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Berger T, Weiss JS, Lisch W, Seitz B. [The latest IC3D classification of corneal dystrophies-Overview and changes of the 3rd edition]. DIE OPHTHALMOLOGIE 2024:10.1007/s00347-024-02066-w. [PMID: 38951244 DOI: 10.1007/s00347-024-02066-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/29/2024] [Accepted: 06/06/2024] [Indexed: 07/03/2024]
Abstract
The International Committee on Classification of Corneal Dystrophies (IC3D) was founded in 2005 to address difficulties arising from the outdated nomenclature for corneal dystrophies (CD) and to correct misconceptions in the literature. For each of the 22 CDs, a separate template was created to represent the current clinical, pathological and genetic knowledge of the disease. In addition, each template contains representative clinical photographs as well as light and electron microscopic images and, if available, confocal microscopic and coherence tomographic images of the respective CD. After the first edition was published in 2008, the revised version followed in 2015. The third edition of the IC3D was published as open access in February 2024. The latest edition is intended to serve as a reference work in everyday clinical practice and facilitate the diagnosis of CD, which might sometimes be difficult. This article provides an overview of the diagnostic and treatment principles of CD and presents the IC3D and its changes over time.
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Affiliation(s)
- Tim Berger
- Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes (UKS), Homburg/Saar, Deutschland.
| | - Jayne S Weiss
- Departments of Ophthalmology, Pathology and Pharmacology, Louisiana State University Eye Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Walter Lisch
- Augenklinik und Poliklinik der Universitätsmedizin Mainz, Johannes Gutenberg-Universität Mainz, Mainz, Deutschland
| | - Berthold Seitz
- Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes (UKS), Homburg/Saar, Deutschland
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Hashemi A, Nabovati P, Hashemi H, Mortazavi AG, Khabazkhoob M. Corneal densitometry and associated factors in an elderly population. Clin Exp Optom 2024; 107:522-529. [PMID: 37674266 DOI: 10.1080/08164622.2023.2242864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/26/2023] [Indexed: 09/08/2023] Open
Abstract
CLINICAL RELEVANCE Knowing normative corneal optical density (COD) values is important for identifying pathologic corneal changes. BACKGROUND The aim of this work is to determine the distribution and associated factors of COD in the elderly population. METHODS This report is a part of a cross-sectional population-based study conducted on the elderly population (≥60 years) of Tehran, Iran from Jan 2019 to Jan 2020. Using a multi-stage stratified random cluster sampling method, a total of 160 clusters were randomly selected from 22 districts of Tehran city. Study participants underwent a complete ocular examination including measurement of visual acuity, refraction, and slit-lamp biomicroscopy. Corneal densitometry was evaluated using the Pentacam HR. Generalized estimating equation (GEE) models were used to investigate associations of COD with study variables. RESULTS A total of 3633 eyes from 2068 individuals were analysed. Of these, 1256 (60.7%) were female, and the mean age of the individuals was 66.42 ± 5.28 (60 to 95) years. The mean entire COD was 21.96 ± 4.45 greyscale unit (GSU) (95% CI: 21.57-22.34). There was a statistically significant difference in the mean COD between the anterior, central, and posterior layers (p < 0.001); the highest and lowest average COD was related to the anterior and posterior corneal layers, respectively. The lowest and highest mean COD were observed in the 0-2 mm [17.21GSU (95% CI:16.87-17.55)], and 10-12 mm annular zones [31.4 GSU (95% CI: 30.89-31.91)], respectively (p < 0.001). According to the multiple GEE model, the COD had a statistically significant direct relationship with age, central corneal thickness, and mean keratometry, while it was significantly inversely associated with female sex, anterior chamber depth, white-to-white distance, and corneal volume. CONCLUSION These normal values of COD in the present study could be used as reference data in older adults. The associated factors of COD should be taken into account to avoid misinterpretation of physiologic changes as pathologic processes.
