Anterior Segment Developmental Anomalies (ASDA)

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Article initiated by:
Grant Hopping, Harry Yihai Liu, James Barnes, Majid Moshirfar, M.D., Uma Vaidyanathan
All contributors:
Grant Hopping, Harry Yihai Liu, James Barnes, Majid Moshirfar, M.D., Uma Vaidyanathan, Yasmyne C. Ronquillo, Marlow Schulz, BS, Karine Duarte Bojikian, MD, PhD, Alpa S. Patel, M.D., Vatinee Y. Bunya, MD, MSCE, Derek W DelMonte, MD, Joobin Khadamy, MD, FEBO, Colleen Halfpenny, M.D., Augustine Hong, MD, Majid Moshirfar, M.D., Karine Duarte Bojikian
Assigned editor:
Daniel Anderson, MD, Maria D. Bernal, MD
Review:
Assigned status Up to Date
 by Augustine Hong, MD on July 9, 2024.


Introduction

The anterior segment of the eye encompasses the cornea, iris, lens, and the aqueous humor, which provides nutrients to the avascular cornea and lens. Developmental disorders of the eye related to this anatomical section of the eye are grouped under the term Anterior Segment Developmental Anomalies (ASDA) and referred to as Anterior Segment Dysgenesis (ASD). These disorders show vast phenotypic and genetic heterogeneity and thus outlined here but described in detail separately. Some symptoms overlap, such as the tendency to develop increased intraocular pressure (IOP). The ciliary body of the iris produces the aqueous humor which must be drained via the trabecular meshwork into Schlemm's canal and by the uveoscleral outflow pathway. Disruptions in this process are frequent in ASD, and thus secondary glaucoma is a common complication.[1] ASD includes Posterior embryotoxon, Axenfeld-Rieger syndrome, Peters anomaly/Peters Plus syndrome, primary congenital glaucoma, Aniridia, Congenital hereditary endothelial dystrophy, Posterior Polymorphous Corneal Dystrophy, Sclerocornea, Megalocornea, Iridocorneal Endothelial Syndrome, Iridogoniodysgenesis syndrome, Congenital Iris Ectropion Syndrome, and Posterior Keratoconus. These specific disorders are further described in separate EyeWiki articles.

Associated Syndromes

Posterior embryotoxon (PE)

Posterior embryotoxon (PE) refers to an anteriorly displaced and thickened Schwalbe’s line. As seen on slit-lamp biomicroscopy, the grey-white Schwalbe’s line is concentric with and anterior to the limbus. PE most often occurs with Axenfeld-Rieger syndrome and arterio-hepatic dysplasia (Alagille’s syndrome).[2]

Molecular and Developmental mechanisms

Alagille syndrome along with posterior embryotoxon have been associated with mutations in the JAG1 gene on locus 20p12.[3]

Inheritance

Autosomal dominant

Axenfeld-Rieger syndrome

Axenfeld-Rieger syndrome (ARS) is an autosomal dominant disorder that presents with both ocular and systemic symptoms. Symptoms are very penetrant varied; they can range from iris hypoplasia and polycoria to microdontia.[1]

Molecular and Developmental mechanisms

Axenfeld Rieger syndrome shows genetic heterogeneity and has been associated with loci on chromosomes 4,6,13, and 16.[1][4][5] Mutations in transcription factors PITX2 (chromosome 4) and FOXC1 (chromosome 6) have been associated with the ocular and hearing symptoms found in ARS.[3]

Inheritance

Autosomal dominant

Peters anomaly and Peters Plus syndrome

Peters anomaly is a congenital disease heterogeneously affecting the anterior segment, often presenting with a central corneal opacity and a defect in the endothelium and Descemet’s membrane of the cornea; the presence of a central corneal opacity is required for diagnosis but the extent of the opacity varies among patients.[1][6] Peters anomaly has been shown to have an autosomal dominant or autosomal recessive mode of inheritance, or even appear sporadically.[1][7] Peters plus syndrome is an autosomal recessive disease that is characterized by defects in the anterior chamber as well as systemic abnormalities, such as cleft lip, growth and mental delay and short stature.[1]

Molecular and Developmental mechanisms

Peters anomaly shows genetic and phenotypic heterogeneity, and is associated with mutations in PAX6, PITX2 and CYP1B1.[1] Peters plus syndrome is an autosomal recessive disease and is associated in defects in glycosylation and mutations in the B3GLCT gene.[8]

Inheritance

Peters anomaly: sporadic, autosomal dominant, or autosomal recessive; Peters Plus syndrome: autosomal recessive

Primary congenital glaucoma (PCG)

PCG is an autosomal recessive disorder defined as having elevated IOP at or within 2 years of birth. It is considered to be a part of ASD as it frequently involves malformations of the structures involved in aqueous humor outflow, such as Schlemm's canal and the trabecular meshwork.

