Finite Element Analysis of Cornea and Lid Wiper during Blink, with and without Contact Lens.

Ocular surface disorders such as Lid Wiper Epitheliopathy (LWE), Superior Epithelial Arcuate Lesion (SEAL), and contact lens-induced Limbal Stem Cell Deficiency (LSCD) as well as Superior Limbic Keratoconjunctivitis (SLK) affect one's quality of life. Hence, it is imperative to investigate the underlying causes of these ocular surface disorders. During blink, the undersurface of the eyelid tends to interact with the cornea and the conjunctiva. The presence of a contact lens can add to the biomechanical frictional changes on these surfaces. To estimate these changes with and without a contact lens, a finite element model (FEM) of the eyelid wiper, eyeball, and contact lens was developed using COMSOL Multiphysics. Biomechanical properties such as von Mises stress (VMS) and displacement were calculated. Our study concluded that (a) maximum VMS was observed in the lid wiper in the absence of contact lens in the eye and (b) maximum VMS was observed in the superior 1.3 mm of the cornea in the presence of the contact lens in the eye. Thus, the development of friction-induced ocular surface disorders such as LWE, SLK, SEAL, and LSCD could be attributed to increased VMS. FEA is a useful simulation tool that helps us to understand the effect of blink on a normal eye with and without CL.

Drug reservoir function of voriconazole impregnated human amniotic membrane: An in vitro study.

Purpose: Earlier our group has demonstrated the drug reservoir function of the human amniotic membrane (HAM) using stable moxifloxacin and fortified cefazolin ophthalmic formulations and found it as a suitable tool to deliver drugs for an extended duration. The purpose of this study was to evaluate the extended-release kinetics of voriconazole from the impregnated human amniotic membrane (HAM) in vitro. Methods: HAM buttons were incubated with freshly prepared 1% topical ophthalmic formulation of voriconazole for 5 different exposure time to investigate the ideal exposure time for the extended-release of voriconazole from HAM. The drug release kinetics was studied in simulated tear fluid for 5 weeks and the amount of voriconazole released at different intervals was estimated using high-performance liquid chromatography (HPLC) with photodiode array (PDA) detector. Results: There was a marginal increase in drug entrapment efficiency with increased drug exposure time but neither the drug entrapment nor the drug release was found to be statistically significant (P ≥ 0.5). Voriconazole was detectable even at 5 weeks. Conclusion: A sustained release of voriconazole was achieved up to 5 weeks, when voriconazole was incubated with amniotic membrane for all the studied drug soaking times. Thus, voriconazole impregnated amniotic membrane can be considered for the sustained delivery for its in fungal keratitis.

Multi-Scale Convolutional Neural Network for Accurate Corneal Segmentation in Early Detection of Fungal Keratitis.

Microbial keratitis is an infection of the cornea of the eye that is commonly caused by prolonged contact lens wear, corneal trauma, pre-existing systemic disorders and other ocular surface disorders. It can result in severe visual impairment if improperly managed. According to the latest World Vision Report, at least 4.2 million people worldwide suffer from corneal opacities caused by infectious agents such as fungi, bacteria, protozoa and viruses. In patients with fungal keratitis (FK), often overt symptoms are not evident, until an advanced stage. Furthermore, it has been reported that clear discrimination between bacterial keratitis and FK is a challenging process even for trained corneal experts and is often misdiagnosed in more than 30% of the cases. However, if diagnosed early, vision impairment can be prevented through early cost-effective interventions. In this work, we propose a multi-scale convolutional neural network (MS-CNN) for accurate segmentation of the corneal region to enable early FK diagnosis. The proposed approach consists of a deep neural pipeline for corneal region segmentation followed by a ResNeXt model to differentiate between FK and non-FK classes. The model trained on the segmented images in the region of interest, achieved a diagnostic accuracy of 88.96%. The features learnt by the model emphasize that it can correctly identify dominant corneal lesions for detecting FK.

Small interfering RNAs (siRNAs) based gene silencing strategies for the treatment of glaucoma: Recent advancements and future perspectives.

