Case #25: Iris Melanoma by Avinash Tantri , MD

[Andrew_Doan]

Case #25 (12-28-2004)
47 yo man referred in 1997 for evaluation of iris lesion OS.

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[aphistis]

That's a really well-presented case, especially with the video. I do have a couple, undoubtedly dumb layman questions about the treatment.

I noticed in the citations the 5-year survival rate for uveal melanoma is dramatically higher than elsewhere in the body (particularly, for example, mucosal melanoma in the oral cavity, in which the treatment is often as disfiguring as the disease). Along those same lines, the excision was pretty conservative. Are there any known explanations for why the neoplasm is so much less aggressive in the eye than elsewhere?

Second, after a surgical procedure like the one shown, what is the prognosis for vision in the affected eye? Is it most likely to be fully functional, partly, or not at all?

 

[Andrew_Doan]

That's a really well-presented case, especially with the video. I do have a couple, undoubtedly dumb layman questions about the treatment.

I noticed in the citations the 5-year survival rate for uveal melanoma is dramatically higher than elsewhere in the body (particularly, for example, mucosal melanoma in the oral cavity, in which the treatment is often as disfiguring as the disease). Along those same lines, the excision was pretty conservative. Are there any known explanations for why the neoplasm is so much less aggressive in the eye than elsewhere?

Second, after a surgical procedure like the one shown, what is the prognosis for vision in the affected eye? Is it most likely to be fully functional, partly, or not at all?

The vision in the surgical eye is 20/20! The surgeons did an awesome job.

The risk of spread is less if the tumor is still confined within the sclera. This is why surgical technique is so important. With surgery, there's always the risk of letting the melanoma out of the eye. I think because the tumors are restrained to the eye because of the sclera and the eye-blood barrier.

I removed an eye today because of a large choroidal melanoma. During the surgery, we took extra precautions to prevent inadvertant perforation of the globe, which could potentially release tumor cells into the orbit.

 

[JennyW]

The vision in the surgical eye is 20/20! The surgeons did an awesome job.

The risk of spread is less if the tumor is still confined within the sclera. This is why surgical technique is so important. With surgery, there's always the risk of letting the melanoma out of the eye. I think because the tumors are restrained to the eye because of the sclera and the eye-blood barrier.

I removed an eye today because of a large choroidal melanoma. During the surgery, we took extra precautions to prevent inadvertant perforation of the globe, which could potentially release tumor cells into the orbit.

Dr. Doan,

How often do patients like this need pupiloplasty or other sorts of iris "reconstructive" surgeries?

Jenny

 

[Andrew_Doan]

Dr. Doan,

How often do patients like this need pupiloplasty or other sorts of iris "reconstructive" surgeries?

Jenny

Jenny,

I was discussing this with Dr. Weingeist (my chairman) today, and he said the patient did not have any problems with photophobia or visual problems. If the patient is not having problems, then nothing needs to be done.

If the patient is close to having cataract surgery, then they can have an iris prosthesis implanted with the intraocular lens.

I've seen 4 patients after iridocyclectomies. Only 1 patient had visual problems requiring reconstruction of the iris. The other 3 patients did well with a large pupil.

 

[PBEA]

Colored contact lens is an option, if symptomatic, and of course far less invasive.

I currently follow a 35yo woman with similiar case (50% of iris removed). At three years out developed unilateral (surgical eye) increase in IOP. Gonio revealed open angle 360. Presumably scarring has affected TB meshwork. What are any thoughts on SLT, etc versus topical meds.

 

[Andrew_Doan]

Colored contact lens is an option, if symptomatic, and of course far less invasive.

I currently follow a 35yo woman with similiar case (50% of iris removed). At three years out developed unilateral (surgical eye) increase in IOP. Gonio revealed open angle 360. Presumably scarring has affected TB meshwork. What are any thoughts on SLT, etc versus topical meds.

We have used contact lenses in patients with large/irregular pupils, and they work well. This is definitely a good option for patients who can tolerate contact lenses.

In your case with increased IOP, I'd be concerned, as you pointed out, that scarring of the TM is affecting aqueous outflow; thus, SLT/ALT and prostaglandin analogs may not be the best treatment options to reduce IOP. I would try selective aqueous suppressants first (beta-blockers/CAI/alpha-agonists).

 

[mdkurt]

In your case with increased IOP, I'd be concerned, as you pointed out, that scarring of the TM is affecting aqueous outflow; thus, SLT/ALT and prostaglandin analogs may not be the best treatment options to reduce IOP. I would try selective aqueous suppressants first (beta-blockers/CAI/alpha-agonists).

