Extracellular matrix (ECM) plays a critical role in cell behavior and development. Organoids generated from human induced pluripotent stem cells (hiPSCs) are in the spotlight of many research areas. However, the lack of physiological cues in classical cell culture materials hinders efficient iPSC differentiation. Incorporating commercially available ECM into stem cell culture provides physical and chemical cues beneficial for cell maintenance. Animal-derived commercially available basement membrane products are composed of ECM proteins and growth factors that support cell maintenance. Since the ECM holds tissue-specific properties that can modulate cell fate, xeno-free matrices are used to stream up translation to clinical studies. While commercially available matrices are widely used in hiPSC and organoid work, the equivalency of these matrices has not been evaluated yet. Here, a comparative study of hiPSC maintenance and human intestinal organoids (hIO) generation in four different matrices: Matrigel (Matrix 1-AB), Geltrex (Matrix 2-AB), Cultrex (Matrix 3-AB), and VitroGel (Matrix 4-XF) was conducted. Although the colonies lacked a perfectly round shape, there was minimal spontaneous differentiation, with over 85% of the cells expressing the stem cell marker SSEA-4. Matrix 4-XF led to the formation of 3D round clumps. Also, increasing the concentration of supplement and growth factors in the media used to make the Matrix 4-XF hydrogel solution improved hiPSC expression of SSEA-4 by 1.3-fold. Differentiation of Matrix 2-AB -maintained hiPSC led to fewer spheroid releases during the mid-/hindgut stage compared to the other animal-derived basement membranes. Compared to others, the xeno-free organoid matrix (Matrix 4-O3) leads to larger and more mature hIO, suggesting that the physical properties of xeno-free hydrogels can be harnessed to optimize organoid generation. Altogether, the results suggest that variations in the composition of different matrices affect stages of IO differentiation. This study raises awareness about the differences in commercially available matrices and provides a guide for matrix optimization during iPSC and IO work.

OBJECTIVE: To compare the histomorphologic changes on the anterior lens capsule by both epithelial and basement membrane side staining to those of only basement membrane side staining of the anterior lens capsule with Trypan Blue (TB).
METHODS: A cross-sectional study was done on 72 samples from patients who underwent cataract surgery between April 2021 and September 2022. After capsulorhexis of the TB-stained capsule, it was made into two halves externally and one half labeled as controls (sample A). The other half was immediately stained further with TB on the epithelial side and was taken as cases (sample B). Samples were analyzed for lens epithelial cells and basement membrane changes.
RESULTS: The loss of intactness of lens epithelial cells, partial or complete detachment of lens epithelial cells, degeneration of lens epithelial cells, and basement edema were significantly higher in cases compared to controls, whereas intactness of the basement membrane did not show any statistical significance between the two groups. There was a statistically significant decrease in cell density in cases compared to controls.
CONCLUSIONS: Staining the epithelial side of the capsular bag with TB is more detrimental to lens epithelial cells and paves the way for a further study of staining the capsular bag before intra-ocular lens implantation to reduce the incidence of posterior capsule opacification.

OBJECTIVE: To examine the retinal displacement and change in mean superficial foveal avascular zone (FAZ) after successful closure of macular hole (MH) with vitrectomy with internal limiting membrane peeling (ILM) and gas tamponade.
METHODS: A total of 45 patients with idiopathic MH who underwent 23G pars plana vitrectomy with ILM peeling and tamponade with 20% SF6/14% C3F8 were included. Follow-up visits were performed at 2, 4, and 8 weeks. OCT and OCT-A scans were performed along with detailed ocular examination. Distance between optic disc and an easily identifiable vascular bifurcation nasal and temporal to fovea, FAZ, was noted. Chi-square test (categorical data) and Mann-Whitney U test and t tests for other parameters were performed for statistical analysis.
RESULTS: The mean displacement (µm) of an easily identifiable vascular bifurcation in the nasal quadrant was 96.58 ± 36.55 at 8 weeks and in the temporal quadrant was 273.07 ± 85.51 at 8 weeks. The change was statistically significant in the temporal quadrant (P = <0.001). The mean BCVA changed from a minimum of 0.08 at the preoperative timepoint to a maximum of 0.23 at 8 weeks (P = <0.001). The mean FAZ area (mm²) decreased from a maximum of 0.37 at the preoperative timepoint to a minimum of 0.19 at 8 weeks (p = <0.001).
CONCLUSIONS: The retina in the temporal quadrant is displaced significantly more than nasal quadrant after successful closure of macular hole. The mean superficial FAZ also decreases suggesting a centripetal movement of the foveal tissue postoperatively.

