Ultra-Widefield-Guided Swept-Source OCT Findings of Peripheral Vitreoretinal Abnormality in Young Myopes.

PURPOSE: To evaluate the ultra-widefield fundus photography (UWF-FP)-guided swept-source OCT (SS-OCT) images of peripheral vitreoretinal abnormality (PVRA) in young asymptomatic myopes. DESIGN: Cross-sectional, single-center study. PARTICIPANTS: A total of 1966 eyes of 983 consecutive patients aged 18 to 42 years with refractive error in the spherical equivalent of < 0 diopters (D) who visited KEYE Eye Center, Seoul, Republic of Korea, for refractive surgery. METHODS: The prevalence of PVRA and their characteristics, including shape, location, presence of pigmentation, membrane, retinal breaks, and detachment, were evaluated. A logistic regression analysis was done to evaluate the risk factors of PVRA and the risk of retinal breaks or detachment among eyes with PVRA. RESULTS: Among 1966 eyes, 317 (16.1%) had PVRA, and 182 (57.4%) and 135 (42.6%) had focal and linear lesions, respectively. The risk of PVRA was increased with axial length of the eyes (odds ratio [OR], 1.238, 95% confidence interval [CI], 1.112-1.379, P < 0.001), corneal astigmatism (OR, 1.320, 95% CI, 1.148-1.519, P < 0.001), presence of discrete margins of different retinal reflectivity (DMDRR; indicating outer retinal disruption from abnormal vitreoretinal traction) (OR, 1.751, 95% CI, 1.334-2.300, P < 0.001), and posterior vitreous detachment (PVD) at the posterior pole of the retina (OR, 1.833, 95% CI, 1.352-2.485, P < 0.001). Among eyes with PVRA, patient age (OR, 1.063, 95% CI, 1.008-1.121, P = 0.025), linear lesions (OR, 15.234, 95% CI, 7.891-29.407, P < 0.001), and multiple lesions (OR, 3.432, 95% CI, 1.780-6.620, P < 0.001) were independently associated with the presence of retinal breaks or detachment. CONCLUSIONS: The follow-up for PVRA among young myopes should be personalized on the basis of their ocular characteristics, including asymmetric ocular expansion (axial length and astigmatism) and vitreoretinal interface status. The treatment plan for PVRA eyes should emphasize the greater risk of retinal breaks and detachment with increasing age and the presence of linear and multiple lesions. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

A review of posterior chamber phakic intraocular lenses.

PURPOSE OF REVIEW: Posterior chamber phakic intraocular lenses (pIOLs) are increasing in popularity as a viable alternative to laser refractive surgery. The purpose of this review is to evaluate the recent updates to pIOLs and to assess the advancements and safety of the procedure. RECENT FINDINGS: Accurate lens sizing is the key determinant to suitable vault prediction, advancements to sizing formulae including the use of very high frequency (VHF) digital ultrasound and the application of artificial intelligence and machine learning has led to improved vault prediction and safety. The introduction of the central aquaport has been shown to reduce the formation of cataract and is now adopted in most myopic pIOLs. Recently published studies have demonstrated that pIOLs have an excellent safety profile with no increased risk of retinal detachment or endothelial cell loss. Advancements have led to the introduction of extended depth of focus pIOLs for the correction of presbyopia, further research is required to evaluate the efficacy of new lens designs. SUMMARY: pIOL surgery is experiencing traction with improved lens design and increased lenses choices such as larger optical zone and presbyopic options. Accuracy of implantable collamer lens sizing is paramount to the safety and clinical outcomes, greater predictability is likely to encourage more posterior chamber pIOL users due to fewer sizing related complications.

Light adjustable intraocular lenses in cataract surgery: considerations.