Molecular and Developmental mechanisms

PCG shows genetic heterogeneity, but has been linked to mutations at the GLC3A locus (2p21) involving the gene CYP1B1, which produces a member of the cytochrome P450 family of enzymes.[9] Other genetic loci include GLC3B (1p36), GLC3C (14q24.3), and more recently GLC3D (14q24), involving the gene LTBP2. The gene myocilin (MYOC) has also been implicated PCG.[10][11]

Inheritance

Autosomal Recessive

Aniridia (Iris Hypoplasia)

Aniridia is an autosomal dominant disorder that involves a variety of ocular manifestations, usually without systemic symptoms, that include but are not limited to: iris hypoplasia, lens dislocation, and corneal opacity.[1] It is primarily a posterior iris defect that can lead to vision loss.[1][5]

Molecular and Developmental mechanisms

Aniridia is primarily associated with the PAX6 gene on chromosome 11.[1][3] Mutations in the genes FOXC1 and CYP1B1 (chromosomes 6 and 2 respectively) have also been linked to aniridia.[3]

Inheritance

Autosomal Dominant

Congenital hereditary endothelial dystrophy (CHED)

Congenital hereditary endothelial dystrophy (CHED) is an autosomal recessive (CHED Type 2) disease that often presents as congenital corneal edema with bilateral corneal opacifications.[12]

Molecular and Developmental mechanisms

CHED has been mapped to chromosome 20p13 and mutations in the ZEB1 gene in PPCD3 and SLC4A11 are associated with CHED Type 2.[13]

Inheritance

Autosomal recessive

Posterior Polymorphous Corneal Dystrophy (PPMD, formerly CHED Type 1)

Posterior Polymorphous Corneal Dystrophy (PPMD) is an autosomal dominant disease of the corneal endothelium and Descemet’s membrane, which can present with bilateral corneal opacities and corneal edema in severe cases.[14][15]

Molecular and Developmental mechanisms

Several loci on chromosomes 1, 8, 10 and 20 have been identified that may affect embryological development of the cornea; mutations in the PPCD1 locus on chromosome 20q11, PPCD2 locus on chromosome 1p34.3 and PPCD3 on chromosome 10p have been associated with PPMD.[13][15] These mutations result in a wide variability in clinical presentation but the disease is associated with a thickened Descemet’s membrane and epithelialization of endothelial cells of the lesion.[16]

Inheritance

Autosomal dominant

Sclerocornea

Sclerocornea is a type of congenital corneal opacification (CCO) that is defined by non-inflammatory, non-progressive ingrowth of vascularized, opaque scleral tissue extending into the peripheral cornea, causing indistinct borders between the sclera and cornea. This disorder can be seen with other ASD syndromes (i.e. Peter’s Anomaly) or as its own entity.[17]

Molecular and Developmental mechanisms

Genes that are implicated in sclerocornea have significant overlap with other forms of ASD, including lens abnormalities like congenital cataracts. Genes that have been linked to sclerocornea include FOXE3, RAX, SOX2, PITX3, PAX6, and PXDN.[17]

Inheritance

Genetic heterogeneity

Megalocornea

Megalocornea is most commonly seen as an X-linked disorder presenting with an enlarged cornea of 12.5 mm or greater.[1][18] The other ocular finding generally includes deep anterior chambers with normal intraocular pressure and normal endothelial cells.[1][18]

Molecular and Developmental mechanisms

CHRDL1 mutations have been shown to cause X-linked megalocornea. The gene has been linked to development of the corneal stroma and endothelium.[19]

Inheritance

X-linked recessive, with a few cases of autosomal recessive inheritance

Iridocorneal Endothelial (ICE) Syndrome

Iridocorneal Endothelial (ICE) syndrome is rare disorder characterized by three different subtypes: Chandler syndrome, Cogan-Reese syndrome, and progressive iris atrophy. It most commonly affects middle-aged adults, showing a slight trend towards females and commonly presents unilaterally. The disorder involves corneal abnormalities with clinical presentation relation to its three subtypes. Chandler syndrome shows corneal edema with few iris abnormalities. Cogan-Reese syndrome shows iris abnormalities along with endothelial cell dystrophy. Progressive iris atrophy shows holes in the iris.[20]

