Acute hydrops in the donor cornea graft in non-keratoconus patients.

A 44-year-old Hispanic male and 91-year-old Caucasian male presented to the clinic with acute vision loss and pain years after penetrating keratoplasty (PKP). Neither patient had a history of keratoconus. Both patients had a history of eye rubbing and intraocular device present in the anterior chamber. The first patient had a history of a glaucoma drainage tube and the second patient had an anterior chamber intraocular lens implanted. Anterior segment ocular coherence tomography showed deep stromal cystic cavities. Both patients exhibited breaks in the endothelium by ultrasound biomicroscopy and the histopathologic examination after repeat PKP. Those findings were most consistent with acute corneal hydrops in the donor graft.

INTRODUCTION

Corneal hydrops is a condition of acute stromal edema that occurs after a rupture in Descemet's membrane. This is not an uncommon sequelae of late keratoconus and is a frequent indication for penetrating keratoplasty (PKP). Approximately, 3% of keratoconus patients experience one or more episodes of corneal hydrops.1 Rarely, it can occur in a corneal graft and is frequently an extension of a break in Descemet's membrane from the host cornea to the donor graft. This has been reported in two separate case reports.23

To the author's knowledge, hydrops in a donor corneal graft has not been described outside of the context of keratoconus. We present two patients with no history of keratoconus that developed acute hydrops in the donor corneal graft.

CASE REPORTS

Case 1

A 44-year-old human immunodeficiency virus positive Hispanic male with undetectable viral load presented to the clinic with a 5-week history of decreased vision, 1 year after undergoing PKP in the left eye. The patient had a history of herpes keratitis complicated by severe glaucoma in that eye. He had received a corneal transplant 2 years before for corneal decompensation. On the day of presentation, his best-corrected vision was 20/20 in the right eye and hand-motion at 6 feet in the left eye. His manifest refraction in the right eye was −3.00 + 0.50 × 148. The intraocular pressure was 15 mm Hg in the right eye. His corneal graft was very edematous, opaque, and protuberant making it impossible to measure the intraocular pressure in the left eye. The glaucoma drainage valve in the superotemporal quadrant was well-covered. There was no evidence of keratoconus in the fellow eye. Ocular coherence tomography (OCT) of the anterior segment showed a deep stromal cystic cavity consistent with hydrops in the left eye [Figure 1a]. Ultrasound biomicroscopy (UBM) of the anterior segment revealed a Descemet's membrane detachment and severe corneal edema with stromal cystic cavities [Figure 1b]. The patient received a repeat PKP of the left eye. During surgery, the glaucoma drainage tube was noted to be positioned close to the cornea and was trimmed under the host cornea rim. Pathology examination revealed a rupture and recoil of Descemet's membrane centrally and a near perforation with a substantial amount of corneal stromal edema, consistent with hydrops [Figure 2].

Figure 1

(a) High-definition anterior segment optical coherence tomographic image of corneal hydrops. There is marked fluid within the corneal stroma (b) Ultrasound biomicroscopy of acute corneal hydrops. Note the apparent break in Descemet's membrane

Figure 2

Pathology slide showing a focal break in Descemet's membrane and large amounts of stromal edema

Case 2

A 91-year-old Caucasian male with a history of PKP in the right eye was referred to the clinic for descemetocele evaluation. He had a corneal transplant of the right eye originally for pseudophakic bullous keratopathy. The patient reported frequent eye rubbing. On examination, he had light perception with projection in the right eye and 20/25 best-corrected vision in the left eye. The manifest refraction in the left eye was −1.50 + 1.50 × 141. Intraocular pressure was not measurable in the right eye and was 14 mm Hg in the left eye. A very large pedunculated cyst was seen within the corneal graft in the right eye [Figure 3]. There was no evidence of keratoconus in the fellow eye. OCT of the anterior segment revealed a deep stromal cystic cavity consistent with the hydrops. UBM of the anterior segment showed the presence of an anterior chamber intraocular lens and a large cystic cavity with a suspected break in the superior region of Descemet's membrane. The patient subsequently received a PKP of the right eye. The anterior chamber intraocular lens was an open-loop Kelman-style and was left in place. The corneal graft was oversized by 0.5 mm. Pathology examination revealed marked central corneal edema consistent with the hydrops. Descemet's membrane was absent except for fragments on both sides of the button.

Figure 3

Acute corneal hydrops within a corneal donor graft

DISCUSSION

Hydrops within a corneal donor graft is a rare complication after corneal transplant for patients with a history of keratoconus. In prior reports, it was believed to occur in patients who developed a tear in Descemet's membrane within the host corneal rim. This break would then extend into the donor cornea and allow the cornea to imbibe the fluid.

Corneal edema after corneal transplant can also be secondary to corneal graft failure from endothelial dysfunction or corneal transplant rejection. In those occasions, the edema is not quite so dramatic. The large fluid clefts in this case series demonstrated by anterior segment OCT and UBM show focal collections of fluid rather than a diffuse distribution consistent with corneal edema secondary to rejection or endothelial failure. Those cases highlight the importance of clinical suspicion and thorough diagnostic evaluation to rule out these other causes since the treatment would be markedly different.

We could not find other reports of patients without a history of keratoconus who developed hydrops in the donor corneal graft. An anterior chamber intraocular lens and a glaucoma drainage tube were the suspected culprits in the two patients who were surgically treated.

The common feature in these patients was eye rubbing, which might be implicated in the unexpected dislocation of intraocular devices and damage of the Descemet's membrane. If this important structure is violated, hydrops could ensue. Corneal transplant patients should be advised not to rub their eyes.