CONJUNCTIVAL RESECTION TREATMENT AND ULTRASTRUCTURAL HISTOPATHOLOGY OF SUPERIOR LIMBIC KERATOCONJUNCTIVITIS PETER C. DONSHIK, M. D., H. BARRY COLLIN, P H . D., C. STEPHEN FOSTER, M. D., H. DWIGHT CAVANAGH, M. D., AND S. ARTHUR BORUCHOFF, M. D. Boston, Massachusetts AND ALFRED J. MAGEE, M.D. Charleston, West Virginia
Theodore1 first described superior lim bic keratoconjunctivitis in 1963. It is characterized by inflammation of the su perior tarsal and bulbar conjunctiva and edema of the corneoscleral limbal con junctiva; corneal filaments are frequently present. Fine punctate fluorescein and rose bengal staining of the superior cor nea are commonly found. This condition is usually bilateral, occurs most frequent ly in females, and has been reported in patients from ages 4 to 81 years.2 Superior limbic keratoconjunctivitis characteristi cally follows a chronic course with remis sions and exacerbations. The prognosis most often is excellent in that eventual resolution occurs without visual impair ment. Laboratory studies in the form of bac terial, viral, or fungal cultures do not help determine diagnosis, cause, or treatment.2 The diagnosis can often be aided by find ing keratinized epithelial cells with de generated nuclei and hyalinized cyto plasm on smears from scrapings of the involved bulbar conjunctiva.3 From the Department of Cornea Research (Drs. Donshik, Foster, and Cavanagh), Eye Research In stitute of Retina Foundation, and the Cornea Service (Drs. Donshik, Collin, Foster, Cavanagh, and Boru choff), Massachusetts Eye and Ear Infirmary. This work was supported in part by Public Health Ser vice research grants EY-00208 and EY-01647, re search fellowships EY-02586 and EY-05081, Insti tutional National Research Service Award EY07018, from the National Institutes of Health, and in part by the Massachusetts Lions Eye Research Fund, Inc. Reprint requests to Peter C. Donshik, M.D., 41 North Main St., West Hartford, CT 06107.
An association with thyroid disease has been reported. Tenzel4 was the first to draw attention to the presence of elevated protein-bound iodine in patients with su perior limbic keratoconjunctivitis. Cher5 reported that five of his ten patients were either thyrotoxic or had undergone treat ment for hyperthyroidism at the time they had superior limbic keratoconjunctivitis. Similarly, Wright6 noted an incidence of 26% of present or past thyroid disease in his patients with superior limbic kerato conjunctivitis. Fells7 stated that 40% of his patients with dysthyroid exophthalmos had superior limbic keratoconjuncti vitis. Theodore8 reported the presence of hypothyroidism in some patients with superior limbic keratoconjunctivitis. The clinical benefits of 0.5% silver ni trate application to the palpebral conjunc tiva of the upper and lower eyelids of superior limbic keratoconjunctivitis pa tients have been advanced by Theodore.9 Other authors, s,e not finding silver nitrate therapy effective, have suggested me chanical removal of the surface cells, top ical use of N-acetylcysteine, 1% adrenal in, and soft contact lenses. The successful results of these various forms of therapy, however, have rarely been dramatic or long lasting. Tenzel10 has reported that recessing the superior limbic conjunctiva resulted in the elimination of symptoms. He also found that resection of the con junctiva with suturing of the free edges to the episclera resulted in long-lasting im provement of symptoms (R. R. Tenzel, M.D., personal communication, 1976).
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The current study was undertaken to investigate the effect of palpebral or bulbar conjunctival resection on the signs and symptoms of superior limbic keratoconjunctivitis and to document, for the first time known to us, the essential ultrastructural histopathologic features dem onstrated in ocular tissues affected by this disorder. Since a viral cause is often pos tulated in diseases of unknown origin, we conducted a specific search for viral parti cles in the excised tissue. CASE REPORTS Case 1—A 56-year-old white woman was exam ined because of intermittent, disabling, bilateral ocular irritation of ten years' duration. Results of thyroid T3 and T4 tests were normal. Examination revealed a corrected visual acuity of 6/6 (20/20) in each eye. Results of the ocular exami nation were unremarkable except for the superior limbic area of both eyes. Mild injection of the conjunctival vessels was present bilaterally. The superior limbic conjunctiva appeared congested, edematous, and thickened. Moderate punctate stain ing with rose bengal was demonstrated over the superior conjunctiva and superior corneal epithe lium. The tarsal conjunctiva showed fine bilateral papillary inflammatory changes. Results of Schirmer tests were normal. Over the ensuing five months, trials of artificial tears, topical corticosteroid therapy, soft contact lenses, and 0.5% silver nitrate applications to the superior tarsal conjunctiva were entirely ineffective. An excision of bulbar conjunctiva of the right eye was performed with immediate relief of symptoms. Postoperative recovery was uneventful. Three weeks after conjunctival resection, examination revealed a quiet, asymptomatic right eye with a smooth limbal conjunctiva, without rose bengal staining. The un treated symptomatic left eye exhibited impressive rose bengal superior limbic conjunctival staining, with congested conjunctival tissue exhibiting a typi cal heaped-up, corrugated appearance adjacent to the corneoscleral limbus. One month later an exci sion of bulbar conjunctiva of the left eye was per formed. Follow-up examinations six and five months after the respective resections showed con tinued improvement. The only complaint was occa sional irritation and the presence of excessive mucus. Ocular examination revealed normal eyes, except for a slight papillary tarsal conjunctival re sponse. The superior corneoscleral limbus was smooth and it did not stain with rose bengal. Case 2—A 56-year-old white woman was referred with a history of bilateral superior limbic keratoconjunctivitis of three years' duration. T3 and T4 studies were normal. She had been unsuccessfully treated with topical corticosteroids, decongestants, antibiot
