AS OCT Research Articles

Value of Anterior Segment Ocular Coherence Tomography (AS-OCT) in Dryness Evaluation in Vitiligo

Abstract Background Vitiligo is an acquired depigmentation disorder of the skin and mucous membranes with an autoimmune proposed pathogenesis. The concurrence of vitiligo and ocular abnormalities has been investigated in different studies, some of which have focused on ocular surface and dry eye evaluation in vitiligo. Aim of the Work Our study aimed at evaluating the tear film changes in patients with vitiligo using clinical assessment, severity indices and AS-OCT, and comparing these findings with healthy matching controls. Patients and Methods A case control observational study that included 60 eyes (the right eye of 30 patients with vitiligo and the right eye of 30 healthy age and sex matched controls). For every patient full dermatological assessment was done and drug history taken. Every study subject was evaluated regarding their dry eye symptomatology using the (OSDI) score questionnaire, clinical effect of dry eye in various tests (Schirmer’s test, TBUT, CFS using Oxford scheme), and using the AS OCT in measuring tear film height. Results We found that vitiligo patients had a lower tear film height when compared with controls (but statistically insignificant). Patients with vitiligo were more symptomatic regarding their dry eye symptoms assessed by OSDI score, they had a shorter tear breakup time than the control group, and a higher CFS grade using Oxford scheme indicating tear film instability. Conclusion Our study revealed lower, but statistically insignificant TFH as compared to the control group. TBUT was shorter, CFS was more evident and Schirmer’s test (although did not reach statistical significance) was shorter in vitiligo patients which revealed a tendency for dry eye syndrome. Supporting these findings, the OSDI score was higher in vitiligo patients. These results indicated worse symptomatology of dry eye in vitiligo patients and lack of stability of their tear film. The findings were supported by multiple previous studies mentioned earlier.

AS OCT as a tool for presumptive diagnosis of conjunctival amyloidosis and follow-up

Clinical diagnosis of conjunctival amyloidosis is quite often difficult, given the diverse clinical manifestations. We report a rare case of primary conjunctival amyloidosis in a 26-year-old male patient in whom a presumptive diagnosis of amyloidosis could be made based on anterior segment optical coherence tomography (AS OCT) and was confirmed histopathologically from the excised specimen. AS OCT revealed multiple, hyperreflective, linear, wavy subepithelial stromal deposits suggestive of amyloidosis. Systemic evaluation by an internist and a hematologist was negative. Herein, we highlight the possible role of AS OCT in diagnosing conjunctival amyloidosis and propose its role as a follow-up tool thus far not described in literature.

3D Mapping of the DMEK Detachment Area from OCT Scans of the Anterior Segment of the Eye - Clinical Applications.

Graft detachment is the most common complication after Descemet membrane endothelial keratoplasty (DMEK). To assess the amount of graft detachment, precision is limited when using slit-lamp biomicroscopy. Detachment of DMEK grafts can be assessed automatically on anterior segment optical coherence tomography (AS OCT) images and allows visualization of the area and volume of detachment using 3D maps. This article provides an overview of its applications such as accurately assessing the course of natural graft attachment, identification of potential risk factors for detachment and evaluation of the long-term effect of graft detachment. The 3D map of DMEK detachment may support researchers and clinicians in precise quantification of the area and volume of graft detachment even in large data sets, and the intuitive, fast and reliable evaluation.

Diagnostic Importance of OCT Pachymetry in Keratoconus.

To demonstrate changes in distance and near fusional vergence measured with prism bars, while compensating for present heterophoria using current ametropia correction. In addition, to determine the differences in values of the AC/A ratio determined by the heterophoric (calculation) and gradient methods. The basic sample includes 19 subjects with a mean age of 21.5 ±3.0 years (min. 18, max. 27). We used the Von Graefe technique for examination of distance and near phoria, and prism bars for examination of fusion vergences measured in prism diopters. We divided the basic cohort into six research sets according to the size of distance and near heterophoria. This was a cohort of patients with distance (D OR) and near orthophoria (N OR), a cohort of patients with distance (D EX) and near exophoria (N EX) and a set of patients with distance (D ES) and near esophoria (N ES). In the case of both groups with exophoria (distance, near) we found a statistically significant result only for negative fusion vergence (NFV). There was a statistically significant increase in NFV in the sample with distance and near exophoria (D EX, p = 0.01 and B EX, p = 0.02, respectively). In our study, we also demonstrated a statistically significant difference (p < 0.001) in the values of the AC/A ratio measured by the gradient and heterophoric methods. The values determined by the gradient method are lower (3.0 ±1.1 pD/D versus 5.8 ±0.9 pD/D) than by the heterophoric method. By comparing fusion vergence values in patients with exophoria and orthophoria, we demonstrated that in the presence of distance or near exophoria there is an increase in ipsilateral fusion vergence. In the case of an increase in ipsilateral fusion vergence, the finding was statistically significant both distance and near (p = 0.01 and p = 0.02, respectively). By contrast, we were unable to prove this fact in the group of patients with esophoria. In our study, we also demonstrated a statistically significant difference (p < 0.001) in the values of the AC/A ratio measured by the gradient and heterophoric methods. The values determined by the gradient method are lower (3.0 ±1.1 pD/D versus 5.8 ±0.9 pD/D) than by the heterophoric method.

