Corneal Icterus Resulting from Stromal Bilirubin Deposition RICHARD B. PHINNEY, MD, BARTLY J. MONDINO, MD, ALBER ABRAHIM, MD

Abstract: Three pairs of donor corneas were noted to be stained yellow after dissection from the whole globe. The peripheral cornea was stained more in­tensely than the central cornea in each case. All three of the donors had had jaundice with elevated serum bilirubin levels for at least 1 month before death. The corneas were finely minced and eluted in chloroform for a period of at least 1 week. Scleras from two of the three donors were similarly treated. Spectro­photometric analysis of the corneal and scleral eluates demonstrated the ab­sorbance spectrum of bilirubin (400-490 nm). Identically prepared eluates of normal corneas and scleras from three donors did not show the absorbance spectrum of bilirubin. Results of slit-lamp examination of both eyes of a severely jaundiced patient disclosed yellow pigmentation of the corneal stroma with the peripheral cornea showing more pigmentation than the central cornea. Corneal bilirubin deposition, a previously undescribed finding, may occur in patients with jaundice. Ophthalmology 96:1212-1214, 1989

Bile pigment deposition in ocular structures has been described, to our knowledge, only in conjunctival and scleral tissues. t-s In jaundice of recent onset, bilirubin is deposited primarily in the subepithelial tissue of the con­junctiva. With long-standing icterus, the bilirubin may also be deposited in the sclera, but the bulk remains in the conjunctiva. 1

•5 We noted a marked yellow staining of

corneas obtained after death from three icteric patients. We report herein the previously undescribed finding of corneal bilirubin deposition.

CASE REPORTS

Case 1. A 59-year-old white man was admitted to the hospital with the diagnosis of hemorrhagic pancreatitis, hepatic failure, splenic vein thrombosis, and renal failure. His history was pos­itive for chronic alcoholism. Physical examination results showed muscular wasting, abdominal ascites, and an icteric complexion.

Originally received: December 15, 1988. Revision accepted: February 13, 1989.

From the Jules Stein Eye Institute, Department of Ophthalmology, UCLA School of Medicine, Los Angeles.

Supported in part by grant EY04607 from the National Eye Institute, Be­thesda, Maryland; the Lee and Mae Sherman Fellowship, and the Was­serman Fund, Los Angeles, California.

Reprint requests to Bartly J. Mondino, MD, Jules Stein Eye Institute, UCLA Medical Center, 10833 LeConte Ave, Los Angeles, CA 90024-1771.

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The total bilirubin level was 26.4 mg/dl (normal, 0.3-1.2 mg/ dl). He underwent hemodialysis and died 1 month later of sys­temic sepsis. No ophthalmologic examination was obtained throughout the hospitalization, and only scleral icterus was ob­served.

After the patient's death, consent for eye donation was ob­tained, and enucleation was performed within 3 hours of death. The eyes were placed in a moist saline chamber and refrigerated. One day after death, the corneas were noted to have a distinct yellow hue at the time of dissection from the whole globe. The peripheral cornea stained more intensely than the central cornea. After removal, the corneas were stored at -70°C for 1 month before processing.

Case 2. A 6-week-old male infant with a diagnosis of pyloric stenosis underwent pyloromyotomy under halothane anesthesia. Several hours after surgery, he became bradycardic, hypothermic, and pale, and showed minimal respiratory effort. Diffuse intra­vascular coagulation was diagnosed. Abdominal girth expanded because of persistent bleeding and the development of a retro­gastric hematoma. He became anuric from acute renal failure, and a small bowel obstruction and obstructive jaundice devel­oped. Scleral icterus was noted within 1 week of the operation, and his complexion became progressively more jaundiced. In the 5 weeks between initial surgery and the time of death, the total bilirubin level rose to a peak of 37 mg/dl, with the direct fraction (conjugated) reaching 18 mg/dl. Results of ophthal­mologic examination 3 days before the infant's death showed scleral icterus, deeply excavated optic nerve heads, and normal retinal backgrounds.

After death, consent for eye donation was obtained, and enu­cleation was performed within 2 hours of death. The eyes were placed in a moist saline chamber. The corneas were dissected from the whole globes 1 hour after enucleation and processed

PHINNEY et al • CORNEAL ICTERUS

Fig 1. Top, icteric donor corneas from case 2. The peripheral cornea shows more yellow pigmentation than the central cornea. Fig 2. Bottom, donor globes from case 3. The iris color appears gray-green in the intact globe on the left and blue after removal of the cornea from the globe on the right.

immediately. They had marked yellow intracorneal staining that was more pronounced peripherally than centrally (Fig 1 ).

