CHOROIDAL OSTEOMA AFTER INTRAOCULAR INFLAMMATION

SUSAN N. T R I M B L E , M.D.

Maywood, Illinois

AND

H O W A R D S C H A T Z , M . D .

San Francisco, California

A 12-year-old girl had had blurred vision and pain behind her left eye for three months. An examination disclosed focal choroiditis and optic nerve edema. Her visual acuity was 20/30. Two similar previous episodes had been diagnosed as scleritis and uveitis and the patient was still on a regimen of 5 mg of prednisone per day and eyedrops containing prednisolone and phenylephrine. A pink choroidal mass superotemporal to the optic disk was negative for calcium by computed tomography and ultrasonography. The corticosteroids were discontin­ued. Three months later, the patient's visual acuity had improved to 20/20 but the choroidal lesion was slightly larger and two new lesions had appeared, one just above the optic disk and the other superotem­poral to the macula.

Three years later the two new lesions had coalesced to form one lesion with vascular channels on its surface. Although a choroidal osteoma was suspected, computed tomography and ultrasonography were still negative for calcium. Five years after the initial examination, computed tomography showed a thin ring of calcium within the choroid at the location of the mass. Ultrasonography also confirmed the presence of calcium.

Choroidal osteomas are rare, benign, bony tumors with a characteristic oph-thalmoscopic appearance; they generally occur in healthy individuals with no his­tory of disease or injury. No cause has been found. A total of 25 cases of choroi­dal osteoma have been reported.1"14 Of the 25 patients, 21 were female and four

Accepted for publication Sept. 19, 1983. From the Department of Ophthalmology, Loyola

University Medical Center, Maywood, Illinois (Dr. Trimble); and the Retina Research Fund, St. Mary's Hospital and Medical Center, San Francisco, and the Department of Ophthalmology, University of Califor­nia, San Francisco, California (Dr. Schatz).

Reprint requests to Howard Schatz, M.D., 390 Laurel St., San Francisco, CA 94118.

were male. They ranged in age from 6 to 43 years, but most were within the sec­ond or third decade of life.15 Twenty-two of the 25 patients were healthy with no medical or ocular histories suggesting a predisposing factor. Two patients had his­tories of blunt trauma2 and one patient had probable histiocytosis X . u

We treated a patient in whom a choroi­dal osteoma developed several years after the onset of intraocular inflammatory dis­ease.

C A S E REPORT

The patient, a 12-year-old girl, was referred to us with a three-month history of blurred vision and pain behind her left eye. One and two years previously, she had had similar episodes of blurred vision and

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760 AMERICAN JOURNAL OF OPHTHALMOLOGY DECEMBER, 1983

pain. At that time, scleritis and uveitis were diag­nosed. During her second attack, one year previous­ly, she underwent a thorough laboratory examination for uveitis but the results were negative. She began systemic cortisone treatment then and was still on this regimen when we first examined her, during her third attack. At this point she was taking 5 mg of prednisone a day and using eyedrops containing prednisolone and phenylephrine.

Her corrected visual acuity was 20/30 and Jl in each eye. The anterior segment of each eye was normal. The right optic nerve showed mild pallor. In the left fundus the optic nerve was slightly edema-tous; there were a few posterior vitreous cells (Fig. 1). There was a pink choroidal mass located just superotemporal to the optic disk which measured 3 X 3 x 0.5 mm (Fig. 2). There was no sensory retinal detachment or cystic retinal changes. On fluorescein angiography, the optic disk hyperfluoresced and the choroidal lesion showed marked early hyperfluores-cence and late hyperfluorescent staining (Fig. 3). Ultrasonography demonstrated a solid, slightly ele­vated choroidal mass; there was no evidence of any calcium within the lesion. A diagnosis of focal cho-roiditis was made. No cause for the optic nerve edema and choroiditis was found. The systemic corti-costeroids were gradually discontinued during the next month.

At her next examination three months later, the patient's visual acuity was 20/20 in each eye. The choroidal lesion in the left fundus was slightly larger, and there were two new small choroidal lesions. One was located just above the optic disk and the other was superotemporal to the macula (Fig. 4). Fluores­cein angiography showed hyperfluorescence and late staining of the three lesions as well as of the optic disk. The patient was given a retrobulbar injection of

Fig. 1 (Trimble and Schatz). Left eye. Optic nerve edema.

40 mg of triamcinolone. When she was examined one month later, her visual acuity was still 20/20. The newer lesion just superotemporal to the macula was larger and the other two lesions were the same size.

Three years later, both the lesion superotemporal to the optic disk and the lesion superotemporal to the macula had enlarged and had coalesced to form one lesion. This lesion had become more yellow-white and had vascular channels on its surface. Visual acuity was 20/20 in each eye. Although a diagnosis of choroidal osteoma was suspected, ultrasonography and computed tomographic scanning remained nega­tive for calcium. It was not until five years after we first examined her that the computed tomographic scan showed a thin ring of calcium within the choroid at the location of the mass. At this time ultrasonog­raphy also was positive for calcium, showing high reflectivity at low decibels (Fig. 5).