ROLE OF ANTERIOR SEGMENT SPECTRAL DOMAIN OCT VS GONIOSCOPY IN DETECTING PRIMARY ANGLE CLOSURE IN A TERTIARY CARE CENTER IN UPPER ASSAM.

Objective- To evaluate anterior chamber angle to detect primary angle closure using anterior segment SD OCT vs Gonioscopy in a Tertiary Care Centre in upper assam. 30 eyes of 20 patients were examined. All patients unde Materials and methods- rwent comprehensive ocular examination, which included best corrected visual acuity, slit lamp examination, dilated fundus examination, intraocular pressure (IOP) measurement by Goldmann applanation tonometer, and gonioscopy. Consecutive patients fullling the inclusion and exclusion criteria were selected . After this, AS SD OCT was performed. Results A total of 30 eyes of 20 patients were examined over a period of six months. The mean age was found to be 50.75 ± 12.05 years. Out of 120 quadrants examined, primary angle closure was found in 75 quadrants in the gonioscopy (PTM not visible) and in 85 quadrants in the anterior segment OCT (Iridotrabecular contact). Overall sensitivity was found to be 95%, and specicity was found to be 70%. The mean trabecular iris angle and angle opening distance at 500 μm were found to be 10 degrees and 185 μm respectively. Conclusion Anterior segment SD OCT is a very sensitive tool that can act as a good screening tool for detecting angle closure

ANTERIOR SEGMENT OPTICAL COHERENCE TOMOGRAPHY IN DETERMINATION OF ENTRY SITE FOR VITRECTOMY IN HIGHLY MYOPIC EYES.

To evaluate the efficacy of anterior segment optical coherent tomography (AS OCT) in estimating the length of the pars plana and optimizing the sclerotomy entry site in vitrectomy for highly myopic eyes, facilitating membrane peeling. Twenty-three eyes with myopic traction maculopathy were studied. The pars plana was examined using two methods: preoperative AS OCT and intraoperative measurement. The distance from the limbus to the ora serrata in two groups was measured to compare differences in length. The actual length of the entry site from the limbus and forceps used were noted in all eyes studied. The mean axial length was 29.2 ± 2.3 mm for all 23 eyes. The average length between the limbus and ora serrata measured with AS OCT and intraoperative examination was 6,710 µ m (SD ± 459) and 6,671 µ m (SD ± 402), respectively, in the superotemporal region ( P > 0.05), and 6,340 µ m (SD ± 321) and 6,204 µ m (SD ± 402), respectively, in the superonasal region ( P >0.05). The mean length of the entry site from the limbus was 6.2 mm, and 28-mm forceps were used in 17 of 23 eyes (77%). The length of the pars plana varies depending on the axial length of the eye. Preoperative AS OCT enables accurate measurement of the pars plana in eyes with high myopia. AS OCT examination can help determine the optimal site for sclerotomy, allowing easier access to the macular region for membrane peeling in highly myopic eyes.

The use of anterior segment optical coherence tomography in infectious keratitis

AbstractPurpose: To describe the anterior segment optical coherence tomography (AS OCT) findings in infectious keratitis.Methods: Forty‐five patients with confirmed microbial keratitis were included in this prospective, observational case series study. All subjects underwent ophthalmologic examination. AS OCT scanning was performed on presentation and at follow‐up.Results: 25 patients (55%) had microbial keratitis, 18 patients (40%) had herpetic keratitis and Two patients (4%) had Fungal keratitis. Twelve different patterns were identified. Thirty‐two of the 45 eyes (71%) had epithelial defect associated with sub‐epithelial infiltrates in twenty cases (44%). In 13 of these cases, hydropic changes were observed. Thirty‐six eyes (80%) showed stromal involvement. Stromal infiltrates were also seen, in twenty cases, as a diffuse or local hyper‐reflective area. Five cases (11%) were associated with uveitis: Retrocorneal hyperreflective deposits, thick inflammatory plaque attached to the endothelium and anterior chamber inflammatory cells were imaged.Conclusions: Infectious keratitis has characteristic features on AS‐OCT images. These patterns are not specific and do not orient towards the nature of the microorganisms but AS‐OCT imaging may provide useful supplementary information for diagnosing and monitoring infectious keratitis.