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Affiliation(s)
- Alireza Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Payam Nabovati
- Rehabilitation Research Center, Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | - Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Abol Ghasem Mortazavi
- Department of Neurosurgery, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Khabazkhoob
- Department of Basic Sciences, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Chang MS, Jun I, Kim EK. Mini-Review: Clinical Features and Management of Granular Corneal Dystrophy Type 2. KOREAN JOURNAL OF OPHTHALMOLOGY 2023; 37:340-347. [PMID: 37336511 PMCID: PMC10427907 DOI: 10.3341/kjo.2023.0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/28/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023] Open
Abstract
Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant corneal stromal dystrophy that is caused by p.Arg124His mutation of transforming growth factor β induced (TGFBI) gene. It is characterized by well demarcated granular shaped opacities in central anterior stroma and as the disease progresses, extrusion of the deposits results in ocular pain due to corneal epithelial erosion. Also, diffuse corneal haze which appears late, causes decrease in visual acuity. The prevalence of GCD2 is high in East Asia including Korea. Homozygous patients show a severe phenotype from an early age, and the heterozygote phenotype varies among patients, depending on several types of compound heterozygous TGFBI mutations. In the initial stage, conservative treatments such as artificial tears, antibiotic eye drops, and bandage contact lenses are used to treat corneal erosion. Different surgical methods are used depending on the depth and extent of the stromal deposits. Phototherapeutic keratectomy removes anterior opacities and is advantageous in terms of its applicability and repeatability. For deeper lesions, deep anterior lamellar keratoplasty can be used as the endothelial layer is not always affected. Recurrence following these treatments are reported within a wide range of rates in different studies due to varying definition of recurrence and follow-up period. In patients who have undergone corneal laser vision-correction surgeries such as photorefractive keratectomy, LASEK, or LASIK including SMILE surgery, corneal opacity exacerbates rapidly with severe deterioration of visual acuity. Further investigations on new treatments of GCD2 are necessary.
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Affiliation(s)
- Myung Soo Chang
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul,
Korea
| | - Ikhyun Jun
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul,
Korea
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul,
Korea
| | - Eung Kweon Kim
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul,
Korea
- Saevit Eye Hospital, Goyang,
Korea
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He Y, Ma BS, Zeng JH, Ma DJ. Corneal optical density: Structural basis, measurements, influencing factors, and roles in refractive surgery. Front Bioeng Biotechnol 2023; 11:1144455. [PMID: 37091331 PMCID: PMC10117965 DOI: 10.3389/fbioe.2023.1144455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023] Open
Abstract
The cornea is the main refractive medium of the human eye, and its clarity is critical to visual acuity. Corneal optical density (COD) is an important index to describe corneal transparency. Intact corneal epithelial and endothelial cells, regular arrangement of collagen fibers in the stroma, and normal substance metabolism are all integral for the cornea to maintain its transparency. In the last two decades, the Pentacam Scheimpflug imaging system has emerged as a breakthrough for the measurement of COD (also called corneal densitometry). It has been found that a wide variety of factors such as age, refractive status, and corneal diseases can affect COD. Different corneal refractive surgery methods also change COD in different corneal regions and layers and affect visual acuity following the surgery. Thus, COD has gradually become a significant indicator to evaluate corneal health, one on which the attention of clinicians has been increasingly focused.
