Is the axial length a risk factor for post-LASIK myopic regression?

Refraction and topographic risk factors for early myopic regression after small-incision lenticule extraction surgery

We sought to evaluate the topographic risk factors for early myopic regression after small-incision lenticule extraction (SMILE). A retrospective case‒control study was conducted, and individuals who underwent SMILE surgery were enrolled. Among them, 406 and 14 eyes were categorized into the nonregression and regression groups, respectively. The preoperative and postoperative parameters in the two groups were collected, including spherical refraction (SE), axial length (AXL) and topographic data. A generalized linear model was adopted to analyze the difference in each parameter between the two groups. After 6 months, UCVA decreased in the regression group, and SE increased in the regression group (both P < 0.05). The increase in the CCT at the thinnest point (P = 0.044), flat corneal curvature (P = 0.012) and TCRP (P = 0.001) were significantly greater in the regression group. Regarding the risk factors for myopic regression, preoperative SE, preoperative sphere power, preoperative AXL, preoperative flat corneal curvature, preoperative SA, early postoperative SE, early postoperative sphere power, early postoperative AXL and early postoperative CCT difference were significantly greater in the regression group (all P < 0.05). The SE, sphere power, AXL, preoperative flat corneal curvature, preoperative SA, and postoperative CCT difference correlate with early myopic regression after SMILE.

Associations of Near Work, Time Outdoors, and Sleep Duration With Myopic Regression 5 Years After SMILE and FS-LASIK: A Cross-sectional Study

PURPOSE

To investigate the association of near work, time outdoors, and sleep duration with myopic regression 5 years after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) .

METHODS

This cross-sectional study included patients who received SMILE or FS-LASIK at Beijing Tongren Hospital 5 years ago. The patients underwent ophthalmic examinations including visual acuity, intraocular pressure, subjective refraction, slit-lamp examination, keratometry, corneal topography, optical coherence tomography, and fundus examination from January 2020 to March 2023. Fluorescein break-up time was measured and the Ocular Surface Disease Index questionnaire was completed to exclude dry eye. A self-administered questionnaire was used to collect data on near work exposure, physical activities, and sleep duration.

RESULTS

A total of 323 eyes were included in the analysis, with a 5-year incidence rate of myopic regression after SMILE or FSLASIK of 16.1%. After adjusted for all confounders, total near work more than 8 hours/day revealed a significant association with myopic regression (odds ratio: 2.461; 95% CI: 1.143 to 5.298, P = .021), particularly in younger adults, women, and patients with high myopia and FS-LASIK treatment. The significant association between sleep duration 8 hours/day or more and myopic regression was restricted to women and patients with FS-LASIK (near significant). However, no significant associations were observed between continuous near work or time outdoors and myopic regression.

CONCLUSIONS

Excessive near work exposure was associated with greater myopic regression 5 years after SMILE or FS-LASIK. It is crucial to maintain good visual behavior and care for preventing regression after SMILE or FS-LASIK, especially for younger patients and eyes with high myopia. [J Refract Surg. 2024;40(1):e10-e19.].

Myopic regression after photorefractive keratectomy: a retrospective cohort study

Background

Myopic regression is a major complication of photorefractive keratectomy (PRK). The rates and causes vary considerably among different studies. This study aimed to investigate myopic regression at six months after myopic PRK.

Methods

In this retrospective cohort study, we included all eligible patients with myopia ranging from - 0.75 to - 9 D, aged 18 to 50 years, who underwent PRK by a single surgeon with the availability of preoperative and postoperative data at six months after the initial procedure. All participants underwent comprehensive ophthalmic examinations preoperatively and at six months post-PRK. Overcorrection was planned based on the participant's age range to achieve the desired refractive result after PRK. All patients received the same postoperative antibiotic and steroid eye drops in a similar dosage regimen, and the contact lenses were removed after complete corneal epithelial healing. Based on the spherical equivalent of refraction six months after PRK, eyes without and with myopic regression were allocated into groups 1 and 2, respectively.