Role of AS‐OCT in DALK and PKP for KC

AbstractOCT has been a diagnostic device in corneal diseases for many years. Non‐contact examination enables obtaining morphological and morphometric data useful in clinical practice. For example, a patient with keratoconus is a diagnostic tool in surgical procedures such as keratoplasty, intracorneal ring implants, and corneal collagen cross‐linking (CXL). The presentation will show the practical aspects of using AS OCT diagnostics in patients with a cone qualified for deep lamellar keratoplasty and penetrating keratoplasty. The use of intraoperative OCT in surgical treatment supported by excimer and femtosecond lasers will also be presented.

TO COMPARE ANTERIOR CHAMBER DEPTH MEASUREMENTS OBTAINED BY PENTACAM WITH THOSE OBTAINED BY IOL MASTER 700, CIRRUS AS-OCT IN NORMAL HEALTHY EYES.

Purpose: To assess the anterior chamber depth measurements obtained by Pentacam with IOL Master 700 and anterior segment optical coherence tomography. Two hundred and six eyes of healthy subjects were underwent anterior chamber depth meas Methods: urements by Scheimpugbased Pentacam (Oculus, Wetzlar, Germany), IOL Master 700 (Carl Zeiss Meditec, Dublin, CA) and anterior segment optical coherence tomography by same individual. The measurements resulted in mean AC depth of 2.89 ( 0.26)m Results: m with Pentacam, 2.92 ( 0.281)mm with AS OCT and 2.91 ( 0.27)mm with IOL Master 700. Distribution of data showed statistically signicant difference in ACD (P= 0.001) between Pentacam and AS OCT. Similarly, there was statistically signicant difference in ACD (P = 0.000) between Pentacam and IOL Master 700. Conclusions: In healthy individuals, ACD measured between Pentacam and AS OCT showed statistically signicant difference. Similarly, measurements with Pentacam and IOL Master 700 also showed signicant difference. Hence these devices cannot be used interchangeably.

EVALUATION OF THE CORNEAL STROMAL DEMARCATION LINE AFTER THE ACCELERATED CORNEAL CROSS-LINKING USING ANTERIOR SEGMENT OCT.

Evaluation of the visibility and depth of the demarcation line in the corneal stroma in eyes with keratoconus 1 month and 3 months after epi-off accelerated corneal cross-linking (ACXL) using anterior segment optical coherence tomography (AS OCT). This study analyses a group of 34 eyes with keratoconus 1 month and 3 months after ACXL (9 mW/cm2 for 10 min). The group was classified based on the ABCD clinical classification of keratoconus according to Belin and Duncan. AS OCT (ZeissCirrus 500, Anterior Segment Premier module) was used to assess the visibility and exact depth of the demarcation line in the corneal stroma. The demarcation line was visible 1 month after ACXL in 76.5% of eyes with a mean depth of 238.13 ±20.36 μm and 3 months after ACXL in 100% of eyes with a mean depth of 263.43 ±12.59 μm. Statistical analysis of the group did not show a significant relationship between the disease stage and the demarcation line visibility; however, there was a trend towards higher age (>30 years) in the group in those eyes where the demarcation line was visible vs. partially visible 3 months after ACXL. We found no difference in the mean and maximum line depth when comparing 1 month and 3 months after the procedure. There were no cases of disease progression 3 months after ACXL in the group. Our study suggests that the assessment of the demarcation line in the corneal stroma is more reliable 3 months compared to 1 month after ACXL. We also observed a trend towards higher patient age in eyes where the demarcation line was clearly visible 3 months after ACXL. We did not confirm a relationship between the stage of keratoconus and the depth of the line, nor a difference in its mean and maximum depth 1 month and 3 months after the procedure.

