Outcomes of sutured scleral-fixated intraocular lens implantation combined with penetrating keratoplasty.

BACKGROUND: The purpose of the study was to assess visual outcomes, complications, intraocular lens (IOL) stability, and corneal status after sutured scleral-fixated intraocular lens implantation combined with penetrating keratoplasty (PKP). METHODS: This retrospective single-arm cohort study included patients who underwent PKP and sutured scleral-fixated intraocular lens implantation between 2013 and 2018 at the Dhahran Eye Specialty Hospital. The eyes were examined postoperatively at 1, 3, 6, 12, and 24 months. Corneal status, complications, and IOL status were also evaluated periodically, and the number of eyes with a BCVA of > 20/200 was recorded. RESULTS: Twenty-two eyes from 22 patients were included. The median duration of follow-up was 3 (IQR 1.8; 4.4) years. Reasons for surgery were traumatic globe rupture (six eyes, 27.3%), bullous keratopathy (nine eyes, 40.1%), failed previous graft (five eyes, 22.7%), and corneal scarring (two eyes, 9.1%). Twelve (54.5%) eyes showed a BCVA of > 20/200 (non-blind) at 12 months after surgery and only five (22.7%) before surgery. Twelve months after surgery, 13 patients showed an improvement in BCVA in two lines (59.1%), seven remained the same (31.8%), and 2 deteriorated (9.1%). The indication for surgery (p = 0.2) and the stability of the sutured-scleral fixated IOL (p = 0.8) were not associated with an improvement in BCVA at the final follow-up. The corneal graft remained clear in nine eyes (40.9%) at a median duration of 3 years. The overall average survival period for all corneal grafts was 42.9 months. CONCLUSIONS: The combination of sutured scleral-fixated intraocular lens implants and PKP is an effective intervention for preserving visual acuity in patients with complex cases. However, the risk of graft failure and then need for repeat transplantation should be taken into consideration.

Anterior Chamber Intraocular Lens Implantation Versus Four-Flanged Scleral Fixation Technique for Patients With Loss of Capsular Support During Routine Cataract Surgery.

PURPOSE: To compare the outcomes of anterior chamber intraocular lens (AC-IOL) implantation versus the four-flanged scleral fixation technique in eyes with loss of capsular support during routine cataract surgery. METHODS: This was a retrospective cohort study of all patients in whom an IOL was implanted either during or after short-term aphakia due to loss of capsular and sulcus support in a routine cataract surgery with at least 6 months of follow-up time between 2015 and 2023 in a tertiary medical center in Israel. Two different IOL implantation techniques were compared: the implantation of an angle-supported ACIOL and four-flanged scleral fixation. Main outcome measures included postoperative complications such as pseudophakic bullous keratopathy, loss of intraocular pressure control and glaucoma, IOL subluxation, and retinal detachment. RESULTS: Sixty-five eyes of 65 patients were included in the study, 33 eyes in the AC-IOL group and 32 eyes in the flange group. Follow-up time was 29.92 ± 20.02 months in the AC-IOL group and 20.17 ± 15.56 months in the flange group (P = .087). Pseudophakic bullous keratopathy was observed in 10 (30.3%) patients in the AC-IOL group and in 1 (3.1%) patient in the flange group (P = .04). This association remained significant using survival analysis (P = .006). In 4 (12.1%) patients in the AC-IOL group, a glaucoma filtering procedure was performed to control the intraocular pressure compared with none in the flange group (P = .042). CONCLUSIONS: In the setting of loss of capsular support during routine cataract surgery, four-flanged scleral fixation showed an overall lower rate of complications and significantly reduced rate of subsequent surgical interventions. [J Refract Surg. 2024;40(8):e520-e526.].

Refractive Outcomes After Scleral Fixation of the Carlevale Intraocular Lens.

