Adjusting Intraocular Pressure for Central Corneal Thickness Does Not Improve Prediction Models for Primary Open-Angle Glaucoma

BACKGROUND Myopia is a complex trait including both genetic and environmental factors as well as gene-environment interactions. It has been recognized as a risk factor for development of glaucoma. Both Myopia and raised IOP are known to increase mechanical stress at optic nerve head leading to glaucomatous nerve damage. This study intends to evaluate the clinical profile of myopic subjects and its correlation with Primary open angle glaucoma (POAG). METHODS A prospective observational study done from November 2019 to December 2020 after taking proper informed consent and ethical clearance. 164 eyes of 96 patients studied were divided into three groups, Group 1: low myopia (< -3.00D), Group 2: moderate myopia (-3.00 D to -5.75 D), Group 3: high myopia (≥ -6.00 D). A complete ocular examination was performed. Intraocular pressure was measured using Goldmann applanation tonometer. Visual field analysis using Humphrey automated perimetry was done in patients with suspected primary open angle glaucoma (POAG). Angle parameters and central corneal thickness (CCT) were measured using anterior segment optical coherence tomography (AS-OCT). RESULTS 164 eyes of 96 Myopic subjects were studied with no dropout during study period. Mean age was 46.05 yr. (range: 25-75 yr.). The refraction ranged from -0.50 DS to -17.00 DS. There was no statistically significant difference between Intraocular pressure (IOP), Central corneal thickness (CCT), corrected IOP and Nasal and Temporal Trabecular-iris Angle (TIA) between male and female of same age group. Mean IOP and mean CCT were found to vary significantly with age and with higher degree of myopia. Corrected IOP, Nasal and Temporal TIA increase significantly with higher degree of myopia. Cup-disc ratio (CDR) was found to be significantly higher in patients with moderate to high degree of Myopia. CONCLUSIONS Myopia is an important risk factor for development of primary open angle glaucoma, with its incidence increasing in patients with moderate to high myopia. KEYWORDS Myopia, Primary Open Angle Glaucoma, Intraocular Pressure, Central Corneal Thickness, Trabecular Iris Angle

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Effect of Corneal Arcus on Central Corneal Thickness, Intraocular Pressure, and Primary Open-angle Glaucoma

Archives of Ophthalmology ◽

10.1001/archophthalmol.2010.252 ◽

2010 ◽

Vol 128 (11) ◽

pp. 1455 ◽

Cited By ~ 4

Author(s):

Renyi Wu

Keyword(s):

Intraocular Pressure ◽

Central Corneal Thickness ◽

Primary Open Angle Glaucoma ◽

Open Angle Glaucoma ◽

Corneal Thickness ◽

Open Angle

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Multicenter study of intraocular pressure level in patients with moderate and advanced primary open-angle glaucoma on treatment

Ophthalmology journal ◽

10.17816/ov2015143-60 ◽

2015 ◽

Vol 8 (1) ◽

pp. 43-60 ◽

Cited By ~ 2

Author(s):

L. D. Abysheva ◽

R. V. Avdeev ◽

A. S. Alexandrov ◽

A. S. Basinsky ◽

E. A. Blyum ◽

...

Keyword(s):

