Top-Ten of the Annual Scientific Meeting of the Pan Arab African
Glaucoma Society:
Management of Glaucoma in Infancy and Childhood
November 19, 2005, Beirut, Lebanon
| Karim Tomey
The Pan Arab (African) Glaucoma Society [PA(A)GS] held its first
annual scientific meeting, in collaboration with the Department of
Ophthalmology at the American University of Beirut.
- The treatment of glaucoma in infancy and childhood is primarily
surgical, yet medical therapy may be necessary in some situations:
for example, in preparation for surgery and in cases where repeated
surgical procedures keep failing and there is no more room for
additional surgery.
- Beta-blockers have been associated with apnea, and alpha-2
agonists with significant (even fatal) central nervous system
depression in infants. Such medications must be used with extreme
caution, or avoided altogether in the very young age groups.
- Topical carbonic anhydrase inhibitors have been shown to be safe
and effective in children. Prostaglandin analogues are also supposed
to be safe, but their long-term efficacy is yet to be determined.
- Goniotomy and trabeculotomy yield the best results in cases with
isolated trabeculodysgenesis that present after birth but before two
years of age. The two procedures seem to have comparable success
rates, but must be performed only by the experienced glaucoma
surgeon or pediatric ophthalmologist. Performing safe goniotomy
requires excellent visibility of the angle, and hence a very clear
cornea. Safety of this procedure is also greatly enhanced by filling
the anterior chamber with viscoelastic. Trabeculotomy, on the other
hand, can be performed on eyes with hazy corneas.
- Trabeculectomy is another viable option in infants and children.
However, special precautions are necessary in stretched globes,
where the limbal anatomy can be greatly distorted. Anterior chamber
entry under the scleral flap needs to be as central (corneal) as
possible, otherwise the risk of injuring the ciliary body, iris
root, or even the vitreous base becomes high. The combination of
trabeculectomy with trabeculotomy in selected cases (usually older
children) is said to have a higher success rate than either
procedure done alone. Adjunctive antifibrotic agents, especially
mitomycin-C, are probably indicated in most, if not all, cases,
because of the strong healing reaction of young tissues. However,
unless such agents are used judiciously, the risks of hypotony and
of bleb-related infections have been reported to increase
significantly in the young age groups (as they do also in adults).
- Non-penetrating glaucoma procedures may offer a safer
alternative in children, insofar as they may as effective as
trabeculectomy in achieving pressure control, but without the
dreaded complications of chamber shallowing, leaks, infections, etc.
Such delicate procedures may be technically more demanding in
stretched globes with thin scleras, as the case is in many
congenital glaucoma eyes, and besides, their long-term efficacy is
yet to be determined.
- Glaucoma drainage devices are indicated in cases where multiple
conventional procedures fail. Tube-cornea touch and erosion of the
device through the conjunctiva are two common problems that are
quite likely to occur over the long lifespan of the child (eye
rubbing; trauma). The failure rates of such devices in the young age
groups are probably also higher than in adults.
- Cyclodestruction is generally the last resort after all the
other incisional procedures fail, and is usually reserved for eyes
with poor visual potential. Although diode laser
cyclophotocoagulation seems to be more promising than
cyclocryotherapy, both modalities are less effective in the young
age groups, and hence multiple treatment sessions are often
required. Complications rates are rather high, the most serious
being hypotony, visual loss, and phthisis.
- Up to 40% of infants undergoing uncomplicated cataract
extraction can develop secondary glaucoma, even decades after
surgery, and for no visible reason. The performance of cataract
surgery below the age of nine months and leaving the eye aphakic
have been shown to be two significant factors that increase the risk
of secondary glaucoma. Of course, a poor surgical technique and/or
the occurrence of intraoperative complications are other risk
factors.
- Controlling the intraocular pressure of an infant's eye does not
necessarily restore its function. There is still the important issue
of amblyopia management. Refractive errors and media opacities are
the two most important factors leading to amblyopia. Corrective
spectacles or contact lenses with occlusion therapy usually take
care of anisometropic amblyopia. With the constant refinement in
cataract surgical techniques and improvement in intraocular lens (IOL)
designs and materials, IOL's are being implanted more and more
liberally in the younger age groups, which has made tackling the
problem of aphakia in children much easier. Addressing corneal
opacification is still a major challenge, as there are still lots of
problems associated with penetrating keratoplasty in the very young.
Issue 7-3
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