PURPOSE OF REVIEW: Light adjustable intraocular lens (LAL) is a promising concept in cataract surgery. This review explores considerations for the use of LALs. RECENT FINDINGS: Through updates, the safety of LALs and light delivery devices have been enhanced, enabling more efficient treatment with lower ultraviolet (UV) energy. Preoperative topography and aberration are essential for understanding indications for LALs. Furthermore, when determining intraocular lens power, it is crucial to factor in potential postoperative myopia or hyperopic adjustments. This is achieved by establishing a proper postimplantation refractive target and considering potential wavefront changes. Postoperative adjustments for defocus and astigmatism have demonstrated excellent outcomes. Monovision strategy by adjustable blended vision of LALs revealed distance vision of 20/20 along with near vision of J2 in 96% of patients. However, the results of clinical studies on postrefractive cataract surgery showed contrasting outcomes at distance, indicating the need for further research results regarding its effectiveness. A new postoperative workflow needs to be designed to enable a systematic follow-up process. SUMMARY: LALs are safe and demonstrate promising refractive outcomes. To achieve appropriate results, understanding the changes in optical characteristics associated with adjustment and constructing a new postoperative workflow are necessary.

Cataract surgery after corneal refractive surgery: preoperative considerations and management.

PURPOSE OF REVIEW: Corneal refractive surgery (CRS) is one of the most popular eye procedures, with more than 40 million cases performed globally. As CRS-treated patients age and develop cataract, the number of cases that require additional preoperative considerations and management will increase around the world. Thus, we provide an up-to-date, concise overview of the considerations and outcomes of cataract surgery in eyes with previous CRS, including surface ablation, laser in-situ keratomileusis (LASIK), and small-incision lenticule extraction (SMILE). RECENT FINDINGS: Challenges associated with accurate biometry in eyes with CRS have been mitigated recently through total keratometry, ray tracing, intraoperative aberrometry, and machine learning assisted intraocular lens (IOL) power calculation formulas to improve prediction. Emerging studies have highlighted the superior performance of ray tracing and/or total keratometry-based formulas for IOL power calculation in eyes with previous SMILE. Dry eye remains a common side effect after cataract surgery, especially in eyes with CRS, though the risk appears to be lower after SMILE than LASIK (in the short-term). Recent presbyopia-correcting IOL designs such as extended depth of focus (EDOF) IOLs may be suitable in carefully selected eyes with previous CRS. SUMMARY: Ophthalmologists will increasingly face challenges associated with the surgical management of cataract in patients with prior CRS. Careful preoperative assessment of the ocular surface, appropriate use of IOL power calculation formulas, and strategies for presbyopia correction are key to achieve good clinical and refractive outcomes and patient satisfaction. Recent advances in CRS techniques, such as SMILE, may pose new challenges for such eyes in the future.

An update on intraocular lens power calculations in eyes with previous laser refractive surgery.

PURPOSE OF REVIEW: There is an ever-growing body of research regarding intraocular lens (IOL) power calculations following photorefractive keratectomy (PRK), laser-assisted in-situ keratomileusis (LASIK), and small-incision lenticule extraction (SMILE). This review intends to summarize recent data and offer updated recommendations. RECENT FINDINGS: Postmyopic LASIK/PRK eyes have the best refractive outcomes when multiple methods are averaged, or when Barrett True-K is used. Posthyperopic LASIK/PRK eyes also seem to do best when Barrett True-K is used, but with more variable results. With both aforementioned methods, using measured total corneal power incrementally improves results. For post-SMILE eyes, the first nontheoretical data favors raytracing. SUMMARY: Refractive outcomes after cataract surgery in eyes with prior laser refractive surgery are less accurate and more variable compared to virgin eyes. Surgeons may simplify their approach to IOL power calculations in postmyopic and posthyperopic LASIK/PRK by using Barrett True-K, and employing measured total corneal power when available. For post-SMILE eyes, ray tracing seems to work well, but lack of accessibility may hamper its adoption.

Surgical options and clinical outcomes for high myopia.

PURPOSE OF REVIEW: Higher degrees of myopia are currently being treated with refractive surgery. However, there is limited characterization and outcomes data for this cohort. This article aims to review the literature on highly myopic patients who had refractive surgery and present a retrospective analysis of 149 patients (270 eyes) with high to extreme myopia (≤-5.0D SE) who underwent refractive surgery [laser-assisted subepithelial keratomileusis (LASIK), photorefractive keratectomy (PRK), or implantable collamer lense (ICL)] at a single practice. RECENT FINDINGS: There is substantial literature on the efficacy of LASIK, PRK, and phakic intraocular lenses for refractive error correction, but a dearth of studies on patients with high to extreme myopia undergoing different types of refractive surgery. Our study reveals that this cohort of patients has excellent outcomes with minimal complications. SUMMARY: Our study reveals that the average preoperative myopia was highest in ICL patients (-10.03D), followed by PRK (-7.21D), and LASIK (-7.04D) patients. Not surprisingly, eyes with high myopia and thin corneas were offered and elected ICLs for their procedure. Highly myopic patients achieved outcomes consistent with data reported in the literature- average postoperative uncorrected visual acuity was 20/20 for LASIK and ICL eyes and 20/25 for PRK eyes.

