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.

Predicting the impact of femtosecond-assisted arcuate keratotomy combined with tri-planar clear corneal incisions on astigmatism in implantable collamer lens surgery: one-year follow-up.

PURPOSE: To investigate the factors associated with and impact on the femtosecond-assisted (FS-assisted) limbal relaxing incision (LRI) combined with the steep-meridian tri-planar clear corneal incision (TCCI) to reduce astigmatism in patients undergoing Implantable Collamer Lens (ICL) surgery. METHODS: Retrospective case series. The study reviewed patients with ICL surgery combined with FS-assisted LRIs paired with steep-meridian TCCIs. Correlation analysis examined the relationship between independent variables, including preoperative characteristics (intraocular pressure, corneal thickness, axial length, et al.), TCCI, and LRI surgical parameters. The predictors of surgically induced astigmatism (SIA) were determined using individual-level analysis and accounting for inter-eye correlation with the generalized estimating equation (GEE). RESULTS: The study enrolled 69 patients, with 114 eyes (55 right and 59 left). The mean spherical equivalent (SEQ) was - 10.29 ± 2.99D and - 9.99 ± 2.72D for the right and left eye, respectively, while the mean preoperative corneal astigmatism was - 1.54 ± 0.47D and - 1.54 ± 0.46D for the right and left eyes, respectively. After 12 months of follow-up, univariate analysis revealed significant correlations between SIA and intraocular pressure (IOP), astigmatism type, TCCI position (degree), peripheral corneal thickness (PCT), LRI arc incision diameter, post depth (%), and angle, respectively (P = 0.046, 0.016, 0.039, 0.040, 0.009, 0.000, 0.000). Multivariate analysis using GEE demonstrated that axial length (AL), astigmatism type, LRI arc diameter, and angle were independent predictors of SIA (P = 0.000, 0.005, 0.029, 0.000). CONCLUSIONS: The type of astigmatism and axial length were independent factors that affected SIA when modifying the LRI arc diameter and angle through FS-assisted steep-meridian TCCI paired with LRI in ICL surgery.

A Deep Learning Model for Automatically Quantifying the Anterior Segment in Ultrasound Biomicroscopy Images of Implantable Collamer Lens Candidates.

OBJECTIVE: This study aimed to develop and evaluate a deep learning-based model that could automatically measure anterior segment (AS) parameters on preoperative ultrasound biomicroscopy (UBM) images of implantable Collamer lens (ICL) surgery candidates. METHODS: A total of 1164 panoramic UBM images were preoperatively obtained from 321 patients who received ICL surgery in the Eye Center of Renmin Hospital of Wuhan University (Wuhan, China) to develop an imaging database. First, the UNet++ network was utilized to segment AS tissues automatically, such as corneal lens and iris. In addition, image processing techniques and geometric localization algorithms were developed to automatically identify the anatomical landmarks (ALs) of pupil diameter (PD), anterior chamber depth (ACD), angle-to-angle distance (ATA), and sulcus-to-sulcus distance (STS). Based on the results of the latter two processes, PD, ACD, ATA, and STS can be measured. Meanwhile, an external dataset of 294 images from Huangshi Aier Eye Hospital was employed to further assess the model's performance in other center. Lastly, a subset of 100 random images from the external test set was chosen to compare the performance of the model with senior experts. RESULTS: Whether in the internal test dataset or external test dataset, using manual labeling as the reference standard, the models achieved a mean Dice coefficient exceeding 0.880. Additionally, the intra-class correlation coefficients (ICCs) of ALs' coordinates were all greater than 0.947, and the percentage of Euclidean distance distribution of ALs within 250 µm was over 95.24%.While the ICCs for PD, ACD, ATA, and STS were greater than 0.957, furthermore, the average relative error (ARE) of PD, ACD, ATA, and STS were below 2.41%. In terms of human versus machine performance, the ICCs between the measurements performed by the model and those by senior experts were all greater than 0.931. CONCLUSION: A deep learning-based model could measure AS parameters using UBM images of ICL candidates, and exhibited a performance similar to that of a senior ophthalmologist.

Immediate versus delayed sequential bilateral ICL implantation: A retrospective comparison of vault height and visual outcomes.

