Expression, characterization, and application of human-like recombinant gelatin.

Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen, belonging to natural biopeptides. With irreplaceable biological functions in the field of biomedical science and tissue engineering, it has been widely applied. The amino acid sequence of recombinant human-like gelatin was constructed through a newly designed hexamer composed of six protein monomer sequences in series, with the minimum repeating unit being the characteristic Gly-X-Y sequence found in type III human collagen α1 chain. The nucleotide sequence was subsequently inserted into the genome of Pichia pastoris to enable soluble secretion expression of recombinant gelatin. At the shake flask fermentation level, the yield of recombinant gelatin is up to 0.057 g/L, and its purity can rise up to 95% through affinity purification. It was confirmed in the molecular weight determination and amino acid analysis that the amino acid composition of the obtained recombinant gelatin is identical to that of the theoretically designed. Furthermore, scanning electron microscopy revealed that the freeze-dried recombinant gelatin hydrogel exhibited a porous structure. After culturing cells continuously within these gelatin microspheres for two days followed by fluorescence staining and observation through confocal laser scanning microscopy, it was observed that cells clustered together within the gelatin matrix, exhibiting three-dimensional growth characteristics while maintaining good viability. This research presents promising prospects for developing recombinant gelatin as a biomedical material.

The Long-term Visual Quality and Rotational Stability After ICL/TICL V4c Implantation in Individuals With High Myopia Older Than 40 Years.

PURPOSE: To investigate the long-term visual quality and rotational stability after the implantation of Implantable Collamer Lens (ICL) and toric ICL (TICL) (STAAR Surgical) in patients with myopia older than 40 years. METHODS: This study included 82 eyes of 41 patients older than 40 years with myopia who underwent ICL/TICL V4c implantation. The refraction sphere, refraction cylinder, spherical equivalent (SE), uncorrected and corrected distance visual acuity, and anterior segmental parameters were measured preoperatively and at the 1-month, 3-month, and last follow-up visits at 33 to 58 months postoperatively (mean follow-up: 42.56 ± 7.17 months). Wavefront aberrations and TICL rotation were measured using OPD-Scan III (Nidek Co Ltd) at the last follow-up visit. RESULTS: At the last follow-up visit, the overall safety and efficacy index were 1.22 ± 0.26 and 0.88 ± 0.34, respectively, without significant differences between the ICL and TICL groups. Postoperative refraction cylinder was -0.95 ± 0.64 and -0.71 ± 0.54 diopters in the ICL and TICL groups, respectively. The average vault was 467.44 ± 231.98 µm. The average TICL rotation was 5.45 ± 6.61 degrees, positively correlated with the preoperative anterior chamber volume (R2 = 0.1118, P = .026) and clockwise TICL alignment degree (R2 = 0.3110, P = .007) and negatively correlated with the 1-month vault (R2 = 0.1218, P = .008). There were no significant differences in the total, corneal, or internal aberrations and modulation transfer function AreaRatio between the ICL and TICL groups. CONCLUSIONS: Both ICL and TICL presented satisfactory long-term safety, efficacy, and visual quality in patients older than 40 years. Postoperative TICL spontaneous rotation was within the manageable range in the long term. [J Refract Surg. 2024;40(6):e381-e391.].

Influence of corneal diameter on the accuracy of corneal tomography in patients with forme fruste keratoconus or thin corneas.

