|Year : 2023 | Volume
| Issue : 2 | Page : 360-363
Imbalanced symmetry of anterior segment dysgenesis – A novel case report and review of literature
Dewang Angmo, Subodh Lakra, Barkha Gupta, Aafreen Bari
Glaucoma Research Facility and Clinical Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
|Date of Submission||26-Jul-2022|
|Date of Acceptance||07-Dec-2022|
|Date of Web Publication||28-Apr-2023|
Room No. 374, Third Floor, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
Anterior segment dysgenesis (ASD) is a spectrum of disorders affecting the anterior chamber structures and is frequently associated with glaucoma and corneal opacity. It usually has bilateral presentation. We report a case of a 22-year-old male with unilateral Peters anomaly. However, on detailed examination, trabeculodysgenesis was noted in the fellow eye. This highlights the importance of a complete bilateral ocular examination with gonioscopy even in unilateral congenital ASD, which can aid in early diagnosis and management.
Keywords: Anterior segment dysgenesis (ASD), iridocorneal adhesions, Peters anomaly, trabeculodysgenesis
|How to cite this article:|
Angmo D, Lakra S, Gupta B, Bari A. Imbalanced symmetry of anterior segment dysgenesis – A novel case report and review of literature. Indian J Ophthalmol Case Rep 2023;3:360-3
|How to cite this URL:|
Angmo D, Lakra S, Gupta B, Bari A. Imbalanced symmetry of anterior segment dysgenesis – A novel case report and review of literature. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Jun 2];3:360-3. Available from: https://www.ijoreports.in/text.asp?2023/3/2/360/374902
Anterior segment dysgenesis (ASD) is the failure of normal development of tissues of the anterior segment of eye, which affects the anterior chamber (AC) structures and is therefore associated with an increased risk of glaucoma and corneal opacity. It should be aptly called neurocristopathy, as opposed to the previous terminology “mesodermal dysgenesis,” since recent studies have reported that the affected embryonic tissues originate from the neural crest rather than the mesoderm. As tissues of other origin, such as the ectoderm-derived lens, may also be involved alongside the cornea and iris, these heterogeneous group of congenital anomalies are described by a broader term “mesenchymal dysgenesis.” Peters anomaly is a specific type of mesenchymal dysgenesis characterized by central corneal leukoma, iridocorneal adhesions, and abnormalities of the posterior corneal stroma, Descemet's membrane, corneal endothelium, lens, and AC.
| Case Report|| |
A 22-year-old male presented to the glaucoma clinic at a tertiary eye care center with history of whitish corneal opacity and diminution of vision in left eye since birth. He had insignificant past history and no systemic illness. There was no family history of any ocular disease or abnormality [Figure 1]. Antenatal and natal history were uneventful; his mother had no infections during pregnancy and he was born of a full-term normal vaginal delivery.
Visual acuity was 20/20 in the right eye and hand movements close to face in the left eye. Intraocular pressure (IOP) in the right eye was 14 mmHg (on latanoprost 0.005%) and 16 mmHg in the left eye. Also, 15° exotropia was noted in the left eye on Hirschberg corneal reflex test. Direct pupillary reaction was brisk in the right eye and sluggish in the left eye, with no relative afferent pupillary defect (RAPD).
The right eye had normal-sized clear cornea with deep AC and normal-patterned brown iris. Gonioscopy revealed multiple prominent iris processes with anterior insertion [Figure 2]a. Fundus showed a vertical cup disk ratio (CDR) of 0.7:1 with nasalization of vessels [Figure 2]b.
|Figure 2: (a) Gonioscopy (OD) showing elongated ciliary process with anterior insertion of iris. (b) Fundus Clinical Photograph (CP) (OD) showing CDR of 0.7:1 with nasalization of vessels. CDR = cup disk ratio|
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The left eye had multiple nebulomacular large, 3 × 2 mm2 paracentral leukomatous corneal opacities [Figure 3]. The anterior chamber was shallow (van Herrick grade II) with partial hypoplasia of anterior iris stroma with a distorted temporal iris pattern and iridocorneal adhesions with anterior polar cataract. Gonioscopy and fundus evaluation were inconclusive due to media opacity.
|Figure 3: (OS) Paracentral leukomatous corneal opacity with distorted temporal iris pattern and iridocorneal adhesions at the temporal margin of corneal opacity. Anterior lens capsular opacity (anterior polar cataract) is also present|
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Systemically, the patient was healthy with normal stature and built, no facial dysmorphism, no hearing abnormality, normal mental health, and no cardiac, neurologic, skeletal, or genitourinary abnormality. Cornea clinic confirmed the diagnosis of Peters anomaly. However, as the corneal opacity was paracentral, patient was advised to follow-up.
