Diagnostic Accuracy of Anterior Segment Optical Coherence Tomography Pachymetry Mapping and Detection for Early Keratoconus using Corneal Topography as Gold Standard

2021 ◽  
Vol 15 (10) ◽  
pp. 2796-2799
Author(s):  
Hafiz Huzaifa Akhlaq ◽  
Syed Ahmad Hassan Waqas Subzwari ◽  
Fatima Akbar Shah ◽  
Rafih Razzaq Wattoo ◽  
Umair Tariq Mirza ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Gold Standard ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Corneal Topography ◽  
Optical Coherence ◽  
Cutoff Value ◽  
Department Of Ophthalmology

Background: Optical coherence tomography (OCT) derived pachymetry mapping has potential in diagnosis of early and advancing keratoconus. The OCT corneal pachymetry map–based logistic regression formula and the keratoconus risk scoring system has been proven to provide very accurate results in keratoconus identification. In keratoconus screening these techniques might be helpful. Objectives: To ascertain the diagnostic accuracy of anterior segment optical coherence tomographic corneal pachymetry to diagnose the cases the cases of early keratoconus by using corneal topography as a high standard with which other techniques of these kinds are compared. Study Design: Cross-sectional (validation) study. Duration: One year from July 01, 2019 to June 30, 2020. Settings: Department of Ophthalmology, Allied Hospital/DHQ Hospital, Faisalabad Pakistan. Methodology: A total of 195 patients having asymmetrical astigmatism (>1 diopter), 12-40 years of age of both genders were included. Patients with corneal ulcer and corneal opacity were excluded. After complete examination corneal topography and anterior segment optical coherence tomography was performed. Tomographic minimum central corneal thickness was recorded and assessed for cutoff value, if exceeding cutoff value patient was diagnosed with the early keratoconus. Results: In OCT pachymetry positive patients, 103 (True Positive) had early keratoconus and 05 (False Positive) had no early keratoconus on corneal topography. Among 87, OCT pachymetry negative patients, 04 (False Negative) had early keratoconus on corneal topography whereas 83 (True Negative) had no early keratoconus on corneal topography (p=0.0001). Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of anterior segment optical coherence tomographic corneal pachymetry to diagnose the cases of early keratoconus in the suspected individuals by using corneal topography as gold standard was 96.26%, 94.32%, 95.37%, 95.40% and 95.38% respectively. Conclusion: This study concluded that diagnostic accuracy of anterior segment optical coherence tomographic corneal pachymetry to find out the cases of early keratoconus is very high. Keywords: Optical coherence tomographic corneal pachymetry, Keratoconus, Sensitivity

scholarly journals Diagnostic accuracy of keratoconus using anterior segment optical coherence tomography

2013 ◽  
Vol 3 (1) ◽  
pp. 2
Author(s):  
Pinakin Gunvant Davey ◽  
Christina Newman ◽  
Anna Ablamowicz ◽  
Daniel Fuller
Keyword(s):  
Optical Coherence Tomography ◽  
Diagnostic Accuracy ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Clinical Findings ◽  
Optical Coherence ◽  
Minimum Thickness ◽  
Severity Of Disease ◽  
Roc Area ◽  
Sensitivity Specificity

The aims of the present study are i) to evaluate the diagnostic accuracy of RTVue non-contact, high-resolution spectral domain optical coherence tomography (RTVue OCT) in identifying keratoconic eyes from a group of healthy eyes; and ii) to examine how the severity of disease affects diagnostic accuracy. Corneal thickness measurements were performed using the RTVue OCT on 58 eyes of 29 individuals (10 males, 19 females). Of them, 28 eyes were deemed to be keratoconic, and 30 eyes healthy on the basis of clinical findings. Sensitivity, specificity and receiver operating characteristic (ROC) area was calculated overall and by grouping eyes by severity of disease. On the whole, the ROC area was highest for the parameters minimum thickness and difference between minimum and maximum thickness of cornea (0.98). The ROC area for the parameters difference in superior nasal and inferior temporal thickness and difference in superior and inferior thickness was 0.81 and 0.77, respectively. The ROC area in identifying eyes with keratoconus varied as a function of severity of disease. From our analysis we can conclude that the RTVue OCT provides excellent diagnostic ability in identifying moderate to advanced cases of keratoconus.

scholarly journals Correlation between Central Corneal Thickness and Degree of Myopia among Malaysian Patients Undergoing Laser Keratorefractive Surgery

2020 ◽  
pp. 52-58
Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Military Hospital ◽  
Moderate Degree ◽  
Optical Coherence ◽  
Corneal Refractive Surgery ◽  
The Mean

