Narayana Nethralaya Eye Hospital

Bangalore, India

Narayana Nethralaya Eye Hospital

Bangalore, India
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Ponnalagu M.,Stem Cell Research Laboratory | Subramani M.,Stem Cell Research Laboratory | Jayadev C.,Narayana Nethralaya Eye Hospital | Shetty R.,Narayana Nethralaya Eye Hospital | Das D.,Stem Cell Research Laboratory
Cytokine | Year: 2017

Diabetic retinopathy is a major complication of diabetes mellitus that can lead to retinal vascular abnormalities and visual impairment. While retinal endothelial pathology is well studied, retinal pigment epithelium (RPE) layer modifications and the patho-physiological regulations are not widely understood. The RPE is a highly specialized pigmented layer regulating not only physiological functions such as transport of nutrients, ions, absorption of light, phagocytosis of photoreceptor membranes, but also secretion of a number of cytokines, chemokines, angiogenic and anti-angiogenic factors. The RPE secretome, though crucial in health and disease, remains elusive in diabetic retinopathy. A knowledge of these secreted factors would help explain and correlate the clinical phase of the disease aiding in improved disease management. A comprehensive knowledge of the secreted factors of the RPE is a potential tool for understanding the differential treatment regime of early diabetic retinopathy, diabetic proliferative retinopathy and diabetic macular edema. In this review, we have delineated the importance of factors secreted by the retinal pigment epithelium and its regulation in the pathogenesis of diabetic retinopathy. © 2017 Elsevier Ltd

Shetty R.,Narayana Nethralaya Eye Hospital | Pahuja N.K.,Narayana Nethralaya Eye Hospital | Nuijts R.M.M.A.,Maastricht University | Ajani A.,Narayana Nethralaya Eye Hospital | And 3 more authors.
American Journal of Ophthalmology | Year: 2015

Purpose To study the effect of different protocols of collagen cross-linking on visual, refractive, and tomographic parameters in patients with progressive keratoconus. Design Prospective randomized interventional study. Methods In this study, 138 eyes of 138 patients with progressive keratoconus underwent corneal collagen cross-linking (CXL). Following detailed preoperative examination, Group I underwent conventional cross-linking (36 patients, 3 mW/cm2 for 30 min); Group II (36 patients, 9 mW/cm2 for 10 min), Group III (33 patients, 18 mW/cm2 for 5 min), and Group IV (33 patients, 30 mW/cm2 for 3 min) underwent accelerated cross-linking. Changes in corrected distance visual acuity (CDVA), spherical equivalent (SE), flat keratometry, steep keratometry, thinnest pachymetry, specular microscopy, and demarcation line were studied at 6 and 12 months. Results Improvement in the mean CDVA and SE were statistically significant in all groups except Group IV (P =.15 at 6 months, P =.17 at 12 months), with Group III (P =.01 at 6 and 12 months) showing the best results. Flattening of steep and flat keratometry was significant in Groups I (P =.01) and II (P =.01) as compared to the other groups. There was no significant difference in the pachymetry or specular microscopy in any of the groups. Groups I and II demonstrated a good demarcation line when compared to other groups. Conclusion Conventional CXL (Group I) and accelerated CXL with irradiations of 9 mW/cm2 (Group II) and 18 mW/cm2 (Group III) showed better visual, refractive, and tomographic improvements at the end of 12 months. © 2015 Elsevier Inc. All rights reserved.

PubMed | Narayana Nethralaya, b Retina Physiology Laboratory and Narayana Nethralaya Eye Hospital
Type: | Journal: Ocular immunology and inflammation | Year: 2016

To study the sheathing of retinal vasculitis in various systemic autoimmune diseases using adaptive optics imaging (AOI).Prospective, observational case series with six patients: Behet disease (n = 1); systemic lupus erythematosus (n = 1); idiopathic retinal vasculitis (n = 2); granulomatosis with polyangiitis (n = 1); and Takayasu aorta arteritis (n = 1). Fundus photograph (FP), fundus fluorescein angiography (FFA) were done in all cases at presentation. Using the Image J software, perivascular sheathing and wall-to-wall diameter of the vessel involved were measured on AOI at time of presentation and on follow-up.AOI was able to pick the pipe-stem sheathing in SLE and IRV(I) and parallel sheathing in rest, which correlated with FP and FFA. Moreover, the decrease and a complete resolution in the sheathing were also noted by AOI on follow-up.AOI can be used as an additional investigative tool for diagnosis and to monitor the disease course during the treatment.