Results

We included 254 eyes of 132 patients who underwent myopic PRK with a mean (standard deviation) age of 30.12 (7.48) years; 82 (62.12%) were women and 50 (37.88%) were men. The frequency of myopic regression was significantly lower in patients with younger age, lower preoperative cylindrical refraction, and lower ablation depth (all P < 0.05). Overcorrection was more successful in eyes with low myopia than in eyes with high myopia (P < 0.05). The highest frequency of myopic regression occurred in eyes with moderate myopia (25.68%), followed by eyes with high myopia (20.0%) and low myopia (6.54%). Among different age groups, patients aged ≤ 30 years had a lower frequency of myopic regression. The frequency of myopic regression in the different age groups was 5.0% at 18 - 20 years, 7.46% at 26 - 30 years, 12.28% at 21 - 25 years, 21.31% at 31 - 35 years, and 26.53% at 36 - 50 years.

Conclusions

Overcorrection was more successful in eyes with low myopia than in eyes with high myopia. The success rate was higher in younger patients with lower astigmatism and ablation depths. Myopic regression was most frequent in eyes with moderate myopia, followed by those with high and low myopia. Further studies should replicate our findings over a longer follow-up period with a larger sample size before generalization is warranted.

IMI-Onset and Progression of Myopia in Young Adults

Myopia typically starts and progresses during childhood, but onset and progression can occur during adulthood. The goals of this review are to summarize published data on myopia onset and progression in young adults, aged 18 to 40 years, to characterize myopia in this age group, to assess what is currently known, and to highlight the gaps in the current understanding. Specifically, the peer-reviewed literature was reviewed to: characterize the timeline and age of stabilization of juvenile-onset myopia; estimate the frequency of adult-onset myopia; evaluate the rate of myopia progression in adults, regardless of age of onset, both during the college years and later; describe the rate of axial elongation in myopic adults; identify risk factors for adult onset and progression; report myopia progression and axial elongation in adults who have undergone refractive surgery; and discuss myopia management and research study design. Adult-onset myopia is common, representing a third or more of all myopia in western populations, but less in East Asia, where onset during childhood is high. Clinically meaningful myopia progression continues in early adulthood and may average 1.00 diopters (D) between 20 and 30 years. Higher levels of myopia are associated with greater absolute risk of myopia-related ocular disease and visual impairment, and thus myopia in this age group requires ongoing management. Modalities established for myopia control in children would be options for adults, but it is difficult to predict their efficacy. The feasibility of studies of myopia control in adults is limited by the long duration required.

Machine learning predicting myopic regression after corneal refractive surgery using preoperative data and fundus photography

PURPOSE

Myopic regression after surgery is the most common long-term complication of refractive surgery, but it is difficult to identify myopic regression without long-term observation. This study aimed to develop machine learning models to identify high-risk patients for refractive regression based on preoperative data and fundus photography.

METHODS

This retrospective study assigned subjects to the training (n = 1606 eyes) and validation (n = 403 eyes) datasets with chronological data splitting. Machine learning models with ResNet50 (for image analysis) and XGBoost (for integration of all variables and fundus photography) were developed based on subjects who underwent corneal refractive surgery. The primary outcome was the predictive performance for the presence of myopic regression at 4 years of follow-up examination postoperatively.

RESULTS

By integrating all factors and fundus photography, the final combined machine learning model showed good performance to predict myopic regression of more than 0.5 D (area under the receiver operating characteristic curve [ROC-AUC], 0.753; 95% confidence interval [CI], 0.710-0.793). The performance of the final model was better than the single ResNet50 model only using fundus photography (ROC-AUC, 0.673; 95% CI, 0.627-0.716). The top-five most important input features were fundus photography, preoperative anterior chamber depth, planned ablation thickness, age, and preoperative central corneal thickness.

CONCLUSION

Our machine learning algorithm provides an efficient strategy to identify high-risk patients with myopic regression without additional labor, cost, and time. Surgeons might benefit from preoperative risk assessment of myopic regression, patient counseling before surgery, and surgical option decisions.