During the two years after the diagnosis was confirmed, the patient had a transient episode of optic nerve edema in her right eye (Fig. 6). The choroidal osteoma in the left eye has enlarged slight­ly, but her visual acuity is still 20/20.

DISCUSSION

In 1978, Williams and associates6 de­scribed the histopathologic features of a choroidal osteoma and called the tumor an osseous choristoma of the choroid. Gass2 indicated that these tumors were probably secondary formations of bone

Fig. 2 (Trimble and Schatz). Left eye. Pink choroi­dal inflammatory infiltrate appears superotemporal to the edematous optic disk. Ultrasonography and com­puted tomography were both negative for calcium.

VOL. 96, NO. 6 CHOROIDAL OSTEOMA 761

Fig. 3 (Trimble and Schatz). Left eye. Left, During the venous phase of the fluorescein angiogram, there is hyperfluorescence of the choroidal lesion and of the optic disk. Right, Fluorescein staining of the choroidal infiltrate and the optic disk during the late phase.

rather than congenital choristomas. He cause could be determined. The first his-described a 22-year-old man with a cho- topathologic study of a choroidal osteoma roidal osteoma in one eye who several was done by Reese16 in 1947 although he years later developed an osteoma in the thought it was ossification of a choroidal previously unaffected second eye. No hemangioma. His findings were similar to

Fig. 4 (Trimble and Schatz). Left eye. Left, Three months later the angiogram shows hyperfluorescence of a small infiltrate superonasal to the optic disk. This infiltrate later disappeared. The optic nerve is still edematous and hyperfluorescent. Right, The initial lesion has enlarged and another choroidal lesion is now present superotemporal to the macula. Both lesions and the optic disk show hyperfluorescence.

762 AMERICAN JOURNAL OF OPHTHALMOLOGY DECEMBER, 1983

Fig. 5 (Trimble and Schatz). Left eye. Five years after the initial examination, fluorescein angiography shows late staining of a choroidal osteoma. The two choroidal lesions have enlarged and coalesced. The tumor is yellow-white and there are vascular chan­nels on its surface. Ultrasonography and computed tomography were positive for calcium.

those of the case described by Williams and associates5 involving a tumor of can-cellous bone localized to the choroid.

Witschel and Font17 reviewed the patho­logic findings in 45 choroidal hemangi-omas and found ossification in 20%, but the bone formation occurred between the choroid and pigment epithelium, not within the choroid.

Intraocular ossification can occur in diseased or disorganized ocular tissues after trauma, severe inflammation, ad­vanced glaucoma, or long-standing reti­nal detachment.18'19 Usually bone forms in the eye at least ten years after the initial injury or disease, but several cases have been reported in which bone formed in less than two years, including one in which the process took just ten weeks.20,21

Some congenital deformities, including microphthalmos, buph tha lmos^and per­sistent hyperplastic primary vitreous16

may produce bone formation. Intraocu­lar ossification was studied as early as 1804, but its occurrence in the eye was proven by Hulke in 1857.w In a study of 2,486 enucleated eyes, Finkelstein and Boniuk21 found bone in 4.8%. In some eyes bone was found in the lens, retina, and cyclitic membranes, but in

Fig. 6 (Trimble and Schatz). Right eye. Left, Six years after the initial examination, the right optic disk is swollen and retinal striae and choroidal folds are present. Right, A fluorescein angiogram shows the choroidal folds as hyperfluorescent and hypofluorescent lines temporal to the optic nerve head.

VOL. 96, NO. 6 CHOROIDAL OSTEOMA 763

most cases, it formed in the region of the pigment epithelium or inner surface of the choroid.21

Although the stimulus for osteogenesis is still not understood,21 we know that osteoblasts are responsible for bone for­mation. They are derived from two types of mesenchymal precursor cells. The first type is the determined osteogenic pre­cursor cell found only in marrow stroma; the second is the inducible precursor cell found in the connective tissue framework of many tissues and in circulating blood.22,23 Yanoff and Fine24 stated that it is not clear whether the retinal pigment epithelium undergoes metaplasia or whether the pigment epithelium induces the surrounding mesenchymal tissue to produce bone. Bone will not form unless an inducing agent is present; such induc­ing agents have been recognized in living epithelium.23 Additionally, an adequate blood supply appears to be necessary for ossification.20 Fibrous metaplasia along the inner choroid and proliferation of the pigment epithelium occur adjacent to most intraocular bone.21 Calcification and ossification are not synonymous; cal­cification is simply the precipitation of calcium salts in abnormal tissue. In osteogenesis, the osteoblasts lay down an organized matrix of collagen and mucopolysaccharide called osteoid. Cal­cium salts are deposited in the osteoid to form bone.26

In a study of 81 ossified globes, Samu­els18 found that bone forms most often in the peripapillary area and, occasionally, at the ora serrata. It can develop between the retina and choroid or within the cho­roid itself. The extent of ossification rang­es from small peripapillary formations to large masses filling most of the posterior segment.21 Samuels18 reported that intra­ocular inflammation can result in osteo­genesis, and he found that severe inflam­mation was the cause of the ossification in 30 of the 81 ossified eyes he examined.

