Mahesh Shanmugam - Academia.edu (original) (raw)
Papers by Mahesh Shanmugam
Surgical Ophthalmic Oncology, 2019
Radiation therapy is an indispensable tool used by eye cancer specialists around the world [1, 2]... more Radiation therapy is an indispensable tool used by eye cancer specialists around the world [1, 2]. However, ophthalmic radiation therapy can be expensive and typically requires collaboration between an ophthalmic oncologist, radiation oncologist, and a medical physicist. This chapter provides an overview of a basic ophthalmic radiation therapy program as well as indications for irradiation of common ocular malignancies. Ionizing radiation has been used to destroy cancers of the eyelids, conjunctiva, iris, retina, choroid, optic nerve, and orbit [3-5]. The most common applications are brachytherapy (implanted and surface applicators), external beam radiation therapy (EBRT), and rarely interstitial orbital brachytherapy techniques. Most of these approaches have a surgical component.
Indian Journal of Ophthalmology - Case Reports
We report the management of a case of inadvertent full-thickness scleral penetration during rhegm... more We report the management of a case of inadvertent full-thickness scleral penetration during rhegmatogenous retinal detachment (RRD) surgery in a 14-year-old high myope while making partial-thickness scleral tunnel for the passage of the 240 silicone band. Sudden and gross hypotony with subretinal hemorrhage were noted post-penetration. Hypotony was immediately addressed by suturing the penetration site with a 7-0 vicryl suture. Subretinal blood was removed by performing 360° relaxing retinotomy and retinectomy and the retina was attached. This case report highlights the possible reasons for the full-thickness scleral penetration and one of the various methods to handle the same.
Indian Journal of Ophthalmology - Case Reports
Retina (Philadelphia, Pa.), 2014
We studied with interest the article by Atmaca LS et al “A long term follow up of Eales’ disease”... more We studied with interest the article by Atmaca LS et al “A long term follow up of Eales’ disease” in your journal (Ocular Immunology and Inflammation 3: 213–221, 2002). The authors do not mention the treatment of the active inflammatory stage of Eales’ disease. We studied the efficacy of systemic and/or periocular corticosteroids in the active inflammatory stage of Eales’ disease. We found that oral prednisolone (0.75 to 1mg/kg of body weight) along with the posterior subtenon injection of a long acting depot steroid of triamcinolone acetonide 0.5ml (40mg/ml) is quite effective if the vasculitis involved 3 quadrants or more, with or without the presence of cystoid macular oedema. Oral prednisolone alone is helpful when retinal vasculitis involves 2 quadrants. Posterior subtenon injection of triamcinolone acetonide alone can be given with one quadrant of retinal vasculitis. How-ever, the natural course of Eales’ disease remained unaltered in spite of corticosteroid therapy. We also found there was no difference in response to treatment in Mantoux positive and Mantoux negative patients. The article does not quote our study on the long term visual results of vitrectomy for Eales disease. We studied 64 eyes of 57 patients who underwent vitrectomy for complications due to Eales’ disease in a referral eye center in India. In contrast to the 53% of eyes that maintained or improved their visual acuity following vitrectomy in Atmaca’s series, our study observed a 69% had improvement in vision. In addition, 50 eyes (79%) either maintained or improved upon their 2 months postoperative visual acuity. We feel vitrectomy is quite gratifying in patients with Eales’ disease with vitreous haemorrhage. Ocular Immunology and Inflammation 0927-3948/04/US$ 22.00
Investigative Opthalmology & Visual Science, 2007
PURPOSE. To investigate the relationship between myopia and macular thickness, as measured by opt... more PURPOSE. To investigate the relationship between myopia and macular thickness, as measured by optical coherence tomography. METHODS. A total of 143 normal subjects comprising 80 eyes with high myopia (spherical equivalent [SE] Ͻ Ϫ6.0 D), 37 eyes with low to moderate myopia (SE between Ϫ6.0 and Ϫ0.5 D), and 26 nonmyopic eyes (SE Ͼ Ϫ0.5 D) were analyzed in this cross-sectional study. Total average, foveal, and inner and outer average macular thicknesses measured by the Stratu-sOCT (Carl Zeiss Meditec Inc., Dublin, CA) were compared among the three diagnostic groups. Associations between macular thickness and refractive error/axial length were evaluated by linear regression analysis. RESULTS. The minimum foveal and average foveal (1-mm ring on the OCT retinal thickness map) thicknesses were significantly greater, and the outer ring macular (3-6-mm) thicknesses significantly lower in the high myopic eyes than in the low to moderate myopic and nonmyopic eyes. No significant difference was found in the inner ring (1-3-mm) macular thickness measurements among the groups. There was a positive correlation between the axial length and the average foveal thickness (r ϭ 0.374, P Ͻ 0.001). Negative correlations were found between axial length and the average outer ring macular thickness (r ϭ Ϫ0.471, P Ͻ 0.001) and total average macular thickness (r ϭ Ϫ0.311, P Ͻ 0.001). CONCLUSIONS. Retinal thickness is related to refractive error/ axial length in normal subjects with regional variations in correlation within the 6-mm macular region. Analysis of macular thickness in the evaluation of macular diseases and glaucoma should be interpreted only in the context of refractive errors and the location of measurement.