OBJECTIVE: To analyze the outcomes following conventional internal limiting membrane (ILM) peeling versus perfluoro octane-assisted inverted flap technique for large macular holes (MH).
METHODS: A consecutive 99 eyes of 99 patients were enrolled {45 - conventional group and 54 - inverted flap (InFlap) group}. The primary outcome was a difference in closure rate. Secondary outcomes were differences in best-corrected visual acuity (BCVA), restoration of external limiting membrane (ELM) and ellipsoid zone (EZ) between groups at 3 (primary endpoint), 6 and 12 (secondary endpoints) months. Additionally, the effect of different gas tamponades on closure rates, ILM flap disintegration in InFlap group, and subfoveal thickness (SFT) between groups in closed.
RESULTS: At 3 months, there was no difference in the closure rate and BCVA between groups. At six months, closure rate was significantly better in the InFlap group. However, this difference was not maintained at 12 months. There was no difference in BCVA between groups at any visit. The ELM recovery was significantly higher in the conventional group at three months; however, there was no difference in ELM/EZ recovery between groups at other visits. The closure rate in the InFlap group was the same irrespective of gas tamponade. The ILM flap was identifiable in one-third of patients at 12 months. In closed MH, SFT was significantly more in InFlap group.
CONCLUSIONS: The closure rate and visual outcomes remained similar in both groups in the immediate and long term. Conventional ILM peeling technique seems to have early ELM recovery when compared to inverted flap technique.

OBJECTIVE: To investigate surgical results for medium-sized (251-400 µ m) macular holes (MHs).
METHODS: This retrospective observational study involved 266 eyes of 262 consecutive patients who underwent internal limiting membrane (ILM) peeling (147 eyes in the ILM peeling group) or inverted ILM flap cover technique (119 eyes in the inverted flap group) for primary medium-sized full-thickness MHs. Macular hole associated with retinal detachment, recurrent MH, and traumatic MH were excluded.
RESULTS: The primary closure rate for overall medium-sized MHs was 100% (119 of 119 eyes) in the inverted flap group, which was significantly higher than that (94.6% [139/147 eyes]; P = 0.010) in the ILM peeling group. Notably, even after adjusting for the minimum MH diameter, presence of high myopia, or preexisting posterior vitreous detachment, the primary closure rate was significantly better in the inverted flap group than in the ILM peeling group (Cochran-Mantel-Haenszel test, overall adjusted P = 0.006, 0.009, 0.005, respectively). The preoperative and postoperative restoration of the outer retinal layers and visual acuity were comparable between the inverted ILM flap and ILM peeling techniques.
CONCLUSIONS: Primary closure for medium-sized MHs was significantly superior in the inverted flap group than in the ILM peeling group.

BACKGROUND: To explore the predictive value of Ellipsoid Zone (EZ) -related angle parameters for the outcome of primary macular hole surgery.
METHODS: This was a retrospective study. Patients diagnosed with large macular hole (MH) (minimum diameter > 500 μm) between 2018 and 2021 were enrolled. All patients underwent 25-gauge pars plana vitrectomy, internal limiting membrane (ILM) peeling and air tamponade. Spectral-domain OCT (SD-OCT) and best corrected visual acuity (BCVA) were measured in preoperative and 2-week post-operative. Classic and angle related parameters were measured via ImageJ. Angle regularity (AR) were defined as the standard deviation of the angle parameters in vertical and horizontal direction.
RESULTS: Seventy-six eyes were included for analysis; 24 eyes showed an unclosed macular hole at the 2-week postoperative and 52 eyes showed a closed hole. Preoperatively, MLD (P < 0.001), BD (P = 0.009) and diameter of EZ/ELM disruption (P = 0.002 and 0.025) in patients failed to close the hole after primary surgery were significantly larger than those succeeded. EZ-MH (P = 0.018), EZ-NFL (P = 0.006), EZ-GCL (P = 0.004), EZ-INL (P = 0.002), EZ-OPL (P = 0.009) and EZ-ONL (P = 0.011) angles were smaller in patients with unclosed hole. AR of the EZ-NFL (P = 0.009), EZ-GCL (P = 0.009), EZ-OPL (P = 0.023), EZ-ONL (P = 0.048) and Basal-NFL (P = 0.030) angles among the unclosed patients were significantly larger than those of the closed group. EZ-NFL (P = 0.015), EZ-GCL (P = 0.004), EZ-INL (P < 0.001), EZ-OPL (P < 0.001), EZ-ONL (P < 0.001), Basal (P = 0.023) and Basal-NFL (P < 0.001) angles of hole-unclosed patients enlarged significantly after the surgery.
CONCLUSIONS: Patients with large macular holes and an increased EZ-related angle and angle AR are more likely to experience unsuccessful outcomes following primary MH surgery. Therefore, EZ-related angles hold potential as valuable parameters for predicting the surgical outcome.

