Predictive value of retinal nerve fibre layer thickness for postoperative visual improvement in patients with pituitary macroadenoma.

OBJECTIVE: To determine the usefulness of retinal nerve fibre layer (RNFL) thickness and a reliable cut-off value that can predict postoperative visual function improvement in patients with pituitary macroadenoma. METHODS AND ANALYSIS: This was a prospective observational study. Preoperative optical coherence tomography of the RNFL was performed in patients with pituitary macroadenoma. Postoperative visual function changes (acuity and visual fields) were identified using predefined criteria. Receiver operating characteristic curves were constructed for RNFL values to define the ideal cut-off value that predicted improvement. Other variables including preoperative visual acuity, mean deviation, visual field index and tumour volume were also analysed. RESULTS: Twenty-nine eligible subjects (58 eyes) were recruited. The mean (±SD) age was 43.9 (±12.85) years and 65.5% were male. The mean (±SE) follow-up duration was 20.8 (±6.42) months. RNFL thickness was significantly thinner in eyes with visual dysfunction and optic disc pallor. Better preoperative logarithmic minimum angle of resolution (logMAR) visual acuity, higher RNFL thickness and smaller tumour volume were associated with postoperative visual field improvement on univariate analysis; however, only mean RNFL thickness had significant association on multivariate analysis. None of the preoperative variables showed significant association with improvement in visual acuity. The best cut-off of mean RNFL thickness for visual field improvement was estimated at 81 µm with 73.1% sensitivity and 62.5% specificity. CONCLUSION: Preoperative RNFL thickness can be an objective predictor of visual field outcomes in patients undergoing surgery for pituitary macroadenomas, with moderate sensitivity and specificity. It is, however, not a good predictor of visual acuity outcome.

An experimental study to test the efficacy of Mesenchymal Stem Cells in reducing corneal scarring in an ex-vivo organ culture model.

In this study, we evaluated the effect of placenta-derived Mesenchymal Stem Cells (MSCs) versus placebo in improving corneal transparency following experimental injury in an ex-vivo organ culture model of post-mortem human corneas. We also compared the influence of MSCs on the basic histopathology of the cornea and the immunohistochemistry markers of fibrotic corneal scarring. Mesenchymal Stem Cells extracted from the placenta were isolated and expanded in-vitro. Five pairs of post-mortem human corneas harvested for the corneal transplant of equal grade were included in the study. Corneas of the same pair were randomly assigned to either the case arm or the control arm. All corneas underwent a standardized superficial keratectomy, 4 mm in diameter. The case and control arm corneas received an intrastromal injection of MSCs and placebo respectively. The corneal button was maintained in an organ culture system for 28 days under the standard protocol. Laser light was passed through the corneas mounted on a self-styled modified artificial anterior chamber. Image analysis was used to quantify corneal transparency. Haematoxylin & Eosin staining and Immunohistochemistry was done for Alpha SMA (Smooth Muscle Actin). Laser scatter measurements were measured using Image Analysis (Image J Software). The difference in the mean of Full-Width Half Maximum (FWHM), Max intensity and Red pixel intensity between the cases and the controls was 101.5, 16.3 and 11.4 respectively which was found to be statistically significant (P < 0.05). Histopathology showed a disorganized Bowman's layer in the controls as compared to the cases. Alpha Smooth Muscle Actin at the injury site stained 3 + in all controls as compared to 1 + in the cases, showing a statistically significant difference (p = 0.005). Based on our findings, we consider that placenta-derived Mesenchymal Stem Cells can alter evolving corneal scarring into a more favourable outcome with better corneal transparency and lesser fibrotic corneal scarring.

Quantification of corneal transparency in post-mortem human corneas using laser scatter image analysis.

BACKGROUND: The cornea is a highly transparent structure covering the anterior one-fifth of the eyeball. The suitability of post-mortem donor corneas for keratoplasty is currently qualitatively assessed. This makes inferences prone to bias and subjective variability. This study aimed to develop a simple, feasible and cost-effective method to quantify corneal transparency. METHODS: An artificial anterior chamber was modified to provide a central transparent passage and a standardised pressure segment. All corneas graded 'fair' were included in this study. The corneoscleral buttons were mounted on the modified artificial anterior chamber. The mounted chamber was held in a horizontal position at a fixed distance from a white projection screen. The laser source was placed in alignment with an artificial anterior chamber so that it passed through the centre of the cornea. A camera mounted on a tripod stand was placed at a prefixed distance. An image of the scattered laser spot that formed after the laser passed through the mounted cornea on the screen was captured with a single digital camera and standardised settings. Image analysis was performed using ImageJ, an open platform for scientific image analysis. The average red pixel intensity, max intensity, and full-width half max were calculated. RESULTS: The average red intensity was 132.45 ± 6.65 SD. The mean for max intensity was 51.1 ± 3.78 SD and the full-width half max 787.7 ± 84.7 SD. CONCLUSION: Laser quantification is a simple and cost-effective method of quantifying corneal transparency. The study lends proof to the principle involved.