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ics, artificial tears, and lubricant ointments. Exami nation demonstrated all the clinical features of su perior limbic keratoconjunctivitis, including bilater al corneal filaments. Schirmer test results were nor mal. A soft bandage contact lens was applied to the right eye with subsequent relief of symptoms and elimination of filaments. The untreated left eye remained objectively, as well as subjectively, un changed. The soft lens was removed from the right eye and a similar lens was applied to the left one. The right eye became symptomatic and corneal filaments de veloped. The superior limbic conjunctiva was again thickened and congested, and rose bengal staining was present. The left eye, under the soft contact lens, was symptomatically improved but objectively unchanged. We resected the bulbar conjunctiva of the right side. The soft contact lens was removed from the left eye. After resection, the patient experienced relief of symptoms in the right eye, but the left eye remained irritated and unchanged for six weeks after removal of the contact lens. A resection of the superior tarsal conjunctiva of the left eye was performed. Postoperatively no rose bengal staining was present in either eye. The tarsal conjunctival papillary reaction was still present in the right eye, but the superior tarsal conjunctival tissue of the left eye appeared normal. Seven months after resection of the conjunctiva, the right eye was asymptomatic with a smooth superior corneoscleral limbus and no evidence of fluorescein or rose bengal staining. The left eye (tarsal conjunc tival resection) was symptomatic and filaments had recurred. Case 3—This 58-year-old woman complained of a slowly progressive, painless decrease in vision in the right eye, accompanied by ocular irritation in both eyes. Ophthalmoscopic examination revealed a corrected visual acuity of R.E.: 6/12 (20/40), and L.E.: 6/120 (20/400). She had a 10-diopter myopia and a large astigmatic error of 15 diopters in the left eye. Ocular examination revealed mild bilateral su perior conjunctival features of superior limbic kera toconjunctivitis. Elevated T3 and T4 values were noted which required subsequent hospitalization and treatment with radioactive iodine. For the next five months, the patient received artificial tears for her complaints of ocular irritation; her clinical ap pearance remained unchanged. A resection of the superior limbic conjunctiva was performed with immediate relief of symptoms. Six months after resection she has remained asymptomatic although slight superior conjunctival injection has remained. Case 4—A 40-year-old woman was referred with a 3V2-year history of recurrent ocular irritation, with filaments and corneal ulcers of the right eye. She had been treated with a variety of drops and ointments including silver nitrate. Thyroid function studies were reported to be normal. Corrected visual acuity was R.E.: 6/9 (20/30), L.E.: 6/6 (20/20). Mild limbal conjunctival thicken ing and injection of the superior corneoscleral lim bus was noted. Superficial punctate staining of the
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Fig. 1 (Donshik and associates). Case 4. Clinical photograph showing limbal epithelial thickening (arrow) and injection.
cornea was present, but filaments were absent (Fig. 1). Schirmer test results were normal. The left eye was unremarkable. Treatment consisting of artificial tears every two hours gave no improvement. The superior limbal conjunctiva was then resected and the patient experienced immediate relief. After re section the corneoscleral limbus was smooth and flat. The patient has remained totally asymptomatic for ten months. METHODS
The bulbar conjunctiva (from one eye in three patients and from both eyes in a fourth patient) was surgically resected under local anesthesia. A block of con junctiva extending from the 10:30 to the 1:30 position at the corneoscleral limbus and posteriorly for 3 to 4 mm was routine ly removed. Erythromycin ointment was instilled and a patch was applied for 48 hours. In one patient approximately 2.5 mm of the upper tarsal conjunctiva of one eye was resected. Erythromycin ointment was instilled and a patch was worn for 24 hours. No surgical complications were encountered, and healing was prompt and complete.
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We performed light and transmission electron microscopy on the five samples of superior bulbar conjunctiva and on the one sample of superior tarsal conjunctiva. Controls consisted of similar tissue from patients who underwent cataract surgery. On removal, tissue for electron micros copy was immediately placed in buffered glutaraldehyde (4% in 0.067M sodium cacodylate at p H 7.35) at room tempera ture. Tissue was dissected into small pieces and processed in one of the follow ing ways: (1) Normal osmium—Tissue was fixed for one hour in 2% osmium tetroxide in 0.067M sodium cacodylate, dehydrated in acetone, and then embedded in Araldite. Uranyl acetate (0.5% in 75% acetone) block stain was used and sections were stained with lead citrate 11 and uranyl ace tate ( 1 % aqueous). (2) Osmium potassium ferrocyanide— Fixation was accomplished with 2% os mium tetroxide and 1.5% potassium fer rocyanide in 0.067M sodium cacodylate for one hour. This is a slight modification of the osmium potassium ferrocyanide method of Dvorak and co-workers. 12 Tis sue was then dehydrated in acetone and embedded in Araldite. Sections were stained with lead citrate only. Sections were cut on an LKB Ultratome III, and examined on an electron microscope. Sections IJJL thick were stained with Richardson's stain. 13 Paraffin sections were also prepared and routinely stain,ed with hematoxylin and eosin for light mi croscopy. RESULTS
Light microscopy—Limbal conjunctiva of control cases demonstrated no signs of keratinization, no intracellular swelling, and no signs of inflammation. Limbal conjunctiva that was removed from all superior limbic keratoconjunctivitis pa tients demonstrated various degrees of keratinization with areas of acanthosis.
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Fig. 2 (Donshik and associates). Case 2. Light micrograph of epithelium and stroma (left) and stroma (right) of the lower corneoscleral limbal conjunctiva showing blood vessels packed with erythrocytes, dilated lymphatic vessels, and stromal tissue that is relatively devoid of inflammatory cells (Richardson's stain, left, x385; right, x960).
Some epithelial cells appeared swollen and in various stages of degeneration. In particular, the nuclei of some cells appeared empty. The stroma showed signs of edema, with grossly dilated lymphatic
vessels. Inflammatory cells-neutrophils, lymphocytes, and plasma cells-were rare and could not be distinguished from cells of normal controls (Fig. 2). Tarsal conjunctiva from one patient revealed an
Fig. 3 (Donshik and associates). Superficial epithelial cells with large nuclei (N) from the superior corneoscleral limbal region of a normal eye. Tissue was removed during cataract surgery (osmium potassium ferrocyanide, x 3,900).