Although inflammation was apparently the precursor of the development of a choroidal osteoma in our case, tumors in other patients may have had different stimuli. More than one cause of ossifica­tion has been reported in more severely diseased eyes18,19 and it is likely that addi­tional causes of choroidal osteoma forma­tion will be identified in the future.

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and Harris, G. : Choroidal osteoma. Arch. Ophthal-mol. 96:428, 1978.

2. Gass, J. D. M.: New observations concerning choroidal osteomas. Int. Ophthalmol. 2:71, 1979.

3. Coston.T. O., and Wilkinson, C. P.: Choroidal osteoma. Am. J. Ophthalmol. 86:368, 1978.

4. Joffe, L., Shields, J. A., and Fitzgerald, J. R.: Osseous choristoma of die choroid. Arch. Ophthal­mol. 96:1809, 1978.

5. Williams, A. T., Font, R. L., VanDyk, H. J., and Riekhof, F. T. : Osseous choristoma of the cho­roid simulating a choroidal melanoma. Arch. Oph­thalmol. 96:1874, 1978.

6. Augsburger, J. J., Shields, J. A., and Rife, C. J.: Bilateral choroidal osteoma after nine years. Can. J. Ophthalmol. 14:281, 1979.

7. Laibivitz, R. A.: An unusual case of intraocular calcification. Choroidal osteoma. Ann. Ophthalmol. 11:1077, 1979.

8. Fava, G. E., Brown, G. C , Shields, J. A., and Brooker, G. : Choroidal osteoma in a 6 year old child. J. Pediatr. Ophthalmol. Strabismus 17:203, 1980.

9. Kayazawa, F., and Shimamoto, S.: Choroidal osteoma. Two cases in Japanese women. Ann. Oph­thalmol. 13:1053, 1981.

10. Baum, M. D., Pilkerton, A. R., Berler, D. K., and Kramer, K. K.: Choroidal osteoma. Ann. Ophthalmol. 11:1849, 1979.

11. Amalric, P.: Osteomes choroidiens. Bull. Soc. Ophtalmol. Fr. 80:47, 1980.

12. Baarsma, G. S., and Craandijk, A.: Osteoma of the choroid. Doc. Ophthalmol. 50:205, 1981.

13. Kelinske, M., and Weinstein, G.: Bilateral choroidal osteomas. Am. J. Ophthalmol. 92:676, 1981.

14. Kline, L. B., Skalka, H. W., Davidson, J. D., and Wilmes, F. J. : Bilateral choroidal osteomas asso­ciated with fatal systemic illness. Am. J. Ophthalmol. 93:192, 1982.

15. Schatz, H.: Essential Fluorescein Angiogra-phy. A Compendium of 100 Classic Cases. San Anselmo, California, Pacific Medical Press, 1983, p. 77.

16. Reese, A. B.: Tumors of the Eye. New York, Paul E. Hoeber, 1951, pp. 277-279 and 320.

17. Witschel, H., and Font, R. L.: Hemangioma of the choroid. A clinicopathologic study of 71 cases

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and a review of the literature. Surv. Ophthalmol. 20:415, 1976.

18. Samuels, B.: Ossification of the choroid. Trans. Am. Acad. Ophthalmol. Otolaryngol. 43:193, 1938.

19. Asbury, M. K., in discussion, Samuels, B.: Ossification of the choroid. Trans. Am. Acad. Oph­thalmol. Otolaryngol. 43:241, 1938.

20. Duke-Elder, S., and Perkins, E. S.: Diseases of the Uveal Tract. In Duke-Elder, S. (ed.): System of Ophthalmology, vol. 9. St. Louis, C. V. Mosby, 1966, pp. 740-747.

21. Finkelstein, E. M., and Boniuk, M.: Intraocu­

lar ossification and hematopoiesis. Am. }. Ophthal­mol. 68:683, 1969.

22. Patrinely, J. R., Green, W. R., and Connor, J. M.: Bilateral posterior scierai ossification. Am. J. Ophthalmol. 94:351, 1982.

23. Vaughan, J. : Osteogenesis and hematopoiesis. Lancet 2:133, 1981.

24. YanofF, M., and Fine, B. S.: Ocular Pathology. A Text and Atlas. New York, Harper and Row, 1975, pp. 642 and 644.

25. Hogan, M. J., and Zimmerman, L. E. : Oph­thalmic Pathology. Philadelphia, W. B. Saunders, 1962, p. 63.