Applications of corneal topography and tomography: a review

Fan, Rachel Y.Y.; Chan, Tommy C Y; Prakash, Gaurav; Jhanji, Vishal

doi:10.1111/ceo.13136

Cited by 103 publications

(68 citation statements)

References 113 publications

(244 reference statements)

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“…Fluorescein, 376.67 dalton weight, is a weak dibasic acid substance with a sodium salt content [ 7 – 10 ]. In routine ophthalmology practice, the fundus is used for fluorescein angiography, applanation tonometry, epithelial defect staining, and tear breakage time [ 9 – 11 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Proparacaine 0.375%-Sodium Fluorescein 0.25% Eye Drop Mixture and Fluorescein Strip on Anterior Segment Parameters

Doğan

Sabaner

Erol

2018

Journal of Ophthalmology

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Purpose To determine the effect of proparacaine 0.375%-sodium fluorescein 0.25% eye drop mixture and fluorescein strip on anterior segment parameters commonly used in routine ophthalmology practice. Methods 115 healthy volunteers without any systemic or ocular disease were divided into two groups. 57 volunteers were in the proparacaine 0.375%-sodium fluorescein 0.25% eye drop mixture group, and 58 volunteers were in the fluorescein strip group. Measurements (CCT (central corneal thickness), topographic pupil diameter, AD (aqueous depth), ACV (anterior chamber volume), ICA (iridocorneal angle), LLD (limbus-limbus distance), and CV (corneal volume)) were taken before and at 1, 5, 15, and 30 minutes after application. Results 59 (51.3%) participants were female, and 56 (48.7%) were male. The mean age of the drop application group was 26.88 ± 8.03, and the mean age of the strip application group was 26.33 ± 7.28. The mean CCT was 556 ± 32 μm before drop application and 569 ± 30 μm in the 1st minute, 560 ± 32 μm in the 5th minute, and 559 ± 31 μm in the 15th minute. The change was statistically significant (p < 0.001, p=0.005, and p=0.013, resp.). Before the strip application, mean CCT was 552 ± 36 μm, while it increased to 556 ± 36 μm at the 1st minute, and this change was statistically significant (p=0.002). The mean CV before dropping was 59.29 ± 3.53 mm3 and 60.62 ± 3.53 mm3 at the 1st minute and 59.66 ± 3.70 mm3 at the 5th minute, which was statistically significant (p < 0.001 and p=0.034). Mean topographic pupil diameters at the 1st, 5th, 15th, and 30th minute after application of drops and strips were not significantly changed compared to the preapplication values in the AD, ACV, ICA, and LLD measurements. Conclusions Proparacaine 0.375%-sodium fluorescein 0.25% eye drop mixture and fluorescein strip application lead to a temporary change in CCT and CV of the anterior segment parameters. Anterior segment measurements with the Scheimpflug camera have to be done before topical fluorescein application.

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Section: Introductionmentioning

confidence: 99%

Effect of Proparacaine 0.375%-Sodium Fluorescein 0.25% Eye Drop Mixture and Fluorescein Strip on Anterior Segment Parameters

Doğan

Sabaner

Erol

2018

Journal of Ophthalmology

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“…Because of insufficient information about the amount and administration of medication as well as dryness of the eyes after surgery [ 29 , 30 ], it was not possible investigate the relationship between these variables and refractive error regression after PRK. Technological advances in corneal imaging have made the precise measurement of anterior and posterior corneal curvature and corneal thickness possible [ 31 ]. The careful use of this data can help in the planning of refractive surgery such as PRK.…”

