Comparative evaluation of corneal and limbal epithelial thickness in brachycephalic dogs with and without corneal diseases using spectral domain optical coherence tomography.

OBJECTIVE: To evaluate alterations in epithelial thickness during corneal degeneration, corneal pigmentation, and additional features observed through spectral-domain optical coherence tomography (SD-OCT) in brachycephalic dogs. ANIMALS AND PROCEDURES: The study used 55 eyes from 49 brachycephalic dogs that underwent OCT-containing ophthalmic examinations. The examined eyes were classified into corneal degeneration, corneal pigmentation, and normal groups according to corneal lesions. For each eye, corneal epithelial thickness (CET) in the central cornea and maximum limbal epithelial thickness (maxLET) in 4 quadrants of limbus (superior, inferior, nasal, and temporal) were measured from OCT images. Additional abnormal findings on OCT images, including irregular epithelium, subepithelial hyperreflectivity, and conjunctivochalasis, were also recorded. RESULTS: The corneal degeneration group had significantly thinner nasal and temporal maxLETs than that of the normal group (p < .001). In the central corneal OCT image of the corneal degeneration group, an irregular epithelium was observed in 70.6% and subepithelial hyperreflectivity in 82.4%, both of which were significantly higher than the normal group (p < .001). In a comparative analysis, the nasal, temporal, and inferior maxLETs were significantly thinner in the corneal pigmentation group than those in the normal group (p < .001, p < .001, and p = .01, respectively). CONCLUSIONS: Morphological changes in the limbal epithelium were observed in dogs with corneal degeneration and corneal pigmentation. LET reduction could be associated with their pathogenesis and would be valuable as an additional parameter for corneal diseases.

Aclaramiento corneal espontáneo tras desprendimiento del injerto en DMEK / Spontaneous corneal clearance after graft detachment in DMEK

El desprendimiento de la membrana de Descemet es una complicación potencial tras la queratoplastia endotelial de la membrana de Descemet (DMEK, acrónimo en inglés de Descemet membrane endothelial keratoplasty). En este artículo presentamos un caso clínico de una cirugía DMEK en un caso complicado, que presentó un desprendimiento casi completo del injerto y posteriormente una opacificación de este y la formación de una seudocámara anterior. En noviembre del 2020, se realizó una cirugía DMEK a un paciente de 64 años debido a una descompensación endotelial. Tres meses después del DMEK, se observó el injerto desprendido y parcialmente adherido, fibrótico en la cámara anterior y formando una seudocámara anterior. Sin embargo, la córnea se mantuvo totalmente transparente con un recuento endotelial de aproximadamente 1.204 células/mm2 y la agudeza visual con corrección fue 20/25. Tres meses más tarde, se objetivó una opacificación significativa del injerto despegado y la agudeza visual disminuyó a 20/63. Procedimos a la extracción del injerto sin realizar una segunda DMEK. Diez meses más tarde, la córnea permaneció transparente con un recuento endotelial de 510 células/mm2 y la agudeza visual con corrección fue 20/25 (AU)

Descemet Membrane detachment is a potential complication after Descemet Membrane Endothelial Keratoplasty (DMEK). Here, we present a unique case of a DMEK surgery in a complicated eye that suffered a nearly complete DMEK graft detachment and later a graft opacification with a pseudo-anterior chamber. In Mid-November 2020, a planned DMEK was performed in a 64-year-old male patient due to corneal decompensation. Four months after DMEK, a fibrotic DMEK graft was seen across the anterior chamber with a pseudo-anterior chamber; however, the recipient cornea showed complete clearance with an endothelial cell count of about 1204 cells/mm2 and a best-corrected visual acuity of 20/25. Three months later, we observed a significant opacification of the detached graft, and the best-corrected distance visual acuity decreased to 20/63. We proceeded with the graft removal without performing a second DMEK. Ten months after graft removal, the cornea remained clear with an endothelial cell count of about 510 cells/mm2, and the best-corrected visual acuity was 20/25 (AU)

Assessment of corneal and limbal epithelial thickness by spectral-domain optical coherence tomography in brachycephalic and non-brachycephalic dogs.