OBJECTIVE: The conventional aqueous outflow pathway, which includes the trabecular meshwork (TM), juxtacanalicular tissue (JCT), and the inner wall endothelium of Schlemm\'s canal (SC), regulates intraocular pressure (IOP) by controlling the aqueous humor outflow resistance. Despite its importance, our understanding of the biomechanics and hydrodynamics within this region remains limited. Fluid-structure interaction (FSI) offers a way to estimate the biomechanical properties of the JCT and SC under various loading and boundary conditions, providing valuable insights that are beyond the reach of current imaging techniques.
METHODS: In this study, a normal human eye was fixed at a pressure of 7 mm Hg, and two radial wedges of the TM tissues, which included the SC inner wall basement membrane and JCT, were dissected, processed, and imaged using 3D serial block-face scanning electron microscopy (SBF-SEM). Four different sets of images were used to create 3D finite element (FE) models of the JCT and inner wall endothelial cells of SC with their basement membrane. The outer JCT portion was carefully removed as the outflow resistance is not in that region, leaving only the SCE inner wall and a few µm of the tissue, which does contain the resistance. An inverse iterative FE algorithm was then utilized to calculate the unloaded geometry of the JCT/SC complex at an aqueous humor pressure of 0 mm Hg. Then in the model, the intertrabecular spaces, pores, and giant vacuole contents were replaced by aqueous humor, and FSI was employed to pressurize the JCT/SC complex from 0 to 15 mm Hg.
RESULTS: In the JCT/SC complex, the shear stress of the aqueous humor is not evenly distributed. Areas proximal to the inner wall of SC experience larger stresses, reaching up to 10 Pa, while those closer to the JCT undergo lower stresses, approximately 4 Pa. Within this complex, giant vacuoles with or without I-pore behave differently. Those without I-pores experience a more significant strain, around 14%, compared to those with I-pores, where the strain is roughly 9%.
CONCLUSIONS: The distribution of aqueous humor wall shear stress is not uniform within the JCT/SC complex, which may contribute to our understanding of the underlying selective mechanisms in the pathway.

BACKGROUND: Indocyanine green (ICG) aids in the visualization of the internal limiting membrane (ILM). Retinal damage from ICG dye toxicity has been reported through in vitro and in vivo studies. However, the clinical toxic effect of ICG during macular surgery has not been functionally evaluated. In this study, we evaluated functional and structural changes in retinal sensitivity and retinal thickness associated with ICG toxicity using microperimetry before and after ICG-assisted ILM peeling in patients with macular holes.
METHODS: ICG staining was performed only on the macular area below the horizontal line connecting the fovea and optic disc. ILM peeling was performed over the entire macular area inside the vascular arcade. Visual acuity assessment, spectral domain optical coherence tomography, and microperimetry were performed at baseline and one, three, and six months postoperatively. The mean retinal sensitivity of four macular areas was calculated and analyzed.
RESULTS: Eleven eyes were included. Macular holes were successfully closed in all patients. Six months postoperatively, retinal sensitivity improved insignificantly in Area 1 (ICG-/ILM-) and Area 2 (ICG-/ILM+) but decreased in Area 4 (ICG+/ILM-). Three months postoperatively, retinal sensitivity significantly decreased in Area 3 (ICG+/ILM+; 26.63 ± 1.80 vs. 25.52 ± 2.08 dB, p = 0.036). However, the statistical significance of this result was lost six months after the surgery (p = 0.059). The change of Gc-IPL thickness in Area 3 was significantly different compared to Area 2 at post-operative 3- and 6-months (p = 0.01, 0.05).
CONCLUSIONS: Retinal sensitivity decreased three months after ICG-assisted ILM peeling. However, the statistical significance was lost six months after surgery. ICG staining can be performed with caution during macular hole surgery.

