August 2010

 

OPHTHALMOLOGY NEWS

 

With one eye shut


by Matt Young EyeWorld Contributing Editor

   

A child with an eye patch Source: National Eye Institute, National Institutes of Health

Since the 1700s, physicians have treated amblyopia patients with occlusion therapy, and that's not changing anytime soon. But beyond patches, adhesive tape on glasses, and opaque contact lenses, for the toughest of amblyopia cases, ophthalmologists will find a new method of occlusion in evidence-based literature. The technique, dubbed "silicone-eyelid closure," involves using sutures and a silicone sleeve to close the eyelid of an amblyopic eye. The silicone band is an important part of the treatment, according to lead study author Ossama M. Hakim, M.D., Magrabi Eye Center, Madina Munwara, Saudi Arabia.

"Including the silicone band in our technique provided us with two important benefits," Dr. Hakim wrote in the study, published online in February in the Journal of Pediatric Ophthalmology & Strabismus. "First, the 1.2 mm of the band that we left medially formed a visual barrier for children when they tried to see through the most medial part of the palpebral fissure. Second, by inserting the band between the eyelids, and with moderate suture tightening, we were able to shut all areas between the suture paths."

The technique was not successful in all respects, but the authors contend "a meaningful improvement in visual acuity could be obtained even for children with deep amblyopia."

What worked and what didn't

Dr. Hakim analyzed silicone-eyelid closure in 15 children aged 4 to 6 years. Each child had a history of deep amblyopia and poor compliance with occlusion treatment. "In this technique, the good eye was closed by passing one limb of a double armed 5-0 polypropylene suture from one eyelid margin through a silicone sleeve and through the corresponding eyelid margin," Dr. Hakim reported. "The other polypropylene limb was passed behind the silicone sleeve and then through the opposite eyelid margin to form a barrier between the sleeve and the cornea. After 2 to 4 weeks, the suture was cut and the silicone sleeve was removed."

Pre-op, patients had severely impaired vision, ranging from counting fingers (CF) at 1 meter to CF at 4 meters. "Following eyelid closure, visual acuity was improved to between 20/40 and 20/200 for 12 patients, whereas three patients did not improve," Dr. Hakim noted. "Complications were seen in 8 patients: marginal eyelid irritation and erythema in 6 and suture break in 2."

Average visual acuity improvement in the 12 patients was 20/67. However, two months after occlusion removal, five of the 12 improved patients demonstrated a decrease in visual acuity of one or two lines. Amblyopia maintenance therapy was then suggested. "Three of the 15 patients had eccentric fixation and showed no improvement in vision," Dr. Hakim reported. "Two of these patients had a history of soft congenital cataract that was extracted with intraocular lens implantation at 2 years of age. The third patient had a history of left congenital sixth nerve palsy with face turn to the right side."

The authors saw considerable advantages in adding this method to treatment options for deep amblyopia. "If we tried to close the palpebral fissure directly, without the band, we could not close that part because it incorporates the lacrimal punctum and the canaliculi," Dr. Hakim reported. "Accordingly, children could peer around the closed eyelids and would be able to see through this area, with failure of the closure technique."

In fact, the main concern was that the silicone band would touch the cornea. "Such corneal protection could be achieved by selecting a rounded silicone band, with a smooth posterior surface, and by positioning one of the Prolene suture arms behind the band," Dr. Hakim noted. "This arm formed a protecting barrier between the silicone band and the cornea."

Dr. Hakim recommended a closure time of two to three weeks to "achieve a reasonable visual acuity improvement with the least complications." "At the beginning of our work, we closed the non-amblyopic eye of 6 of our patients for 4 weeks," Dr. Hakim reported. "On follow-up, we noticed that not much improvement in visual acuity could be achieved after the third week and most improvement in vision, when it occurred, was achieved after 2 weeks."

John D. Sheppard, M.D., professor of ophthalmology, microbiology, and immunology, Eastern Virginia Medical School, Norfolk, Va., said ophthalmology has come a long way in understanding suppression therapy. "We've come the whole nine yards," said Dr. Sheppard, who puts much less stock in patches than yesteryear. "Patches are always difficult and kids find a way to look around them. Atropine penalization is as effective and is more convenient."

But he agreed that in extremely amblyopic eyes, complete suppression of the amblyopic eye is warranted. While a surgical procedure involving sutures may not make sense in an infant, it could work in a 7-year-old, he said. Surgeons should be aware that severe penalization of the good eye could lead to amblyopia in both eyes, he said. A child undergoing surgical treatment for the correction of amblyopia should be closely supervised, he said.

Editors' note: Dr. Hakim has no financial interests related to this study. Dr. Sheppard has no financial interests related to his comments.

Contact information

Hakim: TTTosshakim@gmail.com
Sheppard: 757-622-2200, docshep@hotmail.com

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