PURPOSE: To assess the refractive predictability of the Carlevale sutureless scleral fixation intraocular lens (IOL) (Sole-ko IOL Division) power calculation. METHODS: This retrospective, non-comparative, interventional case series included patients without a capsular support having undergone sutureless scleral fixation IOL implantation in two French hospitals between October 2019 and April 2022. IOL calculation was performed with the Barrett Universal II, Hoffer Q, Holladay 1, and SRK/T formulas with constant optimization to achieve a mean arithmetic prediction error equal to zero. The main outcomes were prediction error (PE) and its standard deviation (SD-PE), the median absolute error (MedAE), the mean absolute error (MAE), and the percentage of eyes with PE within ±0.50, ±1.00 and ±2.00 diopters (D) 6 months after surgery. RESULTS: Thirty eyes of 30 patients were included in the study. The mean age was 66.6 years, the mean axial length was 24.31 mm, and the mean keratometry was 43.07 D. SDPE ranged from 0.73 to 0.87 D depending on the formula. MedAE ranged from 0.38 to 0.61 D, and MAE from 0.52 to 0.68 D. Between 46.7% and 56.7% of eyes were within ±0.50 D, 76.7% and 90.0% were within ±1.00 D, and 96.7% were within ±2.00 D of target equivalent. No statistically significant difference was observed between the four formulas for any outcomes. CONCLUSIONS: This study confirmed that the design of the Carlevale sutureless scleral fixation IOL provides satisfactory refractive results. [J Refract Surg. 2024;40(8):e527-e532.].

Comparison of safety and effectiveness of micropulse transscleral cyclophotocoagulation and "slow cook" diode laser transscleral cyclophotocoagulation in patients with refractory open-angle glaucoma.

PURPOSE: This study aimed to compare the safety and effectiveness of intraocular pressure reduction between micropulse transscleral cyclophotocoagulation and "slow cook" transscleral cyclophotocoagulation in patients with refractory primary open-angle glaucoma. METHODS: We included patients with primary open angle glaucoma with at least 12 months of follow-up. We collected and analyzed data on the preoperative characteristics and postoperative outcomes. The primary outcomes were a reduction of ≥20% of the baseline value (criterion A) and/or intraocular pressure between 6 and 21 mmHg (criterion B). RESULTS: We included 128 eyes with primary open-angle glaucoma. The preoperative mean intraocular pressure was 25.53 ± 6.40 and 35.02 ± 12.57 mmHg in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p<0.001). The mean intraocular pressure was reduced significantly to 14.33 ± 3.40 and 15.37 ± 5.85 mmHg in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups at the last follow-up, respectively (p=0.110). The mean intraocular pressure reduction at 12 months was 11.20 ± 11.46 and 19.65 ± 13.22 mmHg in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p<0.001). The median preoperative logMAR visual acuity was 0.52 ± 0.69 and 1.75 ± 1.04 in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p<0.001). The mean visual acuity variation was -0.10 ± 0.35 and -0.074 ± 0.16 in the micropulse- and "slow cook" transscleral cyclophotocoagulation, respectively (p=0.510). Preoperatively, the mean eye drops were 3.44 ± 1.38 and 2.89 ± 0.68 drugs in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p=0.017), but those were 2.06 ± 1.42 and 1.02 ± 1.46 at the end of the study in the "slow cook" and micropulse transscleral cyclophotocoagulation groups, respectively (p<0.001). The success of criterion A was not significant between both groups. Compared with 11 eyes (17.74%) in the "slow cook" transscleral cyclophotocoagulation group, 19 eyes (28.78%) in the micropulse transscleral cyclophotocoagulation group showed complete success (p=0.171). For criterion B, 28 (42.42%) and 2 eyes (3.22%) showed complete success after micropulse- and "slow cook" transscleral cyclophotocoagulation, respectively (p<0.001). CONCLUSION: Both techniques reduced intraocular pressure effectively.

Exome-wide association study identifies KDELR3 mutations in extreme myopia.

Extreme myopia (EM), defined as a spherical equivalent (SE) ≤ -10.00 diopters (D), is one of the leading causes of sight impairment. Known EM-associated variants only explain limited risk and are inadequate for clinical decision-making. To discover risk genes, we performed a whole-exome sequencing (WES) on 449 EM individuals and 9606 controls. We find a significant excess of rare protein-truncating variants (PTVs) in EM cases, enriched in the retrograde vesicle-mediated transport pathway. Employing single-cell RNA-sequencing (scRNA-seq) and a single-cell polygenic burden score (scPBS), we pinpointed PI16 + /SFRP4+ fibroblasts as the most relevant cell type. We observed that KDELR3 is highly expressed in scleral fibroblast and involved in scleral extracellular matrix (ECM) organization. The zebrafish model revealed that kdelr3 downregulation leads to elongated ocular axial length and increased lens diameter. Together, our study provides insight into the genetics of EM in humans and highlights KDELR3's role in EM pathogenesis.

