Contact lenses, specifically spherical rigid gas permeable lenses (RGP), have long been considered by many pratitioners to slow the progression of myopia although the research does not support this theory to any great extent.
Soft bifocal type contact lenses have recently shown much promise in slowing myopia.
Orthokeratology lenses (molds) are a specialized type of lens with their own section.Carly Siu Yin Lam, Wing Chun Tang, Dennis Yan-Yin Tse, Ying Yung Tang, Chi Ho To. (2014) Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial. (FULL TEXT) British Journal of Ophthalmology VOL 98 PG 40-45 doi: 10.1136/bjophthalmol-2013-303914
MyopiaPrevention.org comment: This is a double-blind randomised controlled trial on 221 children to test whether a soft contact lens designed with concentric rings of alternating full distance correction with an additional +2.50 power would be able to slow myopia progession. It did, but clinically it appears to be a small amount. The controls progressed .47 diopters per year and the concentric ring subjects progressed .30 diopters per year. While the results are correctly termed "significant", the actual clinical usefullness of the 36% slowing is less clear. It does show promise and other designs may be able to increase the effect.Ticak, Anita; Walline, Jeffrey J.. (2012) Peripheral Optics with Bifocal Soft and Corneal Reshaping Contact Lenses. (FULL TEXT) Optometry and Vision Science Volume 90 - Issue 1 - p 3–8 doi: 10.1097/OPX.0b013e3182781868
MyopiaPrevention.org comment: Proclear Multifocal "D" contact lenses (CooperVision) with a +2.00 diopter add power were compared to CRT orthokeratology lenses (Paragon) for peripheral refractions. A relatively small study of 14 patients. From the conclusions: "The corneal reshaping contact lens shows an increase in relative peripheral myopic refraction, a pattern achieved by other studies, but the bifocal lens does not exhibit such a pattern."
This is another study that shows multifocal soft contact lenses do not create the same pattern of relative peripheral plus on the retina. If, as some studies have shown, soft bifocal lenses slow myopia, there may need to be a better explanation of the effect than creation of peripheral plus, the method most commonly used to explain why orthokeratology slows myopia.Robert Rosén, Bart Jaeken, Anna Lindskoog Petterson, Pablo Artal, Peter Unsbo, Linda Lundström. (2012) Evaluating the peripheral optical effect of multifocal contact lenses. (ABSTRACT) Ophthalmic and Physiological Optics VOL 32 no. 6 PG 527-534 doi 10.1111/j.1475-1313.2012.00937.x
MyopiaPrevention.org comment: Center near bifocal type soft contact lenses are postulated to have a myopia prevention effect due to their creation of a peripheral increase in power, creating a peripheral myopia which then slows myopia progression. This study looked at three lens designs on four patients and found that they did not create very much peripheral plus. It was postulated that any benefit would have to come from lenses with different designs than those tested.Jeffrey J. Walline, Liz McVey. (2011) Myopia Control With a Soft Bifocal Contact Lens. (ABSTRACT) Optometry and Vision Science VOL 88 - Issue 3 pp 395-403 doi: 10.1097/OPX.0b013e31820ca987 (original reference is here: Myopia: Proceedings of the 13th International Conference
MyopiaPrevention.org comment: This is a preliminary report in a poster format for the Bifocal Lens Inhibition of Myopia Progression Study (BLIMP). Although soft bifocals were shown to slow myopic progression, the standard deviations between the control and treatment groups showed a significant overlap in the two groups. The treatment was determined to be "not statistically significant with preliminary data." Although not mentioned in the abstract, it appears from the data that several of the soft bifocal patients actually regressed in their myopia.Padmaja Sankaridurg, Brien Holden, Earl Smith III, Thomas Naduvilath, Xiang Chen, Percy Lazon de la Jara, Aldo Martinez, Judy Kwan, Arthur Ho, Kevin Frick and Jian Ge. (2011) Decrease in Rate of Myopia Progression with a Contact Lens Designed to Reduce Relative Peripheral Hyperopia: One-Year Results. Investigative Ophthalmology & Visual Science Published online before print October 28, 2011. doi: 10.1167/iovs.11-7260 (ABSTRACT)
MyopiaPrevention.org comment: This study of contact lens induced relative peripheral myopia showed a 34% reduction in expected myopic progression compared to control eyes. The result was a -.57D progression with treatment and -.86D progression without treatment.Nicola S. Anstice, John R. Phillips (2011) Effect of Dual-Focus Soft Contact Lens Wear on Axial Myopia Progression in Children (ABSTRACT) pdf download of full text Ophthalmology Volume 118, Issue 6, June 2011, Pages 1152-1161 doi:10.1016/j.ophtha.2010.10.035
MyopiaPrevention.org comment: The Dual-focus Inhibition of Myopia Evaluation in New Zealand (DIMENZ) study. A nice study design with significant results showing that a custom designed multi-focal lens reduces myopic progression in one eye while the control eye wears a single vision lens. When the lenses were reversed, the progression rates reversed so that the two eyes ended up being equally myopic at the end of the study. Only progressing myopes were chosen for the study. Refractive error and axial length progression were reduced by 37% and 49% respectively in the first period.Yue Liu and Christine Wildsoet (2010) The Effect of Two-Zone Concentric Bifocal Spectacle Lenses on Refractive Error Development and Eye Growth in Young Chicks. (ABSTRACT) Investigative Ophthalmology & Visual Science Published online before print September 22, 2010, doi: 10.1167/iovs.10-5716 February 22, 2011 vol. 52 no. 2 1078-1086
MyopiaPrevention.org comment: Multiple lens designs were fit to chicks during their emmetropization phase. Four basic lens types were used: Plus and