A 21-month-old girl with congenital cranial dysinnervation disorder—an umbrella diagnosis that includes Moebius syndrome, congenital hypotonia with severe ptosis, bilateral tonic pupils, and congenital fibrosis—presented with symmetric abduction deficit, ophthalmoplegia, exotropia, and a chin-up position owing to ptosis. At the time of her birth, a gastronomy tube was placed because of inadequate feeding. A genetic consult revealed a benign duplication, but no abnormalities to explain the full medical picture.
A dense white stromal opacity in the right eye was attributed to exposure and treated with lubrication. A visual evoked potential test showed reduced visual acuity, and the patient underwent bilateral frontalis sling procedures to prevent amblyopia. She did well postoperatively and had good lid elevation and no closure during sleep.
Five months later, the girl’s parents noticed that she was rubbing her eyes, and they saw a glob of mucus on the surface of the right eye. They brought her to the emergency department, where the examination was significant for mild injection, mucus, and a 4 mm x 4 mm outpouching of the cornea. The eye was soft and Seidel negative, and the chamber appeared shallow but formed. The patient was given topical antibiotics, and a tape tarsorrhaphy was performed in preparation for definitive repair in the operating room.
The Surgery
In the OR, examination under anesthesia revealed a hypotonous right eye with conjunctival injection, a 5 mm x 6 mm paracentral protuberant area of the cornea with thin spots, mild haze surrounding the lesion, and an otherwise clear cornea (Figure 1). The chamber was shallow. Other findings included a 3-mm pupil, an atrophic iris with visible vessels, and a clear lens. Anterior segment OCT revealed highly cystic corneal tissue with large intrastromal fluid cystic cavities throughout and up to the epithelium.
Figure 1. Examination under anesthesia revealed a hypotonous eye, paracentral protuberance of the cornea with visibly thin areas and mild haze, shallow chamber, 3-mm pupil, atrophic-appearing iris with visible vessels, and clear lens. Anterior segment OCT showed highly cystic corneal tissue with large intrastromal fluid cystic cavities throughout.
Figure 2. Pathology identified a large central defect. Peripherally and paracentrally, the endothelium was mildly attenuated in some areas with foci of discontinuity. The corneal stroma exhibited widespread scarring, fibrosis, areas of necrosis, and a severe mixed inflammatory infiltrate. The Bowman layer is present only in the peripheral cornea. The corneal epithelium was edematous, disorganized, widely variable in thickness, and contained microcystic bullae. Adherent iris tissue showed congested blood vessels.
A therapeutic penetrating keratoplasty was performed. A 7.75-mm corneal graft was decentered to the limbus inferonasally. The corneal button had extensive iris incarceration into the lesion and was firmly incorporated within the cystic stromal degeneration of the cornea. Synechiae were broken, and the firmly adhered iris was excised. A conjunctival resection was performed where graft went to limbus. A partial, temporary tarsorrhaphy was performed to prevent exposure and encourage healing.
Pathology Findings
The corneal button was submitted in formalin to Eye Pathology, where H&E-, GMS-, Gram-, and PAS-stained slides were examined. Pathology revealed a large central defect where the endothelium, Descemet membrane, stromal tissue, and Bowman layer were largely absent. The corneal stroma exhibited widespread scarring, fibrosis, areas of necrosis, and a severe mixed inflammatory infiltrate comprised primarily of neutrophils and lymphocytes. The corneal epithelium was edematous, disorganized, widely variable in thickness, and contained microcystic bullae. Adherent iris tissue showed congested blood vessels.
Gram staining showed gram-negative diplococci. Given the quiet presentation and the hypothesis of exposure keratopathy as the cause, microbiology was not sent at the time of surgery. Fortunately, we were able to send the formilin-fixed specimen for 16S ribosomal DNA PCR processing. The gram-negative diplococci was speciated to Moraxella nonliquifaciens. The patient was already being treated with ofloxacin, which has good efficacy against Moraxella, so that therapy was continued.
Key Learning Points
This case presented several learning opportunities. First, be cautious when repairing ptosis in patients with ophthalmoplegia. Second, send cultures to pathology even if infection is not high on the differential, because Moraxella and many other infections can be present without an obvious infiltrate; however, if microbiology was not sent during surgery, speciation can be determined with DNA PCR of a formalin-preserved pathology specimen. Finally, hypotony can be induced from confluent bullae, and therapeutic keratoplasty is an effective treatment.
Acknowledgments: Evan Warner, MD; Sarah Nehls, MD; Yasmin Bradfield, MD; Breanna Aldred, MD; Katherine Dalzotto, MD; Heather Potter, MD; Nikki Duncan, MD; and Regis Kowalski, MS.