BCLA CLEAR presbyopia: Management with scleral techniques, lens softening, pharmaceutical and nutritional therapies.

The aging eye undergoes the same progressive crosslinking which occurs throughout the body, resulting in increased rigidity of ocular connective tissues including the lens and the sclera which impact ocular functions. This offers the potential for a scleral treatment that is based on restoring normal biomechanical movements. Laser Scleral Microporation is a laser therapy that evaporates fractional areas of crosslinked tissues in the sclera, reducing ocular rigidity over critical anatomical zones of the accommodation apparatus, restoring the natural dynamic range of focus of the eye. Although controversial and challenged, an alternative theory for presbyopia is Schachar's theory that suggests a reduction in the space between the ciliary processes and the crystalline lens. Widening of this space with expansion bands has been shown to aid near vision in people with presbyopia, a technique that has been used in the past but seems to be obsolete now. The use of drugs has been used in the treatment of presbyopia, either to cause pupil miosis to increase depth of focus, or an alteration in refractive error (to induce myopia in one eye to create monovision). Drugs and laser ablation of the crystalline lens have been used with the aim of softening the hardened lens. Poor nutrition and excess exposure to ultraviolet light have been implicated in the onset of presbyopia. Dietary nutritional supplements, lifestyle changes have also been shown to improve accommodation and the question arises whether these could be harnessed in a treatment for presbyopia as well.

A retrospective analysis of surgical outcome in sutureless glueless scleral fixation of foldable intraocular lens.

INTRODUCTION: Cataract surgery constitutes one of the highest volume surgeries performed worldwide approximating 10 million annually, varying from 100 to 6000 per million population. Implantation of scleral fixated intra-ocular lens (SFIOL) is getting popular in managing difficult situations like aphakia, subluxated lens, and dislocated cataracts. OBJECTIVE: This retrospective series evaluated our experience with foldable 3-piece acrylic SFIOL implantation for various challenging surgical scenarios in a tertiary care ophthalmic institute in the southern part of India. RESULTS: The data from the first 150 patients, those operated in our hospital in the aforementioned technique, have been reviewed and analyzed. The mean age of the population was 46.43 years. The most common indication was found to be surgical aphakia (34.66%) followed by traumatic subluxated lens (8.33%). Postoperative BCVA at 3 months improved to 0.255 on the LogMAR scale from preoperative BCVA of 0.795 (P < 0.01). Intraocular pressure was found to stabilize over 3 months follow-up (P = 0.002). The various intraoperative and postoperative complications have been recorded. Ten patients required resurgery out of which eight had postoperative haptic dislocation. A detailed comparison of the role of a surgeon's experience in influencing outcomes has been evaluated. CONCLUSION: The technique offers physiological IOL placement using minimal surgical maneuvers. We strongly recommend this as a technique of choice for the surgical management of complicated scenarios with inadequate capsular bag support.

Effects of Different Scleral Photo-Crosslinking Modalities on Scleral Stiffness and Hydration.

Purpose: The purpose of this study was to evaluate the biomechanical and hydration differences in scleral tissue after two modalities of collagen cross-linking. Methods: Scleral tissue from 40 adult white rabbit eyes was crosslinked by application of 0.1% Rose Bengal solution followed by 80 J/cm2 green light irradiation (RGX) or by application of 0.1% riboflavin solution followed by 5.4 J/cm2 ultraviolet A irradiation (UVX). Posterior scleral strips were excised from treated and untreated sclera for tensile and hydration-tensile tests. For tensile tests, the strips were subjected to uniaxial extension after excision. For hydration-tensile tests, the strips were dehydrated, rehydrated, and then tested. Young's modulus at 8% strain and swelling rate were estimated. ANOVAs were used to test treated-induced differences in scleral biomechanical and hydration properties. Results: Photo-crosslinked sclera tissue was stiffer (Young's modulus at 8% strain: 10.7 ± 4.5 MPa, on average across treatments) than untreated scleral tissue (7.1 ± 4.0 MPa). Scleral stiffness increased 132% after RGX and 90% after UVX compared to untreated sclera. Scleral swelling rate was reduced by 11% after RGX and by 13% after UVX. The stiffness of the treated sclera was also associated with the tissue hydration level. The lower the swelling, the higher the Young's modulus of RGX (-3.8% swelling/MPa) and UVX (-3.5% swelling/MPa) treated sclera. Conclusions: Cross-linking with RGX and UVX impacted the stiffness and hydration of rabbit posterior sclera. The Rose Bengal with green light irradiation may be an alternative method to determine the efficacy and suitability of inducing scleral tissue stiffening in the treatment of myopia.

