Effect of Central Corneal Thickness, Corneal Curvature, and Axial Length on Applanation Tonometry

Aim: To study the various ocular anatomical and physiological parameters in presbyopia. Materials and methods: We studied the various ocular anatomical and physiological parameters like corneal curvature (keratometry readings: K1 and K2), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) in 100 presbyopic patients between 35 - 55 years of age. The patients were divided into two age groups: I (35 – 44 years) and II (45-55 yrs). ACD, AL and LT were measured using an Ascan. CCT was measured with ultrasonic pachymetry. Results: The CCT decreased (BE), LT increased and ACD decreased (RE) significantly with increasing age (p < 0.05). There was no significant difference in males and females. Nearly 3/4th of the total increase in lens thickness was responsible for the decrease in the anterior chamber depth and the rest, 1/4th , goes posteriorly. Corneal curvature and AL showed no significant change with age. Conclusions: The mean of CCT decreased significantly with advancing age. As age increased, the mean value of lens thickness increased and anterior chamber depth decreased. Nearly 3/ 4th of total increase in LT was anteriorly, decreasing the ACD. Corneal curvature and AL has no relation with age. Key words: Presbyopia, central corneal thickness, anterior chamber depth, lens thickness, axial length DOI: http://dx.doi.org/10.3126/nepjoph.v3i2.5269 Nepal J Ophthalmol 2011; 3(2): 155-158

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Comparison of Goldmann applanation tonometry and Pascal dynamic contour tonometry in relation to central corneal thickness and corneal curvature

Clinical Ophthalmology ◽

10.2147/opth.s115203 ◽

2016 ◽

Vol Volume 10 ◽

pp. 2477-2484 ◽

Cited By ~ 7

Author(s):

Konstantinos Andreanos ◽

Chrysanthi Koutsandrea ◽

Dimitris Papaconstantinou ◽

Andreas Diagourtas ◽

Andreas Kotoulas ◽

...

Keyword(s):

Central Corneal Thickness ◽

Corneal Thickness ◽

Applanation Tonometry ◽

Goldmann Applanation Tonometry ◽

Dynamic Contour Tonometry ◽

Corneal Curvature

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Correlation of central corneal thickness and axial length to the optic disc and peripapillary atrophy among healthy individuals, glaucoma and ocular hypertension patients

Clinical Ophthalmology ◽

10.2147/opth.s4293 ◽

2008 ◽

pp. 981 ◽

Cited By ~ 8

Author(s):

George Tomais

Keyword(s):

Ocular Hypertension ◽

Optic Disc ◽

Axial Length ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Healthy Individuals ◽

Peripapillary Atrophy

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Effect of Desonide 0.25% Ophthalmic Solution on Central Corneal Thickness and Intraocular Pressure of Patients with Allergic Conjunctivitis

Asian Journal of Ophthalmology ◽

10.35119/asjoo.v12i3.305 ◽

1970 ◽

Vol 12 (3) ◽

pp. 156-158

Author(s):

Ozlem Gurses Sahin

Keyword(s):

Intraocular Pressure ◽

Allergic Conjunctivitis ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Ophthalmic Solution ◽

Applanation Tonometry ◽

Goldmann Applanation Tonometry ◽

Mean Values ◽

Conjunctival Hyperaemia ◽

Significant Difference

Aim: To evaluate whether a significant difference exists between the initial and final mean central corneal thickness that might affect Goldmann applanation tonometer recordings of patients with allergic conjunctivitis treated with desonide 0.25% ophthalmic solution, and to determine the effect of desonide on intraocular pressure by using adjusted intraocular pressure values.Methods: This double-blind randomised placebo-controlled trial enrolled 30 patients (60 eyes) with allergic conjunctivitis. Patients were randomly assigned to receive desonide to 1 eye (study eye) and preservative-free tear supplement (Tears Naturale Free®) to the other eye (control eye) 3 times daily for 3 weeks. Goldmann applanation tonometry and central corneal thickness of both eyes were recorded on the day of presentation and 3 weeks later.Results: Regression of itching, tearing, conjunctival hyperaemia, and tarsal conjunctival papillary reaction were noted in the study eyes after 3 weeks of treatment. The control eyes showed mild regression of pruritis, tearing, conjunctival hyperaemia, and tarsal conjunctival papillary reaction after 3 weeks. There was a significant difference between the initial and final mean central corneal thickness values for the study eyes (p = 0.003). There were no statistically significant differences between the initial and final mean values of Goldmann applanation tonometry and adjusted intraocular pressure for the study eyes. No statistically significant differences were found between the initial and final mean values of any of the parameters for the control eyes.Conclusion: Inflammation-induced increase in central corneal thickness of patients with allergic conjunctivitis treated with desonide showed statistically significant regression. However, this regression did not significantly affect Goldmann applanation tonometry and adjusted intraocular pressure values of the treated eyes.

