Russian Ophthalmological Journal, 2017; 1:74-79
E.L. Efimova1, V.V. Brzhesky1, I.E. Panova2, A.S. Aleksandrova1, M.A. Zertsalova1, Ya.M. Poroger3 1 Federal State Budgetary Educational Institution of Higher Education "St. Petersburg State Pediatric Medical University" of the Ministry of Health of Russia 2 St. Petersburg branch of the Federal State Institution MNTK "Eye Microsurgery" named after. Academician S.N. Fedorova Ministry of Health of Russia 3 Medical, Chelyabinsk
Purpose of the work: to evaluate the nature of the effect of the drugs Irifrin 2.5% and Irifrin-BC 2.5% on the main parameters of accommodation, as well as on tear production, stability of the tear film and the epithelium of the ocular surface in patients with computer visual syndrome (CVS) against the background of low myopia and medium degree. Material and methods. We examined 52 people aged from 17 to 34 years (average 22.30 ± 2.72 years) with CLC, divided into two groups. For 4 weeks, patients in group 1 received Irifrin 2.5% daily at night; patients in group 2 received preservative-free Irifrin-BC 2.5%. Before and after the course of therapy, the nature of the effect of these drugs on the main parameters of accommodation, as well as on tear production, the stability of the tear film and the epithelium of the ocular surface was assessed. Results. The effectiveness of the studied drugs 2.5% Irifrin was established against both pathogenetic links of CCD: both accommodation disorders and associated accommodative asthenopia, and secondary dry eye syndrome. All examined patients showed a decrease in the frequency and severity of manifestations of asthenopia, an increase in uncorrected visual acuity, the volume of absolute accommodation, as well as the values of the positive and negative parts of the volume of relative accommodation, which can be associated with the effect of phenylephrine hydrochloride. In addition, there is a decrease in subjective discomfort, the severity of staining of the corneal epithelium with a solution of sodium fluorescein and the conjunctiva with a solution of rose bengal, as well as an increase in the stability of the precorneal tear film, apparently due to the presence of hydroxypropyl methylcellulose in both preparations and the absence of a preservative in the preparation Irifrin-BK 2.5%.
Key words: computer visual syndrome, dry eye syndrome, accommodation, Irifrin, Irifrin-BK.
In recent years, a steady trend has emerged towards a change in the nature of visual work, mainly among schoolchildren and students. This trend is due to the active introduction of modern information technologies and the increasing computerization of the educational process and workplaces. Of course, increasing the intensity of such visual load concerns primarily young people - students and schoolchildren, as well as people whose professional activities involve intense visual work at close range [1–3].
The peculiarities of visual work at a computer naturally cause an excessive load on the accommodative apparatus of the eye, contribute to the development of habitually excessive tension and even spasm of accommodation, visual fatigue and, finally, myopization of the eye. At the same time, the already mentioned groups of people (students, etc.) are most susceptible to these processes.
Another “result” of long-term work at a computer is the development of secondary dry eye syndrome (DES), associated mainly with a decrease in the frequency of blinks during intense visual work at the monitor [1, 4].
The circumstances considered were the reason for identifying the so-called computer visual syndrome (CVS) as an independent nosological form. Currently, this term is widely used in domestic and foreign literature. The main “components” of this syndrome are accommodative (or accommodative-refractive) asthenopia and dry eye syndrome, which together cause a fairly intense symptom complex that reduces the performance and quality of life of people working at a computer [3, 5, 6].
Accordingly, increasing attention has naturally been paid to the study of physiological mechanisms of accommodation and the possibilities of correcting their disturbances in patients with CHD in recent years [1, 5, 7].
The basis of therapeutic measures for such patients is, on the one hand, the normalization of the ciliary muscle, and on the other, increasing the stability of the precorneal tear film. Of course, the main pathogenetically oriented direction of drug treatment of the pathology in question is the impact on the autonomic innervation of the main portions of the ciliary muscle using instillations of M-anticholinergics (atropine sulfate, cyclopentolate hydrochloride, tropicamide, etc.) and/or α-adrenergic agonists (phenylephrine hydrochloride) [5, 8, 9].
