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Home , Cycloplegia, Myopia, Phoropter, Subjective refraction

MYOPIA MANAGEMENT

Practical tips for managing

Michael Morton This article presents a summary of Online Education Coordinator: practical approaches to diagnosing Brien Holden Vision myopia, myopia management Institute, Sydney, . (with particular attention to low resource settings), reviewing myopia progression, and collecting data for myopia management programmes. Ling Lee Research Officer/ Optometrist: Part 1 Diagnosing and prescribing Brien Holden Vision Institute, Sydney, for myopia

Australia. While myopia might be initially detected by a patient EDGARDO CONTRERAS, COURTESY OF IAPB (e.g. reporting distance blur), or an adult observing is the first step. MEXICO behaviour changes in a child (e.g. squinting or • Monocular estimate method (MEM) . viewing things closer than expected), myopia is generally An objective method to determine a child’s diagnosed by an care professional. accommodative (near focussing) status at near. Priya Morjaria Equipment Retinoscopy should be conducted with a near target. Research Fellow: Accommodative facility. A subjective method to Department of The minimum required equipment to diagnose myopia • Clinical Research, and assess progression includes: assess function (ability of eye to London School focus at near). A high-contrast distance (VA) chart (e.g., of Hygiene and • • Subjective phorias. A subjective method to Tropical Medicine, Snellen, logMAR, E, or LEA) determine whether the prefer to converge in or International Centre • A room or space where the viewing distance for VA diverge out, at distance and near. for Eye Health, is at least 3m/10ft. The chart should be well lit and • Vergence reserves. A subjective method that London, UK. calibrated for the working distance measures the eyes’ ability to converge in and • Occluder (ideally with pinhole occluder) diverge out. • Retinoscope • AC/A ratio. Assesses the interaction between • Trial set (including Jackson Cross Cylinder) or accommodation and convergence. Equipment that could assist with myopia diagnosis, Cycloplegic refraction management and estimation of progression: An accurate refraction is very important in diagnosing myopia and monitoring myopia progression. Ideally, • Near VA chart a child with myopia should undergo cycloplegic • refraction at the initial presentation and then at least • measurement method (e.g., MIM card every 12 months. This allows the clinician to accurately or Howell phoria card) determine the without the effect of an • Lens flippers (±1.00 and ±2.00 D) active accommodation system. However, if cycloplegic • Prism bars refraction is not possible, a careful • Optical biometer for axial length measurement must suffice. • Cycloplegic eye drops (e.g., , or ). Common agents used for include cyclopentolate Clinical techniques (0.5% or 1%), tropicamide (0.5% or 1.0%) and atropine (1%). Studies have found tropicamide 1% to be effective To prescribe for myopia appropriately, the clinical in monitoring standard cases of myopia progression.1,2 techniques below are recommended as a minimum: Therefore, tropicamide 1% is worth considering for • Visual acuity (VA) cycloplegic refraction as it reduces the duration of glare and • Retinoscopy near symptoms compared to other options. Subjective refraction • If conducting cycloplegic refraction, inform patients that Ocular health assessment. • the eye drops may sting for a few seconds before instilling The following clinical techniques are recommended and them into the eye. Advise that their vision may be blurred, should be conducted where possible: especially at near, and they may be light sensitive for a few hours, so sunglasses should be worn if possible. • Cycloplegic refraction / autorefraction • Axial length measurement. What should you prescribe? The tests below can measure the effect Use the cycloplegic refraction results from retinoscopy of a myopia management strategy on the individual’s or autorefraction as the starting point and then refine binocular vision status and visual comfort. This will to achieve the best possible VA. If there is a large help you to determine the appropriateness of a myopia difference between the cycloplegia objective and management strategy for that person. subjective refraction, recheck your results.