Hallahan K.M.,Cleveland Clinic | Rocha K.,Cleveland Clinic | Rocha K.,Medical University of South Carolina | Roy A.S.,Cleveland Clinic | And 5 more authors.
Eye and Contact Lens | Year: 2014

Purpose: To assess changes in Ocular Response Analyzer (ORA) waveforms after UVA/riboflavin corneal collagen cross-linking (CXL) using investigatorderived and manufacturer-supplied morphometric variables in patients withkeratoconus (KC) and postrefractive surgery ectasia. Design: Prospective randomized trial of a standard epithelium-off CXL protocol. Participants: Patients with progressive KC (24 eyes of 21 patients) or postrefractive surgery ectasia (27 eyes of 23 patients) were enrolled. Methods: Replicate ORA measurements were obtained before and 3 months after CXL. Pretreatment and posttreatment waveform variables were analyzed for differences by paired Student t tests using measurements with the highest waveform scores. Main Outcome Measures: Corneal hysteresis, corneal resistance factor, 37-s generation manufacturer-supplied ORA variables, and 15 investigatorderived ORA variables. Results: No variables were significantly different 3 months after CXL in the KC group, and no manufacturer-supplied variables changed significantly in the postrefractive surgery ectasia group. Four custom variables (ApplanationOnset- Time, P1P2avg, Impulse, and Pmax) increased by small but statistically significant margins after CXL in the postrefractive surgery ectasia group. Conclusions: Changes in a small subset of investigator-derived variables suggested an increase in corneal bending resistance after CXL. However, the magnitudes of these changes were low and not commensurate with the degree of clinical improvement or prior computational estimates of corneal stiffening in the same cohort over the same period. Available air-puff-derived measures of the corneal deformation response underestimate the biomechanical changes produced by CXL. Copyright © 2014 Contact Lens Association of Opthalmologists, Inc.

Jeyabalan N.,Narayana Nethralaya Eye Hospital | Shetty R.,Narayana Nethralaya Eye Hospital and 121 C Chord Road | Ghosh A.,Narayana Nethralaya Eye Hospital | Anandula V.R.,Narayana Nethralaya Eye Hospital | And 2 more authors.
Indian Journal of Ophthalmology | Year: 2013

Keratoconus (KC; Mendelian Inheritance in Man (OMIM) 14830) is a bilateral, progressive corneal defect affecting all ethnic groups around the world. It is the leading cause of corneal transplantation. The age of onset is at puberty, and the disorder is progressive until the 3 rd -4 th decade of life when it usually arrests. It is one of the major ocular problems with significant social and economic impacts as the disease affects young generation. Although genetic and environmental factors are associated with KC, but the precise etiology is still elusive. Results from complex segregation analysis suggests that genetic abnormalities may play an essential role in the susceptibility to KC. Due to genetic heterogeneity, a recent study revealed 17 different genomic loci identified in KC families by linkage mapping in various populations. The focus of this review is to provide a concise update on the current knowledge of the genetic basis of KC and genomic approaches to understand the disease pathogenesis.

To intraoperatively determine and compare the characteristics and predictability of LASIK flaps made by the WaveLight FS200 femtosecond laser (Alcon Laboratories Inc) and Hansatome (Bausch & Lomb) microkeratome using a hand-held spectral domain ophthalmic imaging system (Bioptigen Inc). Sixty eyes from 30 patients undergoing bilateral LASIK were prospectively evaluated. Patients were divided into two equal groups to undergo flap creation with either 100-microm femtosecond laser flaps (FS flap group) or 120-microm microkeratome flaps (MK flap group). Flap thickness was measured intraoperatively after creation of the flap but prior to lifting using the hand-held probe of the spectral domain imaging system. Geometry of the flap edge and smoothness of the stromal bed after lifting the flap was also evaluated in all cases. Mean difference between planned and achieved flap thickness in the paracentral region was 2.84 +/- 3.16 mm for the FS flap group and 11.33 +/- 10.27 mm for the MK flap group, whereas in the periphery, it was 5.72 +/- 3.26 mm in the FS flap group and 24.67 +/- 10.35 mm in the MK flap group. The differences between groups were statistically significant (P < 0.001, Kruskal-Wallis test). The edges of the flaps were vertical in the FS flap group and the stromal bed was smoother, whereas in the MK flap group, the edges were more sloping and the stromal bed more irregular. The WaveLight FS200 femtosecond laser is able to produce planar flaps with a high degree of predictability between the desired and achieved flap thickness. The ability to study the flap characteristics intraoperatively (when flap edema and stromal bed hydration changes have not yet occurred) with the hand-held probe of the Bioptigen imaging system ensures greater accuracy than measurements done postoperatively using other anterior segment optical coherence tomography prototypes.

Malhotra C.,Narayana Nethralaya Eye Hospital | Shetty R.,Narayana Nethralaya Eye Hospital | Kumar R.S.,Narayana Nethralaya Eye Hospital | Veluri H.,Narayana Nethralaya Eye Hospital | And 2 more authors.
Journal of Refractive Surgery | Year: 2012