Section: Discussionmentioning

confidence: 99%

Studying the factors related to refractive error regression after PRK surgery

et al. 2018

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BackgtoundPhotorefractive keratectomy (PRK) is used for a wide range of refractive errors such as low to moderate myopia, hyperopia and astigmatism. While many improvements have been made in laser application and accuracy as well as the modes of corneal flap removal, and although the results are somewhat predictable, regression of refractive errors is still a common complaint among the patients undergoing refractive surgery with Excimer Laser. We aimed to determine related factors of regression following photorefractive keratectomy (PRK) in different types of refractive errors.MethodsThis cross-sectional study included patients who had undergone PRK more than 6 months previously and investigated refractive error regression and related factors. The participants were those who had PRK eye surgery for the first time from 2013 to 2016 using Technolas 217z100. A refraction value of spherical equivalent > 0.75 D after cycloplegic refraction was defined as refractive error regression.ResultsA total of 293 eyes on 150 subjects were studied. The preoperative refractive error of the eyes were as follows: 5.5% were myopic, 1% were hyperopic, 4.8% had astigmatism, 76% had myopic astigmatism and 12.6% had hyperopic astigmatism. Regressed and non-regressed eyes were assessed using the generalized estimating equations for the probabilistic variables of demographic characteristics, topography and eye refraction. The variables of simulated keratometry astigmatism (simK) (OR = 2.8; p = 0.04), 5 mm irregularity (OR = 3.56; p = 0.01) and sphere value (OR = 1.98; p = 0.01) were significantly related to refractive error regression. There was no significant relationship between the regressed and non-regressed eyes of the same person (p ≥ 0.05).ConclusionThere was a positive relationship between the increase of 5 mm irregularity, simK, sphere value before surgery and refractive error regression. Age, sex and type of refraction error of the patient and the expertise of the PRK surgeon could change the general results; therefore, not all cases should be dealt with identically.

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“…Beberapa metode yang umum digunakan dapat dikategorikan ke dalam dua kategori: topografi dan tomografi kornea. Topografi kornea memetakan kondisi permukaan dari anterior kornea, sedangkan tomografi kornea memetakan kondisi lapisan kornea [2], [7]- [10]. Metode yang digunakan pada topografi korena dapat dibagi menjadi dua kategori: metode berbasis refleksi dan metode berbasis proyeksi.…”

Section: Pendahuluanunclassified

Perangkat Fotokeratoskopi dengan Analisa Citra Digital untuk Deteksi Awal Astigmatisme

Zahra

Fitri

Fransisca

et al. 2020

joki

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Astigmatisme adalah kelainan refraksi mata yang disebabkan oleh perubahan kelengkungan kornea. Untuk mendeteksi astigmatisme, dilakukan pemetaan terhadap informasi kelengkungan kornea salah satunya dengan metode fotokeratoskopi. Fotokeratoskopi merupakan metode yang menggunakan pola cincin konsentris yang disebut pola Placido. Pada kornea sehat, pola Placido menghasilkan refleksi yang simetris dengan jarak antar cincin yang konsisten. Pada penelitian ini dilakukan pengembangan purwarupa fotokeratoskop dan penelitian terhadap standar refleksi pola Placido pada kornea sehat. Pemrosesan citra yang dilakukan meliputi pemilihan region of interest, perbaikan bayangan, dan penentuan properti untuk topografi kornea Algoritma pemrosesan citra meneliti dua properti topografi kornea, yaitu (1) koefisien korelasi K yang menggambarkan simetrisitas refleksi, dan (2) jarak antarcincin yang menggambarkan konsistensi topografi. Dari ragam pola Placido yang diuji, didapat pola terbaik dengan K > 0,5 untuk kornea sehat dan K < 0,5 untuk kornea astigmatik. Selain itu dari pola tersebut juga didapat daya optis rata-rata kornea sehat +46 ± 0,999 D sesuai dengan standar daya optis kornea sehat yaitu +46D. Melalui uji algoritma simetrisitas serta hasil perhitungan daya optis yang presisi, disimpulkan bahwa purwarupa fotokeratoskopi ini memiliki potensi besar untuk terus dikembangkan untuk deteksi awal astigmatisme.

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Applications of corneal topography and tomography: a review

Cited by 103 publications

References 113 publications

Effect of Proparacaine 0.375%-Sodium Fluorescein 0.25% Eye Drop Mixture and Fluorescein Strip on Anterior Segment Parameters

Effect of Proparacaine 0.375%-Sodium Fluorescein 0.25% Eye Drop Mixture and Fluorescein Strip on Anterior Segment Parameters

Studying the factors related to refractive error regression after PRK surgery

Perangkat Fotokeratoskopi dengan Analisa Citra Digital untuk Deteksi Awal Astigmatisme

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