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Affiliation(s)
- Ye He
- Changsha Aier Eye Hospital, Changsha, China
| | - Bo-Sheng Ma
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jun-Hao Zeng
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Dai-Jin Ma
- Changsha Aier Eye Hospital, Changsha, China
- *Correspondence: Dai-Jin Ma,
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New algorithm for corneal densitometry assessment based on anterior segment optical coherence tomography. Eye (Lond) 2021; 36:1675-1680. [PMID: 34341484 PMCID: PMC9307768 DOI: 10.1038/s41433-021-01707-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 07/01/2021] [Accepted: 07/16/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To describe a new algorithm to measure corneal densitometry based on images obtained by swept source anterior segment ocular coherence tomography (SS-AS-OCT) and establish standard densitometry values in a group of normal eyes. METHODS A total of 111 healthy participants (195 eyes) were enrolled in this study. Using a MATLAB designed algorithm, the cornea was segmented into three layers: anterior, posterior and mid-stroma, and it was divided into two concentric areas, 0-2 and 2-4 mm, resulting in nine areas for the analysis. The mean corneal densitometry values were calculated and expressed as grayscale units (GSU). RESULTS The mean age was 57 years (range 22-87), with 100 (51.3%) right eyes and 95 (48.7%) left eyes. The total corneal densitometry was 86.9 ± 12.1 GSU. The mid-stroma layer had the highest densitometry values, 87.4 ± 12.1 GSU, and the anterior layer had the lowest values, 81.9 ± 14.2 GSU. Densitometry differences between the anterior layer and the mid-stroma layer (P < 0.001), as well as the anterior layer and the posterior layer (P < 0.05) were statistically significant. The 0-2 mm concentric area had higher mean densitometry values, 97.8 ± 12.7 GSU, and the differences were significant compared to the 2-4 mm concentric area (P < 0.001). No correlation was found between the corneal densitometry values and gender or age. CONCLUSIONS The new MATLAB segmentation algorithm for the analysis of corneal SS-AS-OCT images is capable to objectively assess corneal densitometry. We provide standard and normal data for better clinical and research approach.
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Rocha-de-Lossada C, Rachwani-Anil R, Colmenero-Reina E, Borroni D, Sánchez-González JM. Laser refractive surgery in corneal dystrophies. J Cataract Refract Surg 2021; 47:662-670. [PMID: 33149045 DOI: 10.1097/j.jcrs.0000000000000468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 09/20/2020] [Indexed: 12/17/2022]
Abstract
Twenty-eight case reports and case series published between 2000 and 2019 concerning laser refractive surgery in patients with corneal dystrophies, resulting in 173 eyes from 94 patients, were included in this systematic review. Best results were achieved in posterior corneal polymorphous and Cogan dystrophy. Unfavorable results were found in Avellino dystrophy and Fuchs endothelial corneal dystrophy (FECD). Photorefractive keratectomy was not indicated in Meesmann and Avellino dystrophy. Laser in situ keratomileusis was indicated in posterior polymorphous corneal dystrophy but not in FECD, Avellino, or Cogan dystrophy. Small-incision lenticule extraction and other dystrophies such as lattice, fleck, Lisch, or François did not achieve enough scientific evidence to report any recommendation.
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Affiliation(s)
- Carlos Rocha-de-Lossada
- From the Department of Ophthalmology, Hospital Clinic de Barcelona, Barcelona, Spain (Rocha-de-Lossada); Department of Ophthalmology, Regional University Hospital of Malaga, Malaga, Spain (Rachwani-Anil); Department of Ophthalmology and Optometry, Vistalaser Clinic, Malaga, Spain (Colmenero-Reina); Department of Doctoral Studies, Riga Stradins University, Riga, Latvia (Borroni); Department of Ophthalmology, Royal Liverpool University Hospital, Liverpool, United Kingdom (Borroni); Department of Physics of Condensed Matter, Optics Area. University of Seville, Seville, Spain (Sánchez-González); Department of Ophthalmology, Tecnolaser Clinic Vision, Refractive Surgery Centre, Seville, Spain (Sánchez-González)
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Nielsen NS, Poulsen ET, Lukassen MV, Chao Shern C, Mogensen EH, Weberskov CE, DeDionisio L, Schauser L, Moore TC, Otzen DE, Hjortdal J, Enghild JJ. Biochemical mechanisms of aggregation in TGFBI-linked corneal dystrophies. Prog Retin Eye Res 2020; 77:100843. [DOI: 10.1016/j.preteyeres.2020.100843] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 12/22/2022]