Considering the excessive cycloplegic effect of M-anticholinergics, accompanied by accommodation paresis, which impairs visual work at close range, as well as prolonged mydriasis, preference today is given to instillations of α-adrenergic agonists [8, 9]. Their effect is associated with a direct stimulating effect on the Ivanov radial fibers of the ciliary muscle and, according to the laws of “feedback,” weakening the function of the muscles that are antagonists of the ciliary body (circular and meridional). Among the medicines of the pharmacological group under consideration, the Register of Medicines of Russia includes phenylephrine hydrochloride preparations as eye drops: Irifrin 2.5%, Irifrin-BK 2.5%, Neosinephrine-POS, Vizofrin. Phenylephrine-induced mydriasis is usually short-lived. The clinical effectiveness of Irifrin 2.5% has already been proven in the treatment of children with habitually excessive stress of accommodation, as well as adults with accommodative asthenopia [5, 6, 7, 9].
At the same time, systematic instillation of drugs containing preservatives is naturally accompanied by a violation of the stability of the tear film and, ultimately, the development of secondary dry eye syndrome [10]. Of course, the use of such drugs in the treatment of patients with CCD is fraught with aggravation of the existing xerosis in such patients, which requires modification of phenylephrine hydrochloride preparations, for example, the introduction of polymer bases of tear substitutes into their composition and/or the exclusion of a preservative. These modified eye drops were: Irifrin 2.5% (contains hyproxypropyl methylcellulose as a phenylephrine prolongator) and Irifrin-BC 2.5% (contains the same polymer and also lacks a preservative). However, their effectiveness in the treatment of patients with CVD remains unstudied.
OBJECTIVE OF THE STUDY: To evaluate the nature of the effect of the drugs Irifrin 2.5% and Irifrin-BC 2.5% on the main parameters of accommodation, as well as on tear production, tear film stability and the ocular surface epithelium in patients with CCD.
How to use drops correctly?
The active substance of the drops is phenylephrine. With its vasoconstrictive properties, it is used not only to treat the eyes, but is also found in allergy and cold medications. This is an effective remedy for nasopharyngeal congestion.
Phenylephrine is used by injection for low pressure in the arteries and weak tone of the vascular wall. In ophthalmology it is used as “Irifrin” in two cases - in diagnosis and therapy.
In diagnostic practice, these drops are prescribed to dilate the pupil before surgery and examine the fundus, as well as determine the depth of the bulbus oculi injection and test for angle-closure glaucoma.
The drug "Irifrin" at a concentration of 2.5% and 10% is used as follows.
- To check the fundus oculi, the doctor prescribes a drop of medicine in each eye. Then, after 15-30 minutes, the pupil should dilate enough to conduct an examination. If the procedure lasts more than an hour, the instillation is repeated. If the pupil is not dilated enough, you need to use a stronger 10% composition.
- The test for angle-closure glaucoma will require 2.5% phenylephrine. First, the doctor measures the eye pressure, after which he instills the drug. He then compares the measurement results - before and after the procedure. With a difference of 3-5 mm Hg, pathology occurs.
- The depth of injection of the eyeball is determined using Irifrin 2.5%. After instillation, wait five minutes and check the result. The disappearance of redness indicates its superficial nature. If hyperemia persists, it spreads to deeper layers. Then a differential diagnosis of the identified pathology is carried out.
- Only 10% phenylephrine is suitable for preparation for surgery. It is administered drop by drop into both eyes 30-60 minutes before surgical procedures.
In what cases will Irifrin be effective? These drops are prescribed for the treatment of glaucomocyclic crisis (10% composition), red eye syndrome (2.5%), false myopia and iridocyclitis. Let's consider these pathologies in more detail.
- Glaucomocyclic crisis is manifested by fluctuations in intraocular pressure and signs of cyclitis (hyperemia, blurred vision, night pain, increased lacrimation).
- Red eye syndrome is caused by vasodilation or hemorrhage in the visual organs. It is characteristic of a number of pathologies caused by allergies, viruses and bacteria. Taking into account the symptoms that appear, the specialist diagnoses the disease.
- The spasm of accommodation is accompanied by a prolonged contraction of the focusing muscle. Otherwise, this condition is called false myopia, which is manifested by chronic tension of the musculus ciliaris. This disease, typical of schoolchildren, is considered curable, but over the years it often develops into true myopia.
- Iridocyclitis is an inflammation of the iris or middle choroid. Its symptoms are redness, swelling, changes in the shape of the pupil, eye pain and blurred vision.