[Comparative evaluation of transscleral laser exposure in anatomical experiment]. / Sravnitel'naya otsenka lazernogo transskleral'nogo vozdeistviya v usloviyakh anatomicheskogo eksperimenta.

PURPOSE: This study comparatively analyzed the morphology of eye tissues after laser exposure using the latest generation of transscleral laser techniques - micropulse transscleral cyclophotocoagulation (MP-TSCPC) and laser activation of scleral hydropermeability (LASH) - in an anatomical experiment. MATERIAL AND METHODS: The study used pulsed-periodic radiation of an Er-glass fiber laser (λ=1.56 µm) and radiation of a diode laser (λ=0.81 µm) in the micropulse mode. A comparative morphological evaluation of histological preparations of target scleral and ciliary body (CB) tissues was performed with the study of laser-induced changes occurring after LASH and MP-TSCPC. RESULTS: The study of histological preparations obtained after MP-TSCPC and LASH did not reveal any noticeable signs of an inflammatory reaction or significant destructive changes. There were no signs of pronounced coagulative changes in the form of disorganization of connective and muscle tissue in the exposure area. At the same time, MP-TSCPC was accompanied by thinning and discontinuity of the CB pigment epithelium in the projection of its flat part and expansion of the gaps between the anterior connective tissue fibers fixing the CB to the sclera, which is likely a factor contributing to uveoscleral outflow. After LASH, in the irradiated areas at the level of the outer layers of the sclera (¾ of its thickness) located in the projection of the flat part of the ciliary body, multiple slit-like cavities and enlargements (stretching) of interfiber spaces were revealed with simultaneous compaction of the inner part of the sclera (» of its thickness). CONCLUSION: The identified morphological changes may indicate certain differences in the mechanisms of intraocular pressure (IOP) reduction after MP-TSCPC and LASH. The results of this study suggest that the enhancement of uveoscleral outflow of intraocular fluid and the hypotensive effect after MP-TSCPC may be associated with laser-induced expansion of the interspaces between the anterior connective tissue fibers of the CB in the suprachoroidal space. With LASH, the possible mechanism of lowering IOP may be related rather to an increase in transscleral filtration due to the appearance of slit-like interfiber spaces in the sclera, caused by local contraction of scleral fibers in the area of laser exposure. The absence of pronounced destructive changes at the histological level indicates the gentle nature of both laser techniques and the possibility of expanding the indications for the use of LASH in the treatment of glaucoma, including at its earlier stages.

[Transscleral fixation of intraocular lens in the treatment of lens subluxation in children]. / Transskleral'naya fiksatsiya intraokulyarnoi linzy v lechenii sublyuksatsii khrustalika u detei.

