December 15, 2021
By Andrew D. Pucker, OD, PhD, FAAO
Attracting adult orthokeratology patients simply starts by making them aware of this technology. Orthokeratology can be an excellent option for patients who want daytime freedom from vision correction devices.
Overnight orthokeratology is the practice of using reverse-geometry, rigid contact lenses for the temporary correction of refractive error.1 This fitting philosophy allows patients to avoid wearing correction during the day after adaption. With orthokeratology becoming one of the standards of care in the myopia management realm for children who have progressive myopia,2-4 many practitioners are starting to lose sight of orthokeratology’s official indication, which is the correction of myopic refractive error for patients of any age. Here are some of the benefits along with some of the considerations that one should take when fitting adults with orthokeratology.
While not all patients can adapt to orthokeratology, studies typically find that about 80% of patients who are treated with orthokeratology are successful.5,6 After one night’s worth of treatment, one study found that about 35% of refractive error is neutralized, which is slightly slower than in children; this difference is likely because an adult’s corneas are less malleable than a child’s.7 If a patient has a first lens fitting success, most of the visual and refractive error changes will occur within the first week, with the remainder of the effects occurring within the first month of lens wear.1,7 First lens fitting success has been determined to occur in about 80% of patients.6,7 With the widespread availability of toric lenses and the high prevalence of corneal astigmatism, fitting success may be further promoted by starting with a toric orthokeratology lens when limbus-to-limbus astigmatism is present, especially if there is a difference in corneal elevation that is greater than 30 μm between the principal meridians.8
Fitting Indications and Considerations
On-label orthokeratology prescribing is typically for patients who have -6.00D of myopia or better and less than 1.75D of astigmatism. While some prescribers may go outside of these ranges, manufactures discourage it, and they may not provide a warranty for these lenses. Orthokeratology fitting regimens overcorrect patients by different compression factors (Jessen Factors) since the treatment is known to regress over the course of the day.9 Different compression factors have been tested to determine if higher compression factors (+1.75D) provide better vision than the typical compression factors (+0.75D), but studies have found limited between-group differences in vision.7,10 Although patients should be instructed to wear their lenses every night for a full night’s sleep (~8 hours) to obtain best treatment outcomes, one study found that 59% of patients skip at least one night of lens wear each week.11 The authors found that the patients who occasionally skip lens wear for a night still had adequate vision, though the treatment effect was lessened, and patients with higher levels of myopia had greater negative visual consequences.11
While orthokeratology is primarily used to reduce myopic refractive error, it can also be used to troubleshoot complicated cases. One case report describes using orthokeratology for treating a patient with symptomatic aniseikonia (between eye-image size differences) with the author reporting resolution of his visual symptoms post-orthokeratology treatment.12 A recent three-month clinical study likewise found that when symptomatic soft contact lens wearers who were on the verge of dropping out of contact lenses were refit into orthokeratology, 72.5% of the patients could be successfully refit into the modality, with the patients also having a significant improvement in their ocular symptoms.6 This symptoms’ improvement likely resulted from not wearing a contact lens during the day and from orthokeratology itself decreasing corneal sensitivity.6,13
Multiple reports have found that orthokeratology-treated patients had better Refractive Error Quality of Life Instrument-42 questionnaire scores than patients who were treated with spectacles or soft contact lenses.14,15 Nevertheless, orthokeratology-treated patients do report worse glare.7,14,15 Many of the visual issues associated with orthokeratology can be attributed to higher-order aberrations secondary to corneal reshaping.5,16 While this side effect frequently occurs early in the treatment regimen, especially while driving at night, patients are generally accepting of glare if they are properly educated; this side effect lessens as the corneal surface evens out.17 Nevertheless, a recent investigation determined that these visual side effects typically subside over the first year of treatment, possibly because of neural adaption. Yet, patients with higher refractive errors may take longer to adapt.11 A recent clinical study found that neophyte orthokeratology patients can quickly learn to apply and remove their lenses within the first week with each act frequently being performed within five minutes.17 This same study found that these patients had high visual satisfaction, good comfort, no issues with sleeping, and good initial impressions of orthokeratology.17
