Prescribing for young children with moderate hyperopia (defined as +3.00 to +6.00 Diopters [D]) and without strabismus and amblyopia has always been a controversial topic. The difference in prescribing philosophy differs not only between providers from optometry versus ophthalmology professions but also among providers from the optometrists. A recent publication by Morrison et al.¹ highlighted such disparity. This study surveyed pediatric eyecare providers to identify current prescribing patterns for hyperopia and found that although most providers within each profession considered similar clinical factors when prescribing, a wide range of hyperopia levels was reported when considering whether to prescribe.

In the following point-counterpoint article, a case scenario is presented, and two clinicians were asked to defend the two opposing sides of prescribing versus not prescribing. Here, Dr. Maureen Plaumann argues for prescribing and provides her rationales for prescribing and what she would prescribe, whereas Dr. Gayathri Srinivasan declares her position of not prescribing as the available evidence does not show the benefits of prescribing.

CASE INFORMATION

3.5-years-old Hispanic female

Case History

• Presented for first eye examination

• No vision or ocular complaints

• No eye turn observed by parents

• Normal development

Pertinent Examination Findings

• Distance Visual Acuity (Lea symbol with matching): 20/40 OD/OS

• Near Visual Acuity (Lea symbol): 20/40 OU

• Cover Test: Orthophoria at distance, 2∆ Esophoria at near

• Dry Retinoscopy: +3.00 OD/OS

• Monocular Estimated Method (MEM): +0.75 OD/OS

• Cycloplegic Retinoscopy: +4.00 D OD/OS

POINT
By Maureen Plaumann

When choosing whether to prescribe for hyperopia in children without amblyopia or strabismus, there are several factors I consider. Given the clinical signs and magnitude of hyperopia compared with age, I choose to prescribe for this child.

Although this child does not have amblyopia or strabismus, it is critical to consider the risk for developing amblyopia or esotropia, given the magnitude of hyperopia present. The risk for developing bilaterally decreased visual acuity is about 10-fold in 4 D of hyperopia compared with refractive error between plano and +1.00 D.² Similarly, there is an increased risk of esotropia with increased levels of hyperopia; this child has a 60-fold increase in esotropia risk.³

Beyond risks for amblyopia and strabismus, the other factors I consider when deciding whether to prescribe include the child’s age, their developmental history, symptoms or signs elicited by the parent or child, visual acuity (distance and near), ocular alignment, accommodative ability, magnitude of hyperopia (both with and without cycloplegia), and stereoacuity, if able to obtain. This child is 3.5 years old, outside of the emmetropization window, which is generally completed by 18 months of age.⁴ Indeed, by 4 years old, 95% of children will have less than 3 D of hyperopia,⁵ putting this child outside of the age norm.

Although there are no signs or symptoms elicited or developmental concerns reported, this does not mean that there are no unidentified issues. I have prescribed hyperopic correction for some patients when parents had no concerns at the initial examination. However, upon follow-up, the parents reported that their child is interacting with their environment in new ways they never realized they were missing out on. Thus, a lack of symptoms and signs should be taken with a grain of salt; this child has little reference for “normal,” just as their parents do not know what their child may not be doing that they should.

Concerning the visual functions, this child’s measured visual acuity falls within the normal range for their age,⁶ and their near acuity is the same as the distance acuity. However, visual acuity is a brief measure and may not represent the child’s ability to maintain clarity throughout the day. Although this child does not present with strabismus, the small esophoria at near falls outside of the expected norms for near alignment.⁷ This indicates that the child has to diverge at near to maintain single vision, a task that could be made easier with a hyperopic correction. Although the monocular estimated method falls within the normal range,⁸ it is on the higher end of normal. Also, younger children generally do not have as robust accommodative ability as we would assume, as the push-up method tends to overestimate the accommodative amplitudes; Anderson and colleagues found that for patients aged 3 to 5 years, on average, objective measures of accommodation found an 8 D amplitude whereas subjective measures with push-up found 16 D.⁹ I am suspicious of this child’s capability to accommodate accurately and comfortably to counteract their hyperopia to continuously maintain clear vision, especially at near.