Purpose: To determine the central corneal thickness in myopic adult patients scheduled for laser corneal refractive surgery and to explore its correlation with degree of refractive error. Materials and Methods: The case records of 130 myopic patients who underwent laser corneal refractive surgery in a military hospital over a period of two years were reviewed to determine the central corneal thickness. All patients had 6/6 vision with best correction, and did not have any other anterior segment or fundus diseases in both eyes. The central corneal thickness was measured with Visante Carl Zeiss anterior segment optical coherence tomography instrument.                                                                                                                        Results: Out of 130 patients, males were more (73, 56.2%); mean age of patients was 33.8 years (range 18-60 years) and majority were Malays (110, 84.6%).  The spherical power of myopia ranged from – 0.5 to – 10.00 D, and the cylindrical power ranged from – 0.25 to – 3.25 D. The mean central corneal thickness of both eyes was 528.2 µm (range 331- 615 µm); in the mild degree of myopia (- 0.50 to - 2.00 D) 527.9 µm, moderate degree (- 2.25 to -5.00 D) 529.4 µm, and high degree (-5.25 to -11.00 D) 523.9 µm. Conclusion: The anterior segment optical coherence tomography provides noncontact, rapid, pachymetry mapping of the corneal thickness. In Malaysian patients, the mean central corneal thickness of both eyes in myopia was 528.1 µm (range 331- 615 µm). There was no correlation between the mean central corneal thickness and degree of myopia, different genders, age groups, ethnic groups and two eyes.

Anterior segment optical coherence tomography and ultrasound biomicroscopy for measuring thickness of corneal and bulbar conjunctival tumours

2021 ◽  
pp. bjophthalmol-2018-312337
Author(s):  
Noémie Lauwers ◽  
Katleen Janssens ◽  
Michelle Mertens ◽  
Danny Mathysen ◽  
Martin Lammens ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Gold Standard ◽  
Imaging Techniques ◽  
Anterior Segment ◽  
Ultrasound Biomicroscopy ◽  
Thickness Measurement ◽  
Histopathological Analysis ◽  
Optical Coherence ◽  
Tumour Thickness ◽  
Thickness Measurements

Background/ObjectiveAnterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) are two non-invasive imaging techniques used for the measurement of tumour thickness in corneal and bulbar conjunctival tumours. Histopathology (HP), however, remains the gold standard for the measurement of tumour thickness. The aim of this study was to determine whether AS-OCT and UBM are as accurate as HP for measuring tumour thickness.MethodsForty-two corneal and bulbar conjunctival tumours were imaged using AS-OCT and UBM. Images were assessed and tumour thickness was measured. Eleven patients subsequently underwent surgical excision. All specimens were measured during histopathological analysis. The correlation of the thickness measurement on HP to AS-OCT and UBM was then statistically analysed. In cases where the tumour was not excised, thickness measurement comparisons between AS-OCT and UBM were analysed.ResultsAS-OCT and UBM measurements of tumour thickness were found to be significantly positively correlated (p=<0.001), as were UBM and HP thickness measurements (p=0.031). HP and AS-OCT measurements, however, only showed a mild but non-significant positive correlation.ConclusionBoth AS-OCT and UBM are useful techniques to image and measure the thickness of corneal and conjunctival bulbar tumours. While AS-OCT provides better details than UBM, it was more limited in visualising the posterior boundary of the tumour, particularly in malignant tumours. While thickness measurements of both methodologies were correlated, neither should yet be considered as replacements to the gold standard of HP.

scholarly journals Indications of Optical Coherence Tomography in Keratoplasties: Literature Review

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Thiago Trindade Nesi ◽  
Daniel Amorim Leite ◽  
Fábio Medina Rocha ◽  
Marco Antônio Tanure ◽  
Pedro Paulo Reis ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Literature Review ◽  
Early Identification ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Secondary Glaucoma ◽  
Optical Coherence

Optical coherence tomography (OCT) of the anterior segment, in particular corneal OCT, has become a reliable tool for the cornea specialist, as it provides the acquisition of digital images at high resolution with a noncontact technology. In penetrating or lamellar keratoplasties, OCT can be used to assess central corneal thickness and pachymetry maps, as well as precise measurements of deep stromal opacities, thereby guiding the surgeon to choose the best treatment option. OCT has also been used to evaluate the keratoplasty postoperative period, for early identification of possible complications, such as secondary glaucoma or donor disc detachments in endothelial keratoplasties. Intraoperatively, OCT can be used to assess stromal bed regularity and transparency in anterior lamellar surgeries, especially for those techniques in which a bare Descemet’s membrane is the goal. The purpose of this paper is to review and discuss the role of OCT as a diagnostic tool in various types of keratoplasties.

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