For glaucomocyclic crises, Irifrin 10% is usually used, instilled 2-3 times a day. In the case of iridocyclitis, the drug removes fluid formed due to inflammation. In this case, drops of 2.5% and 10% are prescribed in a similar dose with the same frequency. The concentration of the active substance in the solution is determined by an ophthalmologist.
To get rid of false myopia, phenylephrine 2.5% is perfect. It is used daily, a drop in both eyes. The duration of the course is one month. If the problem is not resolved and the spasm is not relieved, increase the dose to 10% and take the drops for two weeks.
Irifrin
Irifrine (phenylephrine) is an ophthalmic drug from the sympathomimetic group. Dilates the pupil, facilitates the evacuation of aqueous humor - the internal environment of the eye, reduces the lumen of the vessels of the conjunctival membrane. Used:
• with inflammation of the iris and ciliary body;
• to dilate the pupil during a number of diagnostic procedures (for example, ophthalmoscopy), ophthalmic surgical (including laser) interventions;
• to eliminate redness of the eyes;
• for the treatment of Kraup-Posner-Schlossmann syndrome;
• with false myopia caused by dysfunction of the ciliary muscle.
Irifrin is a vasoconstrictor whose mechanism of action is similar to that of norepinephrine. Its angiotonic effect is somewhat less pronounced than that of norepinephrine, but is more persistent. The vasoconstrictor effect of the drug begins to develop 30-90 seconds after instillation. The duration of the vasoconstrictor effect is 2-6 hours. Pupil dilation is observed 10-60 minutes after instillation of a single dose. This state is maintained for two hours (with instillation of a 2.5% solution), up to 3-7 hours (with instillation of a 10% solution). Paralysis of the ciliary muscle of the eye does not occur, because phenylephrine (the active component of the drug) has only a minor effect on the ciliary muscle. To dilate the pupil, as a rule, a 2.5% solution is used with the possibility of repeated instillation if it is necessary to maintain the pupil in a state of mydriasis for a longer period of time.
In patients with a hard (rigid) and pigmented iris, a 10% solution can be used. For false myopia, use a 2.5% solution before bedtime in each eye for one month. In case of persistent dysfunction of the ciliary muscle in patients over 12 years of age, a 10% solution can be used for 14 days. For inflammation of the iris and ciliary body, both 2.5% and 10% solutions are used. Frequency of use: 2-3 times a day. In patients with diabetes mellitus, special caution should be exercised when using the drug due to the increased risk of developing hypertension due to autonomic disorders. The same applies to older people: with age, the risk of reactive constriction of the pupils increases. Combining Irifrin with monoamine oxidase inhibitors (MAOIs) should be under regular medical supervision, which should also be present for three weeks after discontinuation of MAO inhibitors. The use of a 12.5% solution in excess of the recommended dosage in patients with traumatic eye injuries, after surgical interventions on the organs of vision, as well as in persons with pathologies of tear production may lead to an increase in the absorption of the active component, which, in turn, increases the risk of systemic adverse reactions . The use of Irifrin during pregnancy and breastfeeding is possible only after a comprehensive assessment of the benefit/risk ratio.
"Irifrin" in childhood
For children under 12 years of age, the drug is prescribed for visual impairment if a diagnosis of farsightedness or myopia is made. When a child comes to school, lessons and electives are added to his usual workload. The eyes are under stress and often in the first grades children complain of fatigue and blurred vision.
To avoid this, you need to teach your child to take short breaks when doing homework and watching TV. And at school you can do an exercise to train your eyes, turning your gaze to distant and close objects. This will benefit the baby.
Against the background of increased loads, Irifrin is used as a monthly course, drops at night in both eyes. You can prescribe two drops every other day. After a course of treatment, lacrimation and pain go away, and fatigue decreases.
Usually, the use of the drug prevents vision loss. To avoid switching to contact lenses or glasses, you need to teach children to take care of their eyes and listen to their feelings. As soon as fatigue appears, you need to take a break, do eye exercises or do a neutral activity. These techniques will help you avoid heavy loads.
