Shyam Sunder Tummanapalli
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Shyam Sunder Tummanapalli has a total of 61 co-authors. Here are the top co-authors by number of shared publications:
- Arun V. Krishnan
UNSW Sydney
12 shared publications - Maria Markoulli
University of New South Wales
9 shared publications Natalie Kwai
Prince of Wales Clinical School, University of New South Wales, Australia
6 shared publications- Tushar Issar
School of Clinical Medicine, University of New South WalesSydney, Kensington, NSW 2033, Australia
6 shared publications Ann M. Poynten
Department of Endocrinology Prince of Wales Hospital Sydney NSW Australia
5 shared publications- Mark Duncan Perry Willcox
School of Optometry and Vision Science University of New South Wales Sydney New South Wales Australia
5 shared publications
Latest Publications
- Open Access
- 23 September 2023
- Published by Wiley in Headache: The Journal of Head and Face Pain
- Vol. 63 (9) , 1327-1329
Neuropathic changes in corneal nerve endings—A potential objective biomarker for migraine frequency and response to treatment
- 23 September 2023
- Published by Wiley in Headache: The Journal of Head and Face Pain
- Vol. 63 (9) , 1327-1329
Open AccessNeuropathic changes in corneal nerve endings—A potential objective biomarker for migraine frequency and response to treatment
- Open Access
- 20 December 2022
- Published by MDPI AG in Journal of Clinical Medicine
- Vol. 12 (1) , 16
Impact of Chronic Kidney Disease on Corneal Neuroimmune Features in Type 2 Diabetes
Aim: To determine the impact of chronic kidney disease on corneal nerve measures and dendritic cell counts in type 2 diabetes. Methods: In vivo corneal confocal microscopy images were used to estimate corneal nerve parameters and compared in people with type 2 diabetes with chronic kidney disease (T2DM-CKD) (n = 29) and those with type 2 diabetes without chronic kidney disease (T2DM-no CKD) (n = 29), along with 30 healthy controls. Corneal dendritic cell densities were compared between people with T2DM-CKD and those with T2DM-no CKD. The groups were matched for neuropathy status. Results: There was a significant difference in corneal nerve fiber density (p < 0.01) and corneal nerve fiber length (p = 0.04) between T2DM-CKD and T2DM-no CKD groups. The two diabetes groups had reduced corneal nerve parameters compared to healthy controls (all parameters: p < 0.01). Immature central dendritic cell density was significantly higher in the T2DM-CKD group compared to the T2DM-no CKD group ((7.0 (3.8–12.8) and 3.5 (1.4–13.4) cells/mm2, respectively, p < 0.05). Likewise, central mature dendritic cell density was significantly higher in the T2DM-CKD group compared to the T2DM-no CKD group (0.8 (0.4–2.2) and 0.4 (0.6–1.1) cells/mm2, respectively, p = 0.02). Additionally, total central dendritic cell density was increased in the T2DM-CKD group compared to T2DM-no CKD group (10.4 (4.3–16.1) and 3.9 (2.1–21.0) cells/mm2, respectively, p = 0.03). Conclusion: The study showed that central corneal dendritic cell density is increased in T2DM-CKD compared to T2DM-no CKD, with groups matched for peripheral neuropathy severity. This is accompanied by a loss of central corneal nerve fibers. The findings raise the possibility of additional local factors exacerbating central corneal nerve injury in people with diabetic chronic kidney disease.