OBJECTIVE: To investigate the variance in corneal epithelial thickness (CET) and limbal epithelial thickness (LET) according to the age and skull type by using spectral-domain optical coherence tomography (SD-OCT) in normal dogs. ANIMALS AND PROCEDURES: This study used an eye each from 46 dogs (24 brachycephalic and 22 non-brachycephalic dogs) assessed to have clear corneas. Each dog was classified according to age into groups 1 (0-5 years), 2 (6-10 years), and 3 (>11 years). OCT imaging was performed on the central cornea for CET and perpendicular to the quadrant of the limbus for LET. The average of the maximum LET (maxLET) value was measured in four eye quadrants. RESULTS: Corneal epithelial thickness was not significantly different according to age in brachycephalic and non-brachycephalic dogs. Visualization of the limbal invagination was better when the maxLET was thick. Nasal and temporal maxLETs were significantly thicker than superior and inferior maxLETs in non-brachycephalic dogs. In brachycephalic dogs, there was a significant decrease in nasal maxLET with age (rs  = -0.489, p = .015). Significant differences between brachycephalic and non-brachycephalic dogs were observed in nasal maxLET (p = .024) and temporal maxLET (p = .011). CONCLUSIONS: Invagination was better visualized in the nasal and temporal limbal quadrants of non-brachycephalic dogs compared with brachycephalic dogs, and the maxLETs of the regions were thicker than those of the brachycephalic dogs. CET and LET measurements using SD-OCT can help in clinical assessment and research on ocular surface diseases in dogs.

Is anterior segment OCT superior to slit-lamp biomicroscopic examination for Kayser Flesicher ring in Wilson's disease?

OBJECTIVE: Detection of the Kayser-Fleischer (KF) ring in the diagnostic scoring and treatment follow-up of Wilson's Disease (WD) is important. Slit lamp (SL) biomicroscopic examination has traditionally been used in the evaluation of the KF ring. The role of Anterior Segment Optical Coherence Tomography (AS-OCT), which is used in various corneal diseases, in the detection of KF rings has attracted attention in recent years. In our study, we tried to demonstrate the effectiveness of AS-OCT in detecting the KF ring by comparing it with SL biomicroscopic examination. PATIENTS AND METHODS: 64 of 356 patients followed in our outpatient clinic due to WD were included in the study in the order of their admission to the outpatient clinic. The KF ring was evaluated in both eyes by SL-biomicroscopic examination and AS-OCT. Ophthalmic examination, and findings were performed by the same physician. RESULTS: Age range was 18-67 years, mean 33.06±10.83 years, gender was 39.1% (n: 25) female. At the time of diagnosis, the mean age was 19.48 ± 9.36 years, range was minimum 5 years and maximum 51 years. Clinical presentation was mixed type involvement n: 18 (28.1%), hepatic involvement n: 32 (50%), neurological involvement n: 14 (21.9%). The follow-up period was 2-257 months (74.6±76.16). The presence of KF ring was evaluated together with both AS-OCT and slit-lamp examination, the presence of KF could be detected in both AS-OCT and SL biomicroscopic examination in 10 patients (15.6%), in 12 (18.8%) of the cases KF ring is positive in AS-OCT but was negative in Slit-lamp biomicroscopic examination, in 65.6 (n: 42) of the cases OCT and slit-lamp biomicroscopic examination results were negative. CONCLUSIONS: The sensitivity of AS-OCT in detecting the KF ring was higher than the slit-lamp biomicroscopic examination. AS-OCT can detect early stage of KF rings in Wilson's Disease patients, so that diagnosis and treatment accuracy can be evaluated effectively.

Evaluation of equine corneal disease using ultrasound biomicroscopy.

OBJECTIVE: To describe the clinical use of ultrasound biomicroscopy (UBM) to evaluate equine corneal disease. METHODS: Images were obtained using a 50-MHz probe ultrasound biomicroscopy system (Quantel Aviso) and Clear Scan® probe cover. Six horses with corneal disease were evaluated via UBM for lesion size, lesion depth, and continuity of Descemet's membrane. Horses were sedated and received auriculopalpebral nerve blocks and application of topical anesthetic prior to UBM. RESULTS: Ultrasound biomicroscopy was easily performed in all cases. UBM evaluation of three cases of corneo-limbal squamous cell carcinoma yielded information regarding lesion depth for planning of keratectomies using fixed-depth keratomes and subsequent ß-radiation therapy. Corneal depth and continuity of Descemet's membrane were determined in two horses with stromal abscesses and allowed for planning of therapeutic options. In one horse with a corneal foreign body, UBM contributed to accurate assessment of the foreign body's stromal depth, which could not be assessed during ophthalmic examination due to extensive corneal cellular infiltrate. The information regarding corneal depth allowed for more accurate pre-surgical planning in patients with opaque corneal lesions. CONCLUSIONS: Ultrasound biomicroscopy was easily performed and provided useful information regarding lesion depth and continuity of Descemet's membrane for patients with corneo-limbal squamous cell carcinoma, stromal abscesses, and a corneal foreign body, allowing for increased precision in pre-surgical planning and development of therapeutic protocols.