An alternative technique for persistent Descemet's membrane detachment following phacoemulsification

Descemet's membrane detachment (DMD) is an uncommon complication of cataract surgery. The prognosis depends upon the prompt recognition and management of DMD. The use of various modalities such as AS OCT, Schiemflug imaging and pachymetry helps in proper diagnosis and selecting appropriate management options. Majority of the DMD are small and spontaneously resolve on their own. For small and limited DMD, Medical management with observation are suffice. For persistent large DMD, descemetopexy with the use of expansile gases have been used to tamponade the DM. Use of HELP algorithm has led to objective assessment of DMD and thinning the grey line between either going for observation or intervention with various modalities available. If descemetopexy fails, corneal venting incision can be used as a last resort before going for Keratoplasty. Keratoplasty still remain the treatment of choice for long standing and persistent DMD.

Long-term results of Boston keratoprosthesis surgery in Polish patients

Abstract Introduction To evaluate the long-term (10 year) outcomes of Boston type 1 keratoprosthesis (BKPro; Massachusetts Eye and Ear Infirmary, Boston, MA) surgery performed in 6 Polish patients. Materials and Methods 6 eyes of 6 patients (1 female and 5 males; mean age 49,5±6,34 years) were qualified for the surgery. Indications for BKPro surgery in the study group included: corneal graft failure (3 patients), chemical ocular burns (2 patients), and post-herpetic keratitis vascularized leucoma (1 patient). Visual acuity, slit-lamp examination with ocular surface assessment, anterior segment optical coherence tomography (AS OCT), fundoscopy, and intraocular digital pressure measurement were performed at each visit. Results Retention of keratoprosthesis was achieved in all patients during the follow-up period. At last recorded visits VA≥0,2 was observed in 3 patients, LP in one patient and NLP in 2 patients. The complications which occurred in our case series were: glaucoma (4 patients preoperatively, 6 patients postoperatively), retroprosthetic membrane formation (1 patient), epimacular membrane formation (2 patients) and severe Meibomian Gland Dysfunction (3 patients). OCT analysis allowed imaging of anterior iris synechiae, AGV tube, protrusion of the BKPro and retroprosthetic membrane not visible on the slit lamp examination. Conclusions BKPro surgery should be considered as a surgery of choice in patients who have high risk of PK failure. OCT plays a role in anterior eye segment monitoring and detection of complications not visible on the slit lamp examination in the follow up period. Implementing the dry eye disease treatment should be recommended in all patients undergoing BKPro surgery.

Impact Of Oct Diagnostics In Wilson-Konovalov Disease. Correlation Between Ocular Changes And Severity Of The Disease

Wilson disease is a genetically transmitted disease with severe hepatic, neurological and psychiatric findings. Purpose: The aim of our survey is to show a new method for objective evaluation of the Keiser-Fleisher Ring in the cornea in patients with Wilson-Konovalov disease. Material and method: In our prospective study 7 patients with Wilson disease and decreased levels of ceruloplasmine under 5.2 g/l were enrolled. They were divided into two groups – with initial finding of the disease – 3 patients and with developed clinical picture – 4 patients. Two patients were after successful liver transplantation. The Keiser-Fleisher ring has been evaluated biomicroscopically, with color photography and with anterior segment ОСТ (Rtvue, Optovue, 3D OCT 2000, Topcone). Results: In the first group of patients with initial stage of the disease on biomicroscopy a slight yellow orange ring in the corneal periphery has been spotted in some of the cases. The AS OCT showed a well outlined hyper-reflective band on the level of the Descemet membrane corresponding to the cooper accumulation in the cornea. In the second group of patients with developed disease, this hyper reflective band was larger with more than 60 mc in comparison to the previous group. In patients after liver transplantation disappearance of the ring and cooper accumulation was observed. The ring vanished form the periphery to the center. Conclusion: Wilson disease is always suspected in cases of undiagnosed liver dysfunction. Its confirmation however, is in many cases subjective and connected with the detection of Keiser-Fleisher Ring. The proposed method with anterior segment OCT is noninvasive, repeatable and can objectively show the presence or absence of cooper depositions in the cornea. OCT diagnostics might be useful also in the follow up of these patients after liver transplantation.

Update on imaging modalities for ocular surface pathologies.

To discuss recent studies of imaging modalities for ocular surface pathologies. Novel micro-ocular coherence tomography technology can produce high-resolution images of corneal cellular and nervous structures. Ocular coherence tomography angiography can aid in detecting early stage limbal stem cell deficiency. Several studies used in vivo confocal microscopy to evaluate corneal nerve metrics and morphology. The applications of anterior segment optical coherence tomography, anterior segment optical coherence tomography angiography, ultrasound biomicroscopy, and in vivo confocal microscopy are useful technologies for imaging the ocular surface. Several studies have used artificial intelligence in combination with imaging technologies to create reliable and effective systems to detect and visualize ocular surface pathologies. AS OCT continues to be a key imaging tool and future development of μOCT technology may further enhance its utility.