PURPOSE: To compare the visual outcomes and risks of suboptimal vault-related complications between immediate sequential bilateral ICL surgery (ISBICLS) and delayed sequential bilateral ICL surgery (DSBICLS). DESIGN: A retrospective cohort study. METHODS: Patients who underwent bilateral ICL implantation between November 2014 and December 2021 at the Eye and ENT Hospital of Fudan University (Shanghai, China) were included and divided into two groups: (1) ISBICLS: both eye surgeries performed on the same day, and (2) DSBICLS: second eye surgery performed < 7 days following the first one. Propensity score matching (PSM) was performed to compare the visual outcomes. Multivariable logistic regression models were used to estimate the odds ratios (ORs) of the suboptimal vaults. RESULTS: Finally, 10,985 eyes were included. After PSM, 204 first surgery eyes and 162 s surgery eyes with complete postoperative data were matched. The safety and efficacy indices did not statistically differ between groups (all > 1.00), except that ISBICLS first surgery eyes achieved better efficacy index than DSBICLS group (1.03 ± 0.26 vs. 1.08 ± 0.23, P = 0.034). Excessive vault was observed in eight (4.06 %) ISBICLS first eyes, one (0.50 %) DSBICLS first eye, and none in the second surgery eye in either group. An insufficient vault was observed in one second eye and one DSBICLS second eye. We found no evidence of differences in the rate of excessive vault (OR = 0.831, 95 % CI: 0.426-1.622, P = 0.588) or insufficient vault (OR = 0.609, 95 % CI:0.062-5.850, P = 0.668). CONCLUSION: ISBICLS provided safety, efficacy, and refraction predictability comparable to DSBICLS without increasing the risk of suboptimal vault-related complications.

Investigation of subclinical ocular inflammation in the aqueous humor of patients with myopia following bilateral sequential collamer lens implantation.

BACKGROUND: The aqueous humor, a transparent fluid secreted by the ciliary body, supports the lens of the eyeball. In this study, we analyzed the cytokine and chemokine profiles within the aqueous humor of the contralateral eye post-implantation of an implantable collamer lens (ICL) to evaluate potential subclinical inflammation in the second eye subsequent to ICL implantation in the first eye. METHODS: Aqueous humor samples were procured from both eyes of 40 patients (totaling 80 eyes) prior to bilateral ICL insertion. Subsequently, a comprehensive statistical analysis was conducted using the Luminex assay to quantify 30 different cytokines in these samples. RESULTS: Compared to the first eye, the aqueous humor of the second eye demonstrated decreased concentrations of IFN-γ (P = 0.038), IL-13 (P = 0.027), IL-17/IL-17 A (P = 0.012), and IL-4 (P = 0.025). No significant differences were observed in other cytokine levels between the two groups. Patients were then categorized based on the postoperative rise in intraocular pressure (IOP) in the first eye. The group with elevated IOP displayed elevated levels of EGF in the aqueous humor of the first eye (P = 0.013) and higher levels of PDGF-AB/BB in the aqueous humor of the second eye (P = 0.032) compared to the group with normal IOP. Within the elevated IOP group, the levels of EGF (P = 0.013) and IL-17/IL-17 A (P = 0.016) in the aqueous humor were lower in the second eye than in the first eye. In the normal IOP group, cytokine levels did not differ notably between eyes. CONCLUSION: Following sequential ICL implantation, it appears that a protective response may be activated to mitigate subclinical inflammation in the second eye induced by the initial implantation in the first eye. Additionally, the increase in IOP subsequent to surgery in the first eye may correlate with the presence of inflammatory mediators in the aqueous humor.

Managing Pigment Dispersion Glaucoma Postbilateral ICL Implantation in High Myopia: A Case Report on the Crucial Role of Gonioscopy in Correcting a Misdiagnosis.

Secondary open-angle glaucoma (SOAG) is a rare yet consequential complication following implantable collamer lens (ICL), also known as a phakic intraocular lens insertion, particularly in high myopia patients. This case report emphasizes the importance of recognizing SOAG and details the diagnostic complexities, reevaluation procedures, and successful long-term management of a 24-year-old bilateral high myopia (-7.00 D) patient who initially received an erroneous diagnosis of secondary angle-closure glaucoma (SACG) after ICL insertion at an external medical facility. Persistent visual issues prompted the patient to seek a second opinion, leading to a comprehensive reevaluation that eventually unveiled pigment dispersion syndrome (PDS) as the underlying cause, subsequently resulting in SOAG. This case not only highlights the diagnostic challenges but also elucidates the re-evaluation process and effective 5-year management strategies employed to restore the patient's visual health and quality of life. How to cite this article: Ramesh PV, Parthasarathi S, Azad A, et al. Managing Pigment Dispersion Glaucoma Postbilateral ICL Implantation in High Myopia: A Case Report on the Crucial Role of Gonioscopy in Correcting a Misdiagnosis. J Curr Glaucoma Pract 2024;18(1):31-36.