CLINICAL RELEVANCE: The detection of subclinical ectasia is important in preoperative screening for laser-refractive surgery. Previous studies have confirmed the impact of corneal diameter on the diagnostic accuracy of several ectasia indices in tomographically normal eyes. BACKGROUND: This study aimed to investigate the influence of corneal diameter on the diagnostic accuracy of Pentacam tomographic indices in eyes with forme fruste keratoconus (FFKC) and thin corneas. METHODS: One hundred and one eyes of 101 patients with FFKC (FFKC group), 104 eyes of 104 patients with a corneal thickness <490 µm (thin cornea group), and 200 eyes of 200 normal subjects (normal group) were analysed in the study. Pentacam ectasia indices were compared between the groups. RESULTS: The results of multiple linear regression analysis showed that the standardised coefficients for corneal diameter and overall deviation of normality (BAD-D) were -0.386, -0.552, and -0.552 for the FFKC, thin cornea, and normal groups, respectively (p < 0.001). Comparing for the classifications (normal versus abnormal) of the individual indices demonstrated that for corneal diameters ≤11.9 mm, the rates of abnormal cases were significantly higher in the FFKC group than in the normal group for seven indices and in the thin cornea group than normal group for nine indices. For corneal diameters >11.9 mm, the rates of abnormal cases were higher in the FFKC than normal group for three indices and higher in the thin cornea group than normal group for seven indices. CONCLUSION: Belin/Ambrosio Enhanced Ectasia display indices may underestimate the risk of ectasia in patients with large corneas, especially those with FFKC.

Binocular imbalance in patients after implantable collamer lens V4c implantation or femtosecond laser-assisted in situ keratomileusis for myopia with presbyopia.

Aim: To investigate the long-term safety, efficacy, and binocular balance of monovision surgery using Implantable Collamer Lens (ICL) V4c implantation and Femtosecond Laser-Assisted in situ Keratomileusis (FS-LASIK) for the treatment of myopic patients with presbyopia. Methods: This case series study involved 90 eyes of 45 patients (male/female = 19/26; average age:46.27 ± 5.54 years; average follow-up time:48.73 ± 14.65 months) who underwent the aforementioned surgery to treat myopic presbyopes. Data on manifest refraction, corrected distance visual acuity, dominant eye, presbyopic addition, intraocular pressure, and anterior segment biometric parameters were collected. The visual outcomes and binocular balance at 0.4 m, 0.8 m, and 5 m were documented. Results: The safety index for the ICL V4c and FS-LASIK groups were 1.24 ± 0.27 and 1.04 ± 0.20 (p = 0.125), respectively. Binocular visual acuity (logmar) for 0.4 m, 0.8 m, and 5 m were -0.03 ± 0.05, -0.03 ± 0.02, and 0.10 ± 0.03 for the ICL V4c group, and -0.02 ± 0.09, -0.01 ± 0.02, and 0.06 ± 0.04 for the FS-LASIK group, respectively. The proportions of all patients with imbalanced vision at 0.4 m, 0.8 m, and 5 m distances were 68.89, 71.11, and 82.22%, respectively (all p > 0.05 between the two groups). There were significant differences in refraction between the balanced and imbalanced vision for patients at 0.4 m distance (for non-dominant eye spherical equivalent [SE]: -1.14 ± 0.17D and -1.47 ± 0.13D, p < 0.001), 0.8 m distance (for preoperative ADD:0.90 ± 0.17D and 1.05 ± 0.11D, p = 0.041), and 5 m distance (for non-dominant SE: -1.13 ± 0.33D and -1.42 ± 0.11D, p < 0.001). Conclusion: ICL V4c implantation and FS-LASIK monovision treatment demonstrated good long-term safety and binocular visual acuity at various distances. After the procedure, the imbalanced patients' vision is primarily related to the age-related presbyopia and anisometropia progression caused by the monovision design.

Clinical evaluation and management of badminton-related eye injuries: a retrospective case series.