Anterior chamber angle classification in anterior segment optical coherence tomography images using hybrid attention based pyramidal convolutional network

As the main cause of irreversible visual impairment, angle-closure glaucoma (ACG) can be detected with anterior segment optical coherence tomography (AS–OCT). The automatic classification of anterior chamber angles (ACA) into closed angle, narrowed angle and open angle in the AS–OCT images is highly significant for understanding glaucoma progression. The traditional techniques for image classification usually rely on the extraction of handcrafted features from the images. Despite the popularity of deep learning methods in image classification, very few researches have been done to utilize them for the multi-class classification of AS–OCT images. In this work, a deep learning based algorithm is proposed for accurate ACA classification in AS–OCT images. The proposed method learns the distinguishable representations from numerous training AS–OCT images using the pyramidal convolution which contains multi-scale of kernels, where each scale includes several kinds of filters with changing depth and size. In this way, it can facilitate capturing the different levels of subtle visual cues that cannot be modeled by the handcrafted features. In addition, the skip connection has been adopted to concatenate the feature maps output at different levels to explore the correlation among them better. Moreover, the hybrid attention module including spatial attention and channel attention is introduced to emphasize important spatial and channel-wise information and reduce redundant information to increase the classification accuracy. We have evaluated classification performance of the proposed algorithm on 2636 ACA images from the Zhongshan Ophthalmic Center, Sun Yat-sen University in China, which is the only public ACG dataset in the world. The experimental results show that our algorithm can classify ACA as closed angle, narrowed angle and open angle effectively and it outperforms existing popular deep learning methods by providing higher specificity, sensitivity, accuracy and balanced accuracy.

A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography

The aim of this study is to compare the scleral thickness of central serous chorioretinopathy (CSC) eyes with controls using anterior segment optical coherence tomography (AS OCT). This prospective case control study included 15 patients (15 eyes) with CSC and 15 age and gender matched healthy subjects. All subjects underwent spectral domain OCT with enhanced depth imaging and swept source AS OCT of temporal sclera. We investigated difference in scleral thickness between the two groups and relationship between choroidal and scleral thickness. Among the 15 eyes in the study group, 1 eye had acute CSC, 4 had recurrent CSC, 7 had inactive CSC, and 3 had chronic CSC. There was no significant difference in terms of age, gender, axial length and spherical equivalent between the two groups. The choroidal and scleral thickness of the study group were significantly greater than those of the control group (P < 0.001, P = 0.034). Choroidal thickness was positively correlated with scleral thickness (P = 0.031). A thick sclera along with a thick choroid were demonstrated in CSC eyes using AS OCT. Scleral characteristics might be involved in the pathogenesis of CSC by affecting outflow resistance of venous drainage in choroidal circulation.

OCT on Anterior Segment Anomalies of the Eye in a Polish Paediatric Cohort: Diagnostic and Therapeutic Challenges.

Purpose To present applications of anterior segment optical coherent tomography (AS OCT) for anomalies of the eye in a Polish paediatric cohort. Materials and Methods Seventy-four eyes of infants and older children were examined. The majority of them underwent general anaesthesia to allow OCT to be performed in the operating room, but a few were examined in a routine way. We focused on corneal, anterior chamber, iris, and lens disorders. Measurements included corneal morphology, anatomy of the anterior chamber, and general involvement of surrounding tissues in pathologic lesions. Results We divided the paediatric patients into several groups by considering the type of disease and involvement of particular tissues. The groups were selected based on OCT usefulness in describing their ocular disorders. Conclusion The collected anterior segment disorders showed huge usefulness for paediatric diagnosis and treatment planning.

