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

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.

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 ◽  
...  

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


2007 ◽  
Vol 48 (12) ◽  
pp. 1643 ◽  
Author(s):  
Hyoung Sub Shim ◽  
Chul Young Choi ◽  
Hee Gyung Lee ◽  
Myoung Joon Kim ◽  
Hung Won Tchah

Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Thiago Trindade Nesi ◽  
Daniel Amorim Leite ◽  
Fábio Medina Rocha ◽  
Marco Antônio Tanure ◽  
Pedro Paulo Reis ◽  
...  

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Junko Yoshida ◽  
Tetsuya Toyono ◽  
Rika Shirakawa ◽  
Takashi Miyai ◽  
Tomohiko Usui

Abstract To determine the risk factors and unique characteristics of keratoconus (KC) progression after penetrating keratoplasty (PK), anterior segment optical coherence tomography parameters were statistically analyzed in comparison with eyes undergoing PK for other diseases as a control. Ninety-one eyes maintaining clear PK grafts for over 10 years were divided into 2 groups according to the primary indication for PK (KC vs Others groups). Corneal thinning indicators (inferior host thinnest corneal thickness/central corneal thickness [IHT/CCT], inferior graft thinnest corneal thickness/CCT [IGT/CCT]), were smaller whereas anterior chamber depth, and steepest corneal power (Ks), and maximum corneal power (Kmax) were larger in the KC group with statistical significance. Graft size, Kmax and Ks correlated with IHT/CCT and IGT/CCT in the KC group. These correlations were not detected in controls. Graft size and postoperative period were selected by multivariate regression analysis as factors for corneal ectatic changes in the KC group. In conclusion, KC eyes long after PK show inferior graft and host corneal thinning, and corneal protrusion. Corneal power parameters such as Kmax or Ks can be used to monitor KC progression after PK. A small graft might lead to KC progression after PK.


PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0228567 ◽  
Author(s):  
Keiichi Fujimoto ◽  
Takenori Inomata ◽  
Yuichi Okumura ◽  
Nanami Iwata ◽  
Kenta Fujio ◽  
...  

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