That's a remarkable video. My hat is off to Dr. Wallace, particularly for doing nearly the whole surgery with one lousy #75 blade! As far as treatment of elevated IOP when the TM is compromised, prostaglandin analogs should work just fine. There's at least one study that I know of showing that they're effective in chronic angle closure.

 

[PBEA]

We have used contact lenses in patients with large/irregular pupils, and they work well. This is definitely a good option for patients who can tolerate contact lenses.

In your case with increased IOP, I'd be concerned, as you pointed out, that scarring of the TM is affecting aqueous outflow; thus, SLT/ALT and prostaglandin analogs may not be the best treatment options to reduce IOP. I would try selective aqueous suppressants first (beta-blockers/CAI/alpha-agonists).

Precisely what we did, for six months she has had 35% IOP reduction with 0.5% timolol qd dosing. Given her age I questioned SLT as an option. I agree the affected TM is probably not a great spot for it, but how about the unaffected TM (hence SLT)?

 

[PBEA]

That's a remarkable video. My hat is off to Dr. Wallace, particularly for doing nearly the whole surgery with one lousy #75 blade! As far as treatment of elevated IOP when the TM is compromised, prostaglandin analogs should work just fine. There's at least one study that I know of showing that they're effective in chronic angle closure.

Interesting, I tend to disagree with your statement about prostaglandin analogs. I'm too lazy to find your article, but I wonder how do you (or they)account for the mechanism of action. If the TM has reduced function, whether by blockage or scarring, then I would expect episcleral venous flow would be reduced. This would'nt be one of those corporate affiliated research papers, would it?

 

[mdkurt]

Interesting, I tend to disagree with your statement about prostaglandin analogs. I'm too lazy to find your article, but I wonder how do you (or they)account for the mechanism of action. If the TM has reduced function, whether by blockage or scarring, then I would expect episcleral venous flow would be reduced. This would'nt be one of those corporate affiliated research papers, would it?

I'm lazy too, so I hate you for making me look this article up. I haven't read the article itself (like I said, lazy), but it looks like a pretty straightforward study. Remember, prostaglandins are supposed to work through uveoscleral outflow. We normally think of this as the face of the ciliary body, but iris is uvea too. Episcleral venous flow shouldn't be reduced in the settings we've been discussing.

Ophthalmology. 2004 Mar;111(3):427-34. Related Articles, Links


Intraocular pressure-reducing effects and safety of latanoprost versus timolol in patients with chronic angle-closure glaucoma.

Chew PT, Aung T, Aquino MV, Rojanapongpun P; EXACT Study Group.

Department of Ophthalmology, National University Hospital, 5 Lower Kent Ridge Road, Main Building Level 3, Singapore 119074. [email protected]

OBJECTIVE: To demonstrate that the intraocular pressure (IOP)-reducing effect of latanoprost once daily is at least as good as that of timolol twice daily in patients with chronic angle-closure glaucoma (CACG). DESIGN: Randomized, double-masked, multicenter 12-week study. PARTICIPANTS: In all, 137 patients with unilateral or bilateral CACG were treated with latanoprost, and 138 were treated with timolol. METHODS: Patients received either latanoprost (9 pm) and a placebo (9 am) or timolol (both 9 am and 9 pm). Intraocular pressure was measured at 9 am and 5 pm at baseline and weeks 2, 6, and 12. MAIN OUTCOME MEASURES: The difference between groups in daily IOP (average of 9 am and 5 pm measures) reduction was the primary outcome. Secondary outcomes included differences between groups in IOP reductions at 9 am and 5 pm, and in proportions of patients reaching specified daily IOP levels. RESULTS: Using repeated measures (analysis of covariance: intent to treat), mean changes from baseline in daily IOP levels during 12 weeks were -8.2 mmHg and -5.2 mmHg for latanoprost- and timolol-treated patients, respectively (difference: -3.0 mmHg [95% confidence interval: -4.0, -2.1], P<0.001). Greater reductions in IOP levels at both 9 am and 5 pm were found in latanoprost-treated patients (P<0.001 for both), and greater proportions of patients receiving latanoprost reached prespecified target daily IOP levels (P<0.001 for all 3 target levels tested). Both drugs were well tolerated. CONCLUSION: Latanoprost administered once daily provides significantly greater IOP reduction in CACG patients than does timolol instilled twice daily.

 

[Andrew_Doan]

Thanks for the update on this mdkurt!

 

[Andrew_Doan]

BTW, I posted new photos of the gonioscopy examination. The patient also had post-operative hypotonous maculopathy that resolved in less than a month. The fundus photos are also posted now.

http://www.eyerounds.org/case25.htm