Early diagnosis and treatment by newborn screening (NBS) or family history is associated with improved visual outcomes for long-chain 3-hydroxyacylCoA dehydrogenase deficiency (LCHADD) chorioretinopathy.

Long chain 3-hydroxyacyl-CoA dehydrogenase (LCHADD) is the only fatty acid oxidation disorder to develop a progressive chorioretinopathy resulting in vision loss; newborn screening (NBS) for this disorder began in the United States around 2004. We compared visual outcomes among 40 participants with LCHADD or trifunctional protein deficiency diagnosed symptomatically to those who were diagnosed via NBS or a family history. Participants completed ophthalmologic testing including measures of visual acuity, electroretinograms (ERG), fundal imaging, contrast sensitivity, and visual fields. Records were reviewed to document medical and treatment history. Twelve participants presented symptomatically with hypoglycemia, failure to thrive, liver dysfunction, cardiac arrest, or rhabdomyolysis. Twenty eight were diagnosed by NBS or due to a family history of LCHADD. Participants diagnosed symptomatically were older but had similar percent males and genotypes as those diagnosed by NBS. Treatment consisted of fasting avoidance, dietary long-chain fat restriction, MCT, C7, and/or carnitine supplementation. Visual acuity, rod- and cone-driven amplitudes on ERG, contrast sensitivity scores, and visual fields were all significantly worse among participants diagnosed symptomatically compared to NBS. In mixed-effects models, both age and presentation (symptomatic vs. NBS) were significant independent factors associated with visual outcomes. This suggests that visual outcomes were improved by NBS, but there was still lower visual function with advancing age in both groups. Early diagnosis and treatment by NBS is associated with improved visual outcomes and retinal function compared to participants who presented symptomatically. Despite the impact of early intervention, chorioretinopathy was greater with advancing age, highlighting the need for novel treatments.

Variable phenotype of secondary congenital corneal opacities associated with microphthalmia with linear skin defects syndrome.

To describe the anterior segment (AS) findings in patients with microphthalmia with linear skin defects syndrome (MLS), also known as microphthalmia, dermal aplasia, and sclerocornea (MIDAS). A retrospective chart review was conducted to identify patients with a diagnosis of MLS syndrome seen at UPMC Children's Hospital of Pittsburgh. Ophthalmic examination, high-frequency ultrasound, AS optical coherence tomography, and molecular testing were reviewed. Five female patients (10 eyes) were identified. One eye was anophthalmic, one was in a status post penetrating keratoplasty, and eight eyes presented with congenital corneal opacity (CCO). Of these, one showed a normal lens and a very small faint CCO; five showed congenital aphakia and characteristic silvery appearance of the cornea with vascularization; and two showed irido-corneal adhesions in association with normal or abnormal lens and localized avascular CCO. Genetic testing was performed and revealed involvement of HCCS in four patients. In MLS patients, kerato-irido-lenticular dysgenesis can be associated with secondary CCO. It is important to distinguish these CCO from sclerocornea, in order to refine the appropriate management and counseling the parents about the prognosis.

Digital eye strain in young screen users: A systematic review.

Digital eye strain (DES) or computer vision syndrome (CVS) is a phenomenon linked to ever increasing digital screen use globally, affecting a large number of individuals. Recognizing causative and alleviating factors of DES may help establish appropriate policies. We aimed to review factors that aggravate or alleviate DES symptoms in young, i.e. pre-presbyopic (< 40 years old), digital device users. We searched PubMed, Scopus, EMBASE, Cochrane, Trip Database, and grey literature up to 1st July 2021. Among a plethora of studies with heterogeneous diagnostic criteria for DES, we only included those using a validated questionnaire for the diagnosis and evaluating associated factors in young subjects. Relevant data were extracted, risk of bias assessment of the included studies and GRADE evaluation of each outcome were performed. Ten studies were included (five interventional, five observational) involving 2365 participants. Evidence coming from studies with moderate risk of bias suggested that blue-blocking filters do not appear to prevent DES (2 studies, 130 participants), while use of screens for > 4-5 h/day (2 studies, 461 participants) and poor ergonomic parameters during screen use (1 study, 200 participants) are associated with higher DES symptoms' score. GRADE evaluation for the outcomes of blue-blocking filters and duration of screen use showed low to moderate quality of evidence. It appears advisable to optimize ergonomic parameters and restrict screen use duration, for minimizing DES symptoms. Health professionals and policy makers may consider recommending such practices for digital screen users at work or leisure. There is no evidence for use of blue-blocking filters.