Molecular and Developmental mechanisms

No cause for ICE syndrome has been discovered, and etiology is still debated. However, it has been proposed that the cause of ICE syndrome is viral in nature, with HSV playing a role in the disorder causing proliferation of corneal endothelial cell dystrophy.[20]

Inheritance

Unknown[20]

Iridogoniodysgenesis syndrome

Iridogoniodysgenesis is a rare autosomal dominant disease associated with malformations of the iris stroma and trabecular meshwork, leading to iris hypoplasia and glaucoma.[21][22][23][23]

Molecular and Developmental mechanisms

The Iridogoniodysgenesis locus is mapped to 6p25, and is thought to be associated with a malfunction in the migration or induction of neural crest cells involved in the formation of the anterior segment.[22] Mutations in the RIEG gene at locus 4q25 have also been found to be associated with Iridogoniodysgenesis syndrome.[23]

Inheritance

Autosomal dominant

Congenital Iris Ectropion Syndrome

Congenital iris ectropion (CIE) is a rare neural crest disorder that commonly presents with developmental glaucoma. It is characterized by posterior iris epithelium presenting on the anterior side of the stroma.[24] The condition is autosomal recessive and most commonly presents in males.[25]

Molecular and Developmental mechanisms

Congenital iris ectropion has been linked to mutation of the PAX-6 gene found on chromosome 11.[26] CIE is characterized by neural crest abnormalities and has been shown to be associated with neurofibromatosis, primary facial hemihypertrophy, Rieger anomaly and Prader-Willi syndrome.[24]

Inheritance

Autosomal recessive

Posterior Keratoconus

Posterior keratoconus is developmental abnormality characterized by outward curvature of the posterior cornea (ectasia).[27] It is thought to be caused by delayed separation of the lens from the ectodermal layers forming the cornea.[28][29] Associations of posterior keratoconus with anterior iridal adhesions, and pigment deposition on the posterior corneal surface have been described in the literature. Overlying stromal opacifications can affect vision depending on severity and location.[27]

Molecular and Developmental mechanisms

No specific genetic mechanisms, including chromosomal abnormalities, have been discovered.[27][28]

Inheritance

Unknown

Congenital Anterior Staphyloma / Congenital Corneal Staphyloma

Congenital anterior staphyloma, also known as congenital corneal staphyloma, is a rare ocular anomaly characterized by the protrusion of the cornea due to thinning and ectasia, often accompanied by opacification and inflammation. This condition is typically present at birth and may be associated with other ocular and systemic abnormalities. The etiology remains largely idiopathic, although genetic and environmental factors may contribute. Clinical presentation includes a pronounced forward bulging of the cornea, leading to visual impairment and aesthetic concerns. Diagnosis is primarily clinical, supported by imaging modalities like ultrasound biomicroscopy and anterior segment optical coherence tomography. Management strategies vary based on the severity and include both medical and surgical interventions aimed at preserving vision, preventing complications, and improving cosmesis. Early detection and multidisciplinary care are crucial for optimizing outcomes.

Molecular and Developmental Mechanisms Congenital anterior staphyloma, or congenital corneal staphyloma, arises from a complex interplay of molecular and developmental mechanisms that result in the abnormal protrusion and thinning of the cornea. During normal eye development, precise regulation of cellular proliferation, differentiation, and extracellular matrix formation is critical for maintaining corneal structure and transparency. Disruptions in these processes can lead to congenital anomalies. Molecular studies have implicated various genetic factors, including mutations in genes involved in corneal morphogenesis and structural integrity. Aberrations in signaling pathways, such as TGF-β and Wnt, have been shown to affect corneal development, leading to ectasia and staphyloma formation. Additionally, environmental factors during pregnancy, such as infections or teratogens, can contribute to the pathogenesis by disrupting normal embryonic development of the eye.