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How Does Light Intensity of the Recording Room Affect the Evaluation of Lens and Corneal Clarity by Scheimpflug Tomography? Cornea 2019; 39:137-139. [DOI: 10.1097/ico.0000000000002212] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ishikawa S, Kato N, Takeuchi M. Quantitative evaluation of corneal epithelial edema after cataract surgery using corneal densitometry: a prospective study. BMC Ophthalmol 2018; 18:334. [PMID: 30572855 PMCID: PMC6302480 DOI: 10.1186/s12886-018-0998-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 12/05/2018] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The optical density of the cornea can be evaluated quantitatively by "densitometry" using a rotating Scheimpflug camera. Densitometry allows evaluation of corneal opacity in the anterior segment of the eye by quantitative measurement of scattering light. In the present investigation, we evaluate quantitatively minimal subclinical corneal edema after cataract surgery using densitometry. METHODS Fifty four eyes of 34 patients who underwent cataract surgery were enrolled. Measurement of corneal density was performed using Pentacam® before and on days 1, 3 and 7 after surgery. RESULTS Densitometry scores increased from 18.12 ± 1.76 before cataract surgery to 21.03 ± 3.84 on day 1 (P < 0.001) and 19.90 ± 2.46 on day 3 (P = 0.018), but recovered to 19.44 ± 1.58 on day 7 (P = 0.131). Total corneal thickness was 549.1 ± 32.7 μm before surgery and increased to 582.7 ± 46.3 μm on day 1 (P = 0.001), but recovered to 566.4 ± 29.7 μm on day 3 (P = 0.097). Densitometry reading correlated positively with corneal thickness (correlation coefficient = 0.13, P = 0.003). CONCLUSIONS Densitometry is useful to detect corneal edema that is not detectable by slit-lamp examination.
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Affiliation(s)
- Sho Ishikawa
- Department of Ophthalmology, Saitama Medical University, 38 Morohongo, Moroyama, Saitama, 350-0495, Japan. .,Department of Ophthalmology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8216, Japan.
| | - Naoko Kato
- Department of Ophthalmology, Saitama Medical University, 38 Morohongo, Moroyama, Saitama, 350-0495, Japan.,Department of Ophthalmology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8216, Japan
| | - Masaru Takeuchi
- Department of Ophthalmology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8216, Japan
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Ghoreishi M, Kashfi A, Peyman M, Hanjani S, Mohammadinia M, Straiko M. Comparison of densitometric profile after deep lamellar keratoplasty with two different techniques for treatment of keratoconus. Int Ophthalmol 2018; 39:1105-1113. [PMID: 29730856 DOI: 10.1007/s10792-018-0921-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 04/09/2018] [Indexed: 10/17/2022]
Abstract
PURPOSE To compare densitometric outcome of two techniques of deep lamellar keratoplasty using Pentacam HR corneal densitometry software. METHODS Postoperative outcomes of 31 patients with big bubble (BB) and 28 patients with Melles (M) surgery for the treatment of keratoconus were evaluated. Data were gathered at least 3 months after the removal of all sutures including demographic data, uncorrected distance visual acuity (UCDVA), best spectacle-corrected visual acuity (BSCVA), refraction and endothelial cell count. Moreover, the Scheimpflug images were taken by Pentacam® HR to assess keratometric profile, densitometric outcomes in different depths and zones of the cornea and central corneal thickness. Anterior segment OCT was performed in ten cases of M group. RESULTS Thirty-one eyes with BB and 27 eyes M surgery were enrolled. Comparison of densitometric profile between groups revealed no statistical significance in zone 0-2 mm, zone 2-6 mm and zone 10-12 mm in all depths (all P values > 0.05). Zone 6-10 mm of M group had lower densitometric readings (more transparent) in anterior, central and posterior layers of the cornea in comparison with BB group (all P < 0.05). Also no statistical difference was found in UCDVA, BSCVA, spherical or cylindrical refractive error, and spherical equivalent, keratometric readings, endothelial cell count and central corneal thickness in two groups (all P values > 0.05). CONCLUSION Densitometric profiles were identical in both methods in visually important zones so as visual and refractive outcomes.