ADAMTSL4-related ectopia lentis: A case of pseudodominance with an asymptomatic parent.

Pathogenic variants of ADAMTSL4 are associated with autosomal recessive ectopia lentis et pupillae and isolated ectopia lentis, often presenting congenitally or in childhood. We describe a pedigree of a 4-year-old female child with bilateral ectopia lentis and her asymptomatic 35-year-old father with mild anterior segment findings. Molecular evaluation revealed compound heterozygosity for ADAMTSL4 pathogenic variants in the proband and homozygosity for an ADAMTSL4 pathogenic founder mutation in her father. The results of genetic testing revealed a pseudodominant inheritance pattern in the family. This case expands variability of ADAMTSL4-related ectopia lentis through the first description of an asymptomatic adult in the 4th decade and highlights importance of clinical and molecular evaluations of family members when investigating genetic disorders.

Somatic KRAS mutation affecting codon 146 in linear sebaceous nevus syndrome.

Linear Sebaceous Nevus Syndrome is a rare disorder that presents with nevus sebaceus in association with corneal dermoids, colobomas, choroidal osteomas, and arachnoid cysts. It is thought to represent a mosaic RASopathy. These are disorders characterized by postzygotic somatic mutation in genes involved in RAS/MAPK signaling pathway. In this report we describe two patients with linear sebaceous nevus syndrome found to have mutations in codon 146 of KRAS with evidence of mosaicism. This specific mutation has previously been reported in Oculoectodermal Syndrome and Encephalocraniocutaneous Lipomatosis, two other mosaic RASopathies with predominantly cerebrooculocutaneous manifestations. These findings suggest that, while initially classified as different syndromes, these disorders should be evaluated and managed as a spectrum of related disorders.

Expansion of the ophthalmic phenotype of SPINT2-related syndromic congenital sodium diarrhea.

A 5-year-old girl presented with treatment-refractory dry eye and recurrent episodes of eye pain. She had been previously diagnosed with syndromic congenital sodium diarrhea (SCSD) caused by a pathogenic variant in SPINT2. Her local pediatric ophthalmologist had made the diagnosis of severe dry eye with corneal erosions, based on which, we arranged an eye exam under anesthesia (EUA) and punctal plug placement. Anterior segment optical coherence tomography (OCT) and corneal photographs were taken during the procedure. There are reports describing similar ophthalmic findings in this syndrome. However, to the best of our knowledge, this is the first case report to document OCT imaging and corneal photographs in a patient with SCSD, which we feel expands the ophthalmic phenotype of this rare genetic disorder.

A comparison of the Grass strobe and new LED photic stimulator for paediatric electroretinogram recordings.