Bilateral Late-Onset Pigment Dispersion Syndrome following Implantable Collamer Lens Surgery: A Case Report.

Introduction: We report a case of bilateral pigment dispersion syndrome after 13 years of uncomplicated implantable collamer lens (ICL) surgery. Case Presentation: A 53-year-old woman was referred from her optometrist to our glaucoma clinic due to early superonasal visual field loss in both eyes. She was asymptomatic with no changes in visual acuity and had undergone bilateral ICL implantation 13 years ago to correct her high myopia. Clinical examination revealed pigment deposition on the corneal endothelium, iris transillumination defects, and iris vaulting at the areas of contact with the ICL. Gonioscopy showed open angles with significant pigmentation of the trabecular meshwork. The diagnosis of pigment dispersion syndrome secondary to ICL implantation was made, and subsequent follow-up visits demonstrated normal intraocular pressure IOP and stable visual fields. Conclusion: Pigmentary dispersion syndrome can occur several years after ICL implantation. This case report emphasizes the need for long-term follow-up and monitoring after ICL surgery.

Bibliometric and visualized analysis of posterior chamber phakic intraocular lens research between 2003 and 2023.

Introduction: Myopia is causing a major public health concern, with its prevalence increasing globally. This study aimed to discuss posterior chamber phakic intraocular lens (pIOL) research publication trends and hotspots over the past 20 years. Methods: Bibliometric analysis was performed using the Web Science Core Collection to investigate posterior-chamber pIOL research publication trends. The extracted records were analyzed, and a knowledge map was built using VOSviewer v.1.6.20. The analysis included visualizing the annual publication count, countries/regions distribution, international and institutional collaborations, author productivity, and journal contribution, in addition to identifying knowledge bases and hotspots. Burst keywords were extracted using CiteSpace v.6.1.R. Results: In total, 791 articles on posterior chamber pIOLs published between 2003 and 2023 were retrieved. China had the highest number of publications, whereas Japanese papers received the most citations. Fudan University had the highest number of publications, with articles from Kitasato University having the highest number of citations. Regarding individual research, Xingtao Zhou has published the most significant number of articles, and Shimizu Kimiya had the highest number of citations. The top productive/influential journal was 'Journal of Cataract & Refractive Surgery'. The top cited references primarily focused on reporting the clinical outcomes of implantable collamer lens (ICL) for individuals with moderate to high myopia. The keywords primarily formed four clusters: posterior chamber pIOL clinical outcomes for myopic astigmatism correction, posterior chamber pIOL implantation complications, ICL size selection and postoperative vault predictions, and postoperative visual quality following posterior chamber pIOL implantation. Conclusion: This study presents the first bibliometric analysis of research trends in posterior chamber pIOL over the past two decades. We investigated the current state and emerging trends of global collaboration and research focal points in this field, offering fresh insights and guidance for researchers.

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.

Phakic anterior chamber intraocular lens removal with simultaneous posterior chamber phakic intraocular lens implantation and Descemet membrane endothelial keratoplasty.

The purpose of this study was to describe a case and clinical course of simultaneous anterior chamber phakic intraocular lens (AC-pIOL) removal, implantation of a posterior chamber phakic intraocular implantable collamer lens (ICL), and Descemet membrane endothelial keratoplasty (DMEK). This was a case report of a 44-year-old male with a unilateral decompensated cornea from a displaced Duet-Kelman lens on his left eye that underwent pIOL extraction and implantation of a posterior chamber phakic intraocular ICL and simultaneous DMEK. After 6 months, the cornea of the left eye had regained clarity, the Descemet membrane was graft stable, and the ICL implanted was centered with good vault. Postoperative anisometropia was avoided. There was no development of cataracts or other complications. The simultaneous pIOL extraction, ICL implantation, and DMEK in our case showed good results with full restoration of anterior segment anatomy and return of transparency of the cornea. The current case shows the feasibility of the simultaneous approach instead of sequential as an alternative for patients with endothelial disease associated with AC pIOLs, restoring vision and anatomy and also avoiding postoperative anisometropia.