Intraoperative Optical Coherence Tomography: Game-Changing Technology.

ABSTRACT: Intraoperative optical coherence tomography (OCT) has the potential to revolutionize lamellar corneal surgery and facilitate many other types of ocular surgery because it readily visualizes ocular structures that can be difficult to discern with a coaxial microscope, particularly through a cloudy cornea. Systems that can provide a high-quality image on demand in the surgeon's oculars, rather than just on an adjacent monitor, are the most useful because they allow the surgeon to rely on the OCT image while operating, without having to look away from the surgical field. Useful applications in lamellar corneal surgery include assessing graft attachment with Descemet stripping endothelial keratoplasty and discerning graft orientation with Descemet membrane endothelial keratoplasty, which otherwise could be challenging in an eye with a cloudy cornea. Intraoperative OCT is particularly helpful when performing deep anterior lamellar keratoplasty in cases in which a big bubble should not be attempted or cannot be achieved because it enables better intraoperative control of the incision depth and allows the surgeon to assess the uniformity of the dissection plane to optimize visual outcomes. Intraoperative OCT is also useful when judging the depth of a scar for a lamellar dissection, when evaluating intraocular lens positioning in the capsular bag, or when locating and removing retained nuclear fragments from an eye with a poor view because of a cloudy cornea. The primary barrier to the adoption of this valuable technology is cost.

Case Series: High-resolution Optical Coherence Tomography as an Optical Biopsy in Ocular Surface Squamous Neoplasia.

SIGNIFICANCE: Ocular surface squamous neoplasias are superficial tumors of the cornea and conjunctiva that can be sight threatening if neglected. Therefore, accurate noninvasive diagnostic modalities are needed. PURPOSE: The purpose of this case series was to describe the hallmark features of ocular surface squamous neoplasia on high-resolution optical coherence tomography (HR-OCT) imaging and its use in the evaluation and management of superficial ocular tumors. CASE SERIES: Five eyes of four patients with ocular surface squamous neoplasia are described. Whereas two eyes displayed the classic clinical features of ocular surface squamous neoplasia, three of the five eyes had more subtle atypical features. However, all shared features on HR-OCT of epithelial thickening and hyperreflectivity with abrupt transitions between normal and abnormal tissue, classic features of ocular surface squamous neoplasia. All lesions ultimately underwent incisional or excisional biopsy and were confirmed to be ocular surface squamous neoplasia on histopathology. CONCLUSIONS: Ocular surface squamous neoplasia may present as a classic tumor but can also have subtle features or masquerade. Accurate methods to diagnose and manage patients with ocular surface squamous neoplasia are necessary. With recent advancements in technology, HR-OCT has been demonstrated to accurately identify ocular surface squamous neoplasia with the repeatable optical findings of (1) epithelial thickening, (2) epithelial hyperreflectivity, and (3) abrupt transition zone between normal and abnormal tissue. This case series demonstrates how HR-OCT can help provide an optical biopsy to guide appropriate diagnosis and management of this neoplastic lesion.

A Novel Network With Parallel Resolution Encoders for the Diagnosis of Corneal Diseases.

OBJECTIVE: To propose a deep-learning network for the diagnosis of two corneal diseases: Fuchs' endothlelial dystrophy and keratoconus, based on optical coherence tomography (OCT) images of the cornea. METHODS: In this paper, we propose a novel network with parallel resolution-specific encoders and composite classification features to directly diagnose Fuchs' endothelial dystrophy and keratoconus using OCT images. Our proposed network consists of a multi-resolution input, multiple parallel encoders, and a composite of convolutional and dense features for classification. The purpose of using parallel resolution-specific encoders is to perform multi-resolution feature fusion. Also, using composite classification features enhances the dense feature learning. We implemented other related networks for comparison with our network and performed k-fold cross-validation on a dataset of 16,721 OCT images. We used saliency maps and sensitivity analysis to visualize our proposed network. RESULTS: The proposed network outperformed other networks with an image classification accuracy of 0.91 and a scan classification accuracy of 0.94. The visualizations show that our network learned better features than other networks. SIGNIFICANCE: The proposed methods can potentially be a step towards the early diagnosis of corneal diseases, which is necessary to prevent their progression, hence, prevent loss of vision.