Torpedo maculopathy is a rare congenital anomaly of RPE in the temporal macula with unknown etiol... more Torpedo maculopathy is a rare congenital anomaly of RPE in the temporal macula with unknown etiology. The diagnosis of this lesion is primarily clinical, often an incidental finding as it tends to spare the fovea. The lesion characteristics includes location temporal to fovea, hypopigmentation, horizonally oval shape with certain variable features like intraretinal cleft, fundus excavation, variable hyperpigmentation and associated visual field defects. Here we report a case of nasal macular location of the lesion which represents a rare clinical presentation and is supported by multimodal imaging findings.
Genetics of Ocular Diseases
Indian Journal of Ophthalmology - Case Reports
We report a rare case of a young lady of 22 years who presented with minor decrease of vision in ... more We report a rare case of a young lady of 22 years who presented with minor decrease of vision in her left eye since two weeks and on examination showed a large brown mass lesion just behind the lens. Based on the clinical features, trans illumination, ultrasonography and magnetic resonance imaging of the orbit, a potential diagnosis of ciliochoroidal melanoma was made. After proper counselling and explanation to the patient and parents keeping in consideration the size of the lesion, the eye was enucleated. Histopathological examination confirmed it to be a mesectodermal leiomyoma of the ciliary body. Such benign lesions can rarely attain large sizes with clinical features simulating tumours like melanoma, thus making management, challenging for the physician.
Indian Journal of Ophthalmology, 2020
A 34‐year‐old gentleman came to the clinic for a regular check‐up. His best‐corrected visual acui... more A 34‐year‐old gentleman came to the clinic for a regular check‐up. His best‐corrected visual acuity was 6/6, N6 in both eyes. Anterior segment examination was unremarkable. On fundus evaluation, the right eye showed a flat, darkly pigmented, circumpapillary lesion with distinct margins and lacunae, without any alteration in the vascular architecture [Fig. 1a]. The left eye fundus was within normal limits. Autofluorecence imaging of the right eye revealed a uniformly hypo‐autofluorescent well‐demarcated lesion [Fig. 1b]. SS‐OCT (Swept source optical coherence tomography) scan showed thickened irregular retinal pigment epithelium (RPE) along with loss of outer retinal layers and a large sub‐retinal cleft [Fig. 1c]. OCT‐angiography at the level of the choroidal vessels showed vascular attenuation over the lesion along with signal void areas [Fig. 2].
American Journal of Ophthalmology, 2003
To report a patient with CHARGE association (coloboma, heart disease, choanal atresia, growth ret... more To report a patient with CHARGE association (coloboma, heart disease, choanal atresia, growth retardation, genital hypoplasia, and ear abnormalities) who developed a choroidal neovascular membrane in association with an optic nerve coloboma. Interventional/observational case report. A 21-month-old boy with CHARGE association developed a grayish choroidal neovascular membrane associated with lipid exudation, subretinal fluid, and retinal hemorrhage at the temporal edge of his right optic nerve coloboma. The patient underwent transpupillary diode laser of the choroidal neovascular membrane. Five months later, it and the serous retinal detachment had resolved. Patients with CHARGE association may develop choroidal neovascular membrane with serous retinal detachments in association with optic nerve colobomas. These neovascular membranes may be treated successfully with transpupillary diode laser.