Uveitis-Glaucoma-Hyphema Syndrome Secondary to Implantable Collamer Lens.

Purpose: To report the first case of uveitis-glaucoma-hyphema (UGH) syndrome post implantable collamer lens (ICL).Methods: Case reportResults: A 41-year-old female presented to our clinic complaining of bilateral eye pain and redness for two weeks. Her past medical history was significant for ICL, in both eyes and multiple sclerosis controlled with treatment. She had a long-standing history of bilateral recurrent uveitis and glaucoma. Ultrasound biomicroscopy revealed several sulcus cysts displacing the ICLs haptic into the ciliary body, leading to iris abrasion and uveitis-glaucoma-hyphema syndrome.Conclusion: We present the first published case worldwide about UGH syndrome secondary to ICL. This is an unusual complication, and measures can be taken to avoid it. This provides evidence of the importance of postoperative follow-up by the surgeon and appropriate work-up when such cases are suspected.

Measurement of the distance between corneal apex and pupil center in patients following small-incision lenticule extraction or implantable collamer lens implantation and its correlation with the surgical-induced astigmatism.

BACKGROUND: To investigate the change in the distance between corneal apex and pupil center after small-incision lenticule extraction (SMILE) or implantable collamer lens (ICL) implantation and its correlation with surgical-induced astigmatism (SIA). METHODS: This study included patients who had undergone SMILE (n = 112) or ICL implantation (n = 110) to correct myopia and myopic astigmatism. The angle kappa was measured using a Scheimpflug imaging device (Pentacam) and represented as Cartesian values between the pupil center and the corneal vertex (X, Y) and chord u ([Formula: see text]orientation), and was compared pre- and post-operative. RESULTS: Following SMILE, the magnitude of chord u[Formula: see text]) significantly increased in both eyes (Wilcoxon signed-rank test, OD: P<0.001; OS: P=0.007), while no significant change was observed in the orientation. A significant correlation was found between the J0 component of SIA and the change in the magnitude of chord u for both eyes (OD: R2=0.128, P<0.001; OS: R2=0.033, P=0.004). After ICL implantation, the orientation of the chord u was significantly different in the right eye (Wilcoxon signed-rank test, P = 0.008), and the Y-intercept significantly decreased in both eyes (Wilcoxon signed-rank test, P<0.001). A significant correlation was found between J0 of SIA and the change in the magnitude of chord u for the right eyes (R2=0.066, P=0.002). A significant correlation was found between J45 of SIA and the change in the magnitude of chord u for the left eyes (R2=0.037, P=0.044). CONCLUSIONS: The magnitude of the chord u increased following the SMILE procedure, whereas the Y-intercept significantly decreased after ICL implantation. SIA was related to the change in the magnitude of chord u.

Corneal Sub-Basal Nerve Plexus Regeneration Pattern following Implantable Collamer Lens Implantation for Myopia: A Prospective Longitudinal In Vivo Confocal Microscopy Study.

Implantable Collamer Lens (ICL) surgery has increasingly been adopted for myopia correction in recent decades. This study, employing in vivo confocal microscopy (IVCM), aimed to assess the impact of corneal incision during ICL surgery on the corneal sub-basal nerve plexus (SNP) and adjacent immune dendritiform cells (DCs). In this longitudinal study, eyes from 53 patients undergoing ICL surgery were assessed preoperatively and postoperatively over a twelve-month period. Quantification of seven SNP parameters was performed using ACCMetrics V.2 software. Ultimately, the final analysis was restricted to one eye from each of the 37 patients who completed a minimum of three months' postoperative follow-up. Preoperative investigations revealed a positive correlation of DC density with patient age and a negative association with corneal nerve fiber density (CNFD). Additionally, both DCs and CNFD were positively linked to spherical equivalent refraction (SER) and inversely related to axial length (AL). Intriguingly, preoperative DC density demonstrated an indirect relationship with both baseline and postoperative CNFD changes. Post-surgery, an initial surge in DC density was observed, which normalized subsequently. Meanwhile, parameters like CNFD, corneal nerve fiber length (CNFL), and corneal nerve fractal dimension (CNFrD) initially showed a decline following surgery. However, at one-year follow-up, CNFL and CNFrD displayed significant recovery, while CNFD did not return to its baseline level. This study thus delineates the regeneration pattern of SNP and alterations in DC density post-ICL surgery, highlighting that CNFD in the central cornea does not completely revert to preoperative levels within a year. Given these findings, practitioners are advised to exercise caution in older patients, those with high myopia, or elevated preoperative DCs who may undergo delayed SNP regeneration.