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essentially normal epithelium, except for some intercellular edema, with no evi dence of keratinization. The goblet cell population appeared similar to control tissue. The underlying stromal tissue showed few inflammatory cells. There were some areas of cellular debris. Transmission electron microscopy— Superior limbal conjunctiva of control patients revealed normal epithelium with small intercellular spaces and no evi dence of glycogen accumulation in the cells (Fig. 3). The most prominent feature of the superficial perilimbal bulbar con junctiva taken from superior limbic keratoconjunctivitis. patients was the consis tent finding of large, pale, swollen cells in which the cytoplasmic organelles were scarce. In some cells the nuclei were large and empty, although the nuclear mem
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brane was often intact; this appeared to be a form of balloon degeneration of the nuclei. In other cells the nuclear envelope was broken and nuclear material was re leased into the cytoplasm. Intercellular spaces were larger than in the normal tissue and there was some breakdown of desmosomes (Fig. 4). Other nuclei also showed changes in the distribution of darkly staining nuclear chromatin, which was aggregated in the center of the nucle us, instead of around the nuclear mem brane or evenly distributed as in normal cells. The nuclear envelope was also more tortuous (Fig. 5). Another prominent feature was the presence of extensive intracellular accu mulations of glycogen granules (Figs. 4 and 5), which appear black (electrondense) when the osmium potassium ferro-
Fig. 4 (Donshik and associates). Case 4. Section of superior limbal conjunctiva. There is a large, pale, swollen cell (E) surrounded by more darkly staining epithelial cells. The nucleus (N) is empty and undergoing balloon degenerative changes. Areas of thickened cell membrane (small arrows) and breakdown of desmosomes (large arrows) are shown. The small black dots represent glycogen granules which are dense in the cells at the lower left of the micrograph (osmium potassium ferrocyanide, x6,750).
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Fig. 5 (Donshik and associates). Superior limbal epithelial tissue from patient 3. The two sections of the nucleus (N) contain an unusual distribution of darkly staining chromatin. The nuclear envelope is abnormally tortuous (arrows). Black dots and areas represent abnormally accumulated glycogen (osmium potassium ferrocyanide, x 14,300).
cyanide method of fixation is used. Al though superficial conjunctival epithelial cells contain some glycogen, 14 it is mini mally present. Thoft and Friend 1 5 found only 8.8 \xM glucose/g of dry weight in rabbit conjunctiva compared to 237.1 H-M/g of dry weight in rabbit corneal tissue. We were unable to demonstrate glycogen granules in the control speci mens, yet the intracellular glycogen gran ules were clearly visible in all the speci mens from patients with superior limbic keratoconjunctivitis. There was extensive evidence of keratinization of the epithelium (Fig. 6). This was in the form of increased numbers and clumping of microfilaments, the presence of secondary lysosomes, thickening of the epithelial cell membrane, and the pres ence of keratohyalin granules in the cyto
plasm (Fig. 7). We are preparing a more complete account of the ultrastructural changes associated with accumulation of keratohyalin granules. In patients who had been treated with silver nitrate, silver granules were depos ited in the intercellular spaces. Although viral particles were diligently searched for, none could be found. Marked inflam matory cells were not present in either the epithelium or stroma of the resected con junctiva. Ultrastructural examination of tarsal conjunctiva taken from one patient with superior limbic keratoconjunctivitis con firmed the light microscopic findings of a relatively normal epithelium, with some edema and an occasional inflammatory cell. Glycogen granules were rare and there was no aggregation of granules. In
Fig. 6 (Donshik and associates). Case 4. Superior limbal conjunctiva (C) showing abnormalities of the superficial epithelial cells. The three cells (E) show loss of cell components and are becoming keratinized. The intercellular spaces are wide and the deeper cells show an increase in the number of cytoplasmic filaments. A small keratohyalin granule (arrow) is present (normal osmium, x6,000).
Fig. 7 (Donshik and associates). Case 4. Part of a superior limbal epithelial cell. There are two keratohyalin granules (arrows) surrounded by what appear to be ribosomes. Microfilaments are numerous (F) and glycogen (black) is present Nucleus (N) (osmium potassium ferrocyanide, x 18,800).
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Fig. 8 (Donshik and asociates). Case 4. Superficial epithelial cells from the upper tarsal conjunctiva. The majority of cells have essentially normal nuclei (N). There are no signs of keratinization and no accumulations of glycogen granules (osmium potassium ferrocyanide, x 6,750).
the stroma there were a few disintegrating cells and some areas of cell debris, but no evidence of an inflammatory response (Fig. 8). DISCUSSION
Previous histologic descriptions of the superior limbic conjunctival tissue of pa tients with superior limbic keratoconjunctivitis have noted keratinization of the epithelium with acanthosis and dyskeratosis, as well as a moderate infiltra tion of inflammatory cells, chiefly neutrophils, lymphocytes, and plasma cells. 3,5 ' 6 Light microscopic examination of the tar sal conjunctiva has shown an increase of mucoid material on its surface together with a slight inflammatory cell infiltra tion. 6 Theodore and Ferry 3 reported a significant infiltration with neutrophils, lymphocytes, and plasma cells with nor mal epithelium.