Floral Pattern of Keratic Precipitates in Vitreoretinal Lymphoma on In Vivo Confocal Microscopy.

PURPOSE: To describe the morphological patterns of keratic precipitates (KPs) in vitreoretinal lymphoma (VRL) using in vivo confocal microscopy (IVCM). METHODS: Six eyes of three biopsy-proven VRL patients were included. KPs were identified and analyzed on IVCM. RESULTS: On examination, pigmented KPs in four eyes, white central KPs in two eyes and anterior chamber cells with flare in six eyes and pseudo hypopyon in one eye were identified. A typical floral pattern of KPs on IVCM was noted in all eyes. Three eyes each showed the complete and incomplete floral patterns, respectively. Resolution of KPs on IVCM was noted after chemotherapy. CONCLUSION: In addition to the routinely used clinical and imaging markers like the visual acuity, presence of lymphomatous cells in the vitreous and optical coherence tomography findings, the presence and appearance of KPs on IVCM can also be considered as a useful, diagnostic and treatment monitoring marker in VRL.

The utility of anterior segment optical coherence tomography angiography for the assessment of limbal stem cell deficiency.

PURPOSE: To determine the utility of anterior segment optical coherence tomography angiography (AS-OCTA) in assessing limbal stem cell deficiency (LSCD). METHODS: Twenty-six eyes of 24 LSCD patients, classified clinically into stage I, II and III, and 12 eyes of 12 healthy subjects were included. AS-OCTA images were analyzed by two masked observers, measuring the maximum corneal vascular extension (CoVE) from the limbus to the furthest vessel over the cornea, and corneal vascular thickness (CoVT) from the most superficial to the deepest corneal vessel. RESULTS: CoVE was 0.27 ± 0.10, 0.79 ± 0.21, 1.68 ± 0.89 and 2.53 ± 0.82 mm in controls, stage I, II and III LSCD, respectively (p < 0.001). The CoVT was 51.0 ± 19.4, 113.7 ± 36.6, 129.7 ± 39.3 and 336.0 ± 85.0 µm, respectively (p < 0.001). There was a significant difference in CoVE and CoVT between all stages compared to controls, and between stage I and III LSCD (p < 0.001). Further, CoVE showed a significant difference between stage I and II, whereas CoVT showed a significant difference between stage II and III LSCD (p < 0.001). BCVA showed strong correlation with CoVT (r = 0.765, p < 0.001) and moderate correlation with CoVE (r = 0.547, p = 0.001). AS-OCTA parameters showed excellent intra- and inter-class correlation coefficients (>0.900). CONCLUSION: LSCD demonstrates significant changes in CoVE and CoVT as early as stage I LSCD in comparison to controls. CoVE and CoVT strongly correlate to both disease severity and BCVA. AS-OCTA may provide novel quantitative and non-invasive parameters to assess LSCD.

OCT-SA en queratólisis sobre anillo intraestromal / AS-OCT in corneal melt overlying intrastromal ring segment

No disponible

The findings of corneal specular microscopy in patients with type-2 diabetes mellitus.

