Other Special Situations

12.4.1 Infants and Children. Initial surgical treatment should not be delayed in an attempt to achieve medical control of IOP in infants with congenital glaucoma. Medications are primarily used preoperatively to allow corneal edema to clear, improving visualization at the time of examination under anesthesia and surgery, and to help control any damage that might occur in the interim preoperatively (see also Chapter 13). If trabeculotomies and/or goniotomies fail and trabeculectomy is believed to be required, some surgeons would attempt medical control at this point.

Long-term medical therapy in infants and children can be difficult because of side effects and compliance problems. Serious adverse effects have been reported from ophthalmic drugs in infants, and parents should be instructed about side effects and taught to perform careful nasolacrimal occlusion. The introduction of new classes of topical agents in the past few years offers greater possibilities for achieving control of IOP.

Prior to the introduction of topical CAIs, acetazolamide suspension, 5 to 10mg/kg body weight divided to three times daily, was considered the safest medication for infants. Topical CAIs should be considered as a first-line agent. Systemic CAIs have been noted to cause rapid and severe acidosis in infants.

Although studies of beta-adrenergic blocking agents in children have shown a minimum of side effects in short-term use, apnea has been reported in neonates. Parents should be cautioned to discontinue the medication if any side effects, such as asthmatic symptoms, develop. The selective beta-1 blockers, such as betaxolol, should have even fewer pulmonary side effects.

Latanoprost is well tolerated in children, with infrequent and mild local side effects. However, the iris color change associated with it could have serious psychological effects, and unilateral therapy should be approached cautiously. Also, while clinical trials have shown a benefit in some children, the responder rates have been lower than those observed in adults.

Brimonidine has been reported to cause serious side effects in infants, including systemic hypotension, severe fatigue, transient unarousability, unresponsiveness, and episodes of fainting.57 Therefore, it should be used with extreme caution and restricted to older children.

Miotics can induce visually disabling myopia in the young patient and are not recommended for infants.

Older children are better able to tolerate topical medications. Again, parents should be carefully apprised of potential side effects of any glaucoma agents being used. If psychological or behavioral difficulties arise, a trial of discontinuing successive potentially causative medications should be undertaken.

12.4.2 Prepresbyopic Adults. Adults younger than about 45 years of age have two particular problems with glaucoma medications. As mentioned above, miotic drops or gels cause visually disabling side effects. When used, these should be initiated at the lowest commercially available concentration, with gradual increase as necessary according to therapeutic effect.

The second problem with glaucoma medications in younger patients is a greater frequency of, or sensitivity to, psychological and sexual side effects. These can include depression, anxiety, confusion, sleep disturbances, drowsiness, weakness, fatigue, memory loss, disorientation, emotional lability, loss of libido, and impotence. Central nervous system side effects of CAIs have been primarily associated with their systemic use and can be described as a complex consisting of general malaise, fatigue, weight loss, depression, anorexia, and loss of libido. Once again, careful instruction on nasolacrimal occlusion can result in reduced dosages of medications and decreased systemic absorption. This is especially important when topical medications are prescribed for pregnant or lactating women.

12.4.3 Patients With Cataracts. A major problem faced by patients with cataracts is dimming of vision and/or decreased visual acuity with miotic treatment. This visual effect can interfere with driving and other daily activities. Patients should be questioned about these effects. Some patients volunteer this information readily and express a desire to eliminate miotic treatment, whereas others exhibit an attitude of forbearance. Not all patients with cataracts have these side effects. Many patients with nuclear sclerosis find their vision improved, instead of worsened, with miotics or are able to read without glasses because of the pinhole effect, and are hesitant to discontinue the miotics once started.

A second problem associated with miotic therapy, noted above, is the increased tendency to posterior synechiae formation in patients with exfoliation syndrome, which increases in prevalence with age.

12.4.4 Panallergic Patients. The word "panallergic" can be used to describe patients who simply cannot tolerate virtually any medication for one reason or another. Allergic reactions to every topical glaucoma agent have been reported. Contact dermatitis is not uncommon with alpha-2 agonists, miotics, CAIs, and beta blockers. Also included in this category are patients who have multiple side effects to medications or who just cannot tolerate the baseline level of burning and stinging associated with their instillation.

Allergic responses, if mild, can sometimes be successfully treated with mast-cell stabilizers, such as olopatadine, cromolyn, lodoxamide, or low-dose corticosteroids, such as medrysone. Preservative-free preparations are available for pilocarpine, epinephrine, timolol, and apraclonidine. Some patients with adverse reactions due to benzalkonium chloride in certain drops may be treated with other drugs using alternative preservatives. In some cases of drug intolerance, dosages below those normally prescribed can sometimes be effective; for example, latanoprost was shown similarly efficacious when given once daily or once weekly.58 However, in many cases, the drugs tolerated are insufficient for control of the glaucoma, and laser or surgical intervention becomes necessary.

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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