Femtosecond laser-assisted in situ keratomileusis versus small-incision lenticule extraction: current approach based on evidence.

PURPOSE OF REVIEW: Laser keratorefractive surgery achieves excellent visual outcomes for refractive error correction. With femtosecond laser, small incision lenticule extraction (SMILE) is an increasingly viable alternative to laser-assisted in situ keratomileusis (LASIK). Comparative studies demonstrate similar efficacy and predictability between SMILE and LASIK, making it difficult for clinicians to choose which to use. This review thus compares femtosecond-LASIK (FS-LASK) and SMILE in various scenarios, to assist clinicians in deciding which refractive surgery procedure to recommend. RECENT FINDINGS: SMILE may be superior for highly myopic eyes due to a smaller decrease in functional optical zone. SMILE further induces less spherical aberration and less overall higher order aberrations in mesopic conditions. SMIILE also has less postoperative dry eye, making it suitable those with preexisting dry eye. For low to moderate myopic astigmatism correction, FS-LASIK has less undercorrection compared to SMILE. Lastly, SMILE has not yet received Food and Drug Administration or Conformité Européenne approval for hyperopic correction, rendering FS-LASIK the choice of procedure for hyperopic correction. SUMMARY: Both FS-LASIK and SMILE demonstrate good efficacy and predictability. Understanding specific clinical scenarios where one may be superior to the other will aid clinicians in choosing the most suitable procedure for personalized care.

Impact of the preoperative cylinder on astigmatism correction in femtosecond lenticule extraction (FLEX): a prospective observational study.

PURPOSE: To explore the impact of the preoperative manifest cylinder on astigmatism correction via femtosecond lenticule extraction (FLEX), or small incision lenticule extraction (SMILE). METHODS: This was a prospective observational study. Eyes were categorized into mild (n = 88), moderate (n = 46), and severe (n = 53) astigmatism groups, based on the preoperative manifest cylinder. Vector analysis was conducted with the back vertex distance set at 12 mm. The primary outcome was the correction index (CI), with secondary outcomes including the safety, efficacy, predictability, and vectoral alterations related to FLEX. RESULTS: The average target-induced astigmatism was 0.45 ± 0.20 D, 0.95 ± 0.17 D, and 1.99 ± 0.65 D in the three groups (P < 0.001), and the average CI was 1.12± 0.05, 1.01 ± 0.03, and 0.95 ± 0.02 (P = 0.020), with the severe astigmatism group displaying a notably lower CI. The efficacy, safety, predictability, or stability of FLEX did not demonstrate any significant differences among the three groups. The CIs exhibited a significant difference in eyes with with-the-rule (WTR) astigmatism and against-the-rule (ATR) astigmatism from the mild to severe astigmatism group. In eyes with oblique astigmatism, the average CI exceeded one. CONCLUSION: Patients with manifest cylinder exceeding 1.25 D have a heightened risk of under-correction in WTR and ATR astigmatism compared to those with mild astigmatism, and mild over-correction may occur in cases of oblique astigmatism.

Characteristics of disk halo size and its correlation with lenticule quality in small incision lenticule extraction for moderate to high myopia.