- 20 December 2022
- Published by MDPI AG in Journal of Clinical Medicine
- Vol. 12 (1) , 16
Open AccessImpact of Chronic Kidney Disease on Corneal Neuroimmune Features in Type 2 Diabetes
Aim: To determine the impact of chronic kidney disease on corneal nerve measures and dendritic cell counts in type 2 diabetes. Methods: In vivo corneal confocal microscopy images were used to estimate corneal nerve parameters and compared in people with type 2 diabetes with chronic kidney disease (T2DM-CKD) (n = 29) and those with type 2 diabetes without chronic kidney disease (T2DM-no CKD) (n = 29), along with 30 healthy controls. Corneal dendritic cell densities were compared between people with T2DM-CKD and those with T2DM-no CKD. The groups were matched for neuropathy status. Results: There was a significant difference in corneal nerve fiber density (p < 0.01) and corneal nerve fiber length (p = 0.04) between T2DM-CKD and T2DM-no CKD groups. The two diabetes groups had reduced corneal nerve parameters compared to healthy controls (all parameters: p < 0.01). Immature central dendritic cell density was significantly higher in the T2DM-CKD group compared to the T2DM-no CKD group ((7.0 (3.8–12.8) and 3.5 (1.4–13.4) cells/mm2, respectively, p < 0.05). Likewise, central mature dendritic cell density was significantly higher in the T2DM-CKD group compared to the T2DM-no CKD group (0.8 (0.4–2.2) and 0.4 (0.6–1.1) cells/mm2, respectively, p = 0.02). Additionally, total central dendritic cell density was increased in the T2DM-CKD group compared to T2DM-no CKD group (10.4 (4.3–16.1) and 3.9 (2.1–21.0) cells/mm2, respectively, p = 0.03). Conclusion: The study showed that central corneal dendritic cell density is increased in T2DM-CKD compared to T2DM-no CKD, with groups matched for peripheral neuropathy severity. This is accompanied by a loss of central corneal nerve fibers. The findings raise the possibility of additional local factors exacerbating central corneal nerve injury in people with diabetic chronic kidney disease.
- 9 March 2022
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 106 (4) , 436-442
Longevity of hand sanitisers on fingers
Hand hygiene is important to reduce the spread of microbes in clinical settings. Hand sanitisers that last longer may be beneficial.Longevity of hand sanitisation products on fingers and hands may ...
- 9 March 2022
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 106 (4) , 436-442
Longevity of hand sanitisers on fingers
Hand hygiene is important to reduce the spread of microbes in clinical settings. Hand sanitisers that last longer may be beneficial.Longevity of hand sanitisation products on fingers and hands may ...
- 30 September 2021
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 105 (2) , 214-221
The ability of face masks to reduce transmission of microbes
Optometrists have been advised to wear face masks during the COVID-19 pandemic. This study examined whether face masks were equally protective against transmission of microbes.The aim of the curren...
- 30 September 2021
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 105 (2) , 214-221
The ability of face masks to reduce transmission of microbes
Optometrists have been advised to wear face masks during the COVID-19 pandemic. This study examined whether face masks were equally protective against transmission of microbes.The aim of the curren...
- 4 July 2021
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 105 (5) , 487-493
Automated analysis of corneal nerve tortuosity in diabetes: implications for neuropathy detection
There is potential benefit in analysing corneal nerve tortuosity as a marker for assessment and progression of systemic diabetic neuropathy.The aim of this work was to determine whether tortuosity ...
- 4 July 2021
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 105 (5) , 487-493
Automated analysis of corneal nerve tortuosity in diabetes: implications for neuropathy detection
There is potential benefit in analysing corneal nerve tortuosity as a marker for assessment and progression of systemic diabetic neuropathy.The aim of this work was to determine whether tortuosity ...