17 COMMUNITY EYE HEALTH JOURNAL | VOLUME 32 | NUMBER 105 | 2019 Uncorrected How to estimate progression In low-resource settings where sphero-cylindrical You can estimate progression by comparing the are unavailable to correct astigmatism, spherical difference in myopia before and after using a myopia lenses might be prescribed to correct myopia. The management strategy. Ideally, you will be comparing level of blur is dependent on the amount and type cycloplegic over at least 12 months. Table 2 of astigmatism and currently there is no evidence is an example of estimating the rate and reduction of on the effect of uncorrected astigmatism on myopia myopia progression: progression. Table 2 Recording and estimating the rate of progression: Under-correction is ineffective an example Studies show prescribing single vision lenses with under-correction (less minus) made no difference Examination date Age Refraction compared to full correction, and in some cases, it made 3 years ago 7 R –1.00 D L –0.75 D the myopia progression worse.3,4 This suggests that if you are only able to prescribe single vision spectacles, 2 years ago (started 8 R –2.00 D L –1.75 D full correction is recommended. myopia management) Today 10 R -3.00 D L -3.00 D Part 2 Options for managing myopia References For children at risk of developing myopia, advise at least • Prior to using myopia management, this patient had 1 Egashira SM, Kish LL, 90 minutes of outdoor time daily,5 and regular breaks progressed –1.00 D in one year. Twelker JD, Mutti DO, Zadnik from near work. • With myopia management, they then progressed K, Adams AJ. Comparison of to R (right eye) –1.00 D and L (left eye) –1.25 D over cyclopentolate versus Myopia management interventions for children tropicamide cycloplegia in 2 years, which is –0.50 D and –0.62 D per year, with progressive myopia can be divided into three children. Optom Vis Sci. respectively. 1993;70(12):1019-26. categories (Table 1). These may not all be available in • This in an approximate reduction of 50% in the right 2 Manny RE, Hussein M, low- or middle-income countries. Each intervention is eye and 38% in the left eye. Scheiman M, Kurtz D, generally prescribed alone. However, you could consider Niemann K, Zinzer K, et al. combination treatment (for example, adding low-dose Estimating progression might be difficult for patients Tropicamide (1%): an atropine to an optical treatment) if there is a high risk of prescribed , and measuring axial effective cycloplegic agent fast progression or poor response to individual treatment. length might assist in these cases. However, you need for myopic children. Invest Ophthalmol Vis Sci. You can prescribe single vision lenses if you consider to be aware that axial length also increases with age in 2001;42(8):1728-35. 8 the patient’s myopia to be stable, especially if the children with (normal eye length). 3 Adler D, Millodot M. The patient is an adult. possible effect of Data collection for myopia management undercorrection on myopic Table 1 Myopia management interventions Record keeping is important to monitor a child’s myopia progression in children. Clin onset, progression, and their response to treatment. Exp Optom. Pharmacological Optical: Optical: 2006;89(5):315-21. This information can also assist in developing a spectacles contact lenses 4 Chung K, Mohidin N, database to use when planning programmes. Record: O'Leary DJ. Undercorrection • Low-dose atropine • Executive • Dual-focus and The child’s age at the onset of myopia (-0.50 D in of myopia enhances rather (might require multifocal centre- • than inhibits myopia a specialist • Progressive distance contact either eye) from a cycloplegic refraction progression. Vision Res. compounding addition lenses • Ethnicity 2002;42(22):2555-9. pharmacy) lenses • Orthokeratology • Family history of myopia 5 Rose KA, Morgan IG, Ip J, • Number of hours or minutes spent outdoors each day Kifley A, Huynh S, Smith W, Choosing a myopia management strategy • Number of hours or minutes spent on near work et al. Outdoor activity Consider: reduces the prevalence of • The type(s) of myopia management prescribed myopia in children. • The options are available in your setting • When the myopia management was initiated/ceased . • Their effectiveness • The amount of myopia (i.e. prescription) at each 2008;115(8):1279-85. • Patient suitability visit, at least annually, with cycloplegia 6 Hsu CC, Huang N, Lin PY, • Axial length (where possible). Fang SY, Tsai DC, Chen SY, et • Patient and carer preference al. Risk factors for myopia Using your clinical judgement, decide which of the available Summary: managing myopia in low- or progression in second- grade primary school options is most appropriate for your patient. If you are middle-income countries children in Taipei: a unable to prescribe that option, refer to a colleague who • It is important that progressive myopia is diagnosed population-based cohort has experience with, and access to, that intervention. study. Br J Ophthalmol. and managed appropriately. 2017;101(12):1611-7. What next? • Know which myopia management strategies are 7 Sankaridurg PR, Holden BA. available in your setting (such as executive or large Review periods Practical applications to segment bifocal spectacles, multifocal contact modify and control the Review every 6 months. More frequent reviews may lenses, orthokeratology and low-dose atropine). development of ametropia. be required for patients when first introduced to each Eye. 2014;28(2):134-41. Consider which myopia management strategy treatment strategy. Ongoing follow-up should be based • would be most appropriate for your patient. 8 Mutti DO, Hayes JR, Mitchell on the patient’s progress, treatment modality and GL, Jones LA, Moeschberger If that option is within your scope of practice, performance. • ML, Cotter SA, et al. prescribe it. If not, refer your patient to a colleague Refractive error, axial length, What is fast progression? who can prescribe it. and relative peripheral Fast progression is progression of myopia of 1.00 D Compare the annual rate of progression with and refractive error before and • after the onset of myopia. 6 or more, per year. Younger children with myopia are without myopia management using subjective Invest Ophthalmol Vis Sci. more likely to progress faster than older children.7 refraction, ideally with cycloplegia. 2007;48(6):2510-9.

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