When considering what to prescribe, I take the same factors into consideration. Because there is no manifest esotropia or large esophoria at any distance, I would prescribe partial hyperopic correction for easier adaptation to glasses. When deciding how much plus “to cut,” I consider the average refractive error for the child’s age and the dry retinoscopy findings. For this child, the average refractive error is +1.00 D, so cutting by 1 D would put this child’s residual refractive error in the normal range for their age group. This would result in a final prescription of +3.00 D, which in this case is the same as the dry retinoscopy findings. If the dry retinoscopy finding were lower than +3.00 D in this case, I might consider cutting more plus to achieve better acceptance of the plus. However, given this patient’s age, I am less concerned about adaptation, and my decision in determining the final lens prescription is less influenced by the dry retinoscopy finding. Age 3.5 years is a great age to start glasses wear. There are fewer preconceived notions on the child’s part about wearing glasses and they also have not gotten used to years of accommodating to see clearly all the time, which are two factors that can make first-time glasses wear for hyperopes in late elementary school more difficult.

When prescribing hyperopic correction, providing thorough parent education and ensuring good understanding is critical. For this patient, I am prescribing the glasses for full-time wear to ensure the child always has the benefit of relatively relaxed accommodation compared with no correction, while also reducing the likelihood of losing the glasses. I discuss that the glasses will not necessarily provide for clearer vision but rather more comfortable vision and place the child in the same refractive error range as their peers. I also emphasize the importance of monitoring for an eye turn with the glasses on and warn that sometimes an eye turn might start to present with the glasses off. There is always the possibility that the child was not fully accommodating when ocular alignment was assessed, and an esodeviation may still present itself, especially as this child is in the age range when accommodative esotropia starts to manifest.¹⁰ Lastly, I discuss the possibility that a change to the lens prescription may be required at the follow-up visit, depending on the clinical findings at that time.

COUNTERPOINT
By Gayathri Srinivasan

When it comes to prescribing for moderate hyperopia in young children, clinicians consider several factors, such as the magnitude of hyperopia, distance and near visual acuity, stereopsis, ocular alignment at distance and near, accommodative function, academic performance, symptoms, and overall development.

The questions I ask myself when seeing a child with similar clinical profile to the case in question are as follows: Is the hyperopia age appropriate? If not, can the child “grow out” of it? How detrimental is hyperopia to vision, ocular alignment, and visual function? What is the risk/benefit to prescribing or not prescribing? After applying these questions to this case, I choose to “not prescribe” and will explain my rationale by summarizing evidence as it pertains to the aforementioned factors.

Hyperopia and Emmetropization

Based on the longitudinal¹¹ and cross-sectional⁵ studies, the average cycloplegic refractive error for a child between 3 and 4 years of age is approximately +1.25 D. In our case, the magnitude of hyperopia is outside this norm. But how far outside is it? For context, a cross-sectional study by Mayer et al.⁵ reported that in 99% of 4-year-old children, the average cycloplegic refractive error was below +3.50 D. Given that the hyperopia is high for this child’s age, understanding the emmetropization process can help clinicians decide if/when to prescribe. The Berkeley Infant Biometry Study, a longitudinal study in children between ages 3 months and 7 years, showed that on average, a 3-month old infant has approximately 2.00 D of hyperopia and by 18 months loses about half of it, with most of the emmetropization completed by 1 year of age.¹¹ Additionally, if a 3-month-old has >5.00 D of hyperopia, the chance of emmetropization (reaching +2.00 D) at 2 years reduces to 50% or less. These results suggest that the moderate hyperopia found in our 3.5-year-old is likely to stay. If so, what is the impact on vision and visual function?