PURPOSE: This study evaluated a new light-emitting diode (LED-S) photic stimulator and compared skin electroretinogram (ERG) responses obtained to those evoked by the Grass Instrument stimulator (GP-S). METHODS: Two sub-studies were combined to evaluate the difference in responses resulting from the LED-S and GP-S stimuli. The first was a photometry study that matched the LED-S stimuli to the GP-S. In the second study, electroretinograms (ERGs) were recorded under scotopic and photopic conditions using stimuli each stimulator. The stimuli were matched photometrically to measurements obtained from the photometer located 30 cm in front of the stimulators. In addition, the ERG responses were recorded from the LED stimulator when photometrically matched to the GP-S blue stimulus presented through a ganzfeld. The amplitudes and time peaks of the resulting ERG a- and b-waves were then measured and compared using paired T-tests. RESULTS: Study 1: The LED-S was matched to the GP-S at various intensity settings measured 30 cm away from the stimulator. Measurement through a ganzfeld full-field stimulator (GFFS) demonstrated that the GP-S had a significant hot spot centrally. Study 2: Photometrically matched ERGs evoked by both stimulators while employing the direct head-on measurements demonstrated multiple similarities. Similarities included component morphology, amplitude and implicit time across the two stimulators, excluding the rod-driven stimulus (GP-S setting employing a blue filter). Differences between the rod-driven ERGs evoked by the GP-S and LED-S while employing head-on photometric measurements were due to the significant difference in intensities between the two stimulators. The GP-S and LED-S evoked similar rod-driven ERG responses when they were matched using the GFFS photometrically matched intensities protocol. CONCLUSION: A hand-held stimulator is essential when recording ERG's in the practice of paediatric visual electrophysiology. The LED-S can match the GP-S stimulus intensities, making it a potential replacement for the GP-S. In addition, the LED-S has uniform intensity across the surface of the device compared to the GP-S, is silent for standard stimuli and can generate prolonged duration stimuli for the recording of on-off ERGs.

Neuroimaging of retinal hemorrhage utilizing adjunct orbital susceptibility-weighted imaging.

Retinal hemorrhages are an integral part of the evaluation of abusive head trauma (AHT). Timely detection of retinal hemorrhage not only facilitates the diagnosis of AHT, but has the potential to prevent further abuse to the child and the siblings and to identify the abuser. The gold standard for diagnosing retinal hemorrhage is a dilated fundoscopy exam, which requires pharmacological dilation. As such, there is a small percentage of patients for whom the dilated fundoscopy exam might be delayed. Evolving literature suggests that MRI, specifically susceptibility-weighted imaging (SWI), of the orbits might provide an alternative diagnostic tool for noninvasively detecting retinal hemorrhages, particularly when there is a delay in administering the dilated fundoscopy exam. In this paper we review the utility of SWI for detecting retinal hemorrhages in abusive head trauma, including discussion of diagnostic limitations and future research.

The Oculome Panel Test: Next-Generation Sequencing to Diagnose a Diverse Range of Genetic Developmental Eye Disorders.

PURPOSE: To develop a comprehensive next-generation sequencing panel assay that screens genes known to cause developmental eye disorders and inherited eye disease and to evaluate its diagnostic yield in a pediatric cohort with malformations of the globe, anterior segment anomalies, childhood glaucoma, or a combination thereof. DESIGN: Evaluation of diagnostic test. PARTICIPANTS: Two hundred seventy-seven children, 0 to 16 years of age, diagnosed with nonsyndromic or syndromic developmental eye defects without a genetic diagnosis. METHODS: We developed a new oculome panel using a custom-designed Agilent SureSelect QXT target capture method (Agilent Technologies, Santa Clara, CA) to capture and perform parallel high-throughput sequencing analysis of 429 genes associated with eye disorders. Bidirectional Sanger sequencing confirmed suspected pathogenic variants. MAIN OUTCOME MEASURES: Collated clinical details and oculome molecular genetic results. RESULTS: The oculome design covers 429 known eye disease genes; these are subdivided into 5 overlapping virtual subpanels for anterior segment developmental anomalies including glaucoma (ASDA; 59 genes), microphthalmia-anophthalmia-coloboma (MAC; 86 genes), congenital cataracts and lens-associated conditions (70 genes), retinal dystrophies (RET; 235 genes), and albinism (15 genes), as well as additional genes implicated in optic atrophy and complex strabismus (10 genes). Panel development and testing included analyzing 277 clinical samples and 3 positive control samples using Illumina sequencing platforms; more than 30× read depth was achieved for 99.5% of the targeted 1.77-Mb region. Bioinformatics analysis performed using a pipeline based on Freebayes and ExomeDepth to identify coding sequence and copy number variants, respectively, resulted in a definitive diagnosis in 68 of 277 samples, with variability in diagnostic yield between phenotypic subgroups: MAC, 8.2% (8 of 98 cases solved); ASDA, 24.8% (28 of 113 cases solved); other or syndromic, 37.5% (3 of 8 cases solved); RET, 42.8% (21 of 49 cases solved); and congenital cataracts and lens-associated conditions, 88.9% (8 of 9 cases solved). CONCLUSIONS: The oculome test diagnoses a comprehensive range of genetic conditions affecting the development of the eye, potentially replacing protracted and costly multidisciplinary assessments and allowing for faster targeted management. The oculome enabled molecular diagnosis of a significant number of cases in our sample cohort of varied ocular birth defects.