PACK-CXL in Reducing the Time to Heal in Suppurative Corneal Ulcers: Observations of a Pilot Study From South India.

PURPOSE: To assess the usefulness of photoactivated chromophore for infectious keratitis-corneal collagen cross-linking in reducing the time to heal in suppurative corneal ulcers in a South Indian tertiary care center. METHODS: This was an observational cohort study with 2 arms. In the prospective arm, 13 patients with suppurative corneal ulcers who presented to the outpatient department were recruited. Their ulcers were exposed to ultraviolet-A with riboflavin (B2) (photoactivated chromophore for infectious keratitis-corneal collagen cross-linking) up to a maximum of 4 sittings at 3-day intervals. Topical antimicrobial therapy was continued as per the standard department protocol. This cohort was compared with a retrospective cohort of 32 consecutive patients who had been admitted and treated at our department for a similar profile of ulcers in the previous 1 year. RESULTS: The ulcers in the prospective arm had an average healing time of 21.6 days, whereas the retrospective arm had an average healing time of 48.8 days. This reduction in the time to heal trends not only toward being statistically significant (P = 0.06) but also highly clinically significant. CONCLUSIONS: CXL reduced the time to heal in suppurative corneal ulcers less than 6 mm in diameter and can be used as an adjuvant to antimicrobial therapy.

Objective quantification of corneal haziness using anterior segment optical coherence tomography.

PURPOSE: To quantify normal corneal transparency by anterior segment optical coherence tomography (AS-OCT) by measuring the average pixel intensity. To analyze the variation in the average pixel intensity in mild and severe grades of corneal opacities. METHODS: This is an observational, cross-sectional study of 38 eyes from 19 patients with mild or severe grades of corneal opacities greater than 3 mm and a normal contralateral cornea. AS-OCT was performed centered on the opacity with a 3 mm cruciate protocol. A similar image is taken of the contralateral clear cornea in the same quadrant. The average pixel intensity was calculated in a standardized manner using MATLAB software. RESULT: The average pixel intensity of the normal cornea was 99.6 ± 10.9 [standard deviation (SD)]. The average pixel intensity of the mild and severe corneal opacities was 115.5 ± 9.1 and 141.1 ± 10.3, respectively. The differences were statistically significant. CONCLUSIONS: AS-OCT images can be used to quantify corneal transparency. Average pixel intensity is a measure that varies significantly with varying corneal opacification.

Tenons Patch Graft in the Management of Large Corneal Perforations.

PURPOSE: To describe a technique to manage corneal perforations between 3 and 6 mm in size using autologous Tenons tissue with cyanoacrylate glue and a bandage contact lens. METHODS: A thin layer of Tenons capsule harvested from the patient's own eye is used to seal the perforation and act as a scaffold. The Tenons patch graft is spread over the perforation and held in place by the application of cyanoacrylate glue. A bandage contact lens is then placed on the eye. RESULTS: A 6-year retrospective review of 28 patients who underwent this procedure was performed. One patient was lost to follow-up. Of the 27 patients who were followed up, 20 healed completely, with an adherent leucoma and preservation of the anterior chamber. The condition of one patient (with a perforated Pseudomonas corneal ulcer) progressively worsened despite maximum medical therapy and had to undergo evisceration. CONCLUSIONS: This procedure makes use of easily available autologous Tenons tissue in patients with corneal perforations too large to be managed with cyanoacrylate glue alone, to preserve eyeball morphology. A corneal transplant can then be done when the cornea has healed.

Rare Presentation of Ophthalmia Nodosa.

We report a rare case of ophthalmia nodosa, presenting as a painless swelling in the lower palpebral conjunctiva for 2 years with no signs of inflammation. Excision biopsy confirmed the diagnosis.

Strabismus surgery before versus after completion of amblyopia therapy in children.