Anterior segment optical coherence tomography imaging in peripheral ulcerative keratitis, a corneal structural description

BackgroundAnterior segment optical coherence tomography (AS OCT) is a helpful tool used to diagnose and manage many corneal conditions, but its use has not been reported in case of peripheral ulcerative keratitis (PUK). The aim of this study is to describe AS OCT findings in cases of PUK.MethodsRetrospective observational case series of six eyes presenting with a PUK and proven systemic vasculitis. Clinical course, slit lamp photographs, and AS OCT findings were the main outcomes.ResultsThe AS OCT findings were found to correlate with the ocular disease’s level of activity. In the acute stage, an absence of corneal epithelium, a scrambled appearance of the anterior stroma and a heterogeneous stromal reflectivity were observed. During the reduction of disease level activity, an irregular hyporeflective epithelium, a smoother anterior stroma, and a homogenous hyperreflective stroma were seen. At the healed stage, a filling of the corneal defect by a hyporeflective thick epithelium, the persistence of the hyperreflective underlying stroma, and a demarcation line were observed. The mean total corneal thickness at last follow-up was significantly thicker (509 ± 147 μm) compared with the mean corneal thickness at onset (408 ± 131 μm; P = 0.03).ConclusionsAS OCT provides an assessment of structural changes occurring in PUK, useful for its diagnosis and monitoring.

Evaluation of glaucoma cases with gonioscopy and optical coherence tomography

Glaucoma is the second leading cause of blindness in the adult population of India. Diagnosis and management depends on categorization of Glaucoma into open or closed angle. : To compare the accuracy of Gonioscopy and Anterior Segment Optical Coherence Tomography (ASOCT) in studying the structures of anterior chamber angle of the eye and find out the agreement between them in detecting angle closure. Cross -sectional observational study. The present study is a hospital based cross-sectional study of patients between 20 to 80 years of age with Glaucoma attending the outdoor patient department in a tertiary care government hospital (New civil hospital), Surat. Patients having Corneal Opacity, and anti-Glaucoma surgeries done were excluded. All diagnosed cases of Glaucoma were evaluated by Gonioscopy in the dark with a Goldman 3 mirror lens Gonioscope at high (16x) magnification for static assessment (without indentation). A narrow slit beam, 2mm* 1mm, was cast during Gonioscopy, avoiding direct illumination over the pupil. The angle in each quadrant was graded with the Shaffer grading system. Anterior Segment OCT was done by TOPCON 3D OCT-1 MAESTRO machine. Imaging was performed in dark room conditions. Patients were imaged gazing straight ahead. Imaging of a single meridional section of the Anterior Chamber Angle at superior, inferior, temporal and nasal quadrants were performed. Grading of Anterior Chamber Angles on AS-OCT is termed as Closed if there is no visualization of Scleral Spur and/or any degree of irido-trabecular contact. kappa value, sensitivity &amp; specificity, positive &amp; negative likelihood ratio. Total 50 Glaucoma patients were examined by Gonioscopy and AS OCT. Total number of Angles examined were 400. Total number of Angles closed on Gonioscopy were 136 (34%). Total number of Angles closed on AS OCT were 190 (47.5%). Agreement between Gonioscopy and AS OCT in detecting angle closure in all 4 quadrants was ‘Moderate to Good’ by Kappa Value.

Assessment of Epithelial Thickness in Keratoconic Patients Before and After Intracorneal Ring Segment Implantation Using Anterior Segment Optical Coherence Tomography

Abstract Background Keratoconus, the most common primary corneal ectasia, is a bilateral asymmetric corneal degeneration accompanied with local corneal thinning and occurs mostly in the inferior and central part of the cornea, it usually causes high myopia and irregular astigmatism which results in poor quality of vision. Based on disease severity, many treatment modalities exist including glasses and contact lenses for mild to moderate disease, while corneal graft preserved for more advanced disease. In advent of alternative treatments, intrastromal ring implantation have been introduced which improves visual acuity and optical aberrations and also corrects refractive errors and mean keratometric data, anterior segment Optical cohehernce Tomography epithelial mapping is anew modality to assess epithelial thickness. Objective: To investigate epithelial thickness changes in keratoconic patients before and after intracorneal ring segment implantation using AS OCT. Methods: Thirty eyes with early to moderate keratoconus were included in this prospective interventional case series study which has been conducted at patients from Ain shams university hospitals, after the approval of the research ethical committee in the Faculty of Medicine, Ain Shams University between March to October. All cases underwent a Complete ophthalmological examination before surgery. the examination included Visual acuity assessment and Best corrected visual acuity. Slit Lamp Biomicroscopy examination with fundus examination through dilated pupil using D lens &amp; Corneal Topography, Anterior segment Optical cohehernce Tomography Epithelial mapping(zeiss). Results: we found that epithelial thickness showing statistically significant change comparing pre and post operative epithelial mapping especially in certain areas in the map,area ( _ ),( _ ) mm. Conclusion: There is increase in epithelium thickness in keratoconic corneas after intracorneal ring segment implantation to compensate for stromal irregularities in patients with keratoconus.