Color vision, contrast sensitivity and higher order aberrations after photorefractive keratectomy

Purpose: To evaluate the effect of myopic photorefractive keratectomy (PRK) on color vision, contrast sensitivity and higher order aberrations (HOAs).Patients and Methods: This prospective study was performed on 46 eyes of 23 patients with 3 to 6 diopter of myopia/myopic astigmatism undergoing PRK. Color vision using Fransworth- Munsell 100 hue test (©2011 X-Rite Inc., Michigan, U.S) and contrast sensitivity using CSV-1000 (Vector Vision, Dayton, OH) were tested preoperatively and 2 and 6 months postoperatively. HOAs were assessed using Zernike analysis map of Pentacam (OCULUS Optikgeräte GmbH, Germany) preoperatively and 6 months postoperatively.Results: No significant change was observed in color vision following PRK. Contrast sensitivity function was also preserved except for an increase in 12 cycles per degree (cpd) spatial frequency 6 months after surgery (P = 0.04). Total HOAs and primary spherical aberrations (total, anterior and posterior surface) increased significantly (P < 0.001), however, primary coma showed no statistically significant change 6 months after surgery compared to baseline values. Induced total HOAs significantly correlated with change in primary vertical coma and total, anterior, and posterior primary spherical aberration. No significant correlation was found between the changes in contrast sensitivity, color vision and HOAs with the amount of preoperative sphere and cylinder.Conclusion: PRK with an aspheric profile in moderate myopia/ myopic astigmatism does not affect color vision and contrast sensitivity at 3, 6 and 18 cpd spatial frequencies. It increases total HOAs and spherical aberration, but not coma. It remains a good option for refractive correction of moderate.Keywords: Color vision, Contrast Sensitivity, Higher order aberrations, Photorefractive keratectomy

Posttraumatic Endophthalmitis: Responsible Microorganisms and Rate of Resistance

Purpose: To identify the microorganisms responsible for the posttraumatic endophthalmitis and evaluate their resistance to seven antibiotics. Patients and Methods: Aqueous and vitreous samples were obtained from 49 patients who underwent vitrectomy for posttraumatic endophthalmitis and were inoculated into blood agar, chocolate agar, and Sabouraud agar media. Susceptibility testing was performed using the Kirby-Bauer disk diffusion method for seven antibiotics (vancomycin, ceftazidime, ciprofloxacin, oxacillin, azithromycin, imipenem, and rifampin).Results: Twenty patients (40.8 %) had intraocular foreign bodies. The cultures were positive in 18 patients (36.7 %). In all patients (except for one case), one species was isolated. The most frequent isolated microorganism was staphylococcus epidermidis in 9 patients (47.4 %), followed by staphylococcus aureus, bacillus species, streptococcus viridans, streptococcus pneumonia, enterococcus, diphtheroid species, and pseudomonas aeruginosa. No case with fungal growth was found. Microorganisms showed higher sensitivity to different antibiotics: all gram-positive cocci were sensitive to vancomycin and 71.4 % were sensitive to ceftazidime or rifampin. All gram-positive bacilli were sensitive to vancomycin, ciprofloxacin and azithromycin. The gram-negative bacillus (pseudomonas) was sensitive to ceftazidime, ciprofloxacin, imipenem, and rifampin. Conclusion: No single antibiotic was effective against all groups of bacteria present in patients undergoing vitrectomy for posttraumatic endophthalmitis. The conventional intravitreal regimen (vancomycin + ceftazidime) seems to be still valuable in treatment of bacterial endophthalmitis among this group of patients.Keywords: Endophthalmitis; Microorganisms; Posttraumatic; Drug resistance

Safety Outcomes of Intrastromal Injection of Sodium Hypochlorite in the Normal Rabbit Cornea

Purpose: To investigate side effects of intrastromal sodium hypochlorite (NaOCl) injection in normal rabbit corneas and to investigate its possible use in treatment of fungal corneal infections.Methods: We conducted a prospective, non-randomized study in a healthy cornea rabbit model. Intrastromal injection of one hundred µl of NaOCl 5 % in one eye and NaOCl 10 % in the other eye was performed in 5 rabbits. Clinical examinations including the study of conjunctival injection, corneal edema, corneal opacity or melting, and limbal ischemia were performed on days 1, 7, 14 and 21after injection.  Specular microscopy and pathological studies were also performed three weeks after corneal injections in enucleated eyes. Results: NaOCl 5 % injection was associated with normal endothelial morphology and cell count in specular microscopy. Some irregularities and drop out was associated with NaOCl 10 % injection.  Conclusion: Intrastromal injection of NaOCl 5 % could be a safe method to treat fungal corneal infections