RNA-interference-based mechanisms, especially the use of small interfering RNAs (siRNAs), have been under investigation for the treatment of several ailments and have shown promising results for ocular diseases including glaucoma. The eye, being a confined compartment, serves as a good target for the delivery of siRNAs. This review focuses on siRNA-based strategies for gene silencing to treat glaucoma. We have discussed the ocular structures and barriers to gene therapy (tear film, corneal, conjunctival, vitreous, and blood ocular barriers), methods of administration for ocular gene delivery (topical instillation, periocular, intracameral, intravitreal, subretinal, and suprachoroidal routes) and various viral and non-viral vectors in siRNA-based therapy for glaucoma. The components and mechanism of siRNA-based gene silencing have been mentioned briefly followed by the basic strategies and challenges faced during siRNA therapeutics development. We have emphasized different therapeutic targets for glaucoma which have been under research by scientists and the current siRNA-based drugs used in glaucoma treatment. We also mention briefly strategies for siRNA-based treatment after glaucoma surgery.

Rare Case of Polymicrobial Keratitis With Balantidium coli.

PURPOSE: To report a rare case of polymicrobial keratitis due to Balantidium coli and gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, in a soft contact lens (CL) wearer. METHODS: We report a case of CL-related keratitis due to B. coli, P. aeruginosa, and K. pneumoniae. RESULTS: The culture of the corneal scrapings, the CL cleaning solution, and the CL revealed the growth of a rare ciliated parasite, B. coli, along with gram-negative bacteria, namely, P. aeruginosa and K. pneumoniae. The patient was successfully treated with topical broad-spectrum antibiotics and intravenous metronidazole. CONCLUSIONS: Polymicrobial keratitis has seldom been reported with B. coli as the causative agent. CL wear can be a risk factor for this infection. Treatment with topical antibiotics may not suffice, and the intravenous route of antiprotozoal drugs may be a useful adjunct. Increasing awareness, early diagnosis, and treatment may improve the final visual outcome.

Sclerosing lipogranuloma of the eyelid: unusual complication following nasal packing in endoscopic sinus surgery.

An eyelid or orbital lipogranuloma can occur following nasal packing with liquid paraffin, petroleum jelly or an antibiotic-based cream. It usually presents a few weeks or months after the initial procedure. We present a report of three such cases of sclerosing lipogranuloma involving the eyelid, which occurred following a sinonasal surgery where nasal packing using petroleum jelly was performed. The typical clinical course and the classical histopathological features are highlighted. All cases were diagnosed by histopathological examination as sclerosing lipogranuloma. Complete surgical removal resulted in complete resolution on 1 month follow-up. The diagnosis is based on a high degree of suspicion following a detailed history of prior use of lipid-based products for nasal packing following endonasal surgery. Histopathology is diagnostic. Surgical excision is the treatment of choice, however, due to its infiltrative nature, it may be difficult to obtain a complete cure.

Juvenile aggressive cemento-ossifying fibroma of the sphenoid sinus with proptosis: a surgical dilemma.

The term fibro-osseous lesion has currently grown in popularity as an overall designation for a number of rare, histologically benign head and neck lesions that are made up of bone, fibrous tissue and cementum. Cemento-ossifying fibroma is a variant of cementifying fibroma and is a fibro-osseous disease. They are usually small innocuous lesions which follow a slow benign course and are commonly seen in the skull bone rather than the sphenoid. It is rare for these tumours to attain large size, behave aggressively, destroy bone and require a radical surgery. One such rapidly growing juvenile cemento-ossifying lesion of sphenoid in our 10-year-old young patient causing proptosis and impaired vision is reported here because of its uncommon nature and its surgical dilemma. Selection of surgical approach to resect this tumour becomes difficult because it is deeply seated and needs a multidisciplinary approach.

Acute post-traumatic endophthalmitis secondary to Propionibacterium acnes.

Propionibacterium acnes has rarely been reported as the causative organism in acute endophthalmitis following penetrating ocular trauma. We report a 53-year-old man, who presented with best corrected vision of counting fingers at 2 m,

A comparison of microdebrider assisted endoscopic sinus surgery and conventional endoscopic sinus surgery for nasal polypi.