Right eye Humphrey visual field 30-2 Swedish Interactive Thresholding Algorithm (SITA) standard (Humphrey HFA II-i 750i field analyzer, Carl Zeiss Meditec Inc., Dublin, CA, USA) showed no significant field loss [Figure 4]. Retinal Nerve Fiber Layer Optical Coherence Tomography (RNFL OCT) (Cirrus HD-OCT; Carl Zeiss Meditech) revealed a normal average RNFL thickness of 103 μm. In the left eye, none of the tests was possible due to media haze.
|Figure 4: Humphrey visual field 30-2 SITA standard (OD) was within normal limits|
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Differential diagnosis for congenital corneal opacity with anterior segment abnormality includes Axenfeld–Rieger syndrome, congenital hereditary endothelial dystrophy (CHED), congenital hereditary stromal dystrophy (CHSD), Descemet's tear during assisted delivery, and microbial keratitis (TORCH (TORCH refers to congenital infections of Toxoplasmosis, Others(Syphillis, Hepatitis B), Rubella, Cytomegalovirus(CMV) and Herpes Simplex) infections).
Based on clinical findings and normal visual fields, patient was advised a 24-h diurnal measurement of IOP after 4 weeks of stopping all medications. The maximum IOP attained was 16 mmHg with diurnal variation of 4 mmHg in the right eye.
Thereafter, the patient was advised to discontinue any glaucoma medications and emphasized on regular lifelong follow-up. The IOP was in the range of 14–16 mmHg (without medication) at 3 and 6 months follow-up in both the eyes.
| Discussion|| |
ASD is characterized by a spectrum of disorders in which any of several abnormalities may exist alone or in combination. The ASD spectrum includes Axenfeld's anomaly, Rieger's anomaly, Peters anomaly, aniridia, iris hypoplasia, and iridogoniodysgenesis, often with an overlap of clinical findings in various groups. Patients often have malformations of the tissues responsible for IOP regulation and aqueous humor drainage and frequently develop elevated IOP, putting them at risk for developing glaucoma.
Peters anomaly, a part of spectrum of ASD, was first described by Albert Peters in 1906. It has been described as a central corneal leukoma with variable synechiae between the iris and cornea and a defect in Descemet's membrane and corneal endothelium. Glaucoma may be present in over 50% of cases. Other less-frequent ocular abnormalities associated are microcornea, microphthalmos, cornea plana, sclerocornea, coloboma, dysgenesis of the angle and iris, ptosis, optic nerve, and foveal hypoplasia. Peters anomaly has been subdivided into three types: 1) Type I characterized by central corneal opacity with iridocorneal adhesions, 2) Type II with central corneal opacity and cataracts or corneolenticular adhesions, and 3) Peters-plus syndrome characterized by Peters anomaly with systemic associations, short stature, developmental delay, and dysmorphic facial features including cleft lip/palate along with cardiac and genital abnormalities. Majority of cases are sporadic without an identifiable genetic cause. Abnormal formation of the anterior segment causes an incomplete separation of the cornea from the iris or lens, leading to corneal opacity and anterior synechiae. In the inherited forms, mutations in PAX6, FOXC1, PITX2, and CYP1B1 genes causing abnormal migration of neural crest cells to the posterior cornea have been linked to Peters anomaly.
Usually, most of the cases of Peters anomaly are bilateral. In a study by Bhandari et al., 67.2% cases were bilateral and 32.8% cases were unilateral. Bilateral cases had higher rate of systemic malformations (71.8%) compared to 36.8% of unilateral cases.
| Conclusion|| |
Visual deprivation secondary to corneal opacity and cataract can also result in sensory deprivation amblyopia. Therefore, it requires early diagnosis and multidisciplinary approach from both cornea and glaucoma specialists for its management.
Our patient had unilateral Peters anomaly with trabeculodysgenesis in the fellow eye, which is also a part of constellation of ASD. Both eyes developed dysgenetic ocular structures at different stages of embryonic development with earlier arrest of neural crest cell migration in the worse eye, while the better eye might have got affected at a much later stage. Thus, there was an imbalanced symmetry of ASD in both eyes.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]