Associations Congenital anterior staphyloma is often associated with a spectrum of ocular and systemic anomalies. Ocular associations include microphthalmia, aniridia, congenital cataracts, and other anterior segment dysgenesis conditions. Systemic associations can range from syndromic presentations, such as Peters Plus syndrome and other craniofacial abnormalities, to isolated ocular findings. The presence of these associations necessitates a thorough systemic and genetic evaluation of affected individuals to identify underlying syndromic conditions and guide management. Furthermore, congenital anterior staphyloma can sometimes be linked with intrauterine infections or exposure to teratogens, underscoring the importance of a detailed prenatal and perinatal history.

Inheritance The inheritance pattern of congenital anterior staphyloma is not fully understood, given its rarity and the heterogeneity of associated conditions. However, both autosomal dominant and autosomal recessive inheritance patterns have been reported in familial cases. Genetic counseling is recommended for affected families to discuss potential risks and recurrence, especially when a genetic mutation has been identified. In some cases, de novo mutations or sporadic occurrences without a clear family history can complicate the inheritance pattern, highlighting the need for comprehensive genetic studies and registries to better understand the genetic basis of this condition.

Genes and Chromosomal Involvement Several genes and chromosomal regions have been implicated in the development of congenital anterior staphyloma. Key genes involved include:

  • FOXE3: Mutations in this gene, which is crucial for lens and anterior segment development, have been linked to anterior segment dysgenesis, including congenital corneal staphyloma.
  • PAX6: Known for its role in eye development, mutations in PAX6 can lead to aniridia and other anterior segment anomalies that may present with staphyloma.
  • CYP1B1: Mutations in this gene are associated with primary congenital glaucoma and other anterior segment dysgenesis disorders.
  • PITX2: This gene is involved in Axenfeld-Rieger syndrome, and Peters anomaly, which can include features of anterior segment dysgenesis.
  • MAB21L2: Associated with microphthalmia and other ocular malformations, mutations in this gene can contribute to the development of staphyloma.

Chromosomal abnormalities, such as deletions or duplications, in regions involving these genes can also lead to congenital anterior staphyloma. Further research is necessary to fully elucidate the genetic underpinnings of this condition and its associated anomalies.[30][31][32][33]

Congenital Microcoria

a.     Summary

Congenital microcoria, characterized by small pupils (rarely exceeding 2 mm in diameter) and iris abnormalities, is a rare ocular condition (Figure 1). Its first mention dates to 1862, in a series of three unrelated individuals displaying pinhole pupils without neurological problems, described as “miosis congenita”[34]. It can be inherited through both an autosomal recessive syndromic condition (Pierson syndrome)[35] or as an autosomal dominant, isolated form. Mutations in chromosome 13q32 have been linked to the condition, impacting pupil function and intraocular pressure regulation. Juvenile glaucoma can occur in congenital microcoria, possibly due to anomalies in anterior chamber angles and trabecular meshwork, though precise mechanisms are unclear. Axial myopia is common in these cases and other ocular anomalies like astigmatism and cataracts may also be present. Some individuals also complain of nyctalopia, and the visual fields can be constricted. Diagnosis involves pupillary response tests and ocular imaging, including ultrasound biomicroscopy (UBM) imaging. Close ophthalmic monitoring is crucial, given the association with myopia and glaucoma.

b.     Disease Entity

i.     Disease

Congenital microcoria is defined as pinpoint pupils with a diameter of less than 2 mm, iris hypopigmentation, and transillumination. It is caused by underdeveloped dilator pupillae muscle.[36] The sphincter pupillae muscle, which acts in opposition to the dilator pupillae muscle to cause constriction of the pupil, is normal, leading to light hypersensitivity and hemeralopia.

ii.     Epidemiology

Globally, just 160 individuals from under fifty families have been documented with this condition.[37] Given its rarity, the epidemiology of congenital microcoria has not been well-defined in large population-based studies. Both the autosomal dominant and autosomal recessive forms demonstrate no difference in occurrence between the sexes.[38]

iii.     Etiology

Studies have found that mutations or deletions within chromosome 13q32 are present in many families with congenital microcoria.[37][38] Structural variations in this gene sequence have also been associated with changes in axial ocular length and intraocular pressure (IOP) regulation, through unknown mechanisms.[39]

iv.     Pathophysiology

The iris is a flat, ring-shaped membrane positioned between the cornea and the lens. It anchors to the corneoscleral junction on the front side and the ciliary body on the back side, adjacent to the lens. Its center contains an opening known as the pupil.[40] The typical structure of the iris consists of a stroma, a bilayer epithelium, and two smooth muscles, the sphincter pupillae and dilator pupillae. These muscles function antagonistically to regulate the size of the pupil in response to changes in light levels[41]. The absence or underdevelopment of these muscles in congenital microcoria leads to persistent constriction (miosis) of the pupil. The integrity of this mechanism is responsible for regulating both the amount of light reaching the retina, as well as IOP.

