A Vignette in Orthokeratology-Based Myopia Management

Orthokeratology has demonstrated efficacy as a form of myopia management, but many children with myopia and their caretakers are unaware of its existence. Andrew Pucker, OD, of the University of Alabama’s School of Optometry uses a hypothetical case report to highlight the benefits associated with this myopia control technique.

Baseline Visit 

Juniper reported to the clinic with her father following a referral from her primary care optometrist. After taking a brief history and reviewing the notes from her referring doctor, you learn that Juniper is a 9-year-old girl who received her first pair of glasses when she was 7-years-old. Both of her parents are myopic and established contact lens (CL) wearers. You learn that Juniper is an avid reader and an active participant on the swim team. You perform a myopia management evaluation, and obtain the values noted in Table 1. These values will help with both treatment selection and judging myopia progression.

After considering the Table 1 data and your patient’s lifestyle, you suggest orthokeratology as your treatment of choice. The family, like many others, was not aware of this technology until visiting your office.¹ You educate them, explaining that orthokeratology is a rigid CL worn while a patient sleeps. You inform them that it works by reshaping their cornea, and once they have adapted to the treatment, they can go without vision correction while awake.² You mention that orthokeratology is a great choice because Juniper is less myopic than than the maximum FDA approved limit (-5.00 D or -6.00 D sphere and -1.75 D or -1.50 D cylinder depending upon the product). It is also an excellent choice for patients who are avid swimmers because CLs should never be worn in the water. You provide evidence-based examples, citing 2 studies showing how patients who were treated with orthokeratology had a 54% reduction in axial length during the study period compared with spectacle wearers, and how patients who were treated with orthokeratology had a 55% reduction in axial length progression compared with those treated with soft CLs.^{3, 4} 

After discussing all other potential treatment options, the family agrees to move forward with orthokeratology. You provide Juniper with educational materials explaining how to wear hard CLs. You schedule her for a 2-week follow up and empirically order a pair of orthokeratology lenses based on her refractive error, horizontal visible iris diameter (HVID), and keratometry values (Table 2). Refraction and keratometry values are needed to determine the base curve, which is primarily responsible for negating a patient’s refractive error. The laboratory will start with the patient’s keratometry values and select a flatter base curve by adding the refractive error plus an additional amount called the Jessen factor, which is typically about 0.75 D.^{2, 5} The Jessen factor accounts for refractive error regression that occurs during the day. It is also needed because there is no strict one-to-one ratio between corneal flattening and diopters of change. HVID is an important measurement because it can help with selecting the lens diameter. It is best to obtain HVID measurements with a topographer rather than a ruler because topographer-based values are more accurate. It is also best to color code each CL since the CLs can easily be mixed up by the patient. One common approach is to color the right lens green because there is a “R” in both “right” and “green.” Likewise, it is preferable to color the left lens blue due to the “L” in both “left” and “blue.” Different color patterns may be used, but it is advisable to have a rationale behind the chosen colors. While colored CLs may initially concern the patient, it is best to remind them that they are typically worn only while sleeping. 

CL Dispense Visit

Juniper reports for her dispense visit. You learn during your brief history that she watched multiple online videos related to orthokeratology lens wear, and are optimistic that training is going to go well. You then perform entrance testing, which includes visual acuity and slit-lamp evaluation, and verify that everything is still normal. You then apply proparacaine to Juniper’s eyes after explaining that the drops will temporarily numb her eyes and improve her initial CL experience. You then apply both CLs, and evaluate them with sodium fluorescein and a Wratten 12 filter. This makes it much easier to discern the sodium fluorescein pattern. Your evaluation determines that each CL has a standard bull’s eye pattern with a 4 mm wide central treatment zone, 2 mm wide return zone, 1 mm wide landing zone, and a 0.5 mm peripheral edge (Figure 1). The central treatment zone and landing zone lack  sodium fluorescein staining, giving a bull’s eye appearance. Sodium fluorescein/tears are still present in these regions, but the tear layer in these zones is too thin for fluorescence to occur. 

Next, you take Juniper to your CL training area and review important habits such as handwashing and cleaning the CLs each day. You remind her that whenever the CLs become dirty during training, she should clean them. This could be facilitated by prescribing a multi-purpose rigid CL care system rather than a hydrogen peroxide-based care system. Parents can help with orthokeratology training since application and removal is typically done at home, but it is best if the patient can accomplish this task on their own. After some coaching, Juniper is able to apply and remove her own CLs. You offer her a small plunger and explain that she can use it if she has trouble removing the lenses. You review the removal technique explaining that the plunger must be applied at the CL edge to avoid excessive suction, which may cause corneal irritation. After successfully completing training, you schedule Juniper for the following morning to address any concerns she may have after the first night of wear. You also want to determine whether Juniper can benefit from soft CLs to correct her residual refractive error. You tell Juniper not to wear her CLs into the office. However, this guidance can vary according to prescribed orthokeratology design. 