PURPOSE: To investigate changes in disk halo size after small incision lenticule extraction (SMILE) and the correlation between halo size and lenticule quality in moderate to high myopia. METHODS: Thirty eyes of 30 consecutive patients (mean age, 24.9 ± 4.5 years; mean spherical equivalent, -6.85 ± 1.18 D) undergoing SMILE were included in this prospective study. Lenticule surface quality was accessed with a scanning electron microscopy by a scoring system. Halo size was measured preoperatively and at 1, 3, and 6 months postoperatively. Multiple linear regression analysis was performed to explore associations between halo size and a range of factors, including lenticule quality. RESULTS: Disk halo size increased slightly at 1 month and then recovered continually from 3 to 6 months postoperatively, with no difference between halo size during the preoperative period and at 6 months postoperatively (P > 0.05). One month after SMILE, halo size (1 cd/m2, 5 cd/m2) was associated only with uncorrected distance visual acuity (P ≤ 0.004). A halo size of 5 cd/m2 at 3 months postoperatively correlated with the anterior surface quality of the lenticule (P = 0.046). At 6 months postoperatively, a halo size of 1 cd/m2 was associated only with the baseline, accounting for 11.9% of the variability (P = 0.041); no correlations were found for the halo size of 5 cd/m2. CONCLUSIONS: Disk halo size after SMILE was enlarged at an early stage postoperatively and subsequently declined to the baseline level during a 6-month follow-up. The quality of the lenticule surface influenced halo size changes in the early phase.

Predictability comparison of sizing parameters for postoperative vault after implantable Collamer lens implantation.

PURPOSE: This study aims to assess the accuracy of three parameters (white-to-white distance [WTW], angle-to-angle [ATA], and sulcus-to-sulcus [STS]) in predicting postoperative vault and to formulate an optimized predictive model. METHODS: In this retrospective study, a cohort of 465 patients (comprising 769 eyes) who underwent the implantation of the V4c implantable Collamer lens with a central port (ICL) for myopia correction was examined. Least absolute shrinkage and selection operator (LASSO) regression and classification models were used to predict postoperative vault. The influences of WTW, ATA, and STS on predicting the postoperative vault and ICL size were analyzed and compared. RESULTS: The dataset was randomly divided into training (80%) and test (20%) sets, with no significant differences observed between them. The screened variables included only seven variables which conferred the largest signal in the model, namely, lens thickness (LT, estimated coefficients for logistic least absolute shrinkage of -0.20), STS (-0.04), size (0.08), flat K (-0.006), anterior chamber depth (0.15), spherical error (-0.006), and cylindrical error (-0.0008). The optimal prediction model depended on STS (R2=0.419, RMSE=0.139), whereas the least effective prediction model relied on WTW (R2=0.395, RMSE=0.142). In the classified prediction models of the vault, classification prediction of the vault based on STS exhibited superior accuracy compared to ATA or WTW. CONCLUSIONS: This study compared the capabilities of WTW, ATA, and STS in predicting postoperative vault, demonstrating that STS exhibits a stronger correlation than the other two parameters.

Analysis on the changes of objective indicators of dry eye after implantable collamer lens (ICL) implantation surgery.

PURPOSE: To explore whether implantable collamer lens implantation has any effect on the postoperative objective indicators of dry eye and to determine the severity of its influence on each indicator. METHODS: This prospective observational trial was performed in the Department of Ophthalmology of West China Hospital and was approved by the Biomedical Ethics Sub-Committee of the West China Hospital of Sichuan University. A total of 89 non-dry eye patients (178 eyes in total) who received ICL implantation surgery at West China Hospital of Sichuan University were enrolled. The noninvasive keratograph tear film breakup time (NIKBUT), noninvasive keratograph tear meniscus height (NIKTMH), score of lipid layer, score of meibomian gland function, and hyperemia index were obtained via the OCULUS Keratograph for all subjects before surgery and at 1 week, 1 month, and 3 months after surgery. The fluorescein tear film breakup time (FBUT), corneal fluorescein staining score (CFS), and Schirmer test I were also measured at the same time. RESULTS: A total of 178 eyes completed the 1-week and 1-month follow-up, and 40 eyes completed the 3-month follow-up. Compared with the preoperative baseline, there was no significant difference in the NIKBUT or the corneal fluorescein staining score at each follow-up time point (P > 0.05, P > 0.05, P > 0.05). The FBUT and Schirmer test I at 1 week, 1 month, and 3 months after surgery were significantly higher than the preoperative baseline (P < 0.01, P < 0.01, P < 0.01). The NIKTMH and the score of lipid layer were significantly lower than the preoperative baseline at 1 week, 1 month, and 3 months after surgery (P < 0.01, P < 0.01, P < 0.05). The score of meibomian gland function and hyperemia index were significantly lower than the preoperative baseline 1 week after surgery (P < 0.01). CONCLUSION: ICL implantation has no adverse effect on the occurrence of postoperative dry eye, but it reduces the basal tear secretion of patients after surgery and has adverse effects on the indices of meibomian gland function in the short term postoperatively.