BACKGROUND: Normal visual development occurs when the brain is able to integrate the visual input from each of the two eyes to form a single three-dimensional image. The process of development of complete three-dimensional vision begins at birth and is almost complete by 24 months of age. The development of this binocular vision is hindered by any abnormality that prevents the brain from receiving a clear, similar image from each eye, due to decreased vision (e.g. amblyopia), or due to misalignment of the two eyes (strabismus or squint) in infancy and early childhood. Currently, practice patterns for management of a child with both strabismus and amblyopia are not standardized. OBJECTIVES: To study the functional and anatomic (ocular alignment) outcomes of strabismus surgery before completion of amblyopia therapy as compared with surgery after completion of amblyopia therapy in children under seven years of age. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2014), EMBASE (January 1980 to July 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to July 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 24 July 2014. A manual search for articles from a review of the references of the selected publications and conference abstracts was completed to identify any additional relevant studies. SELECTION CRITERIA: We searched for randomized controlled trials (RCTs) that provided data on strabismus surgery in children less than seven years of age, performed after initiation of, but before completion of amblyopia therapy, as compared with strabismus surgery after completion of amblyopia therapy. DATA COLLECTION AND ANALYSIS: Two authors independently assessed studies identified from the electronic and manual searches. MAIN RESULTS: There were no RCTs that fit our inclusion criteria and so no analysis was possible. AUTHORS' CONCLUSIONS: As there are no RCTs currently available and the best existing evidence is only from non-randomized studies, there is a need for prospective RCTs to investigate strabismus surgery in the presence of strabismic amblyopia. The optimal timing of when to perform strabismus surgery in children with amblyopia is unknown.

Series of five cases of Papulaspora equi keratomycosis.

PURPOSE: The aim of this study was to describe a case series of Papulaspora equi keratomycosis, with clinical and laboratory characteristics of an organism that has not been reported from scrapings of corneal ulcers from humans. METHODS: This is a retrospective chart review of 5 patients whose diagnostic corneal scrapings had grown P. equi on culture between 2008 and 2013. The clinical presentation, diagnostic tests, management, and the outcome of the ulcers are described. RESULTS: All patients showed characteristic features of fungal corneal ulcers on clinical examination. Only 2 of the 5 patients reported having a history of injury to their eyes. One patient showed surface pigmentation that could mimic a dematiaceous ulcer. All the patients responded to topical antifungal treatment with 5% natamycin or prepared 2% ketoconazole drops. CONCLUSIONS: Corneal ulcers may be caused by rare organisms, as in our series of patients who had P. equi keratomycosis, a hitherto unreported human pathogen. All the patients responded to treatment with conventional topical antifungal medications.

Optical coherence tomography in a patient with chloroquine-induced maculopathy.

We herein report the optical coherence tomography (OCT) findings in a case of chloroquine-induced macular toxicity, which to our knowledge, has so far not been reported. A 53-year-old lady on chloroquine for treatment of rheumatoid arthritis developed decrease in vision 36 months after initiation of the treatment. Clinical examination revealed evidence of retinal pigment epithelial (RPE) disturbances. Humphrey field analyzer (HFA), fundus fluorescein angiography (FFA) and OCT for retinal thickness and volume measurements at the parafoveal region were done. The HFA revealed bilateral superior paracentral scotomas, FFA demonstrated RPE loss and OCT revealed anatomical evidence of loss of ganglion cell layers, causing marked thinning of the macula and parafoveal region. Parafoveal retinal thickness and volume measurements may be early evidence of chloroquine toxicity, and OCT measurements as a part of chloroquine toxicity screening may be useful in early detection of chloroquine maculopathy.

An "epidemic" of post cataract surgery endophthalmitis by a new organism.

We report a case series of endophthalmitis by an organism hitherto not reported in the eye. Nineteen of 63 cataract patients operated in a high-volume setup were urgently referred to us with acute onset of decreased vision one to two days following cataract surgery. All patients had clinical evidence of acute endophthalmitis with severe anterior chamber exudative reaction. Vitreous tap was done in three representative patients and repeated intravitreal injections were given as per established protocol. The vitreous sample from all three patients grew Enterobacter amnigenus Biogroup II, a gram-negative bacillus which, to the best of our knowledge, has never been reported in the eye. With prompt and accurate microbiological support, it was possible to salvage 17 of these eyes without performing vitrectomy. Six eyes regained 6/200 or better vision.