Extracellular-Vesicle-Based Therapeutics in Neuro-Ophthalmic Disorders

Extracellular vesicles (EVs) have been recognized as promising candidates for developing novel therapeutics for a wide range of pathologies, including ocular disorders, due to their ability to deliver a diverse array of bioactive molecules, including proteins, lipids, and nucleic acids, to recipient cells. Recent studies have shown that EVs derived from various cell types, including mesenchymal stromal cells (MSCs), retinal pigment epithelium cells, and endothelial cells, have therapeutic potential in ocular disorders, such as corneal injury and diabetic retinopathy. EVs exert their effects through various mechanisms, including promoting cell survival, reducing inflammation, and inducing tissue regeneration. Furthermore, EVs have shown promise in promoting nerve regeneration in ocular diseases. In particular, EVs derived from MSCs have been demonstrated to promote axonal regeneration and functional recovery in various animal models of optic nerve injury and glaucoma. EVs contain various neurotrophic factors and cytokines that can enhance neuronal survival and regeneration, promote angiogenesis, and modulate inflammation in the retina and optic nerve. Additionally, in experimental models, the application of EVs as a delivery platform for therapeutic molecules has revealed great promise in the treatment of ocular disorders. However, the clinical translation of EV-based therapies faces several challenges, and further preclinical and clinical studies are needed to fully explore the therapeutic potential of EVs in ocular disorders and to address the challenges for their successful clinical translation. In this review, we will provide an overview of different types of EVs and their cargo, as well as the techniques used for their isolation and characterization. We will then review the preclinical and clinical studies that have explored the role of EVs in the treatment of ocular disorders, highlighting their therapeutic potential and the challenges that need to be addressed for their clinical translation. Finally, we will discuss the future directions of EV-based therapeutics in ocular disorders. Overall, this review aims to provide a comprehensive overview of the current state of the art of EV-based therapeutics in ophthalmic disorders, with a focus on their potential for nerve regeneration in ocular diseases

Horner Syndrome Following Penetrating Neck Injuries: A Case Series

To report three cases of Horner syndrome associated with penetrating neck injuries and the result of surgery for correcting the resulting ptosis. This is a retrospective case series study of 3 patients with Horner syndrome with past history of penetrating trauma to the neck. The patients’ history and the surgical results are presented. Muller’s muscle conjunctival resection was successfully used to treat ptosis in traumatic Horner syndrome in two cases. In the clinical setting of acute traumatic injury to the neck, careful evaluation for signs and symptoms of Horner syndrome should be performed. Horner syndrome and associated ptosis can be effectively managed using Muller’s muscle conjunctival resection.Keywords: Wounds; Penetrating; Neck; Horner Syndrome; Ptosis

The success of simultaneous balloon dacryoplasty and stenting in failed congenital nasolacrimal duct intubations and its indications

Background: Congenital nasolacrimal duct obstruction (CNLDO) is one of the most prevalent orbital diseases in children and treatment of recalcitrant cases is always challenging. The purpose of this study is to identify the effectiveness of balloon dacryoplasty and stenting in persistent congenital nasolacrimal duct obstruction following previous intubation of nasolacrimal duct. Methods: Our study was an interventional study from January 2015 to January 2018 on 16 lacrimal systems of 11 patients (5 males and 6 females) with congenital obstruction of the lacrimal duct (CNLDO) and a history of unsuccessful probing and stenting, in Farabi Hospital of Tehran (affiliated to Tehran University of Medical Sciences). Children who presented to our hospital and had previously been probed with or without intubation by another surgeon first underwent reprobing and re-intubation with a Crawford tube. Endoscopy of the nasolacrimal system was performed in suspected cases of false stent passage or in the presence of a history indicating nasal pathology. Crawford's Monoka tube was removed after two months. Balloon dacryoplasty with intubation was performed as the third surgery in cases who did not respond to probing and stenting after 3-6 months. The success after six months was evaluated using fluorescein dye disappearance test (FDDT) and also the resolution of the patients' symptoms. Results: The age of the patients was 67±35.01 months (range: 26-121). The site of the canalicular stenosis in our patients was in the common canaliculi or within 2-3 mm from it. After 6 months, surgery was successfully performed in 13 lacrimal systems (81.25%). One patient with congenital lacrimal duct obstruction and Down syndrome and two other patients did not respond to balloon dacryoplasty and stenting and subsequently underwent dacryocystorhinostomy (DCR). Conclusion: Balloon dacryoplasty combined with Monocrawford intubation is an effective surgical procedure that should be considered in cases of congenital nasolacrimal duct obstruction who have not responded to the probing and stenting of the lacrimal system