Use of neuroimaging measurements of optic nerve sheath diameter to assess intracranial pressure in craniosynostosis.

PURPOSE: This study aims to evaluate accuracy of optic nerve sheath diameter (ONSD) measurements obtained by magnetic resonance imaging (MRI) in patients with craniosynostosis (CS) for detection of high intracranial pressure (ICP) and to correlate MRI-derived ONSD measurements with those obtained by computed tomography (CT) scans in CS patients. METHODS: A retrospective review was conducted on CS patients who had MRI- and age-matched controls with normal MRI. Diagnosis of intracranial hypertension was based on presence of papilledema, direct ICP monitoring, and/or lumbar puncture. The search also included patients with MRI and CT done within 30 days apart. ONSDs were measured 3 mm behind the globe on both modalities. RESULTS: The study identified 56 CS patients (mean age 3.8 ± 3.47 years) and 49 controls (mean age 3.7 ± 3.62 years). Mean ONSD in patients with high ICP was significantly higher than in patients without high ICP (P = 0.0001) and in controls (P < 0.0001). The optimal ONSD threshold for predicting raised ICP in patients >1 year old was 6 mm (71.4% sensitivity, 89.7% specificity). Nineteen patients with 38 single-eye MRI/CT pairs were identified. Substantial agreement between both modalities resulted (r = 0.959, 95% CI 0.923-0.978), and Bland and Altman Plot analysis showed that 95% of measurements fell within limits of agreement (1.96 SD; ± 0.6 mm). CONCLUSION: In CS patients, ONSD measured by MRI represent indirect non-invasive means of ICP assessment. Both MRI and CT measurements of ONSD gave comparable results, and the use of CT-derived ONSD measurements may give some idea about ICP in CS patients.

Mutation of SALL2 causes recessive ocular coloboma in humans and mice.

Ocular coloboma is a congenital defect resulting from failure of normal closure of the optic fissure during embryonic eye development. This birth defect causes childhood blindness worldwide, yet the genetic etiology is poorly understood. Here, we identified a novel homozygous mutation in the SALL2 gene in members of a consanguineous family affected with non-syndromic ocular coloboma variably affecting the iris and retina. This mutation, c.85G>T, introduces a premature termination codon (p.Glu29*) predicted to truncate the SALL2 protein so that it lacks three clusters of zinc-finger motifs that are essential for DNA-binding activity. This discovery identifies SALL2 as the third member of the Drosophila homeotic Spalt-like family of developmental transcription factor genes implicated in human disease. SALL2 is expressed in the developing human retina at the time of, and subsequent to, optic fissure closure. Analysis of Sall2-deficient mouse embryos revealed delayed apposition of the optic fissure margins and the persistence of an anterior retinal coloboma phenotype after birth. Sall2-deficient embryos displayed correct posterior closure toward the optic nerve head, and upon contact of the fissure margins, dissolution of the basal lamina occurred and PAX2, known to be critical for this process, was expressed normally. Anterior closure was disrupted with the fissure margins failing to meet, or in some cases misaligning leading to a retinal lesion. These observations demonstrate, for the first time, a role for SALL2 in eye morphogenesis and that loss of function of the gene causes ocular coloboma in humans and mice.