The cause of glaucoma in congenital microcoria is not well understood. While some cases show shallow anterior chambers and narrow angles upon gonioscopic examination, most individuals with both congenital microcoria and glaucoma have wide-open chamber angles. However, they often exhibit prominent iris processes extending over the trabecular meshwork and a high insertion of the iris root into various ocular structures. Although such iris processes are common in the general population and are not typically associated with regulating IOP, some authors suggest that additional chamber anomalies may hinder the outflow of aqueous humor, potentially leading to glaucoma.[42] Terms like open-angle goniodysgenetic or developmental glaucoma have been proposed to describe these cases, but their classification remains debated since the chamber angle anomaly in congenital microcoria doesn't neatly fit existing iris dysgenesis categories[36]. Moreover, similar gonioscopic findings are prevalent in microcoria individuals with normal IOP, suggesting a complex relationship.[36][42]

c.     Diagnostic tests

In congenital microcoria, pupillary size should not change after administration of dilating drops, including 1% atropine. UBM images will reveal thin or absent iris dilator muscles and persistent pupillary membrane.

d.     Management and Monitoring

Close ophthalmic observation in patients with microcoria is necessary as the condition is strongly correlated to glaucoma myopia, and astigmatism in small family studies.[36] Glaucoma is sporadically associated with congenital microcoria, with cases reported across different generations and ethnicities.[36] It's characterized by elevated intraocular pressure (IOP), challenging optic nerve examination due to pupil constriction, and anatomical anomalies affecting aqueous humor drainage. While the exact cause remains unclear, it's suggested that abnormalities in the extracellular matrix of the trabecular meshwork might contribute. Besides close monitoring from diagnosis throughout childhood, providers should maintain a high index of suspicion for the development of glaucoma, a 2005 study that followed patients for 25 years found they may develop late-onset goniodysgenetic glaucoma.[43]

Myopia is prevalent in congenital microcoria cases, possibly due to associated biometric changes and likely aggravated by elevated IOP. Independent of the presence of microcoria, population-based studies have demonstrated a strong association between myopia and the development of glaucoma, even suggesting that the risk of glaucoma increases with an increasing degree of myopia.[44]  Studies of families with congenital microcoria have shown a high degree of myopia which was present independent of elevated IOP.[38] Again, due to the rarity of congenital microcoria, the exact mechanism underlying trends noted in small family studies remains elusive. Astigmatism, corneal edema, megalocornea, and cataracts are additional ocular anomalies sometimes observed in individuals with congenital microcoria, though their association with the condition is less clear.

Congenital Acorea

a.     Disease summary

Acorea is a rare congenital absence of the pupillary aperture due to failed regression of the mesoderm of the iris during embryogenesis.[45] The lack of pupil prevents light from reaching the retina, leading to severe sensory impairment. Though case reports are few, acorea seems to demonstrate an autosomal dominance inheritance pattern and has been associated with other ocular abnormalities such as cataract, microphthalmos, and iridocorneal dysgenesis in five affected families.[45] [46]A recent study of a family with acorea-microphthalmia-cataract syndrome underwent genome sequencing, revealing a mutant GJA8 gene, suggesting its association with congenital acorea.[47]

b.     Diagnosis

Patients most often present with very limited visual acuity (often light perception or hand movement) as well as deprivation amblyopia in the affected eye. Slit lamp examination and anterior segment OCT will reveal the absence of pupillary opening .[48] In some cases, slit lamp examination following dilation will reveal a “slit-like” pupil.[49] While congenital microcoria, discussed above, should also be on the differential, these patients are less likely to present with dense amblyopia and severe visual acuity impairment than those with acorea.

c.     Management

Without early intervention, patients are very likely to develop stimulus deprivation amblyopia. Pupilloplasty is the treatment of choice and should be performed as early as possible to prevent significant amblyopia; allowing light to reach the retina also contributes greatly to the development of the visual pathway.[49]  