Binocular Vision Considerations
It is well known that myopes converge more when wearing soft contact lenses compared to being corrected at the spectacle plane.18 Therefore, it has been long suspected that orthokeratology treatment may worsen binocular vision disorders. While in theory, binocular vision may change post-orthokeratology treatment, well-conducted studies have in general not found orthokeratology to have an impact on the adult accommodative system.18-20
Attracting adult orthokeratology patients simply starts by making them aware of this technology.7 This lack of orthokeratology awareness is highlighted by one study finding that 36% of the included adult patients had not been informed about the modality until they learned about the investigation.17 Orthokeratology can be an excellent option for patients who want daytime freedom from vision correction devices. This treatment may be particularly appealing to patients who have demanding jobs, participate in active sports, or who have dry eye disease. While the overall fitting process is similar to fitting children, adults tend to have greater visual demands, making adults more aware of the minor visual side effects associated with orthokeratology. If glare is an issue for adult patients, practitioners can help reduce glare by increasing the optic zone of the lens. This change is thought to help because it may even out the corneal treatment zone. Nevertheless, when patients are properly educated, they frequently do very well with this treatment.17
|Andrew D. Pucker, OD, PhD, FAAO, is an Assistant Professor and the Director of Clinical Research and Myopia Control at the University of Alabama at Birmingham. He earned his OD, MS, and PhD degrees from The Ohio State University. This article is sponsored by Euclid.|
- Nichols JJ, Marsich MM, Nguyen M, Barr JT, Bullimore MA. Overnight orthokeratology. Optom Vis Sci 2000;77:252-259.
- Walline JJ. Myopia Control: A Review. Eye Contact Lens 2016;42:3-8.
- Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol 2009;93:1181-1185.
- 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;30:71-80.
- Hiraoka T, Okamoto C, Ishii Y, et al. Patient satisfaction and clinical outcomes after overnight orthokeratology. Optom Vis Sci 2009;86:875-882.
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- Tomiyama ES, Logan AK, Richdale K. Corneal Elevation, Power, and Astigmatism to Assess Toric Orthokeratology Lenses in Moderate-to-High Astigmats. Eye Contact Lens 2021;47:86-90.
- Chan B, Cho P, Mountford J. The validity of the Jessen formula in overnight orthokeratology: a retrospective study. Ophthalmic Physiol Opt 2008;28:265-268.
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- Santolaria E, Cervino A, Queiros A, Brautaset R, Gonzalez-Meijome JM. Subjective satisfaction in long-term orthokeratology patients. Eye Contact Lens 2013;39:388-393.
- Kwan SCK, Khuu SK, Kang P. Changes in aniseikonia of an axial anisometrope at various stages of orthokeratology lens wear. Cont Lens Anterior Eye 2020;43:60-64.
- Hiraoka T, Kaji Y, Okamoto F, Oshika T. Corneal sensation after overnight orthokeratology. Cornea 2009;28:891-895.
- Berntsen DA, Mitchell GL, Barr JT. The effect of overnight contact lens corneal reshaping on refractive error-specific quality of life. Optom Vis Sci 2006;83:354-359.
- Queiros A, Villa-Collar C, Gutierrez AR, Jorge J, Gonzalez-Meijome JM. Quality of life of myopic subjects with different methods of visual correction using the NEI RQL-42 questionnaire. Eye Contact Lens 2012;38:116-121.
- Chang CF, Cheng HC. Effect of Orthokeratology Lens on Contrast Sensitivity Function and High-Order Aberrations in Children and Adults. Eye Contact Lens 2020;46:375-380.
- Duong K, Pucker AD, McGwin G, Jr., Franklin QX, Cox J. Established soft contact lens wearers’ awareness of and initial experiences with orthokeratology. Ophthalmic Physiol Opt 2021;41:673-682.
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- Kang P, Watt K, Chau T, Zhu J, Evans BJW, Swarbrick H. The impact of orthokeratology lens wear on binocular vision and accommodation: A short-term prospective study. Cont Lens Anterior Eye 2018;41:501-506.
- Gann D, Nichols DD. 2020 Report on Dry Eye Diseases. Contact Lens Spectrum. July 2020.