Choroidal melanoma and rhegmatogenous retinal detachment

Hesham Lakosha, * MD, FRCS(Edin); Rand Simpson,* MD, FRCSC; David Wong,t MD, FRCSC

R etinal breaks with rhegmatogenous retinal detachment are rare in patients with choroidal

melanoma. It has been estimated that less than 1% of eyes with this tumour will have a rhegmatogenous retinal detachment. 1 In a review of the English­language literature, we found 22 such cases.2- 13 The relation of the tumour to the retinal break is obscure.

CASE REPORTS

Case I

A 74-year-old woman was referred to the Ocular Oncology Service with retinal detachment in associa­tion with a choroidal melanoma in her left eye. Six months earlier she had noted photopsia in that eye, fol­lowed by progressive deterioration of vision. She reported that the vision in her left eye had been blurry for a long time and the cause was unclear. She had controlled hypertension.

Ocular examination showed a visual acuity of 20/50 with +0.25 in the right eye and counting fingers with +0.25 in the left. The intraocular pressure, as measured by applanation tonometry, was 18 mm Hg bilaterally. There was a relative afferent pupillary defect in the left eye. Funduscopy of the left eye with the pupil dilated revealed a pigmented mass at the posterior pole measur­ing 10.5 mm by 6.5 mm in basal diameters. Lipofuscin pigment was visible on the surface of the lesion. An infe-

From *the Ocular Oncology Service, Princess Margaret Hospital, Toronto, Ont., and tthe Vitreoretinal Service, Saint Michael's Hospital, Toronto, Ont.

Presented at the International Congress of Ocular Oncology held in Philadelphia May 2-6, 1999

Accepted for publication Dec. 6, 1999

Correspondence to: Dr. Rand Simpson, Ocular Oncology Service, Princess Margaret Hospital, 610 University Ave., Toronto ON MSG 2M9; fax: (416) 946-2189

Can J Ophthalmol 2000;35: I 5 1-3

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rior hemispheric retinal detachment was noted involving the retina overlying the tumour. The detached retina had an undulated surface (Fig. 1). There was a small equato­rial retinal hole on one side of a sclerosed segment of a blood vessel, about 2 mm from the inferior margin of the tumour. The vitreous was clear. The fellow eye dis­played long-standing branch retinal vein occlusion that appeared nonperfused on fluorescein angiography.

Standardized echography showed a dome-shaped tumour with a thickness of 3.2 mm. Fluorescein angiography revealed dilated retinal blood vessels with staining of their walls and areas of retinal capil­lary nonperfusion inferior to the tumour (Fig. 2). A diagnosis was made of a medium-sized choroidal melanoma with an ischemic retinal hole. Metastatic investigation did not show any abnormalities, and the patient underwent iodine-125 brachytherapy.

Four months postoperatively the woman's visual acuity was stable, at counting fingers. Fundus exami­nation remained unchanged, although ultrasonography showed a decrease in the tumour height to 2.9 mm.

Case 2

A 50-year-old man presented to his ophthalmologist

Fig. 1-Case I: Fundus photograph, showing choroidal mela­noma (T) and inferior retinal detachment. Note undulated appearance of detached retina.

lSI

Choroidal melanoma-Lakosha et al

Fig. 2-Case I: Fluorescein angiogram, showing hyperfluores­cent tumour (T), dilated retinal blood vessels with staining of their walls and areas of retinal capillary nonperfusion (N).