Our studies by both light and transmis sion electron microscopy confirm the presence of abnormal superior limbic epi thelium consisting of keratinized epithe lial cells with swollen and degenerated nuclei. The stroma, although edematous, demonstrated no evidence of significant inflammatory cellular infiltrate. An in flammatory cell response in the patients studied by Theodore and Ferry may well have been secondary to prior silver nitrate treatment. The symptoms in superior limbic keratoconjunctivitis may stem from the inter action of three abnormal elements: the elevated bulbar conjunctiva, the superior corneal epithelium, and the papillary re action of the superior tarsal conjunctiva. The elevated bulbar conjunctiva in appo sition to the tarsal conjunctiva could pro duce a foreign-body sensation. Further more, the raised bulbar conjunctiva can
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prevent the tear film from adequately wet ting the superior cornea, causing superior punctate desiccation and filament forma tion. Although the cause of superior limbic keratoconjunctivitis is unknown, ther apy should be directed toward decreasing the limbal engorgement and adequately moistening the conjunctiva and cornea. This can be accomplished by mechanical debridement (scraping), chemical de bridement (silver nitrate therapy), or soft contact lenses. Wright 6 postulated that the initial patho logic process may reside in the upper tarsal conjunctiva. He argued that the presence of a chronically inflamed upper eyelid may be responsible for a disturb ance in the normal maturation of the bulbar conjunctiva] cells. He believed the normal upper eyelid, in the presence of mucus of normal composition and viscos ity, to be responsible for removing the superficial cells of the conjunctiva. If this process is impaired by an abnormality of either the eyelid or mucus, then the bul bar conjunctival cells persist in situ and progress toward keratinization. Any con junctival irritation can cause an increased goblet cell activity with increased mucus production and an alteration of the mucus-tear relationship. 1 6 Although this is a possible explanation, we were unable to identify definitively either the superior limbal conjunctiva or the palpebral conjunctiva as the primarily involved tissue. Several observations in dicate that the abnormality resides in the bulbar conjunctiva. In Case 4 the pres ence of papillary tarsal reaction in the right eye did not result in the reappear ance of abnormal keratinization of the superior limbic conjunctiva after resec tion. In Case 2 removal of either palpe bral or bulbar conjunctiva was enough to break the abnormal cycle and produce immediate relief. However, symptoms did return in the eye that underwent tarsal resection. Furthermore, we were unable to demonstrate any structural abnormali
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ties or increased goblet cells in the tarsal conjunctiva. In our cases, by removing the abnormal tissue, a normal relationship between the involved structures was re-established. Thus conjunctival resection affords longlasting remissions of symptoms, and should be considered as a therapeutic modality in patients with superior limbic keratoconjunctivitis who have either not responded to a trial of medical manage ment or who have experienced frequent symptomatic recurrences on medical therapy. Possible causes include dry eye, endo crine imbalance, viral involvement, and immunologic abnormalities. Our patients had normal Schirmer test results, but one was thyrotoxic. There was no histologic evidence of viral involvement. While autoimmunity is an attractive possibility, one would then expect corticosteroid therapy to have a beneficial effect, but it does not. The possibility that the inciting agent is an abnormal quality or quantity of mucus should be considered and warrants fur ther investigation. Two of our patients (Cases 1 and 2) had recurrence of mild symptoms in the presence of moderate discharge. SUMMARY
Four patients with symptomatic superi or limbic keratoconjunctivitis underwent resection of the superior bulbar conjunc tiva. One of these patients also underwent a tarsal conjunctival resection in the other eye. Three of the patients had previously been treated by various regimens without resolution; the fourth had had no prior treatment. All four patients had immedi ate and continued relief of the ocular symptoms after the superior bulbar con junctiva was excised. The patient who underwent tarsal conjunctival resection experienced only short-term relief. We studied the conjunctival tissue by light and transmission electron microsco-
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py. Both techniques revealed abnormali ties related to the bulbar conjunctival surface with keratinization of the epithe lium, acanthosis, degeneration of the nu clei, and intracellular accumulation of glycogen. Inflammatory cells were mini mally present. The tarsal conjunctiva ap peared essentially normal.
ACKNOWLEDGMENT
Deborah Pavan-Langston, M.D., and Claes Dohlman, M.D., allowed us to study their respective patients. REFERENCES . 1. Theodore, F. H.: Superior limbic keratocon junctivitis. Eye Ear Nose Throat Mon. 42:25, 1963. 2. : Superior limbic keratoconjunctivitis. Further studies. In XXI Concilium Ophthalmologicum Acta, Mexico D.F. 8-4, March 1970. Amster dam, Excerpta Medica, 1971, p. 666. 3. Theodore, F. H., and Ferry, A. P.: Superior limbic keratoconjunctivitis. Clinical and pathologi cal correlations. Arch. Ophthalmol. 84:481, 1970. 4. Tenzel, R. R.: Comments on superior limbic filamentous keratitis. Part 2. Arch. Ophthalmol. 79: 508, 1968. 5. Cher, I.: Clinical features of superior limbic keratoconjunctivitis in Australia. Arch. Ophthalmol. 82:580, 1969.
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6. Wright, P.: Superior limbic keratoconjunctivi tis. Trans. Ophthalmol. Soc. U. K. 92:555, 1972. 7. Fells, P.: Discussion on superior limbic kerato conjunctivitis. Trans. Ophthalmol. Soc. U. K. 92: 560, 1972. 8. Theodore, F. H.: Comments on findings of elevated protein-bound iodine in superior limbic keratoconjunctivitis. Part 1. Arch. Ophthalmol. 79: 508, 1968. 9. : Further observations on superior lim bic keratoconjunctivitis. Trans. Am. Acad. Ophthal mol. Otolaryngol. 71:341, 1967. 10. Tenzel, R. R.: Resistant superior limbic kera toconjunctivitis. Arch. Ophthalmol. 89:439, 1973. 11. Reynolds, E. S.: The use of lead citrate at high pH as an electron-opaque stain in electron microsco py. J. Cell. Biol. 17:208, 1963. 12. Dvorak, A. M., Hammond, M. E., Dvorak, H. F., and Karnovsky, M. J.: Loss of cell surface materi al from peritoneal exudate cells associated with lymphocytemediated inhibition of macrophage mi gration from capillary tubes. Lab. Invest. 27:561, 1972. 13. Richardson, K. C , Jarrett, L., and Finke, E. H.: Embedding in epoxy resins for ultrathin section ing in electron microscopy. Stain Technol. 35:313, 1960. 14. Hogan, M. J., Alvarado, J. A., andWeddell, J.: Histology of the Human Eye. An Atlas and Text book. Philadelphia, W.B. Saunders Company, 1971, p. 128. 15. Thoft, R. and Friend, J.: Biochemical trans formation of regenerating ocular surface epithelium. Invest. Ophthalmol. 16:14, 1977. 16. Wright, P.: Filamentary keratitis. Trans. Oph thalmol. Soc. U. K. 95:260, 1975.