References

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Ito YA, Walter MA. Genomics and anterior segment dysgenesis: a review. Clin Experiment Ophthalmol. 2014;42(1):13-24.doi:10.1111/ceo.12152
  2. ↑ Rennie CA, Chowdhury S, Khan J, et al. The prevalence and associated features of posterior embryotoxon in the general ophthalmic clinic. Eye. 2005;19(4):396-399. doi:10.1038/sj.eye.6701508    
  3. ↑ 3.0 3.1 3.2 3.3 Reis LM, Semina E V. Genetics of anterior segment dysgenesis disorders. Curr Opin Ophthalmol. 2011;22(5):314-324. doi:10.1097/ICU.0b013e328349412b
  4. ↑ Phillips JC, del Bono EA, Haines JL, et al. A second locus for Rieger syndrome maps to chromosome 13q14. Am J Hum Genet. 1996;59(3):613-619. http://www.ncbi.nlm.nih.gov/pubmed/8751862. Accessed June 8, 2019.    
  5. ↑ 5.0 5.1 Idrees F, Vaideanu D, Fraser SG, Sowden JC, Khaw PT. A Review of Anterior Segment Dysgeneses. Surv Ophthalmol. 2006;51(3):213-231. doi:10.1016/j.survophthal.2006.02.006
  6. ↑ Hanson IM, Fletcher JM, Jordan T, et al. Mutations at the PAX6 locus are found in heterogeneous anterior segment malformations including Peters’ anomaly. Nat Genet. 1994;6(2):168-173. doi:10.1038/ng0294-168
  7. ↑ Bhandari R, Ferri S, Whittaker B, Liu M, Lazzaro DR. Peters Anomaly: Review of the Literature. Cornea. 2011;30(8):939-944. doi:10.1097/ICO.0b013e31820156a9    
  8. ↑ Lesnik Oberstein SA, Ruivenkamp C AL, Hennekam RC. Peters Plus Syndrome. University of Washington, Seattle; 1993. http://www.ncbi.nlm.nih.gov/pubmed/20301637. Accessed June 9, 2019.
  9. ↑ Chouiter L, Nadifi S. Analysis of CYP1B1 Gene Mutations in Patients with Primary Congenital Glaucoma. J Pediatr Genet. 2017;06(04):205-214. doi:10.1055/s-0037-1602695
  10. ↑ Lim S-H, Tran-Viet K-N, Yanovitch TL, et al. CYP1B1, MYOC, and LTBP2 mutations in primary congenital glaucoma patients in the United States. Am J Ophthalmol. 2013;155(3):508-517.e5. doi:10.1016/j.ajo.2012.09.012
  11. ↑ Faiq M, Sharma R, Dada R, Mohanty K, Saluja D, Dada T. Genetic, Biochemical and Clinical Insights into Primary Congenital Glaucoma. Dada T, Sherwood M, Singh K, Shaarawy T, eds. J Curr Glaucoma Pract with DVD. 2013;7(2):66-84. doi:10.5005/jp-journals-10008-1140
  12. ↑ Nischal KK. Genetics of Congenital Corneal Opacification—Impact on Diagnosis and Treatment. Cornea. 2015;34:S24-S34. doi:10.1097/ICO.0000000000000552    
  13. ↑ 13.0 13.1 Aldave AJ, Han J, Frausto RF. Genetics of the corneal endothelial dystrophies: an evidence-based review. Clin Genet. 2013;84(2):109-119. doi:10.1111/cge.12191
  14. ↑ Ahn YJ, Choi S Il, Yum HR, Shin SY, Park SH. Clinical Features in Children with Posterior Polymorphous Corneal Dystrophy. Optom Vis Sci. 2017;94(4):476-481. doi:10.1097/OPX.0000000000001039
  15. ↑ 15.0 15.1 Cibis G, Gulani AC. Posterior Polymorphous Corneal Dystrophy. StatPearls Publishing; 2019. http://www.ncbi.nlm.nih.gov/pubmed/28613630. Accessed June 5, 2019.
  16. ↑ Klintworth GK. Corneal dystrophies. Orphanet J Rare Dis. 2009;4(1):7. doi:10.1186/1750-1172-4-7
  17. ↑ 17.0 17.1 Ma AS, Grigg JR, Prokudin I, Flaherty M, Bennetts B, Jamieson RV. New mutations in GJA8 expand the phenotype to include total sclerocornea. Clin Genet. 2018;93(1):155-159. doi:10.1111/cge.13045    