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Affiliation(s)
- Mohammad Ghoreishi
- Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.,Parsian Vision Science Research Institute, Mir St., Isfahan, Iran
| | - Abolfazl Kashfi
- Parsian Vision Science Research Institute, Mir St., Isfahan, Iran.
| | | | - Shahriar Hanjani
- Parsian Vision Science Research Institute, Mir St., Isfahan, Iran
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Chan TCY, Wong ES, Chan JCK, Wang Y, Yu M, Maeda N, Jhanji V. Corneal backward scattering and higher-order aberrations in children with vernal keratoconjunctivitis and normal topography. Acta Ophthalmol 2018; 96:e327-e333. [PMID: 29090512 DOI: 10.1111/aos.13566] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/30/2017] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate the corneal backward scattering and higher-order aberrations (HOAs) in children with vernal keratoconjunctivitis (VKC) and normal topography. METHODS Thirty-six eyes of 22 patients with VKC and 54 eyes of 34 normal subjects were included. All participants had clear cornea, absence of dry eyes and a normal corneal tomography. Scheimpflug imaging was used to measure corneal backward scattering in zones centred on the corneal apex (central 2-mm zone and paracentral 2- to 6-mm zone), and HOAs were compared between VKC and normal control. RESULTS The mean age of participants was 12.0 ± 4.1 years in VKC group and 11.2 ± 4.1 years in control group (p = 0.339). There was no significant intergroup difference in mean keratometry, astigmatism and apex pachymetry (p ≥ 0.076). Total corneal backscatter was higher in the VKC group compared to the control group (p ≤ 0.012). Anterior and posterior cornea displayed a higher level of backward scattering in the VKC group (p < 0.001 for anterior; p ≤ 0.048 for posterior). Patients with VKC exhibited higher total HOAs and coma (p ≤ 0.036). There were significant correlations between total anterior HOAs and backward scattering measured at the central (r = 0.500; p = 0.032) and paracentral zones (r = 0.470; p = 0.024) for VKC. CONCLUSION The current study showed optical quality changes in patients with clear corneas and quiescent VKC. An increase in corneal backward scattering and HOAs was noted in patients with VKC as compared to normal patients.
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Affiliation(s)
- Tommy C. Y. Chan
- Department of Ophthalmology & Visual Sciences; The Chinese University of Hong Kong; Hong Kong China
- Hong Kong Eye Hospital; Hong Kong China
| | - Emily S. Wong
- Department of Ophthalmology & Visual Sciences; The Chinese University of Hong Kong; Hong Kong China
- Hong Kong Eye Hospital; Hong Kong China
| | - Jason C. K. Chan
- Department of Ophthalmology & Visual Sciences; The Chinese University of Hong Kong; Hong Kong China
- Hong Kong Eye Hospital; Hong Kong China
| | - Yumeng Wang
- Department of Ophthalmology & Visual Sciences; The Chinese University of Hong Kong; Hong Kong China
| | - Marco Yu
- Department of Mathematics and Statistics; Hang Seng Management College; Hong Kong China
| | - Naoyuki Maeda
- Department of Ophthalmology; Osaka University Graduate School of Medicine; Suita Osaka Japan
| | - Vishal Jhanji
- Department of Ophthalmology & Visual Sciences; The Chinese University of Hong Kong; Hong Kong China
- Department of Ophthalmology; University of Pittsburgh School of Medicine; Pittsburgh PA USA
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Spadea L, Maraone G, Verboschi F, Vingolo EM, Tognetto D. Effect of corneal light scatter on vision: a review of the literature. Int J Ophthalmol 2016; 9:459-64. [PMID: 27158621 DOI: 10.18240/ijo.2016.03.24] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 06/08/2015] [Indexed: 11/23/2022] Open
Abstract
The cornea is the transparent connective tissue window at the front of the eye. The physiological role of the cornea is to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Therefore, good vision requires maintenance of the transparency and proper refractive shape of the cornea. The surface structures irregularities can be associated with wavefront aberrations and scattering errors. Light scattering in the human cornea causes a reduction of visual quality. In fact, the cornea must be transparent and maintain a smooth and stable curvature since it contributes to the major part of the focusing power of the eye. In most cases, a simple examination of visual acuity cannot demonstrate the reduction of visual quality secondary light scattering. In fact, clinical techniques for examining the human cornea in vivo have greatly expanded over the last few decades. The measurement of corneal back scattering qualifies the degree of corneal transparency. The measurement of corneal forward-scattering quantifies the amount of visual impairment that is produced by the alteration of transparency. The aim of this study was to review scattering in the human cornea and methods of measuring it.