Theodore1 first described superior lim bic keratoconjunctivitis in 1963. It is characterized by inflammation of the su perior tarsal and bulbar conjunctiva and edema of the corneoscleral limbal con junctiva; corneal filaments are frequently present. Fine punctate fluorescein and rose bengal staining of the superior cor nea are commonly found. This condition is usually bilateral, occurs most frequent ly in females, and has been reported in patients from ages 4 to 81 years.2 Superior limbic keratoconjunctivitis characteristi cally follows a chronic course with remis sions and exacerbations. The prognosis most often is excellent in that eventual resolution occurs without visual impair ment. Laboratory studies in the form of bac terial, viral, or fungal cultures do not help determine diagnosis, cause, or treatment.2 The diagnosis can often be aided by find ing keratinized epithelial cells with de generated nuclei and hyalinized cyto plasm on smears from scrapings of the involved bulbar conjunctiva.3 From the Department of Cornea Research (Drs. Donshik, Foster, and Cavanagh), Eye Research In stitute of Retina Foundation, and the Cornea Service (Drs. Donshik, Collin, Foster, Cavanagh, and Boru choff), Massachusetts Eye and Ear Infirmary. This work was supported in part by Public Health Ser vice research grants EY-00208 and EY-01647, re search fellowships EY-02586 and EY-05081, Insti tutional National Research Service Award EY07018, from the National Institutes of Health, and in part by the Massachusetts Lions Eye Research Fund, Inc. Reprint requests to Peter C. Donshik, M.D., 41 North Main St., West Hartford, CT 06107.
An association with thyroid disease has been reported. Tenzel4 was the first to draw attention to the presence of elevated protein-bound iodine in patients with su perior limbic keratoconjunctivitis. Cher5 reported that five of his ten patients were either thyrotoxic or had undergone treat ment for hyperthyroidism at the time they had superior limbic keratoconjunctivitis. Similarly, Wright6 noted an incidence of 26% of present or past thyroid disease in his patients with superior limbic kerato conjunctivitis. Fells7 stated that 40% of his patients with dysthyroid exophthalmos had superior limbic keratoconjuncti vitis. Theodore8 reported the presence of hypothyroidism in some patients with superior limbic keratoconjunctivitis. The clinical benefits of 0.5% silver ni trate application to the palpebral conjunc tiva of the upper and lower eyelids of superior limbic keratoconjunctivitis pa tients have been advanced by Theodore.9 Other authors, s,e not finding silver nitrate therapy effective, have suggested me chanical removal of the surface cells, top ical use of N-acetylcysteine, 1% adrenal in, and soft contact lenses. The successful results of these various forms of therapy, however, have rarely been dramatic or long lasting. Tenzel10 has reported that recessing the superior limbic conjunctiva resulted in the elimination of symptoms. He also found that resection of the con junctiva with suturing of the free edges to the episclera resulted in long-lasting im provement of symptoms (R. R. Tenzel, M.D., personal communication, 1976).
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The current study was undertaken to investigate the effect of palpebral or bulbar conjunctival resection on the signs and symptoms of superior limbic keratoconjunctivitis and to document, for the first time known to us, the essential ultrastructural histopathologic features dem onstrated in ocular tissues affected by this disorder. Since a viral cause is often pos tulated in diseases of unknown origin, we conducted a specific search for viral parti cles in the excised tissue. CASE REPORTS Case 1—A 56-year-old white woman was exam ined because of intermittent, disabling, bilateral ocular irritation of ten years' duration. Results of thyroid T3 and T4 tests were normal. Examination revealed a corrected visual acuity of 6/6 (20/20) in each eye. Results of the ocular exami nation were unremarkable except for the superior limbic area of both eyes. Mild injection of the conjunctival vessels was present bilaterally. The superior limbic conjunctiva appeared congested, edematous, and thickened. Moderate punctate stain ing with rose bengal was demonstrated over the superior conjunctiva and superior corneal epithe lium. The tarsal conjunctiva showed fine bilateral papillary inflammatory changes. Results of Schirmer tests were normal. Over the ensuing five months, trials of artificial tears, topical corticosteroid therapy, soft contact lenses, and 0.5% silver nitrate applications to the superior tarsal conjunctiva were entirely ineffective. An excision of bulbar conjunctiva of the right eye was performed with immediate relief of symptoms. Postoperative recovery was uneventful. Three weeks after conjunctival resection, examination revealed a quiet, asymptomatic right eye with a smooth limbal conjunctiva, without rose bengal staining. The un treated symptomatic left eye exhibited impressive rose bengal superior limbic conjunctival staining, with congested conjunctival tissue exhibiting a typi cal heaped-up, corrugated appearance adjacent to the corneoscleral limbus. One month later an exci sion of bulbar conjunctiva of the left eye was per formed. Follow-up examinations six and five months after the respective resections showed con tinued improvement. The only complaint was occa sional irritation and the presence of excessive mucus. Ocular examination revealed normal eyes, except for a slight papillary tarsal conjunctival re sponse. The superior corneoscleral limbus was smooth and it did not stain with rose bengal. Case 2—A 56-year-old white woman was referred with a history of bilateral superior limbic keratoconjunctivitis of three years' duration. T3 and T4 studies were normal. She had been unsuccessfully treated with topical corticosteroids, decongestants, antibiot
