Fix and Fit
A Rare Challenge…The Ptosis Crutch
By Alex Yoho, A.B.O.M.FIX AND FIT
A Rare Challenge…The Ptosis Crutch
By Alex Yoho, A.B.O.M.
When you mention "ptosis crutch" to patients, most don't know what you're talking about. It is one of the most unusual modifications that can be made to a frame. But if you are faced with fitting eyewear to a person who requires one, it could also be one of the most gratifying experiences of your career
The optical world has derived "ptosis" from the word blepheroptosis [Gr. bleferon, eyelid + ptosis, a falling]-in simple terms, a drooping upper eyelid. As the eyelid droops, the vision is reduced or cut off altogether.
There are a number of causes for blepheroptosis. The congenital, or hereditary form may be found in very young patients. Surgery can be helpful, but is usually delayed until at least age four.
Using HotFingers to install a crutch on a plastic frame
Acquired blepheroptosis can be the result of aging, trauma, or damage to the muscle or nerves that pertain to the eye. In this case the affected eye will droop lower in a downward gaze. There are basically three types of acquired blepheroptosis-myogenic, neurogenic, and mechanical. In any of these you may notice that the patient keeps the head tilted back in order to make the bottom eyelid open. Brow muscles may also be exerted continually to keep the eyes from closing. Options include: Treating an underlying condition, surgical corrections, and the ptosis crutch, which is any device used to hold the eyelid open.
Temporary solution. The ptosis crutch may be a permanent or temporary fixture to the frame. It is usually attached in a way that will leave holes in a frame, or a residue of solder after it is removed. There are temporary methods of keeping eyelids open if it is fairly certain that the need is temporary. Tape is probably the most common and, if chosen carefully, can be reasonably comfortable, though rather unsightly. If it is certain that the situation may improve, this may be the best solution since it has nothing to do with the frame.
Permanent solution. When it becomes evident that a permanent crutch is needed, it will have to be attached to the frame. This usually means attaching a piece of wire to one or both sides of the frame to hold the eyelids in place. It may also be accomplished with a plastic semicircular shelf on a plastic frame. These are very difficult to adjust so it is critical that the frame and crutch fit nearly perfectly from the start. It may be advisable to use cable or riding bow temple in conjunction with a ptosis crutch, since any slippage will allow the lid to slip down.
The position of the crutch is generally where the orbital fold would be if the lid were normal. The crutch should create a fold just above the eye, tucking the lid in and raising it above the pupil. If there has been trauma near the lid margin or the fold, it may be necessary to devise a means to lift the skin just under the brow. This is more of a lifting up than creating a tucked fold.
Sometimes this can be fashioned from a nose pad arm that is welded to the eyewire. Silicone pads are used since they have a greater coefficient of friction.
The wire type is probably the most favored since it is the most adjustable. It can be straight, curved in or out, and rounded upward in the center so as not to impinge on the globe. Though it can be anchored on the nasal or temporal side, I tend to prefer the nasal anchor. A distinct advantage of the wire anchored on one side as opposed to the commercially available ptosis crutches is that most of them are anchored on both sides. In an impact this would be devastating, while the wire anchored on one side would give considerably and possibly save the eye and surrounding tissues.
A properly fit ptosis crutch on a plastic frame
Though gold used to be preferred, a good wire is stainless steel welding rod, which also has hypoallergenic qualities and holds adjustment well.
Connecting to the Frame
Metal frames. To connect a wire to a metal frame, weld it along the back of the bridge. Use a piece about six inches long to start. You should curve about 10mm of the wire to lay nicely in the curve of the bridge. Then heat the bridge and apply enough solder to lightly coat the back. Using a pair of hemostats to hold the hot pieces, reheat the bridge and the wire while holding them in place, and allow the solder to sweat them together.
Air cool the pieces rather than dunking them in water since that would make the wire too soft. Restore the finish the frame had to begin with and then rough the wire into the position you think it will be. You can try it on yourself and get very close to the adjustment you will end with.
A properly fit ptosis crutch on a metal frame
After you have roughed in the crutch, you will have a few inches of excess wire to eliminate. Before removing it though, you should bend the un-anchored end away from the eye to avoid any possibility of injury. I take one other precaution after cutting the wire by using a cupping bur to radius the end of it.
Plastic frames. A ptosis crutch on a plastic frame is done differently. I start with about six inches of wire and put a 90-degree bend about 10mm from one end. Then, laying it on an anvil, I flatten the 10mm until it is about twice the width of the original wire. Try not to flatten the 90-degree bend, but just up to it. This will be the end that will be inserted into the plastic frame. Flattening it will prevent the wire from turning as time goes on.
You may insert the wire, using a Hilco "Hot Fingers" machine, into a part of the frame that has plenty of stock. It may be necessary to reduce the sharpness of the bend to allow insertion from the side rather than straight in since a plastic frame often fits very close to the bridge area. Adding adjustable nose pads may be beneficial.
When fitting the ptosis crutch to the patient, keep in mind that the more contact the wire makes, the more comfortable it will be. Don't fit it too tight. The idea is generally to create a fold in the lid so it will sort of roll up the globe and expose the pupil. The patient should not feel any pressure on the globe, nor should the crutch protrude into the orbit too far.
Chat with the patient for a while after you've completed the adjustment to make sure that eventually the lid will slip back down. If it doesn't, it is probably fit too tight. This will inhibit good blood flow in the lid, and the eye will dry out very quickly. Dry eye is always a problem so be sure to tell the patient to arrange for lubricating drops with the doctor.
Fortunately, this is not something you see every day. But like other challenging jobs, the gratitude of patients and their families is definitely worth the hard work. EB