BACKGROUND: To describe the clinical features, visual outcomes, management, and complications of ocular injury in badminton and investigate risk factors associated with visual impairment. METHODS: Data on patients injured while playing badminton admitted to Department of Ophthalmology, Eye, Ear, Nose, and Throat Hospital, Fudan University between January 2018 to December 2020.The relationship between visual acuity (VA) and demographic and clinical variables was also analyzed. Patients were managed medically or surgically as per their needs, followed up for at least 18 months. The visual outcomes were predicted using ocular trauma score (OTS), predicted outcomes were compared with actual outcomes using statistical tests. RESULTS: This study involved 102 patients (78 men, 24 women) with a mean age of 43.8 ± 16.1 years (7-71 years). Of these, 93 patients had closed-globe injuries and 9 had open-globe injuries. Vision-threatening findings included lens subluxation(31.4%),retinal detachment(13.7%),hyphema(12.7%). Open-globe injury had significantly lower presenting VA and final VA (P= 0.0164, 0.0053).Final VA was found to be correlated with presenting VA, maculopathy, retinal detachment, and OTS (P=0.0000, 0.0494, 0.0001, 0.0000 respectively), it was worse in patients who were under 20 years of age and were female. OTS prediction was not significantly different when compared with actual visual outcomes postoperatively in OTS3, OTS4, and OTS5 (P > 0.05),while the prognosis of patients with OTS1 and OTS2 was better than OTS study (P=0.001, 0.007, respectively). CONCLUSION: Badminton-related closed-globe injuries were more frequent; open-globe injuries were usually more serious. Younger and female patients have poorer visual recovery prognoses. OTS was found to be a reliable tool for predicting visual outcomes.

Predictive models for IOPs measured with NCT, GAT, and ORA among patients undergoing SMILE.

Purpose: To develop predictive models for the intraocular pressure (IOP) of patients undergoing small incision lenticule extraction (SMILE) procedures, measured with a noncontact tonometer (NCT), Goldmann applanation tonometry (GAT), and an ocular response analyzer (ORA). Methods: In this prospective study, a total of 104 eyes (-6.23 ± 2.06 diopters) of 52 patients (24.38 ± 4.76 years) undergoing SMILE procedures were included. The intraocular pressure was measured (IOPNCT with NCT, IOPGAT with GAT, and IOPcc and IOPg with ORA) before surgery and at postoperative 6 months. Information on age, preoperative and attempted spherical equivalent (SE), ablation depth, preoperative values and postoperative changes in central corneal thickness (CCT), K1, K2, Km, corneal hysteresis (CH) and corneal resistance factor (CRF) values was collected in order to predict IOPs. Results: All surgeries were uneventful. At postoperative 6 months, the efficacy and safety index were 1.04 ± 0.15 and 1.08 ± 0.18, respectively. Significant decreases were detected in postoperative IOPNCT, IOPGAT, IOPcc, and IOPg compared to preoperative values (all p < 0.001). No relationship was found between any IOP and ablation depth, attempted SE, and preoperative SE, as well as CCTdifference (all p > 0.05). Predictive models for IOPs were constructed to predict preoperative values, and R 2 values were 67.5% (IOPNCT), 64.5% (IOPGAT), 78.7% (IOPcc), and 82.0% (IOPg). The prediction band of IOPNCT and IOPGAT was 7.4-15.1 mmHg and 8-16 mmHg, respectively. Conclusion: Predictive models for IOP measurements after SMILE procedures can be helpful in clinical practice.

Long-term follow-up for monovision surgery by Implantable Collamer Lens V4c implantation for myopia correction in early presbyopia.