The Frequency of Signs of Meibomian Gland Dysfunction in Children with Epidermolysis Bullosa.

PURPOSE: To determine the frequency of meibomian gland dysfunction (MGD) in children with epidermolysis bullosa (EB). DESIGN: Hospital-based cross-sectional study. PARTICIPANTS: One hundred five children with different forms of EB. METHODS: Prospective ophthalmic examination of children with EB presenting over seventeen months including meibomian gland assessment using a recognized classification. MAIN OUTCOME MEASURES: Frequency of MGD. RESULTS: One hundred five children were recruited, 8.6% with junctional EB, 34.3% with simplex EB, 34.3% with autosomal recessive dystrophic EB, and 22.9% autosomal dominant dystrophic EB. Mean age was 7.42 years (range, 0.08-17.75 years). Ninety-two children (87.62%) demonstrated 1 or more features of MGD. CONCLUSIONS: Most children with EB exhibit signs of MGD. To the best of our knowledge, this is the first prospective ocular surface evaluation in children with EB to include lid margin evaluation using a recognized classification system. Our findings help explain some of the ocular surface anomalies seen in children with EB.

Functional analysis of FOXE3 mutations causing dominant and recessive ocular anterior segment disease.

Mutations in FOXE3 are associated with both recessive and dominant inheritance of severe anterior ocular malformations and glaucoma. However, functional analyses of putative pathogenic mutations have not been performed. We tested the hypothesis that variations in FOXE3 activity underlie the different modes of inheritance and disease phenotype. In band shift assays, three recessive mutants showed loss-of-function, one retained DNA binding activity, whereas two dominant mutants showed altered activity. All six mutants showed reduced transactivation function compared with wild-type, and modeling the heterozygous state resulted in an intermediate level of activity providing no evidence for dominant negative action. Our in vitro data are consistent with loss-of-function below a dosage sensitive threshold as a mechanism of action for recessive mutations, but indicate an altered mutant protein function rather than a haploinsufficient mechanism for dominant mutations. This study provides the first functional evidence demonstrating that FOXE3 mutations identified in patients impair protein function with differential effects.

Variable Phenotype of Congenital Corneal Opacities in Biallelic CYP1B1 Pathogenic Variants.

PURPOSE: The aim of this study is to describe the variable phenotype of congenital corneal opacities occurring in patients with biallelic CYP1B1 pathogenic variants. METHODS: A retrospective chart review was conducted to identify patients with congenital corneal opacities and CYP1B1 pathogenic variants seen at UPMC Children's Hospital of Pittsburgh. Ophthalmic examination, high-frequency ultrasound, anterior segment optical coherence tomography, histopathologic images, and details of genetic testing were reviewed. RESULTS: Three children were identified. All presented with raised intraocular pressure. Two patients showed bilateral limbus-to-limbus avascular corneal opacification that did not resolve with intraocular pressure control; 1 showed unilateral avascular corneal opacity with a crescent of clear cornea, iridocorneal adhesions, iridolenticular adhesions, and classical features of congenital glaucoma in the fellow eye (enlarged corneal diameter, Haab striae, and clearing of the corneal clouding with appropriate intraocular pressure control). The first 2 patients were visually rehabilitated with penetrating keratoplasty. Histopathology revealed distinct features: a variably keratinized epithelium; a thick but discontinuous Bowman-like layer with areas of disruption and abnormal cellularity; Descemet membrane, when observed, showed reduced endothelial cells; and no pathological changes of Haab striae were identified. Two patients had compound heterozygous pathogenic variants in CYP1B1 causing premature stop codons, whereas 1 was homozygous for a pathogenic missense variant. CONCLUSIONS: Congenital corneal opacities seen in biallelic CYP1B1 pathogenic variants have a variable phenotype. One is that commonly termed as Peters anomaly type 1 (with iridocorneal adhesions, with or without iridolenticular adhesions) and the other is a limbus-to-limbus opacity, termed CYP1B1 cytopathy. Clinicians should be aware of this phenotypic variability.