Nasal polyposis is often encountered in rhinology practice. Those who fail conservative management, a definitive surgery is essential to achieve sufficient ventilation and drainage of the affected sinuses by using either microdebrider or conventional instruments for functional endoscopic sinus surgery (FESS). A prospective study was conducted on 40 cases of nasal polypi in a tertiary care hospital. 20 cases were operated by conventional endoscopic instruments and 20 using the microdebrider. The study aimed at comparing the intra operative (blood loss, duration of surgery) and post operative results (crusting, scarring, discharge, symptoms, recurrence) between the two groups using Lund-Mackay scoring system and the data was statistically analysed. There was no statistically significant difference in surgical outcome for patients when either conventional endoscopic instruments or microdebrider was used. However, there was a significant symptomatic improvement in cases undergoing microdebrider FESS. Microdebrider assisted polypectomy is precise, relatively bloodless surgery though the precision depends on the surgeon's anatomical knowledge and operative skills. Study substantiates that these instruments are helpful but not a prerequisite for successful outcomes in FESS. The study re-emphasises the utility of the microdebrider to young learning FESS surgeons.

Analysis of prenatal and postnatal risk factors of retinopathy of prematurity in a tertiary care hospital in South India.

CONTEXT: Recent advances in neonatology have influenced the incidence and severity of ROP in a dichotomous fashion. AIMS: To determine the incidence of ROP and to analyse its risk factors. SETTINGS AND DESIGN: Prospective clinical case series. MATERIALS AND METHODS: 282 preterm infants with birthweight < 1500 g and/or gestational age ≤ 32 weeks and also those with gestational age > 32 weeks, with birthweight between 1500-2000 g, who were at risk for ROP were selected. Weight gain proportion was measured as weight at 6 weeks minus birthweight divided by birthweight. STATISTICAL ANALYSIS: Univariate and multivariate logistic regression. RESULTS: Incidence of any ROP was 21.6% while severe ROP was 6.7%. Prenatal factors like multiple gestation (P = 0.510) and antenatal steroids (P = 0.104) were not significantly associated with ROP. On multivariate analysis, postnatal factors like weight at birth < 1250 g (P = 0.01) and gestational age between 31-32 weeks (P = 0.02) were independent risk factors for any ROP, while intraventricular hemorrhage (P = 0.03) was the only independent risk factor for severe ROP. Mean birthweight of infants with severe ROP was 1056 µ 207 g (P = 0.004), which was significantly low. After logistic regression, the mean weight gain proportion at 6 weeks, of those neonates with severe ROP was 30%. CONCLUSIONS: Low birthweight and prematurity were the most important risk factors for developing any ROP, while intraventricular hemorrhage was the independent risk factor for developing severe ROP. The mean postnatal weight gain at 6 weeks was not statistically significant in neonates with severe ROP.

Endoscopic repair of cerebrospinal fluid rhinorrhea - Manipal experience.

Otolaryngologists play a major role in the management of cerebrospinal fluid (CSF) rhinorrhea. A thorough understanding of the underlying pathophysiology and the various treatment options available is essential to achieve the best possible results.In this paper, we are highlighting the pathophysiology, diagnosis and surgical technique involved in the repair of cerebrospinal fluid rhinorrhea. A retrospective study conducted in the department of ENT and Head and Neck Surgery, Kasturba Hospital, Manipal is presented to highlight our experience with cerebrospinal fluid rhinorrhea.Eleven patients were managed in the department of otolaryngology between 1999 and 2005. Seven had spontaneous CSF rhinorrhea, three were due to trauma and one iatrogenic, following surgery. Commonest anatomic site of leak was the cribriform plate in 4 cases. Other sites included sphenoid [2], lateral lamella [2], fovea ethmoidalis [2] and olfactory groove [1]. Onlay technique was performed in 10 out of 11 patients. Closure was successful in 10 out of 11 cases in the first attempt. One patient underwent revision surgery. Patients were followed up for a period ranging from 3 months to 3 years.CSF rhinorrhea is a potentially fatal condition which requires precise and urgent treatment. The transnasal endoscopic repair of CSF leak has a high success rate with low morbidity when performed by experienced endoscopic sinus surgeons. Our experience in managing this condition is presented.