with a 2-week history of a "shadow" interfering with the vision in his left eye. He was in good general health. On examination his visual acuity was 20/20 with -6.25 in the right eye and 20/150 with -6.25 in the left. The intraocular pressure, as measured by applanation tonometry, was 20 mm Hg bilaterally. The pupils were equal and reactive. Slit-lamp biomicroscopy of the left eye showed pigment cells in the anterior vitreous (Fig. 3). Funduscopy of the left eye with the pupil dilated revealed a pigmented tumour occupying the nasal peripheral fundus extending from 7:30 to 10 o'clock meridian. The tumour measured 17 mm by 16 mm in basal diameters. There was an associated inferior hemi­spheric retinal detachment. Overlying the tumour and approximately at the 9 o'clock meridian there was a horseshoe tear near the ora serrata. Another U-shaped tear was noted at the superotemporal periphery between 1 and 2 o'clock meridian. Ultrasonography showed a maximum tumour thickness of 6.6 mm. The diagnosis was that of a medium-sized choroidal melanoma asso­ciated with two U-shaped retinal breaks. Metastatic investigation did not show any abnormalities. The patient was treated with 125I brachytherapy.

Three months postoperatively the patient's visual acuity had decreased to hand motions owing to the development of proliferative vitreoretinopathy. Ultra­sound examination showed a decrease in the height of the tumour to 5. 7 mm.

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Fig. 3-Case 2: Fundus photograph, showing pigment cells in anterior vitreous.

COMMENTS

The diagnosis and management of uveal melanoma and coexisting rhegmatogenous retinal detachment have rarely been addressed. 3 The characteristics of the retinal detachment should be evaluated carefully. The presence of pigment cells in the vitreous and the undu­lated appearance of the retina draw attention to the existence of a retinal break.

In our patient 1 the occurrence of a retinal hole near a sclerosed segment of a retinal blood vessel suggest­ed an ischemic origin. This conclusion was supported by retinal capillary nonperfusion on fluorescein angi­ography and by the fact that the fellow eye had ischemic branch retinal vein occlusion. Retinal holes have been reported to occur secondary to vascular accidents, and these holes are usually equatorial. 14 The serous fluid secreted by the tumour may contribute, and it may have increased the amount of subretinal fluid seen in this case. It is unlikely that the tumour produced hole formation since the retinal hole was remote from the tumour margin.

A horseshoe tear is usually caused by localized vit­reous traction on the retina, elevating a flap of retina that is hinged anteriorly. Persistent vitreous traction on the flap can encourage elevation of the tear by the sub­retinal fluid, causing a retinal detachment. Shammas and W ood5 reported a case of choroidal melanoma associated with a horseshoe tear. Histopathological examination of the enucleated eye showed attachment of vitreous to the anterior flap.

In our patient 2 the presence of two peripheral horseshoe tears, one overlying the tumour and the other remote from the tumour, may indicate the lack of

a causative relation between the two disorders. The occurrence of retinal breaks in different parts of the fundus suggests that since the eye was myopic, it was predisposed to retinal tear formation. One of the tears had a pigmented margin, which suggested that it was long-standing. Tobacco dusting is a sign of rheg­matogenous retinal detachment due to migration of pigment cells from the retinal pigment epithelium to the vitreous through a retinal break. The detection of pigment cells in a patient with choroidal melanoma raises concern about vitreous seeding by the tumour. The early onset of proliferative vitreoretinopathy after brachytherapy in our case indicates that the underly­ing cause was the presence of pigment cells in the vit­reous and not a radiation effect. A radiation dose of 100 cGy was delivered to the tumour apex at a rate of 42 to 105 cGy/h. Radiation retinopathy does not usu­ally develop before 32 months at this dose rate and total dose delivered with this radiotherapeutic proce­dure.15

The decision to proceed with retinal detachment repair should be considered carefully, given the guard­ed prognosis for vision and the limited information available about the long-term risks of repair in these eyes. In view of these risks, some physicians recom­mend enucleation as a primary treatment. Several eye­saving procedures have recently been used to treat choroidal melanoma. 15-17