Retina-the Journal of Retinal and Vitreous Diseases, 2003
Diagnosis of intraocular tuberculosis is often difficult. A choroidal granulomalike lesion suspec... more Diagnosis of intraocular tuberculosis is often difficult. A choroidal granulomalike lesion suspected to be the result of tuberculosis could be of other inflammatory, infective, or neoplastic causes. We report two cases in which a choroidal granuloma with exudative retinal detachment was diagnosed as tuberculosis by the detection of acid-fast bacilli in subretinal fluid. Interventional case series. Two female patients had choroidal granulomas with surrounding exudative retinal detachment. Detailed laboratory investigations were unhelpful in diagnosis, and the patients' conditions worsened with systemic steroid therapy. Subretinal fluid was tapped and revealed acid-fast bacilli and grew Mycobacterium tuberculosis on culture. Subretinal fluid analysis can help in the detection of tuberculous granuloma and facilitate successful management.
Indian Journal of Ophthalmology - Case Reports
Indian Journal of Ophthalmology
Oman Journal of Ophthalmology
Background: The supply of Cilioretinal artery (CRA) to different layers of the retina influences ... more Background: The supply of Cilioretinal artery (CRA) to different layers of the retina influences retinal pathologies such as diabetic retinopathy (DR). Since the supply of CRA is segmental, our aim was to analyze the location of CRA with respect to noncenter involving diabetic macular edema (DME) differentiated by various segments and center involving DME based on Early Treatment of Diabetic Retinopathy Study (ETDRS) scale using optical coherence tomography (OCT). Methods: A retrospective study was conducted in which forty-three patients with various stages of DR and the presence of CRA were identified. Presence and location of CRA was recognized using fundus fluorescein angiography. Classification of DME was based on ETDRS subfields on OCT. Results: Evaluation of 26 men and 17 women with varying degrees of severity involving DR revealed the presence of unilateral CRA in 40 subjects and bilateral CRA in 3 subjects. When CRA supplied the central area, maximum retinal thickness was noted at the temporal quadrant (271.67 ± 164.02 μm) along with non-center involving DME (194.87 ± 121.06 μm); when CRA supplied the lower area, maximum retinal thickness was noted at the superior quadrant (293.64 ± 159.36 μm) along with center involving DME (395 ± 285.75 μm) and when it supplied the upper area, maximum retinal thickness was noted at the nasal quadrant (293.49 ± 176.18 μm) along with center involving DME (292 ± 192.79 μm). Conclusion: The presence of CRA seems to influence the morphology of the retina amongst patients diagnosed with DR by altering the segments involved in DME based on its supply location. However, further studies with a larger sample size are warranted to strenghten this association.
Indian Journal of Ophthalmology
Ophthalmic Surgery, Lasers and Imaging Retina
Surgical Ophthalmic Oncology, 2019
Radiation therapy is an indispensable tool used by eye cancer specialists around the world [1, 2]... more Radiation therapy is an indispensable tool used by eye cancer specialists around the world [1, 2]. However, ophthalmic radiation therapy can be expensive and typically requires collaboration between an ophthalmic oncologist, radiation oncologist, and a medical physicist. This chapter provides an overview of a basic ophthalmic radiation therapy program as well as indications for irradiation of common ocular malignancies. Ionizing radiation has been used to destroy cancers of the eyelids, conjunctiva, iris, retina, choroid, optic nerve, and orbit [3-5]. The most common applications are brachytherapy (implanted and surface applicators), external beam radiation therapy (EBRT), and rarely interstitial orbital brachytherapy techniques. Most of these approaches have a surgical component.
Indian Journal of Ophthalmology - Case Reports
We report the management of a case of inadvertent full-thickness scleral penetration during rhegm... more We report the management of a case of inadvertent full-thickness scleral penetration during rhegmatogenous retinal detachment (RRD) surgery in a 14-year-old high myope while making partial-thickness scleral tunnel for the passage of the 240 silicone band. Sudden and gross hypotony with subretinal hemorrhage were noted post-penetration. Hypotony was immediately addressed by suturing the penetration site with a 7-0 vicryl suture. Subretinal blood was removed by performing 360° relaxing retinotomy and retinectomy and the retina was attached. This case report highlights the possible reasons for the full-thickness scleral penetration and one of the various methods to handle the same.