BACKGROUND: We aimed to compare the morphological characteristics of corneal endothelial cells in type 2 diabetic patients and age-matched healthy subjects by specular microscopy. We also aimed to determine the association of corneal morphological features with the general characteristics and laboratory data of diabetic patients, including disease duration, haemoglobin A1c (HbA1c) levels and urine albumin creatinine ratio. METHODS: A total of 195 diabetic patients and 100 healthy controls were enrolled in the study. All participants underwent a complete ophthalmological examination. Corneal endothelial measurements were performed using a noncontact specular microscopy. Laboratory data including serum fasting glucose, haemoglobin A1c levels, creatinine levels, and the urinary albumin-to-creatinine ratio were recorded. Diabetic patients were further subdivided into 3 groups according to the presence and stage of diabetic retinopathy. Specular microscopy findings and central corneal thickness of all patients were compared. RESULTS: The ECD and hexagonal cell ratio were significantly lower, while the average cell size, CV%, and central corneal thickness were determined to be significantly higher in diabetic patients than in healthy controls (p = 0.001). With the presence and advancement of diabetic retinopathy, the ECD and hexagonal cell ratio decreased, while the average cell size, CV%, and central corneal thickness increased. When correlation analysis was performed between corneal morphological features and laboratory data of diabetic patients, ECD showed a significant negative correlation with diabetes duration (p = 0.028). HbA1c levels, urinary albumin-creatinine ratio (p = 0.041), average cell size and CV showed a positive correlation with these parameters. CONCLUSION: In conclusion, keratopathy is an important complication of type 2 diabetes. With an increase in the stage of diabetic retinopathy, alterations in corneal findings also increased. In that respect, we can suggest that keratopathy should be evaluated more cautiously in diabetic patients.

Collector Channels: Role and Evaluation in Schlemm's Canal Surgery.

OBJECTIVES: 1) To elucidate the role of collector channels in the aqueous humor outflow pathway 2) To suggest anatomic and functional methods of imaging collector channels in-vitro and in-vivo and 3) To discuss the role of such imaging modalities in the surgical management of glaucoma. METHODS: A thorough literature search was conducted on databases for studies published in English regarding the available methods to determine the role of collecting channels in normal and glaucomatous patients and to assess their patency. RESULTS: Intraocular pressure (IOP) exists as a balance between aqueous humor production and aqueous humor outflow. Collector channels are an essential anatomical constituent of the distal portion of the conventional aqueous humor outflow pathway. There are different surgical options for glaucoma management and with the recent advances in Schlemm's canal-based surgeries, collector channel's patency became a key factor in determining the optimum management for the glaucomatous eye. The advent of anatomic imaging methods has improved the ability to visualize collector channel morphology in-vitro, including swept-source optical coherence tomography (SS-OCT), spectral domain optical coherence tomography (SD-OCT), micro-computed tomography (micro CT), new immunohistochemistry techniques and scanning electron microscopy. The recent advent of real-time assessment of collector channel patency (including evaluation of episcleral venous outflow, observation of episcleral venous fluid wave, and tracer studies utilizing fluorescein, indocyanine green, and trypan blue) has been validated by the aforementioned anatomic imaging modalities. CONCLUSIONS: New modalities of in-vitro and in-vivo studies of collector channels provide promise to aid in the assessment of collector channel patency and individualization of surgical management for glaucoma patients.

Tomografía de coherencia óptica de segmento anterior de alta resolución como método de diagnóstico diferencial entre neoplasia intraepitelial córneo-conjuntival y pterygium / High resolution anterior segment optical coherence tomography for differential diagnosis between corneo-conjunctival intraepithelial neoplasia and pterygium

OBJETIVO: Valorar si la tomografía de coherencia óptica de segmento anterior (OCT-SA) es un método de diagnóstico no invasivo adecuado para diferenciar lesiones córneo-conjuntivales benignas (pterygium) de las premalignas (neoplasia intraepitelial córneo-conjuntival [CIN]). MATERIAL Y MÉTODOS: Estudio observacional, analítico y transversal de 22 ojos con diagnóstico de sospecha de pterygium y CIN durante 2 años. Con la OCT-SA se estudiaron las características morfológicas y se compararon espesores epiteliales (EE) y grado de extensión sobre la superficie corneal (GIC). Posteriormente se confirmó el diagnóstico con el estudio histopatológico tras exéresis quirúrgica. RESULTADOS: La edad media de los pacientes con pterygium (n = 18) fue de 52,67 ± 15 años y 74 ± 12 años en los sujetos con CIN (n = 4) (p < 0,021). En los pterygium, la OCT-SA mostró EE normal, adelgazado o levemente aumentado (77,4 ± 26 μm), además de aumento del tejido subepitelial en forma de cuña. Los CIN presentaron un aumento del EE (262,5 ± 124 μm), que era fuertemente hiperreflectivo, con transición abrupta entre epitelio sano y patológico. El análisis de los EE en OCT-SA entre pterygium y CIN reveló diferencias estadísticamente significativas (p < 0,002). La curva ROC reveló una sensibilidad y especificidad del 100% de la OCT-SA en la diferenciación entre CIN y pterygium, utilizando EE de 141μm como punto de corte. CONCLUSIÓN: La OCT-SA es una herramienta útil para la diferenciación entre pterygium y CIN, ya que proporciona características morfológicas típicas. Un aumento del espesor del EE córneo-conjuntival mayor de 141 μm en OCT-SA sugiere una sensibilidad y especificidad del 100% para diagnosticar CIN