Influencing factors comparing different vault groups after phakic implantable collamer lens implantation: review and meta-analysis.

BACKGROUND: Studies on the factors affecting vault after posterior chamber phakic Implantable Collamer Lens (ICL) have been carried out, but most of them are single-centered and subjective selections of parameters. The present study aimed to systematically analyze the factors for vault. METHODS: A systematic review of case series, case-control, and cohort studies derived from the articles published in PubMed, the Cochrane Library, Embase, Web of Science, CNKI, CBM, Wanfang and VIP, as well as ClinicalTrials, which were conducted to search for studies on factors of vault using four core terms: phakic intraocular lenses, vault, risk factor and observational study, from January 01, 1997, to February 20, 2023. The included studies were meta-analyzed quantitatively and described qualitatively. Subsequently, meta-regression and subgroup analysis were used. RESULTS: We identified 13 studies (1,607 subjects), and 14 factors were considered. Meta-analysis showed that anterior chamber depth (ACD), horizontal corneal white-to-white (hWTW), ICL-size, and age are dual effects of the abnormal vaults; anterior chamber volume (ACV) and lens thickness (LT) are a one-way effect; while axial length (AL), ICL- spherical equivalent (ICL-SE) and Km are insignificant. In addition, descriptive analysis of anterior chamber angle (ACA), horizontal sulcus to sulcus (hSTS), ciliary processes height (T value), crystalline lens rise (CLR), and gender showed that all factors except gender tend to have significant effects on vault. Sensitivity analysis showed stable combined results. Country and design respectively affect the heterogeneity in ACD and ICL-size at low vault, while design affects the heterogeneity in ACD at high vault. No publication bias exists. CONCLUSIONS: Vault after ICL is related to multiple factors, especially anterior segmental biologic parameters, and they are weighted differently. We hope to provide a reference for the selection and adjustment of ICL.

Comparison of pain between bilateral ICL surgeries in patients with myopia.

PURPOSE: The purpose of this study was to compare the preoperative anxiety, aqueous humor monocyte chemoattractant protein-1 (MCP-1) concentration, intraoperative pain, and degree of cooperation of the first eye implantable collamer lens (ICL) surgery with the second eye surgery, of the 1-day interval group with the 1-week interval group, and to investigate the possible causes of these differences, as well as to determine the appropriate interval between bilateral eye ICL surgeries. METHOD: The study was a prospective observational study. A total of 120 patients who underwent bilateral ICL surgery at the Department of Ophthalmology, West China Fourth Hospital, Sichuan University, from July to September 2023, were enrolled. The patients were divided into a 1-day interval group and a 1-week interval group. The ICL surgery was performed on both eyes according to the schedule. Anxiety levels, aqueous humor MCP1, cooperativeness, surgical time, pain and satisfaction, and patients' estimations of the time spent in the operation were recorded for each eye. The patients were instructed to recall the intraoperative pain of the first eye surgery after the operation of the second eye. Statistical analyses (two independent samples t-test,two paired samples t-test, the rank-sum test, the chi-square test, non-parametric test with multiple independent samples) were performed to compare the differences between each score in both eyes and two groups. Furthermore, we examined the relationship between pain levels and the reproductive history of the patients. RESULTS: In the 1-day interval group, male/female is 22/52, average age is 25.24±5.00. In the 1-week interval group, male/female is 17/29, average age is 25.39±5.57. There was no statistically significant difference between the two groups. In both groups, patients were less nervous, had significantly more pain, had less surgical satisfaction, had a longer estimated operative time, and had elevated preoperative MCP1 during the second eye operation. In the second eye surgery, the patient's cooperation worsened, but it did not lead to an increase in surgical time. A significant proportion of patients, particularly in the 1-week interval group, recalled experiencing reduced pain during the first eye surgery. The 1-week interval group had a higher difference in all indicators between the bilateral surgeries. In the second eye surgery, patients in the 1-week interval group experienced more severe pain, less cooperation, longer estimated operation duration, and a greater MCP1 than those in the 1-day interval group. CONCLUSION: Patients undergoing second eye ICL surgery had decreased nervousness, increased pain, decreased cooperation, and satisfaction, and increased MCP1 compared to the first eye surgery. It is recommended that an interval of about one week should be avoided between bilateral surgeries when developing a surgical schedule to improve patients' cooperation, satisfaction, and comfort.