The effect of irrigation and aspiration on the corneal endothelial cell density in patients undergoing Implantable Collamer Lens with a central hole implantation for myopia correction.

PURPOSE: In the conventional technique, viscoelastic agents are typically rinsed away with balanced salt solution (BSS), but it may lead to a series of complications such as viscoelastic residue, anterior chamber instability and intraoperative TICL rotation. The utilization of irrigation and aspiration (I/A) has been shown to be effective in maintaining anterior chamber stability, reducing the incidence of postoperative high intraocular pressure, and minimizing postoperative fundus complications. However, there is a lack of previous studies investigating the impact of I/A on corneal endothelial cells during ICL implantation. The objective of this study was to examine the effect of I/A on corneal endothelial cells in patients undergoing myopia correction through implantation of Implantable Collamer Lens with a central hole (V4c ICL). METHODS: A retrospective selection was made of 344 eyes from 172 patients who underwent V4c ICL implantation and I/A to remove viscoelastic agent from the anterior chamber between 2021 and 2022. The intraocular pressure (IOP) was measured at 1 h, 2 h and 3 h after surgery. Corneal endothelial cell density (ECD), coefficient of variation in cell size (CV), standard deviation of cell area (SD), and percentage of hexagonal cells (HEX) were evaluated at 1 week postoperatively to assess corneal endothelial cells. The first two represent polymegethism or morphological variation, while the third parameter represents the degree of polymorphism of the corneal endothelial cells. Electronic medical records were utilized for data collection purpose. RESULTS: All surgeries proceeded without complications. The IOP was 16.50 ± 3.42 mmHg (range: 11.5-22.3 mmHg) prior to surgery and increased to 21.25 ± 5.61 mmHg (range: 9.5-34.8 mmHg), 19.85 ± 5.18 mmHg (range: 11.4-36.2 mmHg) and finally settled at an average of 18.81 ± 4.57 mmHg (range: 10.1-38.8 mmHg) at the respective time points of 1 h, 2 h and 3 h after surgery. The preoperative ECD was recorded as being approximately 3004 ± 295 cell/mm2, which exhibited a marginal decreased of 1.17% postoperatively, resulting in an average ECD value of 2969 ± 303 cell/mm2 one week after surgery (P = 0.12). Similarly, the preoperative CV was determined as 31.10 ± 3.78%, and it experienced a slight reduction with an average CV value of 30.74 ± 3.77% at week after surgery (P = 0.21). And, the preoperative SD was reported as 104.76 ± 17.26, and it remained virtually unchanged with an average SD value of 104.85 ± 18.75 at one week after surgery (P = 0.95). The preoperative HEX was calculated as 55.38 ± 8.94%, and it remained its stability with an average HEX value of 55.45 ± 8.73% one week after surgery (P = 0.92). CONCLUSION: The utilization of I/A led to a slight decrease in postoperative ECD when compared to conventional surgical techniques. Nevertheless, the reduction in ECD remained within acceptable limits, taking into accout the avervantaged it offered, such as stabilization of the anterior chamber and decreased occurrence of viscoelastic residue after surgery. It is challenging to anticipate the long-term safety of corneal endothelial cells based on current short-term studies. However, this study provides a valuable reference indicating that neither anterior chamber irrigation nor I/A aspiration have an adverse impact on the safety of corneal endothelial cells in the short term. Further research is imperative to enhance our understanding of their effects over an extended period.

Influence of anterior chamber depth and vault on anterior chamber angle morphology after phakic posterior chamber intraocular lens implantation.