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Affiliation(s)
- Leopoldo Spadea
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Giorgia Maraone
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Francesca Verboschi
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Enzo Maria Vingolo
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Daniele Tognetto
- Eye Clinic, Ospedale Maggiore, University of Trieste, Trieste 34010, Italy
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Pathogenesis and treatments of TGFBI corneal dystrophies. Prog Retin Eye Res 2015; 50:67-88. [PMID: 26612778 DOI: 10.1016/j.preteyeres.2015.11.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 11/22/2022]
Abstract
Transforming growth factor beta-induced (TGFBI) corneal dystrophies are a group of inherited progressive corneal diseases. Accumulation of transforming growth factor beta-induced protein (TGFBIp) is involved in the pathogenesis of TGFBI corneal dystrophies; however, the exact molecular mechanisms are not fully elucidated. In this review article, we summarize the current knowledge of TGFBI corneal dystrophies including clinical manifestations, epidemiology, most common and recently reported associated mutations for each disease, and treatment modalities. We review our current understanding of the molecular mechanisms of granular corneal dystrophy type 2 (GCD2) and studies of other TGFBI corneal dystrophies. In GCD2 corneal fibroblasts, alterations of morphological characteristics of corneal fibroblasts, increased susceptibility to intracellular oxidative stress, dysfunctional and fragmented mitochondria, defective autophagy, and alterations of cell cycle were observed. Other studies of mutated TGFBIp show changes in conformational structure, stability and proteolytic properties in lattice and granular corneal dystrophies. Future research should be directed toward elucidation of the biochemical mechanism of deposit formation, the relationship between the mutated TGFBIp and the other materials in the extracellular matrix, and the development of gene therapy and pharmaceutical agents.
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Kim EK, Lee H, Choi SI. Molecular Pathogenesis of Corneal Dystrophies: Schnyder Dystrophy and Granular Corneal Dystrophy type 2. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:99-115. [PMID: 26310152 DOI: 10.1016/bs.pmbts.2015.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The International Committee for Classification of Corneal Dystrophies (IC3D) provides updated data to ophthalmologists by incorporating traditional definitions of corneal dystrophies with new genetic, clinical, and pathologic information. Recent advances in the genetics of corneal dystrophies facilitate more precise classifications and elucidate each classification's molecular mechanisms. Unfortunately, the molecular mechanisms and underlying pathogenic mechanisms have remained obscure, with the exception of Schnyder corneal dystrophy (CD), granular CD type 2 (GCD2), and Fuch's endothelial CD. Here, we review the pathogenesis of Schnyder CD and GCD2.
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Affiliation(s)
- Eung Kweon Kim
- Department of Ophthalmology, Vision Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; BK21 Plus Project for Medical Science and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Hun Lee
- Department of Ophthalmology, Vision Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seung-Il Choi
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
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Inhibitory Effect of Tranilast on Transforming Growth Factor-Beta-Induced Protein in Granular Corneal Dystrophy Type 2 Corneal Fibroblasts. Cornea 2015; 34:950-8. [PMID: 26020822 DOI: 10.1097/ico.0000000000000466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate the effects of tranilast, an inhibitor of chemical mediators and fibroblast proliferation, on the expression of transforming growth factor-beta (TGF-β)-induced protein (TGFBIp) in wild-type (WT) and homozygous (HO) granular corneal dystrophy type 2 corneal fibroblasts. METHODS Cell proliferation and cytotoxicity were measured by Cell Counting Kit-8 and lactate dehydrogenase assay. Western blotting and real-time polymerase chain reaction were used to determine changes in the expression of TGFBIp and TGFBI mRNA. We determined the effects of tranilast on phosphorylated Smad2 (pSmad2) and pSmad3, wound-healing, and expression of alpha-smooth muscle actin (α-SMA), type I collagen, and integrins. RESULTS High concentrations of tranilast decreased proliferation of corneal fibroblasts but did not cause elevation of lactate dehydrogenase, except at 1.0 mM tranilast. TGF-β increased the expression of TGFBIp and TGFBI mRNA in WT and HO corneal fibroblasts. Cotreatment of corneal fibroblasts with tranilast and TGF-β reduced the levels of TGFBIp and TGFBI mRNA. In addition, application of tranilast reduced pSmad2 in WT and HO corneal fibroblasts and pSmad3 in HO corneal fibroblasts, both of which were increased initially by TGF-β. Tranilast delayed wound healing and reduced the expression of α-SMA, type I collagen, and some of integrins in WT and HO corneal fibroblasts. CONCLUSIONS Application of tranilast in WT and HO corneal fibroblasts inhibited the expression of TGFBIp by blocking TGF-β signaling. Thus, tranilast may be useful in delaying or preventing the recurrence of corneal opacity in TGFBI-linked corneal dystrophies if clinical studies confirm these findings.