Comparative visual outcomes of the first versus second eye following small-incision lenticule extraction (SMILE).

BACKGROUND: This study aimed to compare the visual outcomes of the first operated eyes with those of the second operated eyes following small-incision lenticule extraction (SMILE). METHODS: A total of 202 patients (404 eyes) underwent SMILE using the tear film mark centration method for myopia and myopic astigmatism correction. Baseline characteristics, objective optical quality, decentered displacement, induced corneal aberrations, and modulation transfer function (MTF) values were assessed. Linear regression analyzed the relationship between decentration and visual quality parameters, including corneal aberrations and MTF values. RESULTS: No significant difference was observed in objective visual quality, efficacy, and safety indexes between the two groups (all P > 0.05). The average decentered displacement for the first and second surgical eyes was 0.278 ± 0.17 mm and 0.315 ± 0.15 mm, respectively (P = 0.002). The horizontal coma in the first surgical eyes were notably lower than in the second (P = 0.000). MTF values at spatial frequencies of 5, 10, 15, and 20 cycles/degree (c/d) were higher in the first surgical eyes compared to the second (all P < 0.05). Linear regression indicated that high-order aberrations (HOAs), root mean square (RMS) coma, spherical aberration, horizontal coma, vertical coma, and eccentric displacement were all linearly correlated. Furthermore, MTF values exhibited a linear relationship with eccentric displacement across these spatial frequencies. CONCLUSIONS: There was no discernible difference in visual acuity, efficacy, or safety between the two operated eyes. Nonetheless, the first operated eyes exhibited reduced decentered displacement and demonstrated superior outcomes in terms of horizontal coma and MTF values compared to the second operated eyes following SMILE. The variations in visual quality parameters were linearly correlated with decentered displacement.

Extended depth of focus IOL in eyes with different axial myopia and targeted refraction.

AIM: To evaluate the objective visual outcomes following implantation of extended depth of focus intraocular lens (EDOF IOL) in individuals with varying axial lengths (AL) and targeted refraction. METHODS: This retrospective study comprised age-matched eyes that underwent implantation of the EDOF IOL. Eyes were categorized based on AL into groups: control group with AL < 26 mm; high myopia group with AL ≥ 26 mm. Each group was then subdivided based on postoperative spherical equivalent (SE). Follow-up at three months included assessment of uncorrected visual acuity at different distances, contrast sensitivity (CS), refractive outcomes, and spectacle independence. RESULTS: Overall, this study included 100 eyes from 100 patients, comprising 50 males (50.00%) and 50 females (50.00%), with 20 eyes in each group. In the control group, the uncorrected distance visual acuity (UDVA) at 5 and 3 m (m) in the - 1.50 to -0.75 group was inferior to that of the - 0.75 to 0.00 group (P = 0.004). Conversely, the uncorrected near visual acuity (UNVA) at 33 cm in the - 1.50 to -0.75 group was superior to that of the - 0.75 to 0.00 group (P = 0.005). Within the high myopia group, the UDVA at 5 and 3 m in the - 2.25 to -1.50 group was worse than in the - 0.75 to 0.00 group (P = 0.009 and 0.008, respectively). However, the UNVA at 33 cm in the - 2.25 to -1.50 group was better than in the - 0.75 to 0.00 group (P = 0.020). No significant differences were observed among the groups for corrected distance visual acuity (CDVA) (P > 0.05). Additionally, in the high myopia group, the CS of the - 2.25 to -1.50 group was lower compared to that of the - 0.75 to 0.00 group (P = 0.017). Among high myopia patients, 90.00% with refraction ranging from - 1.50 to -0.75 reported achieving overall spectacle independence. CONCLUSIONS: Implantation of extended depth of focus intraocular lenses (IOLs) yields satisfactory visual and refractive outcomes in eyes with axial myopia. Among high myopia patients, a refraction ranging from - 1.50 to -0.75 diopters achieves superior visual quality compared to other postoperative myopic diopters.

Topographic and surgical risk factors for high postoperative residual astigmatism after small incision lenticule extraction in patients with different degrees of myopia: a retrospective cohort study.