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ics, artificial tears, and lubricant ointments. Exami nation demonstrated all the clinical features of su perior limbic keratoconjunctivitis, including bilater al corneal filaments. Schirmer test results were nor mal. A soft bandage contact lens was applied to the right eye with subsequent relief of symptoms and elimination of filaments. The untreated left eye remained objectively, as well as subjectively, un changed. The soft lens was removed from the right eye and a similar lens was applied to the left one. The right eye became symptomatic and corneal filaments de veloped. The superior limbic conjunctiva was again thickened and congested, and rose bengal staining was present. The left eye, under the soft contact lens, was symptomatically improved but objectively unchanged. We resected the bulbar conjunctiva of the right side. The soft contact lens was removed from the left eye. After resection, the patient experienced relief of symptoms in the right eye, but the left eye remained irritated and unchanged for six weeks after removal of the contact lens. A resection of the superior tarsal conjunctiva of the left eye was performed. Postoperatively no rose bengal staining was present in either eye. The tarsal conjunctival papillary reaction was still present in the right eye, but the superior tarsal conjunctival tissue of the left eye appeared normal. Seven months after resection of the conjunctiva, the right eye was asymptomatic with a smooth superior corneoscleral limbus and no evidence of fluorescein or rose bengal staining. The left eye (tarsal conjunc tival resection) was symptomatic and filaments had recurred. Case 3—This 58-year-old woman complained of a slowly progressive, painless decrease in vision in the right eye, accompanied by ocular irritation in both eyes. Ophthalmoscopic examination revealed a corrected visual acuity of R.E.: 6/12 (20/40), and L.E.: 6/120 (20/400). She had a 10-diopter myopia and a large astigmatic error of 15 diopters in the left eye. Ocular examination revealed mild bilateral su perior conjunctival features of superior limbic kera toconjunctivitis. Elevated T3 and T4 values were noted which required subsequent hospitalization and treatment with radioactive iodine. For the next five months, the patient received artificial tears for her complaints of ocular irritation; her clinical ap pearance remained unchanged. A resection of the superior limbic conjunctiva was performed with immediate relief of symptoms. Six months after resection she has remained asymptomatic although slight superior conjunctival injection has remained. Case 4—A 40-year-old woman was referred with a 3V2-year history of recurrent ocular irritation, with filaments and corneal ulcers of the right eye. She had been treated with a variety of drops and ointments including silver nitrate. Thyroid function studies were reported to be normal. Corrected visual acuity was R.E.: 6/9 (20/30), L.E.: 6/6 (20/20). Mild limbal conjunctival thicken ing and injection of the superior corneoscleral lim bus was noted. Superficial punctate staining of the
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Fig. 1 (Donshik and associates). Case 4. Clinical photograph showing limbal epithelial thickening (arrow) and injection.
cornea was present, but filaments were absent (Fig. 1). Schirmer test results were normal. The left eye was unremarkable. Treatment consisting of artificial tears every two hours gave no improvement. The superior limbal conjunctiva was then resected and the patient experienced immediate relief. After re section the corneoscleral limbus was smooth and flat. The patient has remained totally asymptomatic for ten months. METHODS
The bulbar conjunctiva (from one eye in three patients and from both eyes in a fourth patient) was surgically resected under local anesthesia. A block of con junctiva extending from the 10:30 to the 1:30 position at the corneoscleral limbus and posteriorly for 3 to 4 mm was routine ly removed. Erythromycin ointment was instilled and a patch was applied for 48 hours. In one patient approximately 2.5 mm of the upper tarsal conjunctiva of one eye was resected. Erythromycin ointment was instilled and a patch was worn for 24 hours. No surgical complications were encountered, and healing was prompt and complete.
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We performed light and transmission electron microscopy on the five samples of superior bulbar conjunctiva and on the one sample of superior tarsal conjunctiva. Controls consisted of similar tissue from patients who underwent cataract surgery. On removal, tissue for electron micros copy was immediately placed in buffered glutaraldehyde (4% in 0.067M sodium cacodylate at p H 7.35) at room tempera ture. Tissue was dissected into small pieces and processed in one of the follow ing ways: (1) Normal osmium—Tissue was fixed for one hour in 2% osmium tetroxide in 0.067M sodium cacodylate, dehydrated in acetone, and then embedded in Araldite. Uranyl acetate (0.5% in 75% acetone) block stain was used and sections were stained with lead citrate 11 and uranyl ace tate ( 1 % aqueous). (2) Osmium potassium ferrocyanide— Fixation was accomplished with 2% os mium tetroxide and 1.5% potassium fer rocyanide in 0.067M sodium cacodylate for one hour. This is a slight modification of the osmium potassium ferrocyanide method of Dvorak and co-workers. 12 Tis sue was then dehydrated in acetone and embedded in Araldite. Sections were stained with lead citrate only. Sections were cut on an LKB Ultratome III, and examined on an electron microscope. Sections IJJL thick were stained with Richardson's stain. 13 Paraffin sections were also prepared and routinely stain,ed with hematoxylin and eosin for light mi croscopy. RESULTS
Light microscopy—Limbal conjunctiva of control cases demonstrated no signs of keratinization, no intracellular swelling, and no signs of inflammation. Limbal conjunctiva that was removed from all superior limbic keratoconjunctivitis pa tients demonstrated various degrees of keratinization with areas of acanthosis.
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Fig. 2 (Donshik and associates). Case 2. Light micrograph of epithelium and stroma (left) and stroma (right) of the lower corneoscleral limbal conjunctiva showing blood vessels packed with erythrocytes, dilated lymphatic vessels, and stromal tissue that is relatively devoid of inflammatory cells (Richardson's stain, left, x385; right, x960).
Some epithelial cells appeared swollen and in various stages of degeneration. In particular, the nuclei of some cells appeared empty. The stroma showed signs of edema, with grossly dilated lymphatic
vessels. Inflammatory cells-neutrophils, lymphocytes, and plasma cells-were rare and could not be distinguished from cells of normal controls (Fig. 2). Tarsal conjunctiva from one patient revealed an
Fig. 3 (Donshik and associates). Superficial epithelial cells with large nuclei (N) from the superior corneoscleral limbal region of a normal eye. Tissue was removed during cataract surgery (osmium potassium ferrocyanide, x 3,900).