Indian Journal of Ophthalmology - Case Reports
Retina (Philadelphia, Pa.), 2014
We studied with interest the article by Atmaca LS et al “A long term follow up of Eales’ disease”... more We studied with interest the article by Atmaca LS et al “A long term follow up of Eales’ disease” in your journal (Ocular Immunology and Inflammation 3: 213–221, 2002). The authors do not mention the treatment of the active inflammatory stage of Eales’ disease. We studied the efficacy of systemic and/or periocular corticosteroids in the active inflammatory stage of Eales’ disease. We found that oral prednisolone (0.75 to 1mg/kg of body weight) along with the posterior subtenon injection of a long acting depot steroid of triamcinolone acetonide 0.5ml (40mg/ml) is quite effective if the vasculitis involved 3 quadrants or more, with or without the presence of cystoid macular oedema. Oral prednisolone alone is helpful when retinal vasculitis involves 2 quadrants. Posterior subtenon injection of triamcinolone acetonide alone can be given with one quadrant of retinal vasculitis. How-ever, the natural course of Eales’ disease remained unaltered in spite of corticosteroid therapy. We also found there was no difference in response to treatment in Mantoux positive and Mantoux negative patients. The article does not quote our study on the long term visual results of vitrectomy for Eales disease. We studied 64 eyes of 57 patients who underwent vitrectomy for complications due to Eales’ disease in a referral eye center in India. In contrast to the 53% of eyes that maintained or improved their visual acuity following vitrectomy in Atmaca’s series, our study observed a 69% had improvement in vision. In addition, 50 eyes (79%) either maintained or improved upon their 2 months postoperative visual acuity. We feel vitrectomy is quite gratifying in patients with Eales’ disease with vitreous haemorrhage. Ocular Immunology and Inflammation 0927-3948/04/US$ 22.00
Investigative Opthalmology & Visual Science, 2007
PURPOSE. To investigate the relationship between myopia and macular thickness, as measured by opt... more PURPOSE. To investigate the relationship between myopia and macular thickness, as measured by optical coherence tomography. METHODS. A total of 143 normal subjects comprising 80 eyes with high myopia (spherical equivalent [SE] Ͻ Ϫ6.0 D), 37 eyes with low to moderate myopia (SE between Ϫ6.0 and Ϫ0.5 D), and 26 nonmyopic eyes (SE Ͼ Ϫ0.5 D) were analyzed in this cross-sectional study. Total average, foveal, and inner and outer average macular thicknesses measured by the Stratu-sOCT (Carl Zeiss Meditec Inc., Dublin, CA) were compared among the three diagnostic groups. Associations between macular thickness and refractive error/axial length were evaluated by linear regression analysis. RESULTS. The minimum foveal and average foveal (1-mm ring on the OCT retinal thickness map) thicknesses were significantly greater, and the outer ring macular (3-6-mm) thicknesses significantly lower in the high myopic eyes than in the low to moderate myopic and nonmyopic eyes. No significant difference was found in the inner ring (1-3-mm) macular thickness measurements among the groups. There was a positive correlation between the axial length and the average foveal thickness (r ϭ 0.374, P Ͻ 0.001). Negative correlations were found between axial length and the average outer ring macular thickness (r ϭ Ϫ0.471, P Ͻ 0.001) and total average macular thickness (r ϭ Ϫ0.311, P Ͻ 0.001). CONCLUSIONS. Retinal thickness is related to refractive error/ axial length in normal subjects with regional variations in correlation within the 6-mm macular region. Analysis of macular thickness in the evaluation of macular diseases and glaucoma should be interpreted only in the context of refractive errors and the location of measurement.
Torpedo maculopathy is a rare congenital anomaly of RPE in the temporal macula with unknown etiol... more Torpedo maculopathy is a rare congenital anomaly of RPE in the temporal macula with unknown etiology. The diagnosis of this lesion is primarily clinical, often an incidental finding as it tends to spare the fovea. The lesion characteristics includes location temporal to fovea, hypopigmentation, horizonally oval shape with certain variable features like intraretinal cleft, fundus excavation, variable hyperpigmentation and associated visual field defects. Here we report a case of nasal macular location of the lesion which represents a rare clinical presentation and is supported by multimodal imaging findings.
Genetics of Ocular Diseases
Indian Journal of Ophthalmology - Case Reports
We report a rare case of a young lady of 22 years who presented with minor decrease of vision in ... more We report a rare case of a young lady of 22 years who presented with minor decrease of vision in her left eye since two weeks and on examination showed a large brown mass lesion just behind the lens. Based on the clinical features, trans illumination, ultrasonography and magnetic resonance imaging of the orbit, a potential diagnosis of ciliochoroidal melanoma was made. After proper counselling and explanation to the patient and parents keeping in consideration the size of the lesion, the eye was enucleated. Histopathological examination confirmed it to be a mesectodermal leiomyoma of the ciliary body. Such benign lesions can rarely attain large sizes with clinical features simulating tumours like melanoma, thus making management, challenging for the physician.