Historically, due to the lack of distinct clinical symptoms, Alport syndrome, a hereditary kidney disease prevalent in children and a leading cause of kidney failure, has often been misdiagnosed as other kidney conditions.
This article presents a comprehensive review and analysis of clinical data concerning a child diagnosed with Alport syndrome, where nephrotic syndrome served as the primary manifestation. The male child in this case exhibited symptoms starting at the age of 6, initially diagnosed as nephrotic syndrome. Consequently, oral steroid medication was administered, proving ineffective. Due to persistent proteinuria and microscopic hematuria, a renal biopsy was performed. Immunofluorescence staining revealed no abnormal expression of the α3, α4, and α5 chains of type IV collagen. Notably, electron microscopy revealed the basement membrane to be partially torn and arachnoid. Genetic testing indicated a hemizygous COL4A5 acceptor-splice-site mutation c.4707-1(IVS50)G > A, inherited from his mother.
This specific mutated locus, being the first of its kind reported, adds valuable information to the existing gene mutation spectrum of Alport syndrome. Consequently, it emphasizes the importance for clinicians to deepen their understanding of rare kidney diseases, contributing to enhanced diagnostic accuracy and improved patient care.

OBJECTIVE: To report on macular hole repair in macular telangiectasia type 2 (MacTel2).
METHODS: Global, multicenter, retrospective case series.
METHODS: Patients undergoing surgery for MacTel2-associated full-thickness macular hole (MTMH).
METHODS: Standardized data collection sheet distributed to all surgeons.
METHODS: Anatomic closure and visual outcomes of MTMH.
RESULTS: Sixty-three surgeries in 47 patients with MTMH were included from 30 surgeons. Mean age was 68.1 years, with 62% female, 72% White, 21% East or South Asian, 2% African American, and 2% Hispanic or Latino. Procedures included 34 internal limiting membrane (ILM) peeling alone, 22 ILM flaps, 5 autologous retinal transplantations (ARTs), 1 retinotomy, and 1 subretinal bleb. For ILM peeling, preoperative visual acuity (VA) was 0.667 ± 0.423 logarithm of the minimum angle of resolution (logMAR). Minimum hole diameter (MHD) was 305.5 ± 159.4 μm (range, 34-573 μm). Sixteen of 34 ILM peels (47%) resulted in MTMH closure. At postoperative month 6, VA was stable at 0.602 ± 0.516 logMAR (P = 0.65). VA improved by at least 2 lines in 43% and at least 4 lines in 24%. For ILM flaps, preoperative VA was 0.878 ± 0.552 logMAR. MHD was 440.8 ± 175.5 μm (range, 97-697 μm), which was significantly larger than for ILM peels (P < 0.01). Twenty of 22 ILM flaps (90%) resulted in MTMH closure, which was significantly higher than for ILM peels (P < 0.01). At postoperative month 6, VA improved to 0.555 ± 0.405 logMAR (P < 0.05). VA improved by at least 2 lines in 56% and at least 4 lines in 28%. For ARTs, preoperative VA was 1.460 ± 0.391 logMAR. MHD was 390.2 ± 203.7 μm (range, 132-687 μm). All 5 ARTs (100%) resulted in MTMH closure. At postoperative month 6, VA was stable at 1.000 ± 0.246 logMAR (P = 0.08). Visual acuity improved at least 2 lines in 25%.
CONCLUSIONS: Surgical closure of macular holes improved VA in 57% of MTMHs. Internal limiting membrane flaps achieved better anatomic and functional outcomes than ILM peeling alone. Autologous retinal transplantation may be an option for refractory MTMHs.
BACKGROUND: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.