  18. ↑ 18.0 18.1 Mackey DA, Buttery RG, Wise GM, Denton MJ. Description of X-linked megalocornea with identification of the gene locus. Arch Ophthalmol (Chicago, Ill  1960). 1991;109(6):829-833. http://www.ncbi.nlm.nih.gov/pubmed/2043071. Accessed June 8, 2019.
  19. ↑ Webb TR, Matarin M, Gardner JC, et al. X-linked megalocornea caused by mutations in CHRDL1 identifies an essential role for ventroptin in anterior segment development. Am J Hum Genet. 2012;90(2):247-259. doi:10.1016/j.ajhg.2011.12.019
  20. ↑ 20.0 20.1 20.2 Sacchetti M, Mantelli F, Marenco M, Macchi I, Ambrosio O, Rama P. Diagnosis and Management of Iridocorneal Endothelial Syndrome. Biomed Res Int. 2015;2015:763093. doi:10.1155/2015/763093    
  21. ↑ Knezević T, Novak-Laus K, Skunca J, Mandić Z. Iridogoniodysgenesis syndrome: a case report. Acta Clin Croat. 2008;47(3):161-164. http://www.ncbi.nlm.nih.gov/pubmed/19175065. Accessed June 10, 2019.
  22. ↑ 22.0 22.1 Mears AJ, Mirzayans F, Gould DB, Pearce WG, Walter MA. Autosomal dominant iridogoniodysgenesis anomaly maps to 6p25. Am J Hum Genet. 1996;59(6):1321. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1914875/. Accessed June 10, 2019.
  23. ↑ 23.0 23.1 23.2 Pearce WG, Mielke BC, Kulak SC, Walter MA. Histopathology and molecular basis of iridogoniodysgenesis syndrome. Ophthalmic Genet. 1999;20(2):83-88. http://www.ncbi.nlm.nih.gov/pubmed/10420192. Accessed June 10, 2019.
  24. ↑ 24.0 24.1 Grieshaber MC, Orgul S, Bruder E, Hadziselimovic F, Flammer J. Congenital Iris Ectropion and Glaucoma Associated With Intestinal Neuronal Dysplasia: A Manifestation of a Neural Crest Syndrome. Arch Ophthalmol. 2006;124(10):1495. doi:10.1001/archopht.124.10.1495
  25. ↑ Nischal KK. Developmental Anomalies of the Anterior Segment and Globe. In: Pediatric Ophthalmology and Strabismus. New York, NY: Springer New York; 2003:369-390. doi:10.1007/978-0-387-21753-6_24    
  26. ↑ Kim WJ, Kim JH, Cho NC. Newly identified paired box 6 mutation of variant familial aniridia: Congenital iris ectropion with foveal hypoplasia. Indian J Ophthalmol. 2017;65(1):55-56. doi:10.4103/0301-4738.202305
  27. ↑ 27.0 27.1 27.2 Silas MR, Hilkert SM, Reidy JJ, Farooq A V. Posterior keratoconus. Br J Ophthalmol. 2018;102(7):863-867. doi:10.1136/bjophthalmol-2017-311097    
  28. ↑ 28.0 28.1 Streeten BW, Karpik AG, Spitzer KH. Posterior Keratoconus Associated With Systemic Abnormalities. Arch Ophthalmol. 1983;101(4):616-622. doi:10.1001/archopht.1983.01040010616019
  29. ↑ Krachmer JH, Rodrigues MM. Posterior Keratoconus. Arch Ophthalmol. 1978;96(10):1867-1873. doi:10.1001/archopht.1978.03910060371016
  30. ↑ Judaibi R, Abu-Amero K, Morales J, Al Shahwan S, Edward D. Mutations of the CYP1B1 gene in congenital anterior staphylomas. Clin Ophthalmol. 2014;8:445-448 https://doi.org/10.2147/OPTH.S53200
  31. ↑ Salour H, Owji N, Sadeghipour A. Congenital corneal staphyloma. J Ophthalmic Vis Res. 2009 Jul;4(3):182-4. PMID: 23198071; PMCID: PMC3498567.
  32. ↑ Tanenbaum HL, Rosen DA. Congenital anterior staphyloma. Am J Ophthalmol. 1966;61(2):336-340. doi:10.1016/0002-9394(66)90292-3
  33. ↑ Leff SR, Shields JA, Augsburger JJ, et alCongenital corneal staphyloma: clinical, radiological, and pathological correlation.British Journal of Ophthalmology 1986;70:427-430.