PURPOSE: To compare the effect of complete versus grid-like epithelial removal on riboflavin penetration during collagen cross-linking (CXL) in vivo using hand-held spectral domain optical coherence tomography (OCT, Bioptigen Inc). METHODS: In this prospective, observational, comparative case series, patients with progressive keratoconus undergoing CXL with riboflavin and ultraviolet A (UVA) light were enrolled. Twenty eyes (20 patients) undergoing CXL using 0.1% riboflavin and UVA light (365 nm) were imaged intraoperatively at 30 and 60 minutes after starting the procedure, using hand-held spectral domain OCT. In 10 eyes, the epithelium was removed completely in the central 7-mm zone (complete removal group) whereas in the remaining 10 eyes, the epithelium was removed in a grid pattern, leaving behind intact islands of epithelium (grid-like removal group). The depth of hyperreflective band (representing penetration of riboflavin) in the anterior corneal stroma was measured. RESULTS: In the complete removal group, the hyperreflective band was homogenous, extending to a mean depth of 54.2±5.2 μm and 72.4±7.1 μm at 30 and 60 minutes, respectively (P<.001). In the grid-like removal group, the mean depth of the hyperreflective band was uneven, being significantly more in the "epithelium off" areas (56.90±4.66 μm and 74.2±6.7 μm at 30 and 60 minutes, respectively) (P<.001) compared to the "epithelium on" areas (18.9±2.3 μm and 24.7±2.3 μm at 30 and 60 minutes, respectively) (P<.001). CONCLUSIONS: Epithelial removal appears to be an essential step prior to performing CXL, as an intact epithelium appears to block penetration of riboflavin in the anterior corneal stroma. Copyright © SLACK Incorporated.

Shetty R.,Narayana Nethralaya Eye Hospital | Nagaraja H.,Narayana Nethralaya Eye Hospital | Jayadev C.,Narayana Nethralaya Eye Hospital | Shivanna Y.,Narayana Nethralaya Eye Hospital | Kugar T.,Narayana Nethralaya Eye Hospital
British Journal of Ophthalmology | Year: 2014

Aim: To evaluate the efficacy and safety of corneal collagen crosslinking (CXL) in the management of culture proven microbial keratitis. Methods: 15 eyes of 15 patients of microbial keratitis were included in the study. Nine patients had bacterial keratitis and six had fungal keratitis. All patients underwent microbiological evaluation to identify the causative organism. The depth of the infiltrate was determined clinically with slit lamp and measured manually using anterior segment optical coherence tomography. Patients were treated with antibiotics/ antifungals and those who did not respond to at least 2 weeks of topical medications underwent CXL as per the standard protocol. The same preoperative topical medications were continued post-CXL. All patients were followed up every third day and observed for signs of resolution of microbial keratitis. Results: Six of nine patients with bacterial keratitis and three of six patients with fungal keratitis resolved following CXL treatment. Patients with deep stromal keratitis or endothelial plaque failed to resolve. All patients had resolution of pain on the first postoperative day. There was an appearance of or increase in hypopyon in seven patients. No intraoperative or postoperative complications were noticed. Conclusions: CXL appears to be an effective procedure in the management of superficial microbial keratitis. It can be used as an adjunctive treatment in the management of non-resolving microbial keratitis.

PubMed | Narayana Nethralaya Eye Hospital
Type: | Journal: BioMed research international | Year: 2016

Purpose. To evaluate the outcomes of a management strategy in patients with irregular corneas and cataract. Methods. Six eyes of four patients presented for cataract surgery with irregular corneas following corneal refractive surgery. Topoguided ablation regularised the cornea, followed by phacoemulsification and intraocular lens implantation. Zonal keratometric coefficient of variation (ZKCV) measured structural changes and visual quality metrics measured functional improvement. Results. The mean duration after corneal refractive surgery was 7.83 2.40 years. The logmar uncorrected distance visual acuity (0.67 0.25) and the corrected distance visual acuity (0.38 0.20) improved to 0.34 0.14 and 0.18 0.10, respectively. The changes in the standard deviations of the zonal keratometry values and the ZKCV were statistically significant in the 2, 3, and 4mm zones. The changes in the Strehl ratio (ANOVA p = 0.043) were also statistically significant. Conclusions. Corneal regularisation followed by phacoemulsification resulted in lower residual refractive error with improved visual quality metrics. This strategy is a viable option in patients with symptomatic cataracts and irregular corneas.

PubMed | Narayana Nethralaya Eye Hospital
Type: | Journal: Retinal cases & brief reports | Year: 2017

To evaluate the efficacy of intravitreal gas (perfluoropropane, C3F8)-assisted displacement of submacular hemorrhage (SMH) secondary to recent or old blunt trauma.An interventional case series of three patients who presented with SMH after blunt trauma, ranging from 2 days to 2 weeks back. All three patients were treated with an intravitreal injection of 0.3 cc of 100% C3F8 with anterior chamber paracentesis. Strict prone position was advised for 2 weeks with a minimum of 6 to 8 hours per day. Documentation was done with serial recording of corrected distance visual acuity, fundus photographs, and spectral domain optical coherence tomography both before and after intervention.The follow-up period ranged from 2 weeks to 3 months. All patients showed a significant displacement of SMH with recovery of the normal foveal contour; foveal thinning was noted in 2 cases. Best spectacle-corrected visual acuity improved from counting finger at 1 m to 20/30 in Case 1 and counting finger 3 m to 20/40 in Case 2. In Case 3, the visual acuity remained unchanged from the preoperative 20/60 which could be attributed to the presence of a choroidal rupture in the foveal area that became evident after the displacement of SMH.Pneumatic displacement is an effective technique in the management of SMH due to recent or old blunt trauma.

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