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essentially normal epithelium, except for some intercellular edema, with no evi dence of keratinization. The goblet cell population appeared similar to control tissue. The underlying stromal tissue showed few inflammatory cells. There were some areas of cellular debris. Transmission electron microscopy— Superior limbal conjunctiva of control patients revealed normal epithelium with small intercellular spaces and no evi dence of glycogen accumulation in the cells (Fig. 3). The most prominent feature of the superficial perilimbal bulbar con junctiva taken from superior limbic keratoconjunctivitis. patients was the consis tent finding of large, pale, swollen cells in which the cytoplasmic organelles were scarce. In some cells the nuclei were large and empty, although the nuclear mem
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brane was often intact; this appeared to be a form of balloon degeneration of the nuclei. In other cells the nuclear envelope was broken and nuclear material was re leased into the cytoplasm. Intercellular spaces were larger than in the normal tissue and there was some breakdown of desmosomes (Fig. 4). Other nuclei also showed changes in the distribution of darkly staining nuclear chromatin, which was aggregated in the center of the nucle us, instead of around the nuclear mem brane or evenly distributed as in normal cells. The nuclear envelope was also more tortuous (Fig. 5). Another prominent feature was the presence of extensive intracellular accu mulations of glycogen granules (Figs. 4 and 5), which appear black (electrondense) when the osmium potassium ferro-
Fig. 4 (Donshik and associates). Case 4. Section of superior limbal conjunctiva. There is a large, pale, swollen cell (E) surrounded by more darkly staining epithelial cells. The nucleus (N) is empty and undergoing balloon degenerative changes. Areas of thickened cell membrane (small arrows) and breakdown of desmosomes (large arrows) are shown. The small black dots represent glycogen granules which are dense in the cells at the lower left of the micrograph (osmium potassium ferrocyanide, x6,750).
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Fig. 5 (Donshik and associates). Superior limbal epithelial tissue from patient 3. The two sections of the nucleus (N) contain an unusual distribution of darkly staining chromatin. The nuclear envelope is abnormally tortuous (arrows). Black dots and areas represent abnormally accumulated glycogen (osmium potassium ferrocyanide, x 14,300).
cyanide method of fixation is used. Al though superficial conjunctival epithelial cells contain some glycogen, 14 it is mini mally present. Thoft and Friend 1 5 found only 8.8 \xM glucose/g of dry weight in rabbit conjunctiva compared to 237.1 H-M/g of dry weight in rabbit corneal tissue. We were unable to demonstrate glycogen granules in the control speci mens, yet the intracellular glycogen gran ules were clearly visible in all the speci mens from patients with superior limbic keratoconjunctivitis. There was extensive evidence of keratinization of the epithelium (Fig. 6). This was in the form of increased numbers and clumping of microfilaments, the presence of secondary lysosomes, thickening of the epithelial cell membrane, and the pres ence of keratohyalin granules in the cyto
plasm (Fig. 7). We are preparing a more complete account of the ultrastructural changes associated with accumulation of keratohyalin granules. In patients who had been treated with silver nitrate, silver granules were depos ited in the intercellular spaces. Although viral particles were diligently searched for, none could be found. Marked inflam matory cells were not present in either the epithelium or stroma of the resected con junctiva. Ultrastructural examination of tarsal conjunctiva taken from one patient with superior limbic keratoconjunctivitis con firmed the light microscopic findings of a relatively normal epithelium, with some edema and an occasional inflammatory cell. Glycogen granules were rare and there was no aggregation of granules. In
Fig. 6 (Donshik and associates). Case 4. Superior limbal conjunctiva (C) showing abnormalities of the superficial epithelial cells. The three cells (E) show loss of cell components and are becoming keratinized. The intercellular spaces are wide and the deeper cells show an increase in the number of cytoplasmic filaments. A small keratohyalin granule (arrow) is present (normal osmium, x6,000).
Fig. 7 (Donshik and associates). Case 4. Part of a superior limbal epithelial cell. There are two keratohyalin granules (arrows) surrounded by what appear to be ribosomes. Microfilaments are numerous (F) and glycogen (black) is present Nucleus (N) (osmium potassium ferrocyanide, x 18,800).
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Fig. 8 (Donshik and asociates). Case 4. Superficial epithelial cells from the upper tarsal conjunctiva. The majority of cells have essentially normal nuclei (N). There are no signs of keratinization and no accumulations of glycogen granules (osmium potassium ferrocyanide, x 6,750).
the stroma there were a few disintegrating cells and some areas of cell debris, but no evidence of an inflammatory response (Fig. 8). DISCUSSION
Previous histologic descriptions of the superior limbic conjunctival tissue of pa tients with superior limbic keratoconjunctivitis have noted keratinization of the epithelium with acanthosis and dyskeratosis, as well as a moderate infiltra tion of inflammatory cells, chiefly neutrophils, lymphocytes, and plasma cells. 3,5 ' 6 Light microscopic examination of the tar sal conjunctiva has shown an increase of mucoid material on its surface together with a slight inflammatory cell infiltra tion. 6 Theodore and Ferry 3 reported a significant infiltration with neutrophils, lymphocytes, and plasma cells with nor mal epithelium.