Recurrent Retinal Detachment in Stickler Syndrome.

Objective: To assess clinical factors leading to recurrent retinal detachment (RD) and characteristics of recurrence in patients with Stickler Syndrome. Methods: Retrospective case series study of patients with clinical diagnosis of Stickler Syndrome who underwent rhegmatogenous RD repair. Recurrent RD after initial surgery was categorized as "early" if the recurrence was within 1 year or "late" if greater than 1 year. Results: Thirty eyes from 22 patients underwent rhegmatogenous RD repair. For initial repair, 13 eyes underwent pars plana vitrectomy combined with scleral buckling (PPV/SB), 16 eyes underwent primary scleral buckling (SB), and 1 eye underwent pneumatic retinopexy (PnR). Recurrent RD occurred in 6 (46%) PPV/SB eyes (5 early and 1 late), 10 (63%) SB eyes (3 early and 7 late), and 0 (0%) PnR eyes (p = 0.61). PPV/SB was preferred for eyes presenting with total detachment (82%), giant retinal tears (100%), and proliferative vitreoretinopathy (PVR) (80%). For eyes with early recurrent RD, 6 (75%) developed PVR leading to recurrence. For eyes with late recurrent RD, 7 (87.5%) developed a new retinal break leading to recurrence, including 4 with a break posterior to the buckle indentation apex. At last follow-up, median LogMAR visual acuity was 0.68 for eyes with recurrent RD compared to 0.29 for eyes without recurrence (p = 0.27). Conclusions: Early recurrent RD was mostly caused by PVR, while late recurrent RD was mostly due to new retinal breaks. Eyes with seemingly uncomplicated rhegmatogenous RD repair with primary SB remained at high risk for late re-detachment.

Calcified Sclero-Choroidal Choristomas in Mosaic RASopathies: A Description of a New Imaging Sign.

PURPOSE: To evaluate the imaging and clinical features of unusual calcified lesions seen in the fundus of patients with mosaic RASopathy. DESIGN: Single-center retrospective observational study. SUBJECTS: Ten eyes with calcified fundus lesions in 7 patients with mosaic RASopathy. METHODS: The lesions were evaluated with fundus photography, oral fundus fluorescein angiography, B-scan ultrasonography, magnetic resonance imaging (MRI), and computed tomography (CT) scan where available. MAIN OUTCOME MEASURES: The imaging characteristics of calcified fundus lesions were assessed. RESULTS: We found 7 patients with mosaic RASopathies, 5 men and 2 women (3 with linear sebaceous nevus syndrome, 3 with oculoectodermal syndrome, and 1 with encephalocraniocutaneous lipomatosis) with molecular confirmation in 5 cases, all 5 having KRAS-pathogenic variants. Calcified fundus lesions were identified in 10 eyes (bilateral in 3 patients), appearing as slightly elevated, creamy-yellow lesions around or adjacent to the optic nerve, extending supero-nasally; all but 2 of these lesions involved both the choroid and sclera, with 2 of them only involving the sclera at the time of examination. One case developed a choroidal neovascular membrane necessitating intravitreal bevacizumab injections. All 7 patients had B-scan ultrasonography, and the lesion appeared as a hyperechogenic area with an acoustic shadow posteriorly despite reduced gain. Five patients had MRI, and where fundus lesions were present, there was a focal defect in the sclero-choroidal layer. Four patients had a CT scan, and all 4 showed calcifications affecting both the posteromedial sclero-choroid and adjacent medial rectus muscle. Two of these patients had normal eye movements, 1 had a unilateral fixed adducted eye and a vestigial fibrous medial rectus muscle seen in imaging and intraoperatively, and the fourth had marked exotropia with a right gaze deficit affecting both eyes. CONCLUSIONS: We propose that the lesions seen in this cohort are calcified sclero-choroidal choristomas and should be suspected in mosaic RASopathies when creamy-yellow lesions are seen in the fundus. If identified, the possibility of choroidal neovascularization should be considered during follow-up. In all cases where a CT scan was performed, a novel sign of sclero-muscular calcification involving the medial rectus muscle was seen. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

A proposal for an updated staging system for LCHADD retinopathy.