BACKGROUND: To evaluate the possible topographic and surgical risk factors for high postoperative residual astigmatism in patients who undergo small-incision lenticule extraction (SMILE) surgery and have different myopia degrees. METHODS: A retrospective cohort study was conducted, and patients who underwent SMILE surgery were enrolled. A total of 80 and 150 eyes from 40 to 75 individuals, respectively, were selected as the low myopia and high myopia groups. The demographic data, visual acuity, refraction, topographic parameters and surgical settings were recorded. Multiple linear regression with interaction tests were performed to survey the risk factors for high postoperative residual astigmatism in each group. RESULTS: Five (6.25%) and 9 (6.00%) eyes presented with high postoperative residual astigmatism in the low myopia and high myopia groups, respectively, but these differences were not significant (P = 0.569). A steep corneal curvature was correlated with a greater risk of high postoperative residual astigmatism in the low myopia group (P = 0.015), while a higher degree of cycloplegic cylinder power, steeper corneal curvature, greater topographic cylinder power, smaller optic zone and longer incision length were associated with a high rate of postoperative residual astigmatism in the high myopia group (all P < 0.05). In addition, the interaction effects of cycloplegic and topographic cylinder power and longer incision length on the incidence of high postoperative residual astigmatism development were more evident in the high myopia group than in the low myopia group (all P < 0.05). CONCLUSIONS: A steep corneal curvature correlates with a high risk of high postoperative residual astigmatism after SMILE surgery, and a higher degree of cycloplegic and topographic cylinder and longer incision are associated with high postoperative residual astigmatism in individuals with high myopia.

Factors affecting long-term myopic regression after corneal refractive surgery for civilian pilots in southwest China.

BACKGROUND: The purpose of this study was to analyze myopic regression after corneal refractive surgery (CRS) in civilian pilots and to explore the factors that may cause long-term myopic regression. METHODS: We included civilian pilots who had undergone CRS to correct their myopia and who had at least 5 years of follow-up. We collected retrospective data and completed eye examinations and a questionnaire to assess their eye habits. RESULTS: A total of 236 eyes were evaluated in this study. 211 eyes had Intrastromal ablations (167 eyes had laser in situ keratomileusis, LASIK, 44 eyes had small incision lenticule extraction, SMILE) and 25 eyes had subepithelial ablations (15 eyes had laser epithelial keratomileusis, LASEK and 10 eyes had photorefractive keratectomy, PRK). The mean preoperative spherical equivalent (SE) was - 2.92 ± 1.11 D (range from - 1.00 to -5.00 D). A total of 56 eyes (23.6%) suffered from myopic regression after CRS. Comparisons of individual and eye characteristics between the regression and non-regression groups revealed statistically significant differences in age, cumulative flight time, postoperative SE (at 6 months and current), uncorrected visual acuity (UCVA), accommodative amplitude (AA), positive relative accommodation (PRA), postoperative period, types of CRS and eye habits. Generalized propensity score weighting (GPSW) was used to balance the distribution of covariates among different age levels, types of CRS, cumulative flying time, postoperative period and continuous near-work time. The results of GPS weighted logistic regression demonstrated that the associations between age and myopic regression, types of CRS and myopic regression, continuous near-work time and myopic regression were significant. Cumulative flying time and myopic regression, postoperative period and myopic regression were no significant. Specifically, the odds ratio (OR) for age was 1.151 (P = 0.022), and the OR for type of CRS was 2.769 (P < 0.001). The OR for continuous near-work time was 0.635 with a P value of 0.038. CONCLUSIONS: This is the first report to analyze myopic regression after CRS in civilian pilots. Our study found that for each year increase in age, the risk of civilian pilots experiencing myopic regression was increased. Intrastromal ablations had a lower risk of long-term myopia regression than subepithelial ablations. There is a higher risk of myopic progression with continuous near-work time > 45 min and poor accommodative function may be related factors in this specific population.

Analysis of surgically induced astigmatism of the anterior, posterior, and total cornea after implantable collamer lens implantation: a comparative study between temporal and superior clear corneal incisions.

