Topical mydriatic and cycloplegic agents are an integral part of the daily routine of eye care specialists, often used for both diagnostic and therapeutic purposes. Mydriasis is dilation of the pupil by means of dilator contraction by adrenergic agonists or sphincter relaxation by muscarinic antagonists. Cycloplegia is the paralysis of the ciliary muscle by antimuscarinics, inhibiting accommodation and decreasing tension on the scleral spur. The efficacy and length of effect produced depends on each agent, as stronger agents tend to be longer acting. Indications for use include cycloplegic refraction, dilation for ophthalmoscopy and testing, surgery, suppression during amblyopic therapy, palliative care for phthisis, and uveitis. Several examples of these medications (eg, atropine, homatropine, and cyclopentolate) actually possess both characteristics and prove to be the most relied upon agents in the treatment of uveitis.
This dual action is useful in uveitis therapy for several reasons. Ocular pain and photophobia induced by ciliary spasm can potentially be reduced. There is thought that decreased vascular permeability may lead to lower amounts of inflammatory cells and protein in the anterior chamber (flare). Most importantly, avoidance of the formation of new and severing of previously formed posterior synechiae, which can severely limit both visual acuity as well as diagnostic capabilities, is achieved during dilation by virtue of decreased contact of the posterior iris with the anterior lens capsule as well as the cycloplegic decrease in lens thickness and convexity .
Opinions vary widely on which agents to use and when to use them. Extreme symptoms of photophobia or more severe or stubborn inflammation may eventually prompt the temporary addition of a cycloplegic, especially with signs of impending synechiae. The most popular treatment options include cyclopentolate 1% and homatropine 2%. Each has sufficient cycloplegic efficacy along with an intermediate length of action (24 hours or more) and can be dosed 2 to 4 times daily until the inflammation recedes. Cyclopentolate may have a disadvantage as it has been shown to be a chemoattractant to inflammatory cells in vitro . A short-acting agent such as tropicamide 1% is useful for diagnostic purposes, and it is arguable that a 4-times-daily dosing schedule may allow sufficient mobility of the iris to prevent synechiae, but this would likely be at the expense of poorly reducing symptoms as it is only weakly cycloplegic. Although rare, local and systemic side effects of mydriatic and cycloplegic agents have been reported . These topical medications have been reported to cause systemic side effects by absorption by the nasal mucosa and gastrointestinal tract mucosa, which is reached through the conjunctiva or the nasolacrimal duct [4, 5].
Besides the local and systemic side effects of these agents; the topic to be considered is; they affect daily life activities such as reading, driving, etc. In this study, we discuss the forensic medicine of our case in addition to eye practices.
A 45-year-old patient applied to the Ataturk University Medical Faculty Hospital for ocular diseases with a complaint of diminished sightings and floating objects on both eyes. It was understood that there was no systemic disease or any trauma story in the patient's history. Vision was 8/10 in the right eye and 8/10 in the left eye too. Tension in both eyes was normal. No pathology was detected in the anterior segment examination. Direct and indirect light reflexes were normal in both eyes. Optical chorens tomography of the retinas of both eyes was normal. Oral consent was obtained from the patient for examination. After then, with the suspicion that there might be degeneration from peripheral retina, retinal detachment from the torn part, and both pupils were enlarged by 1% in the tropicalamide for fundus examination. After waiting 10 minutes, the patient's fundus examination was performed and it was seen that both of them were normal. No treatment has been started for the patient. At this time, the patient was informed that the eye drops given during the eye examination may cause visual impairment, so that the use of the car may be objectionable for at least six hours, verbally, in accordance with the pamphlet.
At the first hour after being discharged from the hospital, he was informed that he was in an anamnesis given by the patient and that he was driving in the opposite direction when driving a car, making a traffic accident, and that his son died in intensive care unit and he had a tibia fracture.
When our case is evaluated especially in terms of good medical practices; it is important to report visual disturbance due to pupil dilation with cycloplegic agents for visualization of peripheral retinas. Informing the patients and their relatives about the effects of this agent which is frequently used in the outpatient setting is done orally. In the Turkish legal system, verbal information is accepted on some conditions and poses a problem in terms of the burden of proof.
Common drugs for mydriasis in fundus examinations are cyclopentolate, tropicamide, and phenylephrine. Opinions vary widely on which agents to use and when to use them. Table shows one such example of an algorithm for using mydriatic and cycloplegic therapy.
Although rare, local and systemic side effects of mydriatic and cycloplegic agents have been reported .
Disadvantages of these agents include the severe stinging many patients experience upon application that can sometimes be more bothersome than the ciliary spasm it was intended to treat. Patients are relieved upon discontinuation not only for this reason, but because of the significant blurring created by cycloplegia. An endpoint in cycloplegic treatment must be considered in every case. There should almost never be a reason to submit to standing doses of these cycloplegic agents. Still, significant active uveitis must always be addressed with aggressive treatment until it is quiet, and it may be reasonable to use these agents for long periods when all efforts to squelch the fire are being thwarted. Along with blurring and the general discomfort produced, ocular side effects include atopic response to the medication or vehicle, which may affect the lids or the ocular surface. Multiple medications and confusion in dosage may increase risk of noncompliance with other more vital therapy. There is also the known danger of mydriatic induction of acute closed-angle glaucoma. Interestingly, intraocular pressure in open-angle glaucoma has also been shown to increase with these drops by a mechanism that is not completely understood. It is thought this may relate to trabecular outflow and the effect of changing tension on the scleral spur. One must be mindful of glaucomatocyclitic crisis, an inflammatory condition where high pressures may possibly be exacerbated by use of these agents. Systemic side effects have also been well documented. Phenylephrine 10% may greatly increase blood pressure in infants, diabetics, and the elderly and, therefore, is usually avoided in these patients. Circulating levels of cycloplegics may exert an effect on muscarinic receptors throughout the body, initially causing dry mouth and flushing. Other more serious documented effects include urinary retention, tachycardia, somnolence, ataxia, hallucinations, and seizures. There have even been reports of abuse of and dependence on cyclopentolate . These are rare and generally stem from overuse of the stronger drops like atropine; however, some severe effects have also been seen with therapeutic levels of even weak cycloplegics. Again, infants and the elderly seem especially prone to this, as well as White males with Down syndrome, and care of these patients should reflect this.
Mydriatic-cycloplegic agents have their place in the treatment of uveitis. Whether they should be used and in what circumstances are up for debate. We suggest they be treated similar to topical steroids in that they may occasionally be used for acute symptoms and rescue (from synechiae), but that they should be discontinued whenever possible
Besides the local and systemic side effects of these agents; the topic to be considered is; they affect daily life activities such as reading, driving, etc. because of the significant blurring created by them.
Mydriatic and cycloplegic agents are frequently used in ophthalmology clinics. The possible topical-systemic side effects and how they will affect daily activities should be explained to the patients. Patients who have spilled a midratic drip should be warned not to drive until the effect of the mydriaticis are over.