PURPOSE: To investigate the long-term safety and efficacy of monovision surgery using implantable collamer lens V4c (ICL V4c) implantation in myopic patients with early presbyopia. SETTING: Eye and ENT Hospital of Fudan University, Shanghai, China. DESIGN: Prospective case series study. METHODS: This study included 64 eyes of 32 patients with early presbyopia, who underwent bilateral ICL V4c implantation for myopia correction. Parameters, including mean spherical equivalent (SE), uncorrected distance visual acuity, corrected distance visual acuity, intraocular pressure, endothelial cell density, presbyopic add power, visual acuity (logMAR) of dominant eyes (D-eye), nondominant (nD-eye) eyes, and both eyes (Bi) at 0.4 m, 0.8 m, and 5 m were recorded at the last follow-up. RESULTS: All surgeries were uneventful. At the last follow-up, the safety indices were 1.23 ± 0.18 (D-eyes) and 1.21 ± 0.18 (nD-eyes) (p > 0.05); the efficacy indices were 0.95 ± 0.27 (D-eyes) and 0.92 ± 0.28 (nD-eyes) (p < 0.05), the SE was -0.62 ± 0.47 D (D-eyes); and - 1.21 ± 0.78D (nD-eyes) (p < 0.05), presbyopic add power was 1.31 ± 0.58 D. The visual acuity (logMAR) of D-eyes, nD-eyes, and binocular (Bi) at 5.0 m were: 0.06 ± 0.15 (D-eye), 0.21 ± 0.18 (nD-eye), (p < 0.01), and 0.04 ± 0.13 (Bi); 0.8 m: 0.03 ± 0.18 (D-eye), 0.08 ± 0.16 (nD-eye), (p > 0.05), and - 0.02 ± 0.11 (Bi); 0.4 m: 0.08 ± 0.09 (D-eye), - 0.02 ± 0.08 (nD-eye), (p < 0.001), and - 0.03 ± 0.09 (Bi). Subjects were very satisfied or felt excellent with their visual acuity at near (81.25%) and far distances (87.50%), respectively (versus preoperative, p < 0.001). CONCLUSION: Monovision surgery using ICL V4c implantation is safe and practicable for correction of myopes with presbyopia, with long-term efficacy at near and far distances and patient satisfaction.

Long-term evaluation of anterior lens density after implantable collamer lens V4c implantation in patients with myopia over 40 years old.

PURPOSE: To investigate the long-term safety and efficacy of implantable collamer lens (ICL) V4c implantation and changes in the anterior lens density (ALD) in patients with myopia ≥40 years of age. METHODS: This prospective study included 104 eyes of 52 patients >40 years of age before ICL V4c implantation. Spherical equivalent (SE), uncorrected distance visual acuity, corrected distance visual acuity (CDVA), intraocular pressure, endothelial cell density, anterior chamber depth, anterior chamber volume and anterior chamber angle preoperatively, at 1 and 3 months, and at 3 years postoperatively were recorded. Pentacam HR was used to analyse ALD changes at a depth of 0.5, 1.0 and 1.5 mm within a 3 mm diameter range around the pupil's centre. RESULTS: The overall follow-up was uneventful at 42±7.1 months; the safety index at last follow-up was 1.26±0.35 and the efficacy index was 0.91±0.41. No eye lost the Snellen line of CDVA, 76% of the eyes had an increase in CDVA for ≥1 line and 62% had an SE within ±0.50 dioptre. The increase in ALD at 0.5, 1 and 1.5 mm was 16.52%±10.46%, 16.72%±9.85% and 17.28%±11.93%, respectively. Preoperative, 1-month and 3-month postoperative ALDs showed correlations with SE and age, and ALD at last follow-up was correlated only with age. There was no correlation between ALD and any other parameters. CONCLUSION: ICL V4c shows long-term safety and efficacy in people ≥40 years of age. ALD increased in such patients, which may be related to age and SE.

Pentacam Scheimpflug Tomography Findings in Chinese Patients With Different Corneal Diameters.