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Usefulness of the Non-Contact Tonometry in Out-Patient Screening

Asian Journal of Ophthalmology ◽

10.35119/asjoo.v15i2.232 ◽

2016 ◽

Vol 15 (2) ◽

Author(s):

Satheesh Solomon T Selvin ◽

Chris Elsa Samson Jacob ◽

Thomas Kuriakose

Keyword(s):

Central Corneal Thickness ◽

Care Center ◽

Corneal Thickness ◽

Tertiary Care ◽

Cross Sectional Study ◽

Applanation Tonometry ◽

Cross Sectional ◽

Significant Difference ◽

Iop Measurement ◽

The Mean

Purpose: Goldmann applanation tonometry (GAT) is considered the gold standard for Intraocular Pressure (IOP) measurement. It has the disadvantages of being a contact device, need for a slit-lamp, non-portability and need of a skilled examiner. Many hospitals are using a Non Contact Tonometry (NCT) as a screening device to save clinician time, however the usefulness is not proved in terms of reliability. This study was aimed to determine the usefulness of the Air-puff tonometer (TONOREF NIDEK II, NIDEK CO., LTD., JAPAN) over a GAT in a tertiary care center. Design: Cross-sectional Study Methods: This was a cross-sectional, non interventional observational study conducted on 224 eyes (right eye) from 224 patients. All patients underwent the IOP measurement with both methods and a central corneal thickness (CCT) measured. The data was analyzed using SPSS 20.0 software. Results: The mean age of the patients was 40.3±11.29 years. There was a statistically significant difference (p<0.001) between the mean NCT and GAT readings which persisted even after correction for central corneal thickness. The correlation between NCT and GAT using Pearson’s correlation coefficient was strong irrespective of the corrections for their corneal thickness (r = 0.751 and 0.718 for uncorrected and corrected values respectively). The correlation of the individual clinicians for the readings varied from moderate to strong. The ROC curve showed the best sensitivity and specificity to occur at around 13 to 14 mmHg. Conclusion: NCT seems to overestimate the IOP at low ranges as compared to the GAT and underestimate at higher ranges. The crossover of the values is seen between 12 to 13 mmHg. The clinician should do an individualized analysis of his/her GAT measurements to the readings of the NCT machine at the clinic to obtain clinician specific nomogram.

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The pattern of central corneal thickness in patients attending a Tertiary Hospital in Dar-Es-Salaam

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2021.9.2.0056 ◽

2021 ◽

Vol 9 (2) ◽

pp. 127-133

Author(s):

Annamary Stanislaus ◽

Ntsilane Susan Mosenene ◽

Celina Mhina ◽

John Stanslaus Kisimbi ◽

Frederick Robert Burgess ◽

...

Keyword(s):

Central Corneal Thickness ◽

Corneal Thickness ◽

Dar Es Salaam ◽

Applanation Tonometry ◽

P Value ◽

Muhimbili National Hospital ◽

National Hospital ◽

Cross Sectional ◽

Significant Difference ◽

The Mean

Background: Central Corneal Thickness (CCT) is an indicator of corneal health status as well as being an essential tool in assessment and management of corneal diseases. It is an important factor in the diagnosis and management of glaucoma as it affects the measurement of intraocular pressure. However, the pattern of central corneal thickness in our population is not known. Our study aimed to describe the CCT measurements and their variation with age and sex among patients attending the eye clinic at Muhimbili National Hospital (MNH), in Dar es Salaam, Tanzania. Methodology: A hospital-based descriptive, cross-sectional study used convenient sampling to recruit adult patients aged 18 years and above, presenting to the MNH between August 2016 and January 2017.Visual acuity assessment, Goldman applanation tonometry and CCT assessment using an ultrasound pachymeter were performed. Patients with previous intraocular surgery were excluded. Results: A total of 398 patients (208 males and 190 females) were recruited. The mean CCT was 526.64±38.30 µm; being 523.99±38.20 µm for males and 529.7±38.3 µm for females. 226 (56.85%) had CCT of less than 520 µm.There was no statistically significant difference in CCT between gender. The proportion of patients with thinner CCT increased with increasing age from 25.8% in those < 30 years to 75% in those aged 71years and above. The mean CCT decreased with increasing age with P-value<0.001. Conclusion: The average CCT in patients attending Muhimbili National Hospital is 526.64 µm (SD 38.30) which is generally thin, inversely proportion to age and similar that of other Africans and African-Americans. This finding has implications for the management of glaucoma in this population.

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Effect of brimonidine on central corneal thickness in normal tension glaucoma patients

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20192501 ◽

2019 ◽

Vol 7 (6) ◽

pp. 2216

Author(s):

Neethu K. V. ◽

Latha N. V. ◽

Praveena K. K.

Keyword(s):

Intraocular Pressure ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Topical Administration ◽

Normal Tension Glaucoma ◽

Thickness Measurement ◽

Applanation Tonometry ◽

Time Period ◽

Field Assessment ◽

History Of

Background: Brimonidine is a potent ocular hypotensive agent widely used in glaucoma treatment. A reduction in central corneal thickness can lead to an underestimation of intraocular pressure by Goldmann applanation tonometry and vice versa. The aim of this study is to determine whether brimonidine has an effect on central corneal thickness.Methods: 30 eyes of patients who attended the Ophthalmology OPD between the time period October 2017 and June 2018 who were newly diagnosed with normal tension glaucoma with no history of any systemic illness or not on any medication were included. Each patient underwent a complete ophthalmic evaluation including fundus examination, visual field assessment, intraocular pressure, central corneal thickness measurement by pachymetry before as well as 1 month and 6 months after starting treatment with 0.2% topical brimonidine twice daily.Results: Administration of brimonidine 0.2% resulted in an increase in central corneal thickness from 525±21 µm before starting brimonidine to 528±21 µm (p<0.05) after 1 month and 535±20 µm (p<0.001) after 6 months. It also resulted in a reduction in intraocular pressure from an initial value of 16±2 mmHg before starting brimonidine to 14±2 mmHg (p<0.05) and 13±2 mmHg (p<0.05), 1month and 6 months after starting treatment, respectively.Conclusions: The data presented in this study show that topical administration of 0.2% brimonidine twice daily results in a significant increase in central corneal thickness in patients with normal tension glaucoma.

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