Congenital subluxation of the lens as a complication of Marfan syndrome, Weill-Marchesani syndrome, microspherophakia, etc. leads to the development of amblyopia and requires timely surgical treatment with removal of the subluxated lens and implantation of an artificial intraocular lens (IOL). IOL implantation in children with pathology of the ligamentous apparatus of the lens remains an urgent problem of ophthalmic surgery due to the lack of a consensus regarding the IOL fixation method among practitioners. PURPOSE: This study evaluated the effectiveness and safety of IOL implantation with transscleral fixation using the knotless Z-suture technique in pediatric patients with congenital lens subluxation. MATERIAL AND METHODS: The study included 24 children (36 eyes) with grade III congenital subluxation of the lens who underwent phacoaspiration of the subluxated lens with IOL implantation with transscleral fixation using the knotless Z-suture performed in the Kazakh Research Institute of Eye Diseases in Almaty in the period from 2017 to 2021. The average observation period was 31.7±11.3 months (2.0 to 4.5 years). The stability of the IOL position, the state of the intrascleral sutures, visual acuity after surgery, the presence and severity of complications in the long-term period were evaluated. RESULTS: All patients (100%) had a significant improvement in visual acuity after surgery. No intraoperative complications were registered in any of the cases. Postoperative complications were noted in 8.3% of cases (n=3). The final functional outcome of surgical treatment depended on the presence of concomitant pathology, the main cause of low vision was the development of refractive amblyopia due to refractive errors. CONCLUSIONS: The presented technique of transscleral fixation of IOL has proven to be reliable, which is especially important for pediatric patients considering their high physical activity and expected lifespan.

Long term surgical results and safety profile of the novel CM T Flex scleral fixated intraocular lens.

PURPOSE: To report the long term visual outcomes and complications with use of the novel CM-T Flex scleral fixated intraocular lens (CMT-SFIOL). MATERIALS AND METHODS: 116 eyes that underwent CMT-SFIOL were reviewed and 57 eyes with CMT-SFIOL that completed a 2-year follow-up were included. Main outcome measures noted were best-corrected visual acuity (BCVA) and complications. Postoperatively, follow-ups were done at 1 week (1w), 1 month (1 m), 1 year (1y) and 2-year (2y) intervals. RESULTS: 40 (70.17%) of 57 eyes received CMT-SFIOL for surgical aphakia. Mean follow up was 39.77 ± 8.44 months. BCVA for distance & near improved from 1.26 ± 0.84 to 0.76 ± 0.77, 0.50 ± 0.72 and 0.51 ± 0.73 & 1.28 ± 0.58 to 0.98 ± 0.49, 0.92 ± 0.44 and 0.89 ± 0.40 at 1 m, 1y and 2y respectively (p < 0.001 for all). At 1w, 10 eyes (17.54%) had corneal edema (CE) and 8 eyes (14.03%) had anterior chamber (AC) reaction. Two eyes (3.50%) had IOP > 30 mm Hg and 1 eye (1.75%) had vitreous hemorrhage (VH). At 1 m, 3 eyes (5.26%) had CE and 5 eyes (8.77%) had AC reaction. Two eyes (3.50%) had IOP > 30 mm Hg and 1 eye (1.75%) had VH. Cystoid macular edema was noted in 3 eyes (5.26%). At 1y and 2y, 2 eyes (3.5%) and 1 eye (1.75%), had CE. No decentration, dislocation, haptic exposure or retinal detachment was noted. No eyes required resurgery. CONCLUSION: CM-T Flex SFIOL is an effective method to correct aphakia, with reliable and safe long-term results.

CHANGES IN SCLERAL THICKNESS IN THE ACUTE PHASE OF VOGT-KOYANAGI-HARADA DISEASE.

PURPOSE: To evaluate changes in scleral thickness in Vogt-Koyanagi-Harada (VKH) disease. METHODS: This study included 34 eyes of 17 treatment-naïve patients with acute-phase VKH disease. Scleral thickness and the presence of ciliochoroidal effusion were examined using anterior segment optical coherence tomography at baseline and 1 week, 2 weeks, and 12 weeks after the start of corticosteroid treatment. Scleral thickness was measured 6 mm posterior to the scleral spur in four directions. RESULTS: Twenty-eight eyes (82.4%) initially had ciliochoroidal effusion, but this rapidly decreased to nine eyes (26.5%) after 1 week. The sclera with ciliochoroidal effusion became thinner from baseline to 1 week at the superior (400.2 ± 46.9-353.5 ± 47.9 µm), temporal (428.4 ± 53.6-387.8 ± 56.1 µm), inferior (451.5 ± 71.0-400.5 ± 50.5 µm), and nasal (452.4 ± 78.0-407.6 ± 62.9 µm) points (P < 0.01 for all), and no further changes were observed. The sclera without ciliochoroidal effusion remained unchanged. CONCLUSION: In VKH disease, eyes with ciliochoroidal effusion exhibited the maximum scleral thickness during the acute phase. This thickening responded rapidly to treatment and became thinner within 1 week. Inflammation in VKH disease may affect not only the choroid but also the sclera.

