correction index (CoI) were significantly better in the second KLEx group via vector analysis (all P < 0.05). Old age, high steep keratometry (K), high topographic cylinder, large angle kappa, and a small optic zone were correlated with greater residual astigmatism in the first KLEx group (all P < 0.05), whereas only a small optic zone was significantly correlated with greater residual astigmatism in the second KLEx group (P = 0.047). The second-generation KLEx is correlated with a lower risk of residual astigmatism.

We aim to evaluate the myopia control effect of defocus incorporated multiple segments’ (DIMS) spectacle lens in combination with different concentrations of atropine (ATR). A retrospective cohort study was conducted and DIMS users were categorized according to ATR concentration: 55 DIMS alone, 55 DIMS-Low ATR (0.01%) and 50 DIMS-High ATR (0.125%) groups. All three myopia control methods were applied for one year. Primary outcomes measures were changes in spherical equivalent refraction (SER) and axial length (AXL). One-way ANOVA was utilized to compare the outcome differences among the three groups, and multiple linear regression was utilized to analyze the effects of age, sex, baseline SER and baseline AXL on myopia progression among the three groups. The cycloplegic SER progression was-0.30 ± 0.25 D, −0.17 ± 0.49 D and − 0.16 ± 0.14 D in DIMS, DIMS-Low ATR and DIMS-High ATR groups respectively. The DIMS group showed a significant higher cycloplegia SER progression (P = 0.003). The AXL elongation was 0.13 ± 0.08 mm, 0.06 ± 0.20 mm and 0.06 ± 0.14 mm in DIMS, DIMS-Low ATR and DIMS-High ATR groups respectively and AXL elongation was significantly higher in DIMS group (P = 0.011). The young age demonstrated positive correlation to the higher cycloplegia SER progression in all groups (all P < 0.05). The young age is also correlated to higher AXL elongation in the DIMS and DIMS-Low ATR groups (both P < 0.05). The myopia control effects of low- and high-concentration ATRs in DIMS users show no significant difference, while the addition of atropine in combination with DIMS spectacles had a greater effect on myopia control than DIMS spectacles alone.

We aimed to evaluate the postoperative visual and refractive outcomes between the first- and second-generation keratorefractive lenticule extraction (KLEx) surgeries. A retrospective cohort study was conducted and patients who had received first- and second-generation KLEx surgeries were enrolled. A total of 80 and 80 eyes were categorized into the first and second KLEx groups after exclusion, respectively. The primary outcomes were the postoperative uncorrected distance visual acuity (UDVA), spherical equivalent (SE), and safety indexes. An independent t-test and generalized estimate equation were implemented to compare the primary outcomes between the two groups. After the KLEx surgery, the UDVA showed no significant difference between the two groups throughout the study period (all p > 0.05), and the postoperative SE and safety index were also statistically identical between the two groups during the follow-up interval (all p > 0.05). There was a similar trend of visual recovery between the two groups (aOR: 0.967; 95% CI: 0.892–1.143; p = 0.844), while the amplitude of the SE change was significantly lower in the second KLEx group (aOR: 0.760; 95% CI: 0.615–0.837; p = 0.005). Nine and two unintended initial dissection of the posterior plane (UIDPP) occurred intraoperatively in the first and second KLEx groups, respectively, and the second group showed a lower risk of UIDPP (p = 0.032). In conclusion, the efficiency, predictability, and safety are similar between first- and second-generation KLEx surgeries.

We aimed to investigate high-order aberration (HOA) change between topography-guided (TG) and wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) in patients with different degrees of myopia. A non-randomized clinical trial was conducted, in which 40 eyes of 20 patients aged 20–50 years old were included. Participants received TG-LASIK in one eye and WFO-LASIK on the alternate eye. Corneal topography and HOAs including coma, trefoil, spherical aberration (SA), and contrast sensitivity (CS) were collected. Moreover, a quality of vision (QoV) questionnaire was completed by each participant. Non-parametric tests were used to infer the difference in HOAs and CS between the TG-LASIK and WFO-LASIK groups, and subgroup analyses stratified by myopia degree were performed. The high-myopia patients with TG-LASIK showed more coma and SA compared to low-myopia individuals (all 95% CI lower limits > 0), and subjects who received WFO-LASIK exhibited more SA in high-myopia status (both 95% CI lower limits > 0). The TG-LASIK group showed lower postoperative trefoil compared to the WFO-LASIK group in the high-myopia population (mean difference: −0.1267, 95% CI: −0.24 to −0.01). The TG-LASIK group yielded less surgically induced haze, better clarity at night, and better total quality scores (all p < 0.05). In conclusion, TG-LASIK might yield less postoperative trefoil in high-myopia patients and higher QoV in the general population compared to the WFO-LASIK procedure.

Purpose: The purpose of this study was to compare the differences in myopic control effects between orthokeratology (OK) contact lenses and defocus incorporated multiple segments (DIMS) spectacle lenses.