Intraocular Pressure ◽

Healthy Subjects ◽

Central Corneal Thickness ◽

Primary Open Angle Glaucoma ◽

Open Angle Glaucoma ◽

Corneal Thickness ◽

Disease Stage ◽

Open Angle ◽

Significant Difference ◽

Advanced Glaucoma

Introduction. For the past several decades, there has been a discussion as to whether elevated intraocular pressure is just ocular hypertension in a healthy eye, or a sign of glaucoma. Objective. To study the IOP values in patients with primary open-angle glaucoma at the beginning of the study and to correlated them with the disease progression and to determine optimal IOP levels. Material and methods. The final protocol included data from 812 right eyes of 637 glaucoma patients and 175 healthy subjects; the latter formed the control group. The mean age of examined patients was 71.8 ± 0.28 years; 72.00 (66.00; 77.00). Mean disease duration in glaucoma patients was 5.41 ± 0.17 years. The following parameters were assessed: visual acuity, clinical refraction, IOP level by Maklakov tonometry, central corneal thickness and IOP-lowering medication use. Results. In the age group - between 60 and 69 y.o., the IOP level in patients with advanced glaucoma was significantly higher than in patients with moderate glaucoma and healthy subjects. There was no significant difference in central corneal thickness either between glaucoma patients and healthy subjects (both male and female) or between glaucoma patients with different glaucoma changes. The IOP level was higher in patients treated with non-fixed combination of beta-blockers (BB) and prostaglandins (PG) regardless of the disease stage. According to the common standards the IOP level was found to be controlled in 69.93 % of patients with moderate glaucoma and 14.42 % of patients with advanced glaucoma. Conclusion. The results of the study could be used as clinical guidelines for determination of the optimal IOP range, choosing the optimal IOP-lowering medication(s) for starting therapy and during the follow-up in patients with moderate and advanced glaucoma stages.

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Central corneal thickness and intraocular pressure in primary open angle glaucoma suspects in a south Indian population. Is it time for “corneal anthropology”?

Indian Journal of Clinical and Experimental Ophthalmology ◽

10.18231/j.ijceo.2020.114 ◽

2020 ◽

Vol 6 (4) ◽

pp. 542-548

Author(s):

Ashok Sharma ◽

Rajan Sharma ◽

Nagaraja K S ◽

Rani Sujatha ◽

Prashant C N ◽

...

Keyword(s):

Intraocular Pressure ◽

Central Corneal Thickness ◽

Indian Population ◽

Primary Open Angle Glaucoma ◽

Open Angle Glaucoma ◽

Corneal Thickness ◽

South Indian Population ◽

Open Angle ◽

South Indian

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Central corneal thickness and intraocular pressure in patients of primary open angle glaucoma and normal population in Nepalese population: A hospital based study

Nepalese Journal of Ophthalmology ◽

10.3126/nepjoph.v11i1.25418 ◽

2019 ◽

Vol 11 (1) ◽

pp. 46-54

Author(s):

Lalit Agarwal ◽

Nisha Agrawal ◽

Badri Prasad Badhu ◽

Poonam Lavaju

Keyword(s):

Intraocular Pressure ◽

Central Corneal Thickness ◽

Primary Open Angle Glaucoma ◽

Open Angle Glaucoma ◽

Normal Population ◽

Corneal Thickness ◽

Open Angle ◽

Glaucomatous Damage ◽

Significant Difference ◽

Primary Glaucoma

Introduction: Central corneal thickness (CCT) is a powerful predictor of primary open angle glaucoma. Individualized risk assessment is critical for early diagnosis and management of glaucoma. Objectives: To compare CCT and intraocular pressure in patients of primary openangle glaucoma (POAG) with those of normal population. Materials and methods: A Comparative Cross-Sectional Study was performed in Ophthalmology department of B. P. Koirala Institute of Health Sciences, Nepal. Newly diagnosed cases of primary glaucoma (open angle, normal tension) of 18 years and above, without known systemic diseases were included. Results: Out of a total of 291 subjects (582 eyes), 105 subjects (210 eyes) were with primary glaucoma and 186 (382 eyes) were normal subjects. There was no significant difference in CCT between glaucomatous (533.57 μm) and normal (530.06 μm) eyes (p=0.1). Cornea was thinner (518.±18.03 μm) in eyes with severe glaucomatous damage (cup:disc ratio > 0.8) than in moderate glaucomatous damage (cup:disc ratio=0.5-0.8)(p=0.003). There was a statistically significant difference of 22.05 μm in CCT between POAG and NTG (p<0.001). A positive correlation was found between IOP & CCT in both cases and control group (p=0.000; r = 0.355, 0.254; r2 =0.126, 0.064 respectively). Conclusion: Majority of studied Nepalese population have CCT less than 550 μm, thus increasing the risk of POAG. CCT decreases with age, and females with glaucoma have significantly thicker cornea than men. There is a significant positive correlation between CCT and IOP, and IOP will have to be adjusted for CCT for proper diagnosis and monitoring of glaucomatous damage in Nepalese population too.

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