Jaime Etxebarria

Plasma rich in growth factors as a therapeutic agent for persistent corneal epithelial defects.

Objective: To evaluate the efficacy of topically applied autologous plasma rich in growth factors (PRGF) as a treatment for persistent epithelial defects (PEDs) of the cornea. Methods: A series of prospective noncomparative cases. Participants: Twenty eyes from 18 patients with PED with various underlying etiopathologies: neurogenic, iatrogenic, associated with burning or secondary to severe dry eye. Patients were treated with a PRGF eyedrop solution. Serial photographs of the cornea were taken until epithelialization was complete. We had previously characterized the levels of a panel of growth factors (platelet-derived growth factor, epithelial growth factor, vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor, and nerve growth factor) in the PRGF of 11 of these patients. The following variables were additionally recorded: (1) duration of PED before treatment, (2) previous treatments, (3) time for complete epithelialization, and (4) treatments required concomitantly with PRGF. Results: Epithelial defects healed in 17 of 20 cases (85%), with a mean therapeutic time of 10.9 weeks (range 2-39 weeks). Mean progression time before treatment was 26.7 weeks (range 2-104 weeks). Growth factor concentrations were platelet-derived growth factor 12645.9 ± 1690.0 pg/mL, epithelial growth factor 468.9 ± 97.6 pg/mL, vascular endothelial growth factor 204.5 ± 119.4 pg/mL, hepatocyte growth factor 149.5 ± 173.5 pg/mL, fibroblast growth factor 82.6 ± 95.9 pg/mL, and nerve growth factor 37.7 ± 18.6 pg/mL. Conclusion: PRGF, when applied as eyedrops, is a highly effective therapeutic agent for the treatment of a broad etiopathological spectrum of corneal PEDs.

In Vitro Effects of Three Blood Derivatives on Human Corneal Epithelial Cells

PURPOSE We compared the effects of three blood derivatives, autologous serum (AS), platelet-rich plasma (PRP), and serum derived from plasma rich in growth factors (PRGF), on a human corneal epithelial (HCE) cell line to evaluate their potential as an effective treatment for corneal epithelial disorders. METHODS The concentrations of epidermal growth factor (EGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and fibronectin were quantified by ELISA. The proliferation and viability of HCE cells were measured by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay. Cell morphology was assessed by phase-contrast microscopy. The patterns of expression of several connexin, involucrin, and integrin α6 genes were analyzed by real-time RT-PCR. RESULTS We found significantly higher levels of EGF in PRGF compared to AS and PRP. However, AS and PRGF induced robust proliferation of HCE cells. In addition, PRGF cultured cells grew as heterogeneous colonies, exhibiting differentiated and non-differentiated cell phenotypes, whereas AS- and PRP-treated cultures exhibited quite homogeneous colonies. Finally, PRGF upregulated the expression of several genes associated with communication and cell differentiation, in comparison to AS or PRP. CONCLUSIONS PRGF promotes biological processes required for corneal epithelialization, such as proliferation and differentiation. Since PRGF effects are similar to those associated with routinely used blood derivatives, the present findings warrant further research on PRGF as a novel alternative treatment for ocular surface diseases.

Corneal Wound Healing Promoted by 3 Blood Derivatives: An In Vitro and In Vivo Comparative Study

Purpose: The aim of this study was to compare the effect on corneal wound healing of 3 differently manufactured blood derivatives [autologous serum (AS), platelet-rich plasma, and serum derived from plasma rich in growth factors (s-PRGF)]. Methods: Scratch wound-healing assays were performed on rabbit primary corneal epithelial cultures and human corneal epithelial cells. Additionally, mechanical debridement of rabbit corneal epithelium was performed. Wound-healing progression was assessed by measuring the denuded areas remaining over time after treatment with each of the 3 blood derivatives or a control treatment. Results: In vitro data show statistically significant differences in the healing process with all the derivatives compared with the control, but 2 of them (AS and s-PRGF) induced markedly faster wound healing. In contrast, although the mean time required to complete in vivo reepithelization was similar to that of AS and s-PRGF treatment, only wounds treated with s-PRGF were significantly smaller in size from 2.5 days onward with respect to the control treatment. Conclusions: All 3 blood derivatives studied are promoters of corneal reepithelization. However, the corneal wound-healing progresses differently with each derivative, being faster in vitro under AS and s-PRGF treatment and producing in vivo the greatest decrease in wound size under s-PRGF treatment. These findings highlight that the manufacturing process of the blood derivatives may modulate the efficacy of the final product.