Risk of Amblyopia and Strabismus

Previous studies have shown that compared with children with emmetropia (<+1.00 D) between 2.5 and 6 years of age, bilateral hyperopia (≥+4.00 D) is associated with 10 times increased risk of bilateral decreased visual acuity (defined as worse than 20/50 in <4-year-olds),² 5 times increased risk of bilateral amblyopia,¹² and approximately 60 times increased risk of esotropia.³

Clinicians use visual acuity findings to diagnose amblyopia and monitor response with amblyopia treatment. Although visual acuity testing can be challenging in young children, the testability is high when using Lea symbols or HOTV with a matching card. Unlike in adults, 20/20 acuity is not commonly measured in young children. Therefore, knowing population-based normative data on monocular distance acuity in children is important. The Multi-Ethnic Pediatric Eye Disease Study found that the normal distance visual acuity measured with HOTV single letter with crowding bars in 3- to 4-year-old children is 20/50 or better, and 94% children tested in this cohort had 20/40 or better acuity. In the context of this case, the distance acuities meet age expected norms. The ocular alignment is also normal at distance and near.

In patients with uncorrected hyperopia, accommodation has to be constantly engaged to overcome the hyperopic blur, with a greater effort needed at near. Therefore, understanding the impact of uncorrected hyperopia on near visual functions such as near visual acuity, stereopsis, and accommodative accuracy (i.e., lag/lead) can assist clinical decision-making.

Impact of Hyperopia on Near Visual Function and Academic Performance

The Vision in Preschoolers–Hyperopia in Preschoolers study compared near visual functions in 4- to 5-year-old children with emmetropia versus with moderate hyperopia (3.00 to 6.00 D) and found that children with hyperopia had worse mean binocular near acuity (20/32 vs. 20/25), worse stereopsis (120" vs. 40"), and higher lag of accommodation (approximately 0.5 to 1.00 D higher lag) compared with children with emmetropia.¹³ The proportion of children with one or more reduced near visual functions increased with increasing level of hyperopia. They also showed that children with moderate hyperopia scored poorly on early literacy tests compared with children with emmetropia, with the greatest deficits found in the children with hyperopia with reduced near visual function compared with those with normal near visual function.¹⁴ Because these results are from older children and cannot be directly applied to our 3.5-year-old patient, the measured near acuity at best can be described as approaching normal. Although the accommodative lag is normal, stereopsis data are not available and should be tested and monitored at follow-up visits.

The evidence summarized thus far should alert clinicians to the possibility of abnormal visual function, reduced acuity, and esotropia in children with moderate hyperopia. It also begs the question, “Does prescribing glasses prevent deterioration of vision or binocularity?”

Impact of Intervention

Although there is general agreement on the need for intervention in children with hyperopia with esotropia or anisometropia, evidence is less clear about prescribing for moderate hyperopia as prophylaxis. A recent randomized clinical trial that compared immediate correction versus delayed correction of moderate hyperopia (3.00 to 6.00 D) in children 3 to 5 years of age found that immediate correction was no more beneficial than delayed correction in preventing deterioration of visual acuity or binocularity.¹⁵ Although the Vision in Preschoolers–Hyperopia in Preschoolers study found association between moderate hyperopia and early literacy skills in 4- to 5-year-olds, the impact of hyperopic correction on early literacy skills is currently unknown and warrants further investigation. Taken together, these results do not offer convincing evidence to support immediate spectacle correction in our 3.5-year-old patient.

In summary, the principal finding in our 3.5-year-old is bilateral moderate hyperopia. Although this alone is a risk factor for bilateral amblyopia, strabismus, and reduced near visual function, the presenting clinical findings appear to be within age-expected norms. When the benefits of prophylactic treatment are not clear, it is reasonable to monitor these children closely and defer glasses for the time being. Although I choose not to prescribe glasses, I will monitor this patient’s visual acuity, stereopsis, and ocular alignment in 4- to 6-month intervals and advise the caregivers about an earlier return to the clinic should they start noticing esotropia at distance and/or near.