Corneal Hydrops in Terrien's Marginal Degeneration H. KAZ SOONG, MD,* JUDITH FITZGERALD, MD,* S. ARTHUR BORUCHOFF, MD, t ALAN SUGAR, MD,* ROGER F. MEYER, MD,* MICHAEL G. GABEL, MD* Abstract: We present four cases of Terrien's marginal degeneration that de- veloped spontaneous ruptures in Descemet's membrane resulting in corneal hydrops. In all cases, the hydrops was characterized by a clear intracorneal pocket of aqueous humor rather than by stromal clouding. In two cases, the pocket extended peripherally to form a conjunctival filtering bleb. Although a lamellar corneal patch graft was used in one case for severe astigmatism, hypotony, and impending perforation, most cases were merely observed without treatment. (Key words: astigmatism, conjunctival filtering bleb, Descemet's membrane, hydrops, Terrien's marginal degeneration.] Ophthalmology 93:340- 343, 1986 Terrien's marginal degeneration is an uncommon, often bilateral, form of corneal ectasia characterized by indo- lently progressive peripheral stromal thinning with intact overlying epithelium. The disease typically produces su- perior corneal gutter formation with vascularization of the base and lipid infiltration at the leading edge. 1 The classical form occurs mostly in patients over age 40 years and shows extremely slow progression associated with minimal clinical or histological inflammation. 1 - 3 A variant form with prominent inflammatory signs occurring in a younger population has been observed. 4 As Terrien's marginal degeneration progresses, severe astigmatism and corneal thinning with an increased risk of perforation may occur. 5 Over the past six years, we have observed spon- taneous ruptures in Descemet's membrane that resulted in corneal intralamellar dissection in four patients with Terrien's marginal degeneration, with the consequent formation of a pocket of aqueous humor. CASE REPORTS Case 1. An 85-year-old woman was told 15 years ago of bi- lateral Terrien's marginal degeneration. She underwent cataract From the Department of Ophthalmology,* W. K. Kellogg Eye Center, Uni- versity of Michigan Medical School, Ann Arbor, and the Massachusetts Eye and Ear Infirmary and Harvard Medical School,t Boston. Presented at an Annual Meeting of the American Academy of Ophthal- mology. Reprint requests to H. Kaz Soong, MD, W. K. Kellogg Eye Center, 1000 Wall Street, Ann Arbor, Ml48105. 340 extractions in both eyes approximately ten years ago, but she had senile dementia and could not provide an accurate history. She was referred to one of us (SAB) in March 1983 by her in- ternist because ofthe "inability to open her eyes." The ophthal- mologic examination was limited by the patient's blepharospasm and poor cooperation. Her visual acuities with spectacle correc- tion (right eye: + 14.00 +0.25 X 140; left eye: + 12.00 + 1.00 X 71) were hand motions at one foot in the right eye and counting fingers at one foot in the left eye. Slit-lamp examination con- firmed the presence of a gutter-like area of peripheral ectasia in each cornea superiorly near the limbus. The epithelium was in- tact over the ectatic regions. Fine, radial interstitial blood vessels were present in these regions and dense lipid deposits were noted anteriorly at their central borders. Within the ectatic region of the right cornea was a small rent in Descemet's membrane with an intralamellar pocket of aqueous humor in the overlying thin stroma (Fig 1 ). This pocket appeared to be walled off posteriorly by Descemet's membrane and anteriorly by Bowman's layer and epithelium, with little stroma in between. The cornea was thus remarkably transparent in this area. A diagnosis of corneal hydrops in Terrien's marginal degeneration was made. An additional finding in this patient was the presence of a diffuse corneal ulcer with white stromal infiltrates at both the superior ectatic zone and also in the "normal cornea" just an- terior to the ectatic regions OD (Fig 1 ). She was started on intense topical antibiotic therapy and the ulcer resolved within one week. Cultures from the ulcer grew abundant Streptococcus pneumo- niae. Six weeks later, despite the complete resolution of the ulcer, the pocket of aqueous humor remained unchanged in the right cornea. The patient died of unrelated causes in May 1983. Her eyes were not available for pathologic examination. Case 2. A 55-year-old man with a history of amblyopia in the right eye due to childhood strabismus was seen in 1972 at the Massachusetts Eye and Ear Infirmary for severe irregular astig- matism in both eyes not fully correctable by spectacles. The visual acuity without correction was 20/200 in the right eye