BACKGROUND: To comparatively analyze the surgically induced astigmatism (SIA) of the anterior, posterior, and total corneas of eyes undertaking implantable collamer lens (ICL) implantation with temporal or superior corneal incisions. METHODS: One hundred and nine eyes of 109 patients who received ICL implantation were recruited: 40 eyes had temporal incisions and 69 eyes had superior incisions. Total corneal refractive power (TCRP); simulated keratometry of the anterior (Sim-KAnt) and posterior (Sim-KPost) corneal curvature; and astigmatism of the anterior (CAAnt), posterior (CAPost), and total (CATCRP) cornea were recorded through a Pentacam preoperatively and 3 months postoperatively. The SIA of the anterior, posterior, and total cornea were also compared between the two groups. RESULTS: There were no significant intergroup differences for TCRP, Sim-KAnt, Sim-KPost, CAAnt, CAPost, or CATCRP, preoperatively. However, values of CAAnt, CAPost, and CATCRP with temporal incision were significantly higher than those parameters with superior incision postoperatively. All of the SIA of the anterior, posterior, and total cornea were significantly lower for temporal incision than those with a superior incision (p < 0.001, p = 0.006 and p = 0.001 respectively). Meanwhile, the superior incisions created against-the-rule (ATR) astigmatism, and temporal incisions always induce with-the-rule (WTR) astigmatism in total cornea. CONCLUSIONS: A superior incision may be suitable for correcting WTR astigmatism, while a temporal incision for correcting ATR astigmatism when using a non-toric ICL. Meanwhile, temporal incision could be a better choice with little preoperative astigmatism or that preoperative astigmatism would be corrected with toric ICLs. TRIAL REGISTRATION: Registration number: ChiCTR2100051739. Prospectively registered: 01 October 2021.

Macular hole following scleral buckling for rhegmatogenous retinal detachment: a case series.

BACKGROUND: Macular hole (MH) development following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) repair is rare. This study presents both full-thickness MH (FTMH) and lamellar MH (LMH) cases following SB for the treatment of RRD. METHODS: Clinical records of patients undergoing SB surgery for treatment of RRD at the Xi'an People's Hospital (Xi'an Fourth Hospital) from January 2016 to December 2021 were reviewed, and cases with postoperative MH were selected. Clinical features and follow-up data were summarised, and possible causes were analysed. RESULTS: Among 483 identified cases (483 eyes), four eyes (three male patients, one female patient) had postoperative MH, with prevalence, mean age, and mean axial length of 0.83%, 43.5 ± 10.66 years, and 29.13 ± 3.80 mm, respectively. All patients did not undergo subretinal fluid (SRF) drainage. The mean time for detecting MH was 26 ± 15.5 days postoperatively. Macula-off RRD with high myopia and FTMH combined with retinal re-detachment were diagnosed in three patients. One patient had macula-on RRD with outer LMH. The average follow-up duration was 7.25 ± 1.5 months. The FTMH closed successfully after reoperation, while the outer LMH closed without intervention. Visual acuity insignificantly improved or slightly decreased in all patients. CONCLUSIONS: Patients with high myopia combined with macula-off RRD might be more susceptible to FTMH, causing MH related retinal detachment. Additionally, LMH following SB was noted in patients with macula-on RRD. Therefore, we should raise awareness of MH following SB for RRD repair.

Interface fluid syndrome caused by the corneal perforation injury after small incision lenticule extraction: a case report.

BACKGROUND: To report a case of interface fluid syndrome (IFS) following traumatic corneal perforation repair after small incision lenticule extraction (SMILE). CASE PRESENTATION: A 23-year-old woman, with a past history of SMILE, was struck in the left eye with a barbecue prod and subsequently underwent corneal perforation repair at local hospital. Primary wound repaired with a single 10 - 0 nylon suture at the area of leakage. After the surgery, her best corrected visual acuity (BCVA) was 20/30. Four days later, she presented at our hospital with blurred vision, and interface fluid syndrome (IFS) was diagnosed. Intraoperative optical coherence tomography (iOCT) was used to guide the resuturing of the corneal perforation in the left eye, followed by anterior chamber gas injection. At the first postoperative month, the BCVA was 20/25. The corneal cap adhered closely to the stroma, the surface became smooth. CONCLUSIONS: This case illustrates that any corneal perforation following lamellar surgery, including SMILE, may lead to IFS. It is crucial to consider the depth of corneal perforation, and intraoperative optical coherence tomography (iOCT) plays a unique role in the repair procedure.