The use of Irifrin as a stimulant of accommodation for distance
Volkova EM, Strahov VV
Department of eye diseases of Yaroslavl State Medical Academy Purpose: to evaluate Irifrin influence on accommodation and the possibility of itХs usage in miopia. Materials and methods: 53 patients at the age from 7 to 53 years were examined. They were divided into 3 groups: in the first group only Irifrin was used, in the second- combination of Irifrin usage and physiotherapeutic procedures and exercises for accommodation training and in the third group P only physiotherapeutic procedures and exercises for accommodation training. Visual acuity, refraction and accommodation reserve were examined. Results: weakening of refraction was observed in all groups. In the 1 group- by 0.17 dioptres in weak myopia and by 0.46 dioptres in medium myopia; in the second group- by 0.52 and 0.3, accordingly; in the third group- by 0.28 and 0.2 dioptres. Increasing of accommodation reserve was observed in 1 group- by 3.1 dioptres and by 2.4 dioptres in the third group. Conclusions: Irifrin usage contributes to eye condidtion in myopia objects. The greatest effectiveness was detected when Irifrin instillations were used in combination with physiotherapeutic procedures and exercises for accommodation training. Myopia remains a pressing clinical and social problem associated with its widespread prevalence, progression and frequent development of complications. In modern stressful conditions of visual work, with the development of computerization, the role of visual load in the etiopathogenesis of myopia has increased significantly. And the explanation of the mechanisms of accommodation is one of the most controversial and debated issues in modern ophthalmology. However, the structures of the eye involved in accommodation became available for study with the advent of ultrasound biomicroscopy (UBM). Using this method, in our clinic, changes in the ciliary body and ligamentous apparatus of the lens were recorded on drug models of various tonic conditions of the ciliary muscle and the presence of an active mechanism of accommodation of the eye was confirmed for both near and distance. The biomechanism that provides the entire volume of accommodation from the further to the nearest point of clear vision and, conversely, from the nearest point of clear vision to the further is under the influence of the sympathetic and parasympathetic parts of the autonomic nervous system and is realized through the active and passive muscle components due to the contraction of the radial Ivanov muscle (sympathetic innervation) and relaxation of the meridional Brücke muscle (parasympathetic innervation). We chose the adrenergic agonist Irifrin as a stimulator of distance accommodation through its effect on the sympathetic nervous system. Irifrin 2.5% (Promed Exports Pvt. Ltd. India) contains 25 mg of phenylephrine hydrochloride and 0.1 mg of benzalkonium chloride in 1 ml. The drug has pronounced alpha-adrenergic activity and, when applied topically in ophthalmology, constricts blood vessels and dilates the pupil without causing cycloplegia. Irifrin easily penetrates into the eye tissue, mydriasis occurs within 10-60 minutes and persists for 4-6 hours after a single instillation. The purpose of this study was to study the effect of the drug Irifrin on the condition of the accommodative apparatus of the eye and to evaluate the effectiveness of its use in the treatment of myopia. Objectives: – to study the effect of the drug irifrin on the dynamics of refraction and accommodation reserves; – develop practical recommendations for the use of this drug in the treatment of mild and moderate myopia. Patients and methods Under observation were 53 patients aged 7-23 years with mild and moderate myopia and often with asthenopic complaints. The patients were divided into 3 groups, in one of which only Irifrin was instilled, in the other - instillations of Irifrin were combined with physiotherapy and functional accommodation training in a hospital setting (typical for those studied), in the third control group standard treatment without Irifrin was used (physiotherapy and functional training accommodation). Irifrin solution 2.5% was prescribed 2 times a day (as an express method). The course of treatment averaged 12-14 days. Subjective visual acuity, the value of maximum correction were determined for all patients, autorefractometry was performed, and the condition of the accommodative apparatus (accommodation reserves) was examined. Results and discussion During the entire observation period, the drug was well tolerated and the symptoms of accommodative asthenopia disappeared. In some cases, patients noted a burning sensation that went away on its own after some time. The results obtained were clinically significant in all observation groups. The dynamics of refraction in the studied groups are shown in the table. It was found that a change in refraction towards weakening occurs in all studied groups. In the group receiving Irifrin instillations, a weakening of refraction was noted by 0.17 D for mild myopia and by 0.46 D for moderate myopia; in the group