- 1 July 2021
- Published by Elsevier in The Ocular Surface
- Vol. 21, 37-51
The role of nitric oxide in ocular surface physiology and pathophysiology
- 1 July 2021
- Published by Elsevier in The Ocular Surface
- Vol. 21, 37-51
The role of nitric oxide in ocular surface physiology and pathophysiology
- 7 March 2021
- Published by Wiley in European Journal of Neurology
- Vol. 28 (6) , 2074-2082
Impact of the metabolic syndrome on peripheral nerve structure and function in type 2 diabetes
Background and purpose: There is a strong association between the metabolic syndrome in diabetes and the development of peripheral neuropathy; however, the pathophysiological mechanisms remain unknown.Methods: Participants with type 2 diabetes and metabolic syndrome (T2DM/MetS, n = 89) and type 2 diabetes alone (T2DM; n = 59) underwent median nerve ultrasound and excitability studies to assess peripheral nerve structure and function. A subset of T2DM/MetS (n = 24) and T2DM (n = 22) participants underwent confocal microscopy to assess central and inferior whorl corneal nerve structure. Neuropathy severity was assessed using the modified Toronto Clinical Neuropathy Score (mTCNS). Diabetes groups were similar for age, sex distribution, diabetes duration, hemoglobin A1c, insulin treatment, and renal function. Sixty healthy controls similar for age and sex distribution were recruited for comparison.Results: Participants with T2DM/MetS manifested with a greater mTCNS compared to T2DM (p < 0.05). Median nerve cross‐sectional area was larger in the T2DM/MetS group compared to the T2DM cohort (p < 0.05). Participants with T2DM/MetS had reductions in central (all p < 0.01) and inferior whorl (all p < 0.05) nerve measures. Compared to T2DM, the T2DM/MetS group demonstrated more severe changes in nerve excitability measures, which was due to reduced sodium channel permeability and sodium–potassium pump function. In comparison, only sodium channel permeability was reduced in the T2DM group.Conclusions: Compared to participants with type 2 diabetes alone, those with diabetes and metabolic syndrome manifested greater alterations in peripheral nerve structure and function, which may be due to reduced function of the sodium–potassium pump.
- 7 March 2021
- Published by Wiley in European Journal of Neurology
- Vol. 28 (6) , 2074-2082
Impact of the metabolic syndrome on peripheral nerve structure and function in type 2 diabetes
Background and purpose: There is a strong association between the metabolic syndrome in diabetes and the development of peripheral neuropathy; however, the pathophysiological mechanisms remain unknown.Methods: Participants with type 2 diabetes and metabolic syndrome (T2DM/MetS, n = 89) and type 2 diabetes alone (T2DM; n = 59) underwent median nerve ultrasound and excitability studies to assess peripheral nerve structure and function. A subset of T2DM/MetS (n = 24) and T2DM (n = 22) participants underwent confocal microscopy to assess central and inferior whorl corneal nerve structure. Neuropathy severity was assessed using the modified Toronto Clinical Neuropathy Score (mTCNS). Diabetes groups were similar for age, sex distribution, diabetes duration, hemoglobin A1c, insulin treatment, and renal function. Sixty healthy controls similar for age and sex distribution were recruited for comparison.Results: Participants with T2DM/MetS manifested with a greater mTCNS compared to T2DM (p < 0.05). Median nerve cross‐sectional area was larger in the T2DM/MetS group compared to the T2DM cohort (p < 0.05). Participants with T2DM/MetS had reductions in central (all p < 0.01) and inferior whorl (all p < 0.05) nerve measures. Compared to T2DM, the T2DM/MetS group demonstrated more severe changes in nerve excitability measures, which was due to reduced sodium channel permeability and sodium–potassium pump function. In comparison, only sodium channel permeability was reduced in the T2DM group.Conclusions: Compared to participants with type 2 diabetes alone, those with diabetes and metabolic syndrome manifested greater alterations in peripheral nerve structure and function, which may be due to reduced function of the sodium–potassium pump.
- 13 September 2020
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 104 (3) , 295-307
Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides
Isolation of antimicrobial‐resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic‐resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic‐resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first‐line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin‐resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad‐spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.
- 13 September 2020
- Published by Taylor & Francis in Clinical and Experimental Optometry
- Vol. 104 (3) , 295-307
Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides
Isolation of antimicrobial‐resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic‐resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic‐resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first‐line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin‐resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad‐spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.