Case 3. A white male infant, the product of an uneventful delivery from a normal full-term pregnancy, was noted to be jaundiced at 2 weeks of age. The diagnosis of biliary atresia was made in the eighth week of life. Portal vein thrombosis and ascending cholangitis were diagnosed at the age of 5 months. From this point until death, the infant had multiple febrile ep­isodes and a progressive deterioration in hepatic function.

He was admitted to the hospital at 9 months of age for eval­uation of possible liver transplantation. The hospital course was complicated by a gradual worsening of the bile stasis. He was noted to have scleral icterus 3 weeks after admission, at which time total bilirubin level measured 7 mg/dl and direct bilirubin level was 5.5 mg/dl. Over the next 1 month, he became deeply jaundiced and the total bilirubin level rose to 34.8 mg/dl with a direct level of 19.2 mg/dl. He ultimately died of pulmonary hemorrhage.

After consent for eye donation was obtained, enucleation was performed within 2 hours of death, and the eyes were placed in moist saline chambers. A yellow discoloration of the cornea was noted by viewing it tangentially, and the irises appeared gray­green. The corneas were removed from the whole globes 1 hour after enucleation. After removal, the corneas appeared distinctly yellow, with the peripheral cornea staining more intensely than the central cornea. The irises now appeared blue instead of gray­green (Fig 2).

Case 4. A 55-year-old white woman with a long-standing his­tory of heavy alcohol use was admitted to the hospital with de­compensated alcoholic liver disease. She had increasing abdom­inal distension with ascites, jaundice, mild renal failure, and evidence of metabolic bone disease with axial compression frac­tures. She had an ocular history of nonexudative macular de­generation. She stated that before jaundice developed, her iris color was blue. Biochemical test results included a total bilirubin level of 46 mg/dl with a conjugated level of 37 mg/dl.

Results of physical examination showed a deeply jaundiced, poorly nourished, chronically ill-appearing woman in no distress. The skin was deeply icteric. Best-corrected visual acuity mea­sured 20/25 in the right eye and 20/50 in the left. The pupils measured 3 mm bilaterally and showed normal direct and con­sensual reflexes. Versions and ductions were normal without nystagmus. Results of slit-lamp examination showed icteric conjunctiva and sclera without evidence of inflammation or dis­charge. The corneal epithelium was intact in each eye and did not stain with fluorescein. The entire corneal stroma was stained yellow, most densely in the peripheral 2 to 3 mm. The irises appeared gray with normal details. The optic nerves were pink and showed normal cupping. The retinas showed age-related macular degeneration without hemorrhages or exudates.

MATERIALS AND METHODS

Processing of corneal and scleral tissue was carried out within 3 hours of donor death for cases 2 and 3, and 1 month after freezing at -70°C in case 1. The donor cor­neas were cut in half with a razor blade. One half was processed for paraffin sectioning and stained with he­matoxylin eosin. The remaining corneal tissue and sclera from two of the three donors (cases 2, 3) were finely minced with a razor blade. The minced tissue was placed in approximately 3 ml of chloroform and stored in a re­frigerator for at least 1 week. Normal corneas and scleras from the eyes of three donors without a history of liver or biliary tract disease were prepared in an identical man­ner. Eluates from the various samples were then analyzed for absorbance at wavelengths between 200 and 700 nm on a Shimadzu UV -160 spectrophotometer (Shimadzu Corporation, Kyoto, Japan).

RESULTS

The spectrophotometric absorbance pattern found in the corneal and scleral eluates from cases 1 to 3 showed absorbance beginning at the 380- to 400-nm wavelength, rising to a peak at 453 nm and falling to baseline at 500 nm (Fig 3). This corresponds precisely to the absorbance spectrum ofbilirubin in chloroform. The eluates from the three control corneas and scleras showed no absorbance from 370 to 700 nm. The corneal sections appeared nor­mal by light microscopy.

DISCUSSION

The staining of tissues resulting from abnormal levels of bilirubin in the serum is referred to as jaundice or ic­terus. The destruction of circulating erythrocytes normally accounts for approximately 80 to 85% of the daily bili­rubin production.6 Hemoglobin released by the reticu­loendothelial cell destruction of erythrocytes is dissociated into globin and the heme moiety, which is then oxidatively cleaved and converted to biliverdin. Bilirubin is then formed from biliverdin by biliverdin reductase. Bilirubin exists in either the conjugated (direct) or unconjugated

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OPHTHALMOLOGY • AUGUST 1989 • VOLUME 96 • NUMBER 8

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Icteric Corneal Eluates --

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Control Corneal &Scleral Eluates -•-

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WAVELENGTH (NM)

Fig 3. Absorbance spectrum from the corneal and scleral eluates (cases I to 3) and controls. Notice the rise from the baseline at approximately 380 to 400 nm and peak at 453 nm with subsequent decline to 500 nm in the eluates from cases I to 3, and the absence of absorbance at wave­lengths from 350 to 500 nm for control corneal and scleral eluates. Both control and icteric samples showed peaks in the 300 to 325 nm range (not shown in Figure 3) that rapidly declined toward baseline. The ab­sorbance of bilirubin interfered with the progressive decline in the icteric sample so that the tracing did not reach baseline but rose to a peak corresponding to the pattern produced by bilirubin.

