Cycloplegics

Cycloplegic mydriatics cause mydriasis and cyclople-gia (paralysis of the ciliary muscle, resulting in an inability to focus the eye). These drugs (see Chap. 25) are used in the treatment of inflammatory conditions of the iris and uveal tract of the eye and for examination of the eye... 

Local adverse reactions associated with administration of tiie cycloplegic mydriatics include increased IOP, transient stinging or burning, and irritation with prolonged use (eg, conjunctivitis, edema, exudates). Systemic adverse reactions include dryness of the mouth and skin, blurred vision, photophobia, corneal staining, tachycardia, headache, parasympathetic stimulation, and somnolence. 

The answer is c. (Hardman, pp 156-158.) A wide variety of clinical conditions are treated with antimuscarinic drugs. Dicyclomine hydrochloride and methscopolamine bromide are used to reduce Gl motility, although side effects—dryness of the mouth, loss of visual accommodation, and difficulty in urination—may limit their acceptance by patients. Cyclopentolate hydrochloride is used in ophthalmology for its mydriatic and cycloplegic properties during refraction of the eye. Trihexyphenidyl hydrochloride is one of the important antimuscarinic compounds used in the treatment of parkinsonism. For bronchodilation in patients with bronchial asthma and other bronchospastic diseases, ipratropium bromide is used by inhalation. Systemic adverse reactions are low because the actions are largely confined to the mouth and airways. 

Cyclopentolate is an effective mydriatic and cycloplegic that begins to act very quickly and has a relatively short duration. It is used also in ophthalmoscopy for causing pre-operational mydriasis. Synonyms of this drag are mydrilate, cyclogyl, cyclomydril, pentolair, and others. 

Reversal of mydriasis - Dosage and strength required are dependent on the cycloplegic used. 

The mydriatic and cycloplegic actions of atropine and scopolamine can persist for a week after topical application to the eye. Shorter-acting drugs, such as cyclopentolate and tropicamide, are now favored for this application because complete recovery of accommodation occurs within 6 to 24 hours and 2 to 6 hours, respectively. 

Cycloplegia Topical One drop of the preferred cycloplegic is placed in each eye, followed in 5 minutes by one drop of phenylephrine HCl 2.5%. 

As mydriatic and cycloplegic agent Atropine is used to produce mydriasis and cycloplegia for testing errors of refraction. Mydriasis is required for fundoscopic examination and in the treatment of iritis and keratitis. 

Endocular inflammation. These inflammations usually generate synechia of the iris with the lens, which must be prevented by the instillation of mydriatic and cycloplegic collyrium. 

Mydriatic activity on rabbits and humans, and cycloplegic activity on humans were tested. It was found that tropicamide bioavailability, both in rabbits and in humans, was not decreased by micellar solubilization. The conclusion was that some poloxamers perform satisfactorily as solubilizing vehicles for tropicamide, producing neutral 1.0-1.5% drug solutions that are better tolerated and more effective than the standard aqueous eyedrops. 

As antidotes to poisoning from curare and the tricyclic antidepressants As preanesthetic medications As mydriatics As cycloplegics... 

Manifest Refraction. Topically applied cycloplegics may affect the manifest (subjective) refractive error. When indicated, cycloplegic refraction may be performed after the initial manifest refraction or as the initial refractive procedure in children (see Chapter 21). 

Amplitude of Accommodation. Because of the cycloplegic and mydriatic effects of anticholinergic drugs, amplitude... 

Cyclopentolate Overdosage for cycloplegic refraction Hallucinatory behavior... 

Figure 3-8 Ophthalmic sprays can be extemporaneously prepared for defivery of suitable mydriatics or cycloplegics. (Available from Lee Pharmacy, Inc., Fort Smith,Arkansas.)...

Figure 3-9 Mydriatic effect of ophthalmic spray applied to closed eyes is comparable with that of eyedrops applied to open eyes. (Reprinted with permission from Wesson MD, Bartlett JD, Swiatocha J, et al. Mydriatic efficacy of a cycloplegic spray in the pediatric population. J Am Optom Assoc 1993 64 637-640.)...

Bartlett JD,Wesson MD, Swiatocha J,WooUeyT. Efficacy of a pediatric cycloplegic administered as a spray. J Am Op tom Assoc 1993 64 617-621. 

The common diagnostic drugs used by optometrists are anesthetics, mydriatics, cycloplegics, and dyes. Routine use of these drugs creates a risk of injury only in very unusual circumstances. Therefore informed consent is rarely a legal issue when they are used. 

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