  34. ↑ Wilde WR (William R, Wilde WR (William R, University College LLS. An Essay on the Malformations and Congenital Diseases of the Organs of Sight / by W. R. Wilde. London : John Churchill; 1862. Accessed May 14, 2024. http://archive.org/details/b21641675
  35. ↑ M P, J C, F H, G R. [AN UNUSUAL CONGENITAL AND FAMILIAL CONGENITAL MALFORMATIVE COMBINATION INVOLVING THE EYE AND KIDNEY]. Journal de genetique humaine. 1963;12. Accessed May 14, 2024. https://pubmed.ncbi.nlm.nih.gov/14136829/
  36. ↑ 36.0 36.1 36.2 36.3 36.4 Toulemont PJ, Urvoy M, Coscas G, Lecallonnec A, Cuvilliers AF. Association of congenital microcoria with myopia and glaucoma. A study of 23 patients with congenital microcoria. Ophthalmology. 1995;102(2):193-198. doi:10.1016/s0161-6420(95)31036-6
  37. ↑ 37.0 37.1 Angée C, Nedelec B, Erjavec E, Rozet JM, Fares Taie L. Congenital Microcoria: Clinical Features and Molecular Genetics. Genes (Basel). 2021;12(5):624. doi:10.3390/genes12050624
  38. ↑ 38.0 38.1 38.2 Polomeno RC, Milot J. Congenital miosis. Can J Ophthalmol. 1979;14(1):43-46.
  39. ↑ Fares-Taie L, Gerber S, Tawara A, et al. Submicroscopic deletions at 13q32.1 cause congenital microcoria. Am J Hum Genet. 2015;96(4):631-639. doi:10.1016/j.ajhg.2015.01.014
  40. ↑ Bloom J, Motlagh M, Czyz CN. Anatomy, Head and Neck: Eye Iris Sphincter Muscle. In: StatPearls. StatPearls Publishing; 2024. Accessed May 12, 2024. http://www.ncbi.nlm.nih.gov/books/NBK532252/
  41. ↑ Forrester JV, Dick AD, McMenamin PG, Roberts F, Pearlman E. Chapter 5 - Physiology of vision and the visual system. In: Forrester JV, Dick AD, McMenamin PG, Roberts F, Pearlman E, eds. The Eye (Fourth Edition). W.B. Saunders; 2016:269-337.e2. doi:10.1016/B978-0-7020-5554-6.00005-8
  42. ↑ 42.0 42.1 Mazzeo V, Gaiba G, Rossi A. Hereditary cases of congenital microcoria and goniodysgenesis. Ophthalmic Paediatr Genet. 1986;7(2):121-125. doi:10.3109/13816818609076120
  43. ↑ Tawara A, Itou K, Kubota T, Harada Y, Tou N, Hirose N. Congenital microcoria associated with late-onset developmental glaucoma. J Glaucoma. 2005;14(5):409-413. doi:10.1097/01.ijg.0000176931.29477.6e
  44. ↑ Mitchell P, Hourihan F, Sandbach J, Wang JJ. The relationship between glaucoma and myopia: the Blue Mountains Eye Study. Ophthalmology. 1999;106(10):2010-2015. doi:10.1016/s0161-6420(99)90416-5
  45. ↑ 45.0 45.1 Kondo H, Tahira T, Yamamoto K, Tawara A. Familial acorea, microphthalmia and cataract syndrome. Br J Ophthalmol. 2013;97(9):1155-1160. doi:10.1136/bjophthalmol-2013-303165
  46. ↑ Acorea- An Isolated Presenting Feature. J Ophthalmol 2018, 3(5): 000162. Published online 2018.
  47. ↑ Dong S, Zou T, Zhen F, et al. Association of variants in GJA8 with familial acorea-microphthalmia-cataract syndrome. Eur J Hum Genet. 2024;32(4):413-420. doi:10.1038/s41431-023-01503-9
  48. ↑ Ramasubramanian S, Majumder PD. Acorea: A rare congenital anomaly. Indian J Ophthalmol. 2018;66(3):450. doi:10.4103/ijo.IJO_900_17
  49. ↑ 49.0 49.1 Priyambada P, Prabu RV, Wasnik RB, Ranjini H. A rare case of acorea: Congenital absence of pupil. Journal of Clinical Ophthalmology and Research. 2021;9(2):85. doi:10.4103/jcor.jcor_22_20
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