(free) form. Unconjugated bilirubin is the only form nor­mally found in the blood. It travels in serum tightly and specifically bound to albumin. Liver cells actively remove unconjugated bilirubin from serum albumin, and the mi­crosomal enzyme, glucuronyl transferase, combines a molecule of free bilirubin with two molecules of gluc­uronic acid to produce conjugated bilirubin. The latter form is water soluble and is loosely bound to albumin. ,Conjugated bilirubin escapes into the serum in diseases such as hepatitis, cirrhosis, and biliary obstruction. In these diseases, the biliary epithelium is damaged and bile leaks back into the bloodstream. Conjugated bilirubin stains elastic tissue and is most readily detected in the conjuctiva, sclera, mucous membranes, and skin overlying the chest and abdomen.6

•7 This form ofbilirubin may undergo ox­

idation to biliverdin, which may cause the stained tissue to take on a greenish hue. Unconjugated bilirubin, which predominates in hyperbilirubinemia of the newborn, col­lects in subcutaneous fat and is more readily seen on the abdomen and extremities. 6

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Bilirubin and biliverdin are soluble in chloroform, al­cohol, and a number of organic solvents. Spectrophoto­metric analysis of bilirubin eluted in chloroform shows absorbance from 400 to 490 nm with the peak at 453 nm. 8 Absorbance of biliverdin in chloroform shows peaks at 640 to 650 nm and 378 to 380 nm.9 The absorbance pattern found in the corneal and scleral eluates from cases 1 to 3 matched that of bilirubin and showed no evidence of biliverdin (Fig 3).

Bile pigment deposition in the cornea has not been recognized, to our knowledge, in the ophthalmic litera­ture.10·11 In this study, the four patients with corneal staining had total bilirubin levels ranging from 26 to 46 mg/dl. We do not know how high serum bilirubin levels must rise, and the length of time necessary for pigment deposition to occur. Similarly, we do not know how long the staining persists after a return of serum bilirubin to normal levels. Bilirubin pigmentation was more promi­nent in the peripheral than in the central cornea in all donor corneas (Fig 1) and in the living patient who was examined at the slit lamp. This pattern suggested that the limbal blood vessels were the source of bilirubin. This differs from corneal blood staining in which hemoglobin­containing breakdown products of red blood cells diffuse through Descemet's membrane into the corneal stroma. 11

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2. Duke-Elder S, ed. System of Ophthalmology, Vol. VIII: Diseases of the Outer Eye. Pt. 1: Conjunctiva. St. Louis: CV Mosby, 1965; 595.

3. Scheie HG, Albert DM. eds. Textbook of Ophthalmology, 9th ed. Philadelphia: WB Saunders, 1977; 21.

4. Spencer WH, Zimmerman LE. Conjunctiva. In: Spencer WH, ed. Ophthalmic Pathology: An Atlas and Textbook, 3rd ed, Vol. I. Phila­delphia: WB Saunders, 1985; 168.

5. Hogan MJ, Zimmerman LE, eds. Ophthalmic Pathology: An Atlas and Textbook, 2nd ed. Philadelphia: WB Saunders, 1962; 257.

6. lsselbacher KJ. Jaundice and hepatomegaly. In: Braunwald E, lssel­bacher KJ, Petersdorf RG, et al, eds. Harrison's Principles of Internal Medicine, 11th ed. New York: McGraw-Hill, 1987; 183-8.

7. lber FL. Diseases of the liver, including jaundice. In: Harvey AM, Cluff LE, Johns RJ, et al, eds. The Principles and Practice of Medicine, 17th ed. New York: Appleton-Century-Crofts, 1968; 985.

8. Windholz M, Budavari S, Blumetti RF, Otterbein ES, eds. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 1Oth ed. Rahway, NJ: Merck, 1983; 172-3.

9. Gray CH, Lichtarowicz-Kulczycka A, Nicholson DC, Petryka Z. The chemistry of the bile pigments. Part II. The preparation and spectral properties of biliverdin. J Chern Soc 1961; Pt. II, June: 2264-8.

10. Duke-ElderS, ed. System of Ophthalmology, Vol. VIII: Diseases of the Outer Eye. Pt. 2: Cornea and Sclera. St Louis: CV Mosby, 1965; 976-92.

11. Spencer WH. Cornea. In: Spencer WH, ed. Ophthalmic Pathology: An Atlas and Textbook, 3rd ed, Vol. I. Philadelphia: WB Saunders, 1985; 369-80.