Novel Molecular Diagnostic System of Limbal Stem Cell Deficiency Based on MUC5AC Transcript Detection in Corneal Epithelium by PCR-Reverse Dot Blot

PURPOSE To evaluate the sensitivity and specificity of a PCR-strip system based on reverse dot blot for detection of MUC5AC mRNA in corneal epithelium samples from patients with limbal stem cell deficiency (LSCD), and to determine the correlation with clinical diagnosis. METHODS We obtained 87 corneal impression cytology (IC) samples from 55 subjects (37 patients clinically diagnosed with LSCD and 18 control subjects). Total RNA was extracted from each IC sample and retrotranscribed to cDNA. MUC5AC mRNA transcript was amplified by a customized RT-PCR assay and detected in PCR strips based on reverse dot blot hybridization and in agarose gels. Conjunctival IC samples were used as positive controls. RESULTS Forty-four of 45 corneal IC samples obtained from patients clinically diagnosed with LSCD were positive for MUC5AC, whereas 34 of 42 corneal ICs from healthy subjects were negative for MUC5AC. Four healthy corneas were found MUC5AC positive, and four rendered inconclusive results. A correlation of 91.4% (P < 0.001) between molecular testing and clinical diagnosis was found. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the PCR-strip system were 98%, 89%, 92%, and 97%, respectively. CONCLUSIONS Corneal epithelium MUC5AC transcript detection by reverse dot blot PCR-strip is a highly sensitive technique for LSCD diagnosis. The test results strongly correlate with clinical diagnosis of characterized LSCD cases. The PCR-strip system may be used for early detection, and for the detection of mild cases of LSCD, and constitutes an objective clinical tool for the monitoring of treatments and surgical decisions.

Serum from plasma rich in growth factors regenerates rabbit corneas by promoting cell proliferation, migration, differentiation, adhesion and limbal stemness

To evaluate the regenerating potential and the mechanisms through which the autologous serum derived from plasma rich in growth factors (s‐PRGF) favours corneal wound healing in vitro and in vivo.

Phase 2 Randomized, Double-Masked, Vehicle-Controlled Trial of Recombinant Human Nerve Growth Factor for Neurotrophic Keratitis

PURPOSE To evaluate the safety and efficacy of topical recombinant human nerve growth factor (rhNGF) for treating moderate-to-severe neurotrophic keratitis (NK), a rare degenerative corneal disease resulting from impaired corneal innervation. DESIGN Phase II multicenter, randomized, double-masked, vehicle-controlled trial. PARTICIPANTS Patients with stage 2 (moderate) or stage 3 (severe) NK in 1 eye. METHODS The REPARO phase II study assessed safety and efficacy in 156 patients randomized 1:1:1 to rhNGF 10 μg/ml, 20 μg/ml, or vehicle. Treatment was administered 6 drops per day for 8 weeks. Patients then entered a 48- or 56-week follow-up period. Safety was assessed in all patients who received study treatment, whereas efficacy was by intention to treat. MAIN OUTCOME MEASURES Corneal healing (defined as <0.5-mm maximum diameter of fluorescein staining in the lesion area) was assessed by masked central readers at week 4 (primary efficacy end point) and week 8 (key secondary end point) of controlled treatment. Corneal healing was reassessed post hoc by masked central readers using a more conservative measure (0-mm staining in the lesion area and no other persistent staining). RESULTS At week 4 (primary end point), 19.6% of vehicle-treated patients achieved corneal healing (<0.5-mm lesion staining) versus 54.9% receiving rhNGF 10 μg/ml (+35.3%; 97.06% confidence interval [CI], 15.88-54.71; P < 0.001) and 58.0% receiving rhNGF 20 μg/ml (+38.4%; 97.06% CI, 18.96-57.83; P < 0.001). At week 8 (key secondary end point), 43.1% of vehicle-treated patients achieved less than 0.5-mm lesion staining versus 74.5% receiving rhNGF 10 μg/ml (+31.4%; 97.06% CI, 11.25-51.49; P = 0.001) and 74.0% receiving rhNGF 20 μg/ml (+30.9%; 97.06% CI, 10.60-51.13; P = 0.002). Post hoc analysis of corneal healing by the more conservative measure (0-mm lesion staining and no other persistent staining) maintained statistically significant differences between rhNGF and vehicle at weeks 4 and 8. More than 96% of patients who healed after controlled rhNGF treatment remained recurrence free during follow-up. Treatment with rhNGF was well tolerated; adverse effects were mostly local, mild, and transient. CONCLUSIONS Topical rhNGF is safe and more effective than vehicle in promoting healing of moderate-to-severe NK.

Infection and inflammation in Boston Type 1 KPro

Purpose We show possible risk factors for extrusion or endophthalmitis , significance of different clinical features, how to approach them clinically and surgically in order to try to obtain the most successful results in patients who underwent Boston KPro type I surgery.