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Lang SJ, Eberwein P, Reinshagen H, Reinhard T, Sundmacher R. Simultaneous transplantation of limbal stem cells may reduce recurrences of granular dystrophy after corneal transplantation: 2 long-term case reports. Medicine (Baltimore) 2015; 94:e789. [PMID: 25997048 PMCID: PMC4602868 DOI: 10.1097/md.0000000000000789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
To present 2 cases with long-term relapse-free intervals only after limbo-keratoplasty but not after conventional penetrating keratoplasty in granular dystrophy.Retrospective review of the patient charts and photographs taken during long-term follow-up of 2 cases with granular dystrophy, in which 1 eye received penetrating keratoplasty and the fellow eye received penetrating limbo-keratoplasty.In the first patient, 1 eye showed extensive recurrence of granular deposits 17 years after penetrating keratoplasty was performed while in the second eye two-thirds of the corneal transplant adjacent to the transplanted limbal area remained clear 12 years after the limbo-corneal transplant. In the second patient, 1 eye showed no signs of recurrence 5 years after limbo-keratoplasty, whereas a recurrence of granular corneal deposits occurred 18 months after surgery in the fellow eye.These cases show that the simultaneous transplantation of healthy donor limbus when performing penetrating keratoplasty may prolong recurrence in granular corneal dystrophy. Although we were unable to prove it on the molecular level, these clinical courses may support the hypothesis that a limbal transplant helps prevent a recurrence.
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Affiliation(s)
- Stefan J Lang
- From the Eye Center, Albert-Ludwigs-University of Freiburg, Freiburg, Germany (TR, RS); Pallas Clinic Olten, Olten, Switzerland (SJL, PE)
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LASIK and surface ablation in corneal dystrophies. Surv Ophthalmol 2014; 60:115-22. [PMID: 25307289 DOI: 10.1016/j.survophthal.2014.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 08/15/2014] [Accepted: 08/19/2014] [Indexed: 11/22/2022]
Abstract
Corneal dystrophies are a rare group of hereditary disorders, that are bilateral, non-inflammatory, and progressive. Clinically, they can be classified based on the anatomic layer of the cornea affected. Refractive surgery and phototherapeutic keratectomy (PTK) can be performed with caution in patients with certain corneal dystrophies, but should be avoided in others. For epithelial basement membrane dystrophy, photorefractive keratectomy (PRK) is the procedure of choice for treatment of refractive error, and PTK may be performed for the treatment of recurrent erosions or irregular astigmatism. PRK and laser-assisted in situ keratomileusis (LASIK) have been associated with exacerbation of combined granular-lattice corneal dystrophy. LASIK and PRK appear to be safe in mild forms of posterior polymorphous corneal dystrophy, whereas LASIK should be avoided in Fuchs dystrophy. The safety of refractive surgery and PTK in the remainder of epithelial, Bowman layer, and stromal dystrophies has yet to be established.