Indian Journal of Ophthalmology, 2020
A 34‐year‐old gentleman came to the clinic for a regular check‐up. His best‐corrected visual acui... more A 34‐year‐old gentleman came to the clinic for a regular check‐up. His best‐corrected visual acuity was 6/6, N6 in both eyes. Anterior segment examination was unremarkable. On fundus evaluation, the right eye showed a flat, darkly pigmented, circumpapillary lesion with distinct margins and lacunae, without any alteration in the vascular architecture [Fig. 1a]. The left eye fundus was within normal limits. Autofluorecence imaging of the right eye revealed a uniformly hypo‐autofluorescent well‐demarcated lesion [Fig. 1b]. SS‐OCT (Swept source optical coherence tomography) scan showed thickened irregular retinal pigment epithelium (RPE) along with loss of outer retinal layers and a large sub‐retinal cleft [Fig. 1c]. OCT‐angiography at the level of the choroidal vessels showed vascular attenuation over the lesion along with signal void areas [Fig. 2].
American Journal of Ophthalmology, 2003
To report a patient with CHARGE association (coloboma, heart disease, choanal atresia, growth ret... more To report a patient with CHARGE association (coloboma, heart disease, choanal atresia, growth retardation, genital hypoplasia, and ear abnormalities) who developed a choroidal neovascular membrane in association with an optic nerve coloboma. Interventional/observational case report. A 21-month-old boy with CHARGE association developed a grayish choroidal neovascular membrane associated with lipid exudation, subretinal fluid, and retinal hemorrhage at the temporal edge of his right optic nerve coloboma. The patient underwent transpupillary diode laser of the choroidal neovascular membrane. Five months later, it and the serous retinal detachment had resolved. Patients with CHARGE association may develop choroidal neovascular membrane with serous retinal detachments in association with optic nerve colobomas. These neovascular membranes may be treated successfully with transpupillary diode laser.
Retina-the Journal of Retinal and Vitreous Diseases, 2003
Diagnosis of intraocular tuberculosis is often difficult. A choroidal granulomalike lesion suspec... more Diagnosis of intraocular tuberculosis is often difficult. A choroidal granulomalike lesion suspected to be the result of tuberculosis could be of other inflammatory, infective, or neoplastic causes. We report two cases in which a choroidal granuloma with exudative retinal detachment was diagnosed as tuberculosis by the detection of acid-fast bacilli in subretinal fluid. Interventional case series. Two female patients had choroidal granulomas with surrounding exudative retinal detachment. Detailed laboratory investigations were unhelpful in diagnosis, and the patients' conditions worsened with systemic steroid therapy. Subretinal fluid was tapped and revealed acid-fast bacilli and grew Mycobacterium tuberculosis on culture. Subretinal fluid analysis can help in the detection of tuberculous granuloma and facilitate successful management.
Indian Journal of Ophthalmology - Case Reports
Indian Journal of Ophthalmology
Oman Journal of Ophthalmology
Background: The supply of Cilioretinal artery (CRA) to different layers of the retina influences ... more Background: The supply of Cilioretinal artery (CRA) to different layers of the retina influences retinal pathologies such as diabetic retinopathy (DR). Since the supply of CRA is segmental, our aim was to analyze the location of CRA with respect to noncenter involving diabetic macular edema (DME) differentiated by various segments and center involving DME based on Early Treatment of Diabetic Retinopathy Study (ETDRS) scale using optical coherence tomography (OCT). Methods: A retrospective study was conducted in which forty-three patients with various stages of DR and the presence of CRA were identified. Presence and location of CRA was recognized using fundus fluorescein angiography. Classification of DME was based on ETDRS subfields on OCT. Results: Evaluation of 26 men and 17 women with varying degrees of severity involving DR revealed the presence of unilateral CRA in 40 subjects and bilateral CRA in 3 subjects. When CRA supplied the central area, maximum retinal thickness was noted at the temporal quadrant (271.67 ± 164.02 μm) along with non-center involving DME (194.87 ± 121.06 μm); when CRA supplied the lower area, maximum retinal thickness was noted at the superior quadrant (293.64 ± 159.36 μm) along with center involving DME (395 ± 285.75 μm) and when it supplied the upper area, maximum retinal thickness was noted at the nasal quadrant (293.49 ± 176.18 μm) along with center involving DME (292 ± 192.79 μm). Conclusion: The presence of CRA seems to influence the morphology of the retina amongst patients diagnosed with DR by altering the segments involved in DME based on its supply location. However, further studies with a larger sample size are warranted to strenghten this association.
Indian Journal of Ophthalmology
Ophthalmic Surgery, Lasers and Imaging Retina