OBJECTIVE: To assess if anterior segment optical coherence tomography (AS-OCT) is a noninvasive diagnostic method suitable to differentiate benign corneo-conjunctival lesions (pterygium) from premalignant lesions (corneo-conjunctival intraepithelial neoplasia, CIN). MATERIAL AND METHODS: An observational, analytical and cross-sectional study was conducted in 22 eyes with conjunctival lesions clinically suspicious for pterygium and CIN during two years. Morphological differences between both lesions were studied with AS-OCT; epithelial thicknesses (EE) and extension length on corneal surface (GIC) were compared between both groups. A surgical excision of the lesion was performed for histopathological diagnosis. RESULTS: Mean age of patients with pterygium (n = 18) was 52.67 ± 15 y.o and 74 ± 12 y.o in subjects with CIN (n = 4) (p < 0.021). In pterygia, AS-OCT showed typical features (normal, thinning or slightly thickened EE; 77.4 ± 26 μm), in addition to an increase in wedge-shaped subepithelial tissue. Patients with CIN had a mean thickened EE (262.5 ± 124μm) and strongly hyperreflective, with abrupt transition between normal and pathological epithelium. Analysis of EE between subjects with pterygium and CIN revealed statistically significant differences (p < 0.002). ROC curve revealed a 100% sensitivity and specificity of OCT-SA in differentiation between CIN and pterygium, using 141μm as cutoff point of EE. CONCLUSION: AS-OCT is a useful tool for the differentiation between pterygium and CIN able to provide typical morphological characteristics. An EE greater than 141 μm in AS-OCT suggests a sensitivity and specificity of 100% for the diagnosis of CIN

Examination of corneal deposits in nephropathic cystinosis using in vivo confocal microscopy and anterior segment optical coherence tomography: an age-dependent cross sectional study.

BACKGROUND: Presence of corneal cystine crystals is the main ocular manifestation of cystinosis, although controversial findings concerning the corneal layer with the highest density have been reported. The aim of this study was the analysis of the characteristics of crystal arrangement in different corneal layers and the assessment of corneal morphological changes with age. METHODS: A cross sectional study was carried out in three children and three adults who had nephropathic cystinosis and corneal cystine depositions. All patients underwent a comprehensive ophthalmological examination including best corrected distance visual acuity, slit-lamp examination, in vivo confocal microscopy and anterior segment optical coherence tomography. An evaluation of the depth of crystal deposits and crystal density in different corneal layers was also performed. Due to the low number of subjects no statistical comparison was performed. RESULTS: Anterior segment optical coherence tomography images revealed deposition of hyperreflective crystals from limbus to limbus in each patient. Crystals appeared as randomly oriented hyperreflective, elongated structures on in vivo confocal microscopy images in all corneal layers except the endothelium. In children the deposits occurred predominantly in the anterior stroma, while in adults, the crystals were mostly localized in the posterior corneal stroma with the depth of crystal deposition showing an increasing tendency with age (mean depth of crystal density was 353.17 ± 49.23 µm in children and it was 555.75 ± 25.27 µm in adults). Mean crystal density of the epithelium was 1.47 ± 1.17 (median: 1.5; interquartile range: 0.3-2.4). Mean crystal density of the anterior and posterior stroma of children and adults was 3.37 ± 0.34 (median: 3.4; interquartile range: 3.25-3.55) vs. 1.23 ± 0.23 (median: 1.2; interquartile range: 1.05-1.35) and 0.76 ± 0.49 (median: 0.7; interquartile range: 0.4-1.15) vs. 3.63 ± 0.29 (median: 3.7; interquartile range: 3.45-3.8), respectively. Endothelium had intact structure in all cases. Some hexagonal crystals were observed in two subjects. CONCLUSIONS: In vivo confocal microscopy and anterior segment optical coherence tomography confirmed an age-related pattern of crystal deposition. In children, crystals tend to locate anteriorly, while in adults, deposits are found posteriorly in corneal stroma.