that used Irifrin with standard treatment - by 0.52 D with mild myopia and by 0.3 with moderate myopia, and in the group that received standard treatment - by 0.28 D with mild myopia and by 0.2 D for moderate myopia. To study the state of accommodation, patients with accommodation reserves before treatment not exceeding 2.0 diopters were selected. Accommodation reserves increased in all study groups: in the group in which Irifrin was prescribed together with training of the accommodative apparatus, accommodation reserves increased by an average of 3.1 D, in the group receiving Irifrin alone - by 0.5 D, in the group using standard treatment - by 2.4 D (Table 2). A more pronounced positive effect was observed in patients who used Irifrin instillations in combination with functional training and physical therapy. Thus, their uncorrected visual acuity increased by 0.14, while in the group of patients receiving only Irifrin it increased by 0.06, and in the control group without Irifrin only by 0.03 (Table 3). Thus, drug stimulation of the sympathetic nervous system has a positive effect on the accommodative apparatus of the eye, increasing accommodation reserves. In the group that received only irifrin instillations, an increase in accommodation reserves by an average of 0.5 D was found. This interesting fact can be associated with the activation of the process of accommodation into the distance and can be considered as clinical confirmation. The best results were observed with simultaneous effects on the parasympathetic nervous system (functional training of accommodation upon presentation of a stimulus for near), the sympathetic nervous system (drug stimulation of accommodation with irifrin for distance), and improvement of the hemodynamics of the eye (physiotherapy). The clinical effectiveness of the drug Irifrin was manifested in the following: – increase in accommodation reserves; – weakening of myopic refraction; – increase in uncorrected distance visual acuity. This effect was more pronounced in the group receiving irifrin instillations with standard treatment (an increase in uncorrected visual acuity by 0.14, an increase in accommodation reserves by 3.1 D and a change in refraction towards weakening in mild myopia by 0.52 D, moderate by 0.3 D). Conclusions 1. The use of the drug Irifrin 2.5% is an effective means of influencing the accommodation of the eye, leading to an increase in accommodation reserves, a slight weakening of the degree of refraction and an increase in uncorrected distance visual acuity. 2. The greatest effectiveness of the drug is observed if it is used in combination with functional training of the accommodative apparatus and physical therapy. 3. According to clinical observations, the drug was well tolerated; no systemic effects on the cardiovascular system were recorded. Recommendations We recommend using Irifrin 2.5% according to the following method: for asthenopia - at night every other day during the period of maximum visual load; for mild and moderate myopia - 1 time every day at night. During the period of maximum visual load - daily.
Literature 1. V.V. Strakhov “Problems of eye accommodation” - Yaroslavl. – 2004. – 32 p. 2. V.V. Strakhov, A.Yu. Suslova, M.A. Buzykin “Accommodation and hydrodynamics of the eye” Russian Medical Journal 2004 3. E.S. Avetisov “Children’s vision protection” – Moscow. – Medicine 1975 4. Yu.E. Batmanov, S.I. Makarov “Irifrin 2.5% is a stimulator of disaccommodative muscles of the ciliary body.” “New in Ophthalmology” 2, 2003 5. V.V. Bakutkin, N.N. Aleksandrova “Spasm of accommodation and its prevention.” Methodical letter. Department of Eye Diseases, Saratov State Medical University. 2003
How does Irifrin work?
When instilling the drug, a slight burning sensation is felt, which disappears after 4-5 seconds. After this, you need to refrain from visual stress for two to three hours. You cannot write, read, work on a computer, watch TV, sew, knit, etc. 15-20 minutes after the procedure, eye accommodation deteriorates, objects become blurred, and bright light causes discomfort. This condition may last for several hours. Doctors recommend instilling Irifrin at night to minimize discomfort.
After using the drops, some patients suffering from hypertension note an increase in blood pressure. This side effect passes quickly and is not a cause for concern. Fans of contact lenses should refrain from wearing them during therapy and use glasses. After a few days you can return to them again. You need to prepare yourself for the fact that after a course of treatment with phenylephrine, your vision will be blurred for another three days. Then everything will get better, and your eyes will see even better.
By constantly using the drug, people note the disappearance of pain and a decrease in eye fatigue. If vision loss is not far from the norm, thanks to Irifrin drops, you can even remove your glasses in the future.
In addition, useful habits - control over eye hygiene, walks in the air and relaxing exercises, alternation of work and rest - will provide the visual organs with normal blood circulation in order to consolidate the therapeutic effect.