PURPOSE: This study aims to investigate the influence of anterior chamber depth (ACD) and vault on the anterior chamber angle (ACA) morphology in myopic individuals implanted with posterior chamber phakic intraocular lenses. METHODS: This retrospective case series involved 231 eyes receiving a 13.2-mm implantable collamer lens (ICL). Preoperative anterior chamber anatomy was assessed using anterior segment optical coherence tomography (AS-OCT) and optical tomography, while postoperative evaluation employed AS-OCT. ACA morphology was characterized pre- and postoperatively through trabecular iris angle (TIA750), ACA distance opening (AOD750) and trabecular iris space area (TISA750). The influence of ACD and vault was examined by categorizing the sample into ACD (shallow, average and deep) and vault (low, optimal and high) groups. RESULTS: Preoperative ACA morphology varied based on ACD, with shallower ACDs exhibiting narrower TIA750, smaller AOD750 and TISA750. ICL implantation induced greater ACA narrowing more in the deep ACD group (TIA750 = 20.1 degrees; AOD750 = 0.82 mm and TISA750 = 0.44 mm2) compared to the shallow ACD group (TIA750 = 15.2 degrees; AOD750 = 0.44 mm and TISA750 = 0.21 mm2). Postoperatively, deeper ACDs showed larger ACAs. Increasing vault magnitude led to increased ACA narrowing, with the low vault group exhibiting smaller closure (TIA750 = 14.3 degrees; AOD750 = 0.56 mm and TISA750 = 0.29 mm2) compared to the high vault group (TIA750 = 20.8 degrees; AOD750 = 0.73 mm and TISA750 = 0.36 mm2). The magnitude of ACA narrowing associated with the vault had a consistent effect across different ACD groups. CONCLUSIONS: Posterior chamber intraocular lens implantation results in ACA narrowing, the extent of which is contingent upon preoperative anterior chamber and ACA morphology, with additional influence from vault magnitude.

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.

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.

Rhegmatogenous retinal detachment in highly myopic eyes with implantable collamer lens.

AIM: To investigate the clinical characteristics, treatment methods and outcomes of rhegmatogenous retinal detachment (RRD) in highly myopic eyes with implantable collamer lens (ICL). METHODS: High myopia patients who received treatment for nontraumatic RRD after ICL implantation surgery at the Retinal Department of Zhongshan Ophthalmic Center from Jan 2018 to Dec 2022 were reviewed. Comprehensive ophthalmologic examinations including visual acuity measurement and digital fundus photography were performed in each patient. RESULTS: A total of nine RRD eyes from nine patients who received V4c-ICL implantation were included. The mean time from ICL implantation surgery to the diagnosis of RRD was 32.44±22.56mo (range, 1-60mo). At the initial visit for RRD, giant retinal tear (GRT), horseshoe tear, simple round hole, and horseshoe tear combined with round hole were detected in 3, 3, 2, and 1 eye(s), respectively, with macula-off in eyes. Eight patients received surgical treatment, and one patient was treated by retinal laser photocoagulation alone. The ICL was preserved in 7 eyes. At the last follow-up, the mean best corrected visual acuity (BCVA) improved significantly from 1.76±1.06 logMAR at presentation to 0.81±1.01 logMAR (P=0.035), and no case of recurrent retinal detachment was found. CONCLUSION: The morphological presentation of retinal breaks is diverse in this study. The ICL can be preserved in most cases during the course of retinal detachment repair surgery in our data, companied with acceptable visual and anatomical outcomes.

Causes and management strategies for elevated intraocular pressure after implantable collamer lens implantation.

With the widespread application of Implantable Collamer Lens (ICL) implantation surgery in the field of myopia correction, a comprehensive understanding of its potential complications, especially those related to intraocular pressure (IOP), becomes crucial. This article systematically reviews various complications that may lead to IOP elevation after ICL surgery. Firstly, common complications after ICL surgery, including residual viscoelastic, steroid response, and excessive vault of the ICL, are detailed, emphasizing their potential impact on intraocular pressure. Regarding residual viscoelastic, we delve into its direct relationship with postoperative elevated IOP and possible preventive measures. For steroid response, we stress the importance of timely adjustment of steroid therapy and monitoring intraocular pressure. Additionally, excessive vault of the ICL is considered a significant potential issue, and we elaborate on its mechanism and possible management methods. In further discussion, we focus on relatively rare complications such as Toxic Anterior Segment Syndrome (TASS), Urrets-Zavalia Syndrome (UZS), Pigment Dispersion Syndrome (PDS), and malignant glaucoma. For these relatively rare complications, this review thoroughly explores their potential mechanisms, emphasizes the importance of prevention, and provides guidance for early diagnosis and treatment. This is a comprehensible review that aims to offer eye care professionals a comprehensive understanding and effective management guidance for complications of elevated IOP after ICL surgery, ultimately providing optimal care for patients' visual health.