Surgical procedures for repairing retinal detach­ment may provide additional routes for extrascleral extension of choroidal melanoma from injections, sclerotomies, suture passes or drainage sites. 18 The operation should be tailored to minimize the possibil­ity of penetrating the sclera and to avoid drainage of subretinal fluid. Moreover, tumour radiotherapy should be performed before proceeding with retinal detachment surgery. Subretinal fluid drainage would then be unlikely to cause extrascleral extension. The optimal timing of retinal detachment surgery remains unknown. Successful results with external buckling and cryopexy without drainage of subretinal fluid and pneumatic retinopexy have been reported. 7 Alterna­tive retinal detachment repair techniques that do not require scleral penetration, such as the Lincoff tempo­rary episcleral balloon, may further reduce the risk of extrascleral extension. 3 In eyes undergoing pars plana vitrectomy or pneumatic retinopexy, the sclerotomy or injection site should be situated away from the tumour. The cytologic features of the vitrectomy cas­sette specimen would help determine whether the pig­ment cells seen in the anterior vitreous are malignant

Choroidal melanoma-Lakosha et al

cells or simply liberated retinal pigment epithelium cells.

REFERENCES

1. Shields JA, Shields CL. Differential diagnosis of posterior uveal melanoma. In: Intraocular tumors: a text and atlas. Philadelphia: WB Saunders; 1992. p. 137-53.

2. Berson E, Bigger JF, Smith MF. Malignant melanoma, retinal hole and retinal detachment. Arch Ophthalmol 1967;77:223-55.

3. Bedford MA, Chignell AH. U-shaped retinal tear associat­ed with a presumed malignant melanoma of the choroid. Br J Ophthalmo/1970;54:200-2.

4. Robertson DM, Curtin VT. Rhegmatogenous retinal de­tachment and choroidal melanoma. Am J Ophthalmoll97l; 72:351-5.

5. Shammas HF, Wood LR. Choroidal melanoma and retinal tear. Arch Ophthalmoll977;95:l825-6.

6. Wang JW, Schepens CL, Albert DM. Choroidal melanoma associated with rhegmatogenous retinal detachment. Ophthalmic Surg 1984;15:302-5.

7. Haimovici R, Mukai S, Schachat A, Haynie GD, Thomas MA, Meredith T A. Rhegmatogenous retinal detachment in eyes with uveal melanoma. Retina 1996;16:488-96.

8. Christensen GR, Linder MW. Bilateral rhegmatogenous retinal detachment associated with unilateral choroidal melanoma. Ann Ophthalmo/1983;15:252-5.

9. Boniuk M, Zimmerman LE. Necrosis of uvea, sclera and retina following operations for retinal detachment. Arch Ophthalmoll96l;66:318-26.

10. Dumas J, Schepens CL. Chorioretinallesions predisposing to retinal breaks. Am J Ophthalmoll966;6l:620-30.

11. Manschot W A. Retinal hole in a case of choroidal mela­noma. Arch Ophthalmo/1965;73:666-8.

12. Bierman EO. Retinal tears associated with tumors. Am J Ophthalmo/1958;46:74-5.

13. Uffer SZL. Macular hole in a case of choroidal melanoma. Eur J Ophthalmo/1997;7:115-8.

14. Regenbogen L, Godel V, Feiler-Ofry V, Stein R. Retinal breaks secondary to vascular accidents. Am J Ophthalmol 1977;84:187-96.

15. Garreston BR, Robertson DM, Earle JD. Choroidal melanoma treatment with iodine-125 brachytherapy. Arch Ophthalmo/1987;105:1394-7.

16. Kertes PJ, Johnson JC, Peyman GA. Internal resection of posterior uveal melanomas. Br J Ophthalmol 1998;82: 1147-53.

17. Shields CL, Shields JA. Trans pupillary thermotherapy for choroidal melanoma. Curr Opin Ophthalmol 1999;10: 197-203.

18. Boniuk M, Zimmerman LE. Occurrence and behavior of choroidal melanoma in eyes subjected to operations for retinal detachment. Trans Am Acad Ophthalmol Oto­laryngo/1961;66:642-58.

Key words: choroidal melanoma, rhegmatogenous retinal de­tachment, retinal break

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