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Lakshminarayanan R, Chaurasia SS, Anandalakshmi V, Chai SM, Murugan E, Vithana EN, Beuerman RW, Mehta JS. Clinical and genetic aspects of the TGFBI-associated corneal dystrophies. Ocul Surf 2014; 12:234-51. [PMID: 25284770 DOI: 10.1016/j.jtos.2013.12.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/05/2013] [Accepted: 12/05/2013] [Indexed: 11/16/2022]
Abstract
Corneal dystrophies are a group of inherited disorders localized to various layers of the cornea that affect corneal transparency and visual acuity. The deposition of insoluble protein materials in the form of extracellular deposits or intracellular cysts is pathognomic. Mutations in TGFBI are responsible for superficial and stromal corneal dystrophies. The gene product, transforming growth factor β induced protein (TGFBIp) accumulates as insoluble deposits in various forms. The severity, clinicopathogenic variations, age of the onset, and location of the deposits depend on the type of amino acid alterations in the protein. Until 2006, 38 different pathogenic mutants were reported for the TGFBI-associated corneal dystrophies. This number has increased to 63 mutants, reported in more than 30 countries. There is no effective treatment to prevent, halt, or reverse the deposition of TGFBIp. This review presents a complete mutation update, classification of phenotypes, comprehensive reported incidents of various mutations, and current treatment options and their shortcomings. Future research directions and possible approaches to inhibiting disease progression are discussed.
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Affiliation(s)
- R Lakshminarayanan
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore
| | - Shyam S Chaurasia
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Shu-Ming Chai
- Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore
| | | | - Eranga N Vithana
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Roger W Beuerman
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore Eye Research Institute, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore National Eye Centre, Singapore; Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
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Abstract
Phototherapeutic keratectomy (PTK) is done regularly for anterior corneal diseases such as corneal dystrophies, corneal degenerations, scars, and band-shaped keratopathy. The various indications include both therapeutic and visual. The aim of this article is to discuss the therapeutic indications for PTK, the specific technique pertaining to a specific etiology, the various other procedures like amniotic membrane graft combined with PTK or PTK being done for recurrences in the grafts, and PTK done before cataract surgery when the anterior corneal pathology coexists with the cataract. Post PTK management such as healing of an epithelial defect, use of steroids in the post PTK period, recurrences of primary disease pathology, and infections, will be discussed. Methods of literature search: A Medline search was carried out for articles in the English language, with the keywords, phototherapeutic keratectomy, band-shaped keratopathy, spheroidal degeneration, scars, bullous keratopathy, and corneal dystrophy. The relevant references are mentioned here.
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Affiliation(s)
- Varsha M Rathi
- Cornea, Anterior Segment and Refractive Surgery Services, L V Prasad Eye Institute, Hyderabad, AP, India.
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Clinical findings and treatments of granular corneal dystrophy type 2 (avellino corneal dystrophy): a review of the literature. Eye Contact Lens 2011; 36:296-9. [PMID: 20724852 DOI: 10.1097/icl.0b013e3181ef0da0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVES To review the literature about clinical findings and treatments of granular corneal dystrophy type 2 (GCD2). METHODS Various literatures on clinical findings, exacerbations after refractive corneal surgery, and treatment modalities of GCD2 were reviewed. RESULTS GCD2 is an autosomal dominant disease. Mutation of transforming growth factor beta-induced gene, TGFBI, or keratoepithelin gene in human chromosome 5 (5q31) is the key pathogenic process in patient with GCD2. Corneal trauma activates TGFBI and then it overproduces transforming growth factor beta-induced gene protein (TGFBIp), which is main component of the corneal opacity. Refractive corneal surgery is a popular procedure to correct refractive error worldwide. However, several cases about exacerbation of GCD2 after corneal refractive surgery such as photorefractive keratectomy, laser in situ keratomileusis, and laser epithelial keratomileusis have been reported. The opacities deteriorate patient's best-corrected visual acuity. Recurrence-free interval varies many factors such as the type of procedure the patient had received and the genotype of the patient. To treat the opacities in GCD2, phototherapeutic keratectomy, lamellar keratoplasty, deep lamellar keratoplasty, and penetrating keratoplasty (PKP) were used. However, the recurrence is still an unsolved problem. CONCLUSIONS Perfect treatment of exacerbation after corneal surface ablation does not exist until now. To prevent exacerbation, refractive surgeons must do a careful preoperative examination of candidates in refractive surgeries.
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