Scleral bridging technique for preventing PreserFlo microshunt exposure: A case report.

INTRODUCTION: The use of the PreserFlo microshunt is gaining popularity owing to its ease of implantation and reduced need for postoperative intervention compared to conventional trabeculectomy. PATIENT CONCERNS: However, microshunt exposure remains a severe complication of PreserFlo surgery, particularly in patients with a thin Tenon capsule and conjunctiva. However, the actual thickness and intensity of the Tenon capsule or conjunctiva can be confirmed only during surgery. DIAGNOSIS: Exfoliation glaucoma with previous several glaucoma surgeries with thinner Tenon capsule or conjunctiva. INTERVENTIONS: We performed PreserFlo implantation with a surgical technique to recover a thin Tenon capsule and conjunctiva by creating a half-thickness rectangular scleral flap under the shunt and covering it over the microshunt until the distal part, similar to the bridge. OUTCOMES: The patient had better intraocular pressure control with positive cosmetic appearance using this technique. CONCLUSION: This technique will be beneficial for both preventing exposure and holding down the top, in addition to improving cosmetic appearance.

Lamina Cribrosa Configurations in Highly Myopic and Non-Highly Myopic Eyes: The Beijing Eye Study.

Purpose: The purpose of this study was to examine characteristics of lamina cribrosa (LC) configuration in highly myopic (HM) eyes. Methods: Participants from the Beijing Eye Study 2011, free of optic nerve or retinal diseases, were randomly selected to examine LC depth (LCD) and LC tilt (LCT) using three-dimensional optical coherent tomography images of the optic nerve head (ONH). LCD and LCT were measured as the distance and angle between the LC plane with two reference planes, including the Bruch's membrane opening (BMO) plane and the peripapillary sclera (PPS) plane, respectively. Each parameter was measured in both horizontal and vertical B-scans. Results: The study included 685 individuals (685 eyes) aged 59.6 ± 7.7 years, including 72 HM eyes and 613 non-HM eyes. LCD measurements showed no significant differences between HM eyes and non-HM eyes in both horizontal (LCD-BMO = 421.83 ± 107.86 µm for HM eyes vs. 447.24 ± 104.94 µm for non-HM eyes, P = 0.18; and LCD-PPS = 406.39 ± 127.69 µm vs. 394.00 ± 101.64 µm, P = 1.00) and vertical directions (LCD-BMO = 435.78 ± 101.29 µm vs. 450.97 ± 106.54 µm, P = 0.70; and LCD-PPS = 401.62 ± 109.9 µm vs. 379.85 ± 110.35 µm, P = 0.35). However, the LCT was significantly more negative (tilted) in HM eyes than in non-HM eyes horizontally (LCT-BMO = -4.38 ± 5.94 degrees vs. -0.04 ± 5.86 degrees, P < 0.001; and LCT-PPS = -3.16 ± 5.23 degrees vs. -0.94 ± 4.71 degrees, P = 0.003), but not vertically (P = 1.00). Conclusions: Although LCD did not differ significantly between HM and non-HM eyes, LCT was more negative in HM eyes, suggesting that the temporal or inferior side of the LC was closer to the reference plane. These findings provide insights into morphological and structural changes in the LC and ONH between HM and non-HM eyes.

The feasibility and safety of biomaterials for posterior scleral reinforcement in rabbits.

To explore the feasibility and safety of biomaterials for posterior scleral reinforcement (PSR) in rabbits. Decellularization and genipin crosslink were applied to the fresh bovine pericardium and porcine endocranium, and then mechanical properties, suture retention strength, and stability were tested. PSR operation was performed on 24 rabbit eyes using treated biological materials. Ophthalmic examination was performed regularly before and after PSR operation (1 week, 1 month, 3 months, 6 months). To evaluate the effectiveness, A ultrasound, diopter, and optical coherence tomography were conducted. General condition, fundus photograph, and pathological examination were recorded to evaluate the safety. Compared with genipin crosslinked bovine pericardium (Gen-BP) (21.29 ± 13.29 Mpa), genipin crosslinked porcine endocranium (Gen-PE) (34.85 ± 3.67 Mpa,P< 0.01) showed a closer elastic modulus to that of genipin crosslinked human sclera. There were no complications or toxic reactions directly related to the materials. Capillary hyperplasia, inflammatory cell infiltration, and collagen fiber deposition were observed, and the content of type I collagen fibers increased after PSR. Overall, the choroidal thickness of treated eyes was significantly thickened at different time points after PSR, which were 96.84 ± 21.08 µm, 96.72 ± 22.00 µm, 90.90 ± 16.57 µm, 97.28 ± 14.74 µm, respectively. The Gen-PE group showed changes that were almost consistent with the overall data. Gen-BP and Gen-PE are safe biological materials for PSR. The Gen-PE group demonstrated more significant advantages over the Gen-BP group in terms of material properties.