First Morning Visit   

Juniper reported for her initial follow-up the next morning and indicated that application and removal went well. She reported that she was able to comfortably wear her CLs while she slept for 9 hours and that her uncorrected vision has improved since yesterday. You then proceed with your evaluation which includes topography, visual acuity, refraction, and a slit-lamp exam (Table 3).

Juniper’s CLs appear centered on topography with the treatment zone starting to form (Figure 2). Her right eye refractive error was reduced by about 60%, which is to be expected for children.¹ However, her left eye refractive error experienced less improvement than expected. While this may indicate the necessity of a CL remake, parameter changes are typically not made until after 7 to 10 days of CL wear— after all, orthokeratology CLs take time to settle in and reshape the cornea. You fit Juniper with daily disposable CLs to correct her residual refractive error, and give her a supply to cycle through until she no longer needs them during the day. Since she seems to be doing well overall, you reinforce CL care and compliance and schedule her for a 1-week follow up visit.  

1-Week Visit 

Juniper reported to her 1-week follow up visit at the end of the day and indicated that everything related to her CLs was going great. She reported consistently wearing her CLs for at least 8 hours each night and that her end of day vision was good. Consistent wear is critical for a good treatment effect, especially while patients are initially adapting to it. Nevertheless, it is not uncommon for patients to intermittently wear their CLs after adapting.⁶ You then proceed to perform a work up similar to the first morning visit (Table 4).

After evaluating her topography images (Figure 4), you determine that a good treatment ring is forming with slight decentration. Since Juniper showed a nearly emmetropic refractive error and was happy with her vision, you determine that no treatment changes are needed at this time and schedule her for a 1-month follow-up visit. 

1-Month Visit 

Juniper reported for her 1-month visit indicating that she did not wish to change anything about her CLs or vision. You repeat your orthokeratology work up, obtaining similar numbers to the 1-week visit. Topography indicates an intensification of the treatment rings, and CL centration has improved slightly (Figure 4). Since Juniper is satisfied with her treatment and assessments reveal an excellent CL fit, you decide to finalize her CL fit and schedule her for a 6-month myopia management evaluation. You also send her a backup pair of CLs, which you worked into your fee schedule in case Juniper breaks or loses one of her CLs. 

1-Year Visit 

Juniper reports to the clinic after undergoing orthokeratology treatment for 1-year. Unfortunately, she missed her 6-month visit because of scheduling challenges. She has no CL-related complaints and is interested in continuing orthokeratology. You complete your standard myopia management work up and compare her 1-year values with her baseline visit (Table 5).

While a refractive error change can be helpful in determining the need for orthokeratology CL parameter changes, it does not indicate myopia progression or axial length changes. If your clinic lacks the ability to obtain axial length measurements, it is acceptable to use residual refractive error as an indicator of myopia progression. Juniper has only progressed about 0.1 mm in each eye after 1 year of treatment, which is consistent with axial length progression in eyes with emmetropia.⁷  Juniper is now 10-years-old and a clinician could expect her axial length to grow 0.25 mm untreated.⁸ You inform Juniper that she appears to be having a good myopia management treatment effect and schedule her for a 6-month follow-up visit.  

References 

1. Ren Q, Yang B, Liu L, Cho P. Orthokeratology in adults and factors affecting success: study design and preliminary results. Cont Lens Anterior Eye. 2020;43(6):595-601. doi:10.1016/j.clae.2020.03.016

2. Lipson M. Contemporary Orthokeratology. Bausch Health; 2019.

3. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005;30(1):71-80. doi:10.1080/02713680590907256

4. Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009;93(9):1181-1185. doi:10.1136/bjo.2008.151365

5. He Y, Liu L, Vincent SJ. Compression Factor and Visual Performance in Adults Treated With Orthokeratology. Eye Contact Lens. 2021;47(7):413-419. doi:10.1097/ICL.0000000000000796

6. Santolaria E, Cervino A, Queiros A, Brautaset R, Gonzalez-Meijome JM. Subjective satisfaction in long-term orthokeratology patients. Eye Contact Lens. 2013;39(6):388-393. doi:10.1097/ICL.0b013e3182a27777

7. Chamberlain P, Lazon de la Jara P, Arumugam B, Bullimore MA. Axial length targets for myopia control. Ophthalmic Physiol Opt. 2021;41(3):523-531. doi:10.1111/opo.12812

8. Nixon A, Brennan N A. Managing Myopia: A Clinical Response to the Growing Epidemic. Johnson & Johnson Vision. https://www.jnjvisionpro.com/education-center/resource-library/managing-myopia-clinical-response-growing-epidemic. Updated April 13, 2021. Accessed February 15, 2022.