Primary Congenital Glaucoma Presenting with Acute Corneal Hydrops: A Challenging Approach to Amblyopia Prevention

Primary congenital glaucoma (PCG) is the most common non-syndromic glaucoma in infancy, resulting from an obstruction in the outflow of aqueous humor due to abnormalities in the trabecular meshwork and anterior chamber angle [1, 2]. Acute hydrops is a rare initial presentation of PCG and is thought to be caused by elevated intraocular pressure (IOP) disrupting Descemet’s membrane, leading to an influx of aqueous humor into the exposed corneal stroma. Immediate intervention is crucial in these cases to reduce IOP and prevent irreversible vision loss [3, 4]. Acute corneal hydrops can result in a visually significant corneal opacity posing an additional risk factor for amblyopia development in PCG patients [5].

A three-days-old female newborn was referred to our department due to bilateral corneal clouding. The infant was born to healthy young parents, and the pregnancy and delivery were uneventful. There was no evidence of systemic pathology, and no relevant family history was reported.

Anterior segment examination revealed bilateral corneal opacification and severe right corneal prolapse, as shown in Figure 1. The right eye exhibited significant corneal edema, rendering anterior chamber structures indiscernible. The left eye presented a deep quiet anterior chamber with no dysgenesis of anterior segment structures. IOP measurements using rebound tonometry (Icare Finland Oy, Vantaa, Finland) exceeded 40 mm Hg in both eyes. Corneal diameters measured 10 mm in the right eye and 12 mm in the left eye. Fundoscopic posterior segment assessment was not possible due to unclear media. B-scan ultrasonography revealed no posterior segment abnormalities.

The patient underwent urgent bilateral superior trabeculotomy on the day of presentation. Postoperatively, sequelae of intense mechanical stretching induced by severely increased IOP were evident, with the right cornea exhibiting a central dense opacity with neovascularization, as shown in Figure 2. Right corneal opacity has been managed with topical corticosteroids, starting with dexamethasone three times daily, tapering to fluorometholone once daily, and has been improving since the surgical procedure. Transparency of the left cornea was fully restored, allowing ocular fundus observation, which revealed a cup/disc ratio of 0.5 and was otherwise unremarkable.

Following the initial surgical procedure, pharmacological treatment was required to manage IOP. In the right eye, IOP remained stable at 15–20 mm Hg with timolol 0.25% twice daily. However, despite maximum medical therapy with timolol 0.25% twice daily, brinzolamide twice daily, and latanoprost once daily, the left eye’s IOP showed an upward trend, reaching levels between 30 and 35 mm Hg. Axial length was monitored using echometry, as displayed in Figure 3, and was found to be exceeding the normal range for the patient’s age in the left eye. Seven months after the first surgical procedure, an inferior trabeculotomy was performed in the left eye.

Eighteen months after the initial presentation, the patient can fixate and follow objects with the right eye. Despite the presence of a dense leucoma, the superior cornea remained unaffected. Therefore, topical atropine was administered in the right eye, and occlusion therapy was applied to the left eye to prevent the development of dense deprivation amblyopia in the right eye. The patient has been proposed for a right eye penetrating keratoplasty. The left eye has a clear cornea and controlled IOP (10–15 mm Hg under treatment with timolol 0.25% and brinzolamide, both administered twice daily).

A normal visual evoked potentials response to a pattern-reversal stimulus was observed in both eyes. Genetic testing was performed to target CYP1B1 gene variants using DNA sequencing analysis, which identified a pathogenic variant, c.1064_1076del and a variant of uncertain significance, c.1426 T>C. Familial analysis confirmed that these variants were transmitted biparentally and segregated with the disease.

Our patient, diagnosed with PCG, presented with a severe increase in IOP and significant corneal edema in both eyes. The right eye was particularly affected, exhibiting a protruding and opaque cornea, which in the absence of birth trauma raised suspicion for severe corneal hydrops.

Early detection and appropriate management of PCG can significantly improve visual outcomes. Unlike adult-onset glaucoma, where optic nerve cupping and visual field loss are permanent, the optic disc cupping in PCG is reversible in the early stages due to the high elasticity of optic nerve tissues in infants and young children [6].

Surgical intervention is the primary treatment for PCG, aiming to eliminate the resistance to aqueous outflow. This can be achieved through an internal approach (goniotomy) or an external approach (trabeculotomy and/or trabeculectomy) [7, 8]. In our patient’s case, severe corneal opacification made goniotomy impossible, and therefore, urgent bilateral trabeculotomy was the chosen course of action.

In the postoperative period, the transparency of the cornea, control of axial length, and optic nerve cupping are key indicators of disease progression [9]. In our patient’s left eye, an increase in axial length in subsequent evaluations indicated PCG progression, warranting further surgical intervention. Despite the absence of signs to support disease progression in the right eye, the resultant severe corneal scarring is of particular concern due to its potential to induce deprivation amblyopia. Penetrating keratoplasty can address this concern, albeit with specific surgical technique challenges and an elevated risk for graft failure in the pediatric population. This risk is further amplified in cases where the patient presents with a concurrent eye disease and requires additional surgical procedures [10]. Other medical or surgical treatments should also be considered to address the risk of amblyopia in these patients. These may include surgical iridotomy or long-lasting dilating drops to enable visual development through a clear area of the cornea, as well as occlusion therapy for the contralateral eye.

Acute corneal hydrops is a rare presentation of PCG. Urgent reduction in IOP is mandatory to improve the visual prognosis. Severe corneal opacification can result from intense mechanical stretching associated with acute corneal hydrops and although its treatment remains a challenge in the pediatric population, it is critical to prevent deprivation amblyopia.

Written informed consent was obtained from the parents for the publication of this case report and accompanying images. Ethical approval is not required for this study in accordance with local or national guidelines. The CARE Checklist has been completed by the authors for this case report and is attached as online supplementary material (for all online suppl. material, see https://doi.org/10.1159/000542340).

The authors have no conflicts of interest to declare.

This study was not supported by any sponsor or funder.

Rita Rodrigues, MD: conceptualization, data curation, formal analysis, investigation, methodology, validation, writing – original draft, and writing – review and editing. João Pinheiro-Costa, MD, PhD; Joana Araújo, MD; António Benevides Melo, MD; Augusto Magalhães, MD: validation, writing – original draft, and writing – review and editing. Sérgio Estrela-Silva, MD: conceptualization, data curation, formal analysis, investigation, methodology, validation, writing – original draft, and writing – review and editing.

All data generated or analyzed during this study are included in this article and its online supplementary material. Further inquiries can be directed to the corresponding author.