The miR-15b-5p/miR-379-3p-FOXO axis regulates cell cycle and apoptosis in scleral remodeling during experimental myopia.

BACKGROUND: Myopia is one of the most common eye diseases in children and adolescents worldwide, and scleral remodeling plays a role in myopia progression. However, the identity of the initiating factors and signaling pathways that induce myopia-associated scleral remodeling is still unclear. This study aimed to identify biomarkers of scleral remodeling to elucidate the pathogenesis of myopia. METHODS: The gene expression omnibus (GEO) and comparative toxicogenomics database (CTD) mining were used to identify the miRNA-mRNA regulatory network related to scleral remodeling in myopia. Real-time quantitative PCR (RT-qPCR), Western blot, immunofluorescence, H&E staining, Masson staining, and flow cytometry were used to detect the changes in the FOXO signaling pathway, fibrosis, apoptosis, cell cycle, and other related factors in scleral remodeling. RESULTS: miR-15b-5p/miR-379-3p can regulate the FOXO signaling pathway. Confirmatory studies confirmed that the axial length of the eye was significantly increased, the scleral thickness was thinner, the levels of miR-15b-5p, miR-379-3p, PTEN, p-PTEN, FOXO3a, cyclin-dependent kinase (CDK) inhibitor 1B (CDKN1B) were increased, and the levels of IGF1R were decreased in Len-induced myopia (LIM) group. CDK2, cyclin D1 (CCND1), and cell cycle block assessed by flow cytometry indicated G1/S cell cycle arrest in myopic sclera. The increase in BAX level and the decrease in BCL-2 level indicated enhanced apoptosis of the myopic sclera. In addition, we found that the levels of transforming growth factor-ß1 (TGF-ß1), collagen type 1 (COL-1), and α-smooth muscle actin (α-SMA) were decreased, suggesting scleral remodeling occurred in myopia. CONCLUSIONS: miR-15b-5p/miR-379-3p can regulate the scleral cell cycle and apoptosis through the IGF1R/PTEN/FOXO signaling pathway, thereby promoting scleral remodeling in myopia progression.

Computational modelling of scleral photocrosslinking: from rat to minipig to human.

Selective scleral crosslinking has been proposed as a novel treatment to increase scleral stiffness to counteract biomechanical changes associated with glaucoma and high myopia. Scleral stiffening has been shown by transpupillary peripapillary scleral photocrosslinking in rats, where the photosensitizer, methylene blue (MB), was injected retrobulbarly and red light initiated crosslinking reactions with collagen. Here, we adapted a computational model previously developed to model this treatment in rat eyes to additionally model MB photocrosslinking in minipigs and humans. Increased tissue length and subsequent diffusion and light penetration limitations were found to be barriers to achieving the same extent of crosslinking as in rats. Per cent inspired O2, injected MB concentration and laser fluence were simultaneously varied to overcome these limitations and used to determine optimal combinations of treatment parameters in rats, minipigs and humans. Increasing these three treatment parameters simultaneously resulted in maximum crosslinking, except in rats, where the highest MB concentrations decreased crosslinking. Additionally, the kinetics and diffusion of photocrosslinking reaction intermediates and unproductive side products were modelled across space and time. The model provides a mechanistic understanding of MB photocrosslinking in scleral tissue and a basis for adapting and screening treatment parameters in larger animal models and, eventually, human eyes.

Effect of Eye Globe and Optic Nerve Morphologies on Gaze-Induced Optic Nerve Head Deformations.