OBJECTIVE: To develop an updated staging system for long-chain 3-hydroxyacyl coenzyme A dehydrogenase deficiency (LCHADD) chorioretinopathy based on contemporary multimodal imaging and electrophysiology. METHODS: We evaluated forty cases of patients with genetically confirmed LCHADD or trifunctional protein deficiency (TFPD) enrolled in a prospective natural history study. Wide-field fundus photographs, fundus autofluorescence (FAF), optical coherence tomography (OCT), and full-field electroretinogram (ffERG) were reviewed and graded for severity. RESULTS: Two independent experts first graded fundus photos and electrophysiology to classify the stage of chorioretinopathy based upon an existing published system. With newer imaging modalities and improved electrophysiology, many patients did not fit cleanly into a single traditional staging group. Therefore, we developed a novel staging system that better delineated the progression of LCHADD retinopathy. We maintained the four previous delineated stages but created substages A and B in stages 2 to 3 to achieve better differentiation. DISCUSSION: Previous staging systems of LCHADD chorioretinopathy relied on only on the assessment of standard 30 to 45-degree fundus photographs, visual acuity, fluorescein angiography (FA), and ffERG. Advances in recordings of ffERG and multimodal imaging with wider fields of view, allow better assessment of retinal changes. Following these advanced assessments, seven patients did not fit neatly into the original classification system and were therefore recategorized under the new proposed system. CONCLUSION: The new proposed staging system improves the classification of LCHADD chorioretinopathy, with the potential to lead to a deeper understanding of the disease's progression and serve as a more reliable reference point for future therapeutic research.

IC3D Classification of Corneal Dystrophies-Edition 3.

PURPOSE: The International Committee for the Classification of Corneal Dystrophies (IC3D) was created in 2005 to develop a new classification system integrating current information on phenotype, histopathology, and genetic analysis. This update is the third edition of the IC3D nomenclature. METHODS: Peer-reviewed publications from 2014 to 2023 were evaluated. The new information was used to update the anatomic classification and each of the 22 standardized templates including the level of evidence for being a corneal dystrophy [from category 1 (most evidence) to category 4 (least evidence)]. RESULTS: Epithelial recurrent erosion dystrophies now include epithelial recurrent erosion dystrophy, category 1 ( COL17A1 mutations, chromosome 10). Signs and symptoms are similar to Franceschetti corneal dystrophy, dystrophia Smolandiensis, and dystrophia Helsinglandica, category 4. Lisch epithelial corneal dystrophy, previously reported as X-linked, has been discovered to be autosomal dominant ( MCOLN1 mutations, chromosome 19). Classic lattice corneal dystrophy (LCD) results from TGFBI R124C mutation. The LCD variant group has over 80 dystrophies with non-R124C TGFBI mutations, amyloid deposition, and often similar phenotypes to classic LCD. We propose a new nomenclature for specific LCD pathogenic variants by appending the mutation using 1-letter amino acid abbreviations to LCD. Pre-Descemet corneal dystrophies include category 1, autosomal dominant, punctiform and polychromatic pre-Descemet corneal dystrophy (PPPCD) ( PRDX3 mutations, chromosome 10). Typically asymptomatic, it can be distinguished phenotypically from pre-Descemet corneal dystrophy, category 4. We include a corneal dystrophy management table. CONCLUSIONS: The IC3D third edition provides a current summary of corneal dystrophy information. The article is available online at https://corneasociety.org/publications/ic3d .