References
1. Efimova EL, Brzheskij VV, Aleksandrova AS Characteristics of visual disorders using electronic textbooks and their possible correction. Russian ophthalmological journal. 2015; 2: 27–33 (in Russian). 2. Zemlyanoj DA, L'vov SN Regional characteristic of the state of health of schoolchildren. Pediatr. 2013; 4 (4): 65–9 (in Russian). 3. Blehm C., Vishnu S., Khattak A., Mitra S., Yee RW Computer vision syndrome: a review. Surv Ophthalmol. 2006; 50: 253–62. 4. Brzheskij VV, Egorova GB, Egorov EA The syndrome of “dry eye” and ocular surface disease: clinical picture, diagnosis, treatment. Moscow: GEOTAR-Media; 2016 (in Russian). 5. Markova E.Yu., Matveev AV, Ul'shina LV, Venediktova LV Multipurpose approach to the treatment of accommodation disorders in children. Review. Oftal'mologiya. 2012; 9 (4): 27–30 (in Russian). 6. Proskurina OV, Tarutta EP, Iomdina EN, Strakhov VV, Brzheskj VV A modern classification of asthenopias: clinical forms and stages. Russian ophthalmological journal. 2016; 9 (4): 69–73 (in Russian). 7. Zharov VV, Egorova AV, Kon'kova LV Comprehensive treatment of accommodation disturbances in acquired myopia. Izhevsk: Nauchnaya book, 2008 (in Russian). 8. Proskurina O.V., Golubev S.U., Markova E.Yu. Subjective accommodation methods. In: Katargina LA, ed. Accommodation: gui-dance for practitioners. Moscow: April; 2012: 40–50 (in Russian). 9. Vorontsova TN, Brzheskiy VV, Efimova EL, et al. Effectiveness of pharmacotherapy of chronic overtension of accommodation in children. Rossiyskaya pediatricheskaya oftal'mologiya. 2010; 2: 17–9 (in Russian). 10. Baudouin C., Labbé A., Liang H., et al. Preservatives in eye drops: the good, the bad and the ugly. Prog. Retin. EyeRes. 2010; 29 (4): 312–34. 11. Bron AJ, Evans VE, Smith JA Grading of corneal and conjunctival staining in the context of other dry eye tests. Cornea. 2003; 22 (7): 640–9. 12. Eliason JA, Maurice DM Staining of the conjunctiva and conjunctival tear film. Brit. J. Ophthalmol. 1990; 74 (9): 519–22. 13. Feenstra RP, Tseng SCG Comparison of fluorescein and rose Bengal staining. Ophthalmology. 1992; 99 (4): 605–17. 14. Norn MS Dessication of the precorneal film. I. Corneal wetting time. Acta Ophthalmol. (Copenh.). 1969; 47:865–80. 15. Schiffman RM, Christianson MD, Jacobsen G, Hirsch JD, Reis BL Reliability and validity of the Ocular Surface Disease Index. Arch Ophthalmol. 2000; 118:615–21. 16. Van Bijsterfeld OP Diagnostic tests in sicca syndrome. Arch. Ophthalmol. 1969; 82:10–4.
Address for correspondence: 194100 St. Petersburg, st. Litovskaya, 2, Federal State Budgetary Educational Institution of Higher Education "St. Petersburg State Pediatric Medical University" of the Ministry of Health of Russia [email protected]
How is the drug released?
Irifrin drops are sold in 5 mm bottles. Once opened, they are suitable for use for another three months. The drug is used as prescribed by a doctor and strictly according to the instructions. You need to tilt your head back, open your lower eyelid and from a short distance squeeze a drop of the composition into each eye. In this case, it is not advisable to touch the mucous membrane with the bottle. If the solution gets on this area, adjust the inner edge of the eye so that it does not soak into where it is not needed. And remember about a gentle regime, avoiding visual stress after phenylephrine.
Precautionary measures
When a high dose of phenylephrine is administered, it quickly enters the bloodstream and causes unpleasant effects. The risk increases during the post-traumatic period of eye recovery, as well as with a lack of tear fluid.
In addition, doctors recommend careful use of the drug for patients with diabetes and the elderly. Diabetics have a high risk of hypertensive crisis, and in people over 65, the pupil may behave inappropriately and quickly shrink instead of the desired expansion.
Summarize. The active component phenylephrine compresses blood vessels and improves the removal of intraocular fluid. Due to the narrowing, the symptom of red eyes is relieved, and the rapid outflow of fluid brings relief from glaucoma. In addition, phenylephrine has been successfully used for diagnosis and preparation for operations, being an effective pupil dilator.