Purpose: The purpose of this study was to investigate the effect of globe and optic nerve (ON) morphologies and tissue stiffnesses on gaze-induced optic nerve head deformations using parametric finite element modeling and a design of experiment (DOE) approach. Methods: A custom software was developed to generate finite element models of the eye using 10 morphological parameters: dural radius, scleral, choroidal, retinal, pial and peripapillary border tissue thicknesses, prelaminar tissue depth, lamina cribrosa (LC) depth, ON radius, and ON tortuosity. A central composite face-centered design (1045 models) was used to predict the effects of each morphological factor and their interactions on LC strains induced by 13 degrees of adduction. Subsequently, a further DOE analysis (1045 models) was conducted to study the effects and potential interactions between the top five morphological parameters identified from the initial DOE study and five critical tissue stiffnesses. Results: In the DOE analysis of 10 morphological parameters, the 5 most significant factors were ON tortuosity, dural radius, ON radius, scleral thickness, and LC depth. Further DOE analysis incorporating biomechanical parameters highlighted the importance of dural and LC stiffness. A larger dural radius and stiffer dura increased LC strains but the other main factors had the opposite effects. Notably, the significant interactions were found between dural radius with dural stiffness, ON radius, and ON tortuosity. Conclusions: This study highlights the significant impact of morphological factors on LC deformations during eye movements, with key morphological effects being more pronounced than tissue stiffnesses.

Clinical outcomes of posterior scleral reinforcement in Chinese high myopia children.

We aim to observe the posterior scleral reinforcement (PSR) clinical outcomes of children with high myopia and analyze the retinal vessel alteration before and after PSR by using angiography optical coherence tomography (angio-OCT). Fifty-six pediatric participants (112 eyes) clinically diagnosed high myopia were recruited and were treated by PSR in Shanghai Children's Hospital from June 1, 2021 to May 1, 2023. The average age ranged from 5.42 to 14.83 years (mean 8.83 years) and mean follow up duration was 8.7 months (3-24 months). The axial length (AL) was significantly shortened after PSR (p < 0.05). The spherical equivalent (SE) and the best-corrected visual acuity (BCVA) were also improved without severe rejection in the follow-up. Compared with baseline, angio-OCT parafoveal vessel indices including vascular area density (VAD) and vascular skeleton density (VSD) on the superficial capillary plexus layer (SCPL), as well as VAD and vessel perimeter index (VPI) on the deep capillary plexus layer (DCPL), were significantly increased after PSR surgery (p < 0.05). VPI on the SCPL, vascular diameter index (VDI) and VSD on the DCPL were also improved without statistical difference after PSR. The VSD on SCPL, VAD on DCPL of the right eyes and the VPI on SCPL of the left eyes were significantly increased after PSR (p < 0.05). PSR surgery can shorten the AL and can stable BCVA and SE in high myopia children. The angio-OCT parameters indicated that the retinal microcirculation supply was significantly improved after PSR.

Comparison of outcomes between modified double-flanged sutureless scleral fixation and conventional sutured scleral fixation.

This retrospective study aimed to compare the outcomes of modified double-flanged sutureless scleral fixation versus sutured scleral fixation. Medical records of 65 eyes from 65 patients who underwent double-flanged scleral fixation (flange group) or conventional scleral fixation (suture group) between 2021 and 2022 were reviewed. Visual and refractive outcomes, as well as postoperative complications, were compared 1, 2, and 6 months after surgery. We included 31 eyes in the flange group and 34 eyes in the suture group. At 6 months postoperatively, the flange group showed better uncorrected visual acuity (0.251 ± 0.328 vs. 0.418 ± 0.339 logMAR, P = 0.041) and a smaller myopic shift (- 0.74 ± 0.93 vs. - 1.33 ± 1.15 diopter, P = 0.007) compared to the suture group. The flange group did not experience any instances of iris capture, while the suture group had iris capture in 10 eyes (29.4%; P < 0.001). In the flange group, all intraocular lenses remained centered, whereas in the suture group, they were decentered in 8 eyes (23.5%; P = 0.005). The double-flanged technique not only prevented iris capture and decentration of the intraocular lens but also reduced myopic shift by enhancing the stability of the intraocular lens.