PURPOSE: To investigate the Pentacam (Oculus Optikgeräte) Scheimpflug tomography findings in Chinese patients with different corneal diameters. METHODS: This prospective cross-sectional study included candidates for correction of myopia with normal tomography (ABCD keratoconus grading system, stage 0). The participants were grouped according to their horizontal corneal diameters. Pentacam ectasia detection indices were compared between different corneal diameter-based groups. RESULTS: A total of 643 eyes were included (corneal diameter ⩽ 11 mm, n = 206; 11 to 12 mm, n = 219; ⩾ 12 mm, n = 218). The corneal powers and the thinnest pachymetry were negatively correlated with corneal diameter (linear regression analysis, P < .001). However, the corneal astigmatism was positively correlated with corneal diameter (R2 = 0.03, P < .001). Both the front (FE) and back (BE) elevations were negatively correlated with corneal diameter (FE: R2 = 0.027, P < .001; BE: R2 = 0.274, P < .001). The three pachymetric progression indices (PPI) (minimum, maximum, and average) were negatively correlated with corneal diameter (PPImin: R2 = 0.164, P < .001; PPImax: R2 = 0.06, P < .001; PPIavg: R2 = 0.158, P < .001). The maximum Ambrósio's relational thickness (ARTmax) also was positively correlated with corneal diameter (R2 = 0.031, P < .001). Five normalized indices were negatively correlated with corneal diameter (deviation of normality of the front elevation [Df]: R2 = 0.122, P < .001; deviation of normality of the back elevation [Db]: R2 = 0.47, P < .001; deviation of normality of pachymetric progression [Dp]: R2 = 0.159, P < .001; deviation of normality of relational thickness [Da]: R2 = .031, P < .001; Belin/Ambrósio Enhanced Ectasia display: R2 = 0.32, P < .001) and Dt was positively correlated with corneal diameter (R2 = 0.015, P = .002). Additionally, it was noted that corneal diameter had the greatest influence on Db, Belin/Ambrósio Enhanced Ectasia display (BAD-D), and BE. CONCLUSIONS: Corneal diameter has an influence on the BAD parameters, especially Db, BAD-D, and BE, and therefore should be incorporated as an additional variable in BAD analysis. The analytical dimensions should be individualized for eyes with individual corneal diameter. [J Refract Surg. 2020;36(10):688-695.].

Effects of erythropoietin-dextran microparticle-based PLGA/PLA microspheres on RGCs.

PURPOSE: We explored the neuroprotective effects of erythropoietin (EPO)-loaded dextran microparticle-based Poly(DL-lactide-co-glycolide)/Poly(DL-lactide) (PLGA/PLA) microspheres (EPO-dextran PLGA/PLA microspheres) on retinal ganglion cells (RGCs) in optic nerve crush rats for a prolonged period of time. METHODS: EPO-dextran PLGA/PLA microspheres were prepared first by a novel solid-in-oil-in-water (S/O/W) technique. Then, the in vitro EPO release profile was assessed. Afterward, the bioactive effect of EPO released from EPO-dextran PLGA/PLA microspheres was explored in vitro on the retinal explants. Lastly, the neuroprotective effects of EPO-dextran PLGA/PLA microspheres on RGCs were evaluated in optic nerve crush rats with TUNEL staining for apoptotic RGCs. The level of glial fibrillary acidic protein (GFAP) expressed in retina was explored by immunohistochemistry staining. Survival RGCs were observed by DiI retrograde labeling using a DiI fluorescent tracer (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate). RESULTS: The results demonstrated that a sustained release of EPO from PLGA/PLA microspheres could last for at least 60 days. EPO released from the microspheres showed as efficaciously neuroregenerative as EPO protein solution on retinal explants (P = 0.2554 for neurite density, P = 0.1004 for neurite length). TUNEL staining revealed that EPO-dextran PLGA/PLA microspheres remarkably reduced RGCs death when compared to the control (untreated) group (P < 0.01 at five days and one week post-crush, P < 0.05 at two weeks post-crush). Increased GFAP expression in retina was reduced greatly in EPO-dextran PLGA/PLA microspheres-administrated rats two weeks post optic nerve crush. DiI retrograde labeling revealed that a single injection of EPO-dextran PLGA/PLA microspheres significantly promoted RGCs survival (P < 0.01 at four and eight weeks post-crush). CONCLUSIONS: A single intravitreal injection of EPO-dextran PLGA/PLA microspheres appeared to have a prolonged protective effect on RGCs in optic nerve crush rats. The PLGA/PLA microspheres may be a feasible protein delivery system, such as EPO, to intravitreal injection for retinal degeneration diseases.