Our studies by both light and transmis sion electron microscopy confirm the presence of abnormal superior limbic epi thelium consisting of keratinized epithe lial cells with swollen and degenerated nuclei. The stroma, although edematous, demonstrated no evidence of significant inflammatory cellular infiltrate. An in flammatory cell response in the patients studied by Theodore and Ferry may well have been secondary to prior silver nitrate treatment. The symptoms in superior limbic keratoconjunctivitis may stem from the inter action of three abnormal elements: the elevated bulbar conjunctiva, the superior corneal epithelium, and the papillary re action of the superior tarsal conjunctiva. The elevated bulbar conjunctiva in appo sition to the tarsal conjunctiva could pro duce a foreign-body sensation. Further more, the raised bulbar conjunctiva can
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prevent the tear film from adequately wet ting the superior cornea, causing superior punctate desiccation and filament forma tion. Although the cause of superior limbic keratoconjunctivitis is unknown, ther apy should be directed toward decreasing the limbal engorgement and adequately moistening the conjunctiva and cornea. This can be accomplished by mechanical debridement (scraping), chemical de bridement (silver nitrate therapy), or soft contact lenses. Wright 6 postulated that the initial patho logic process may reside in the upper tarsal conjunctiva. He argued that the presence of a chronically inflamed upper eyelid may be responsible for a disturb ance in the normal maturation of the bulbar conjunctiva] cells. He believed the normal upper eyelid, in the presence of mucus of normal composition and viscos ity, to be responsible for removing the superficial cells of the conjunctiva. If this process is impaired by an abnormality of either the eyelid or mucus, then the bul bar conjunctival cells persist in situ and progress toward keratinization. Any con junctival irritation can cause an increased goblet cell activity with increased mucus production and an alteration of the mucus-tear relationship. 1 6 Although this is a possible explanation, we were unable to identify definitively either the superior limbal conjunctiva or the palpebral conjunctiva as the primarily involved tissue. Several observations in dicate that the abnormality resides in the bulbar conjunctiva. In Case 4 the pres ence of papillary tarsal reaction in the right eye did not result in the reappear ance of abnormal keratinization of the superior limbic conjunctiva after resec tion. In Case 2 removal of either palpe bral or bulbar conjunctiva was enough to break the abnormal cycle and produce immediate relief. However, symptoms did return in the eye that underwent tarsal resection. Furthermore, we were unable to demonstrate any structural abnormali
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ties or increased goblet cells in the tarsal conjunctiva. In our cases, by removing the abnormal tissue, a normal relationship between the involved structures was re-established. Thus conjunctival resection affords longlasting remissions of symptoms, and should be considered as a therapeutic modality in patients with superior limbic keratoconjunctivitis who have either not responded to a trial of medical manage ment or who have experienced frequent symptomatic recurrences on medical therapy. Possible causes include dry eye, endo crine imbalance, viral involvement, and immunologic abnormalities. Our patients had normal Schirmer test results, but one was thyrotoxic. There was no histologic evidence of viral involvement. While autoimmunity is an attractive possibility, one would then expect corticosteroid therapy to have a beneficial effect, but it does not. The possibility that the inciting agent is an abnormal quality or quantity of mucus should be considered and warrants fur ther investigation. Two of our patients (Cases 1 and 2) had recurrence of mild symptoms in the presence of moderate discharge. SUMMARY
Four patients with symptomatic superi or limbic keratoconjunctivitis underwent resection of the superior bulbar conjunc tiva. One of these patients also underwent a tarsal conjunctival resection in the other eye. Three of the patients had previously been treated by various regimens without resolution; the fourth had had no prior treatment. All four patients had immedi ate and continued relief of the ocular symptoms after the superior bulbar con junctiva was excised. The patient who underwent tarsal conjunctival resection experienced only short-term relief. We studied the conjunctival tissue by light and transmission electron microsco-
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py. Both techniques revealed abnormali ties related to the bulbar conjunctival surface with keratinization of the epithe lium, acanthosis, degeneration of the nu clei, and intracellular accumulation of glycogen. Inflammatory cells were mini mally present. The tarsal conjunctiva ap peared essentially normal.
ACKNOWLEDGMENT
Deborah Pavan-Langston, M.D., and Claes Dohlman, M.D., allowed us to study their respective patients. REFERENCES . 1. Theodore, F. H.: Superior limbic keratocon junctivitis. Eye Ear Nose Throat Mon. 42:25, 1963. 2. : Superior limbic keratoconjunctivitis. Further studies. In XXI Concilium Ophthalmologicum Acta, Mexico D.F. 8-4, March 1970. Amster dam, Excerpta Medica, 1971, p. 666. 3. Theodore, F. H., and Ferry, A. P.: Superior limbic keratoconjunctivitis. Clinical and pathologi cal correlations. Arch. Ophthalmol. 84:481, 1970. 4. Tenzel, R. R.: Comments on superior limbic filamentous keratitis. Part 2. Arch. Ophthalmol. 79: 508, 1968. 5. Cher, I.: Clinical features of superior limbic keratoconjunctivitis in Australia. Arch. Ophthalmol. 82:580, 1969.
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6. Wright, P.: Superior limbic keratoconjunctivi tis. Trans. Ophthalmol. Soc. U. K. 92:555, 1972. 7. Fells, P.: Discussion on superior limbic kerato conjunctivitis. Trans. Ophthalmol. Soc. U. K. 92: 560, 1972. 8. Theodore, F. H.: Comments on findings of elevated protein-bound iodine in superior limbic keratoconjunctivitis. Part 1. Arch. Ophthalmol. 79: 508, 1968. 9. : Further observations on superior lim bic keratoconjunctivitis. Trans. Am. Acad. Ophthal mol. Otolaryngol. 71:341, 1967. 10. Tenzel, R. R.: Resistant superior limbic kera toconjunctivitis. Arch. Ophthalmol. 89:439, 1973. 11. Reynolds, E. S.: The use of lead citrate at high pH as an electron-opaque stain in electron microsco py. J. Cell. Biol. 17:208, 1963. 12. Dvorak, A. M., Hammond, M. E., Dvorak, H. F., and Karnovsky, M. J.: Loss of cell surface materi al from peritoneal exudate cells associated with lymphocytemediated inhibition of macrophage mi gration from capillary tubes. Lab. Invest. 27:561, 1972. 13. Richardson, K. C , Jarrett, L., and Finke, E. H.: Embedding in epoxy resins for ultrathin section ing in electron microscopy. Stain Technol. 35:313, 1960. 14. Hogan, M. J., Alvarado, J. A., andWeddell, J.: Histology of the Human Eye. An Atlas and Text book. Philadelphia, W.B. Saunders Company, 1971, p. 128. 15. Thoft, R. and Friend, J.: Biochemical trans formation of regenerating ocular surface epithelium. Invest. Ophthalmol. 16:14, 1977. 16. Wright, P.: Filamentary keratitis. Trans. Oph thalmol. Soc. U. K. 95:260, 1975.