- 16 April 2020
- Published by Wiley in Diabetic Medicine
- Vol. 37 (9) , 1553-1560
Associations between acute glucose control and peripheral nerve structure and function in type 1 diabetes
Aim: To examine the associations between continuous overlapping net glycaemic action (CONGA), percentage time in hyperglycaemia (%HG) or normoglycaemia (%NG) and peripheral nerve structure and function in type 1 diabetes.Methods: Twenty‐seven participants with type 1 diabetes underwent continuous glucose monitoring followed by corneal confocal microscopy and nerve excitability assessments. CONGA, %HG (> 10.0 mmol/l) and %NG (3.9–10.0 mmol/l) were correlated against corneal nerve fibre length and density in the central cornea and inferior whorl region, corneal microneuromas, and a nerve excitability score while controlling for age, sex, diabetes duration and HbA1c.Results: An increase in CONGA [median 2.5 (2.0–3.1) mmol/l] or %HG (mean 46 ± 18%) was associated with a worse nerve excitability score (r = –0.433, P = 0.036 and r = –0.670, P = 0.0012, respectively). By contrast, greater %NG (51 ± 17%) correlated with better nerve excitability scores (r = 0.672, P = 0.0011). Logistic regression revealed that increasing %HG increased the likelihood of abnormal nerve function [odds ratio (OR) 1.11, 95% confidence interval (CI) 1.01–1.23; P = 0.037). An increase in CONGA and %HG were associated with worsening nerve conduction measures, whereas longer %NG correlated with improved nerve conduction variables. CONGA and %HG were associated with inferior whorl corneal nerve fibre length (r = 0.483, P = 0.034 and r = 0.591, P = 0.021, respectively) and number of microneuromas (r = 0.433, P = 0.047 and r = 0.516, P = 0.020, respectively).Conclusions: Short‐term measures of glucose control are associated with impaired nerve function and alterations in corneal nerve morphology.
- 16 April 2020
- Published by Wiley in Diabetic Medicine
- Vol. 37 (9) , 1553-1560
Associations between acute glucose control and peripheral nerve structure and function in type 1 diabetes
Aim: To examine the associations between continuous overlapping net glycaemic action (CONGA), percentage time in hyperglycaemia (%HG) or normoglycaemia (%NG) and peripheral nerve structure and function in type 1 diabetes.Methods: Twenty‐seven participants with type 1 diabetes underwent continuous glucose monitoring followed by corneal confocal microscopy and nerve excitability assessments. CONGA, %HG (> 10.0 mmol/l) and %NG (3.9–10.0 mmol/l) were correlated against corneal nerve fibre length and density in the central cornea and inferior whorl region, corneal microneuromas, and a nerve excitability score while controlling for age, sex, diabetes duration and HbA1c.Results: An increase in CONGA [median 2.5 (2.0–3.1) mmol/l] or %HG (mean 46 ± 18%) was associated with a worse nerve excitability score (r = –0.433, P = 0.036 and r = –0.670, P = 0.0012, respectively). By contrast, greater %NG (51 ± 17%) correlated with better nerve excitability scores (r = 0.672, P = 0.0011). Logistic regression revealed that increasing %HG increased the likelihood of abnormal nerve function [odds ratio (OR) 1.11, 95% confidence interval (CI) 1.01–1.23; P = 0.037). An increase in CONGA and %HG were associated with worsening nerve conduction measures, whereas longer %NG correlated with improved nerve conduction variables. CONGA and %HG were associated with inferior whorl corneal nerve fibre length (r = 0.483, P = 0.034 and r = 0.591, P = 0.021, respectively) and number of microneuromas (r = 0.433, P = 0.047 and r = 0.516, P = 0.020, respectively).Conclusions: Short‐term measures of glucose control are associated with impaired nerve function and alterations in corneal nerve morphology.
- 1 March 2020
- Published by Elsevier in Clinical Neurophysiology
- Vol. 131 (3) , 780
Erratum to ‘Association of corneal nerve loss with markers of axonal ion channel dysfunction in type 1 diabetes’. [Clin. Neurophysiol. 131 (2020) 145–154]
- 1 March 2020
- Published by Elsevier in Clinical Neurophysiology
- Vol. 131 (3) , 780
Erratum to ‘Association of corneal nerve loss with markers of axonal ion channel dysfunction in type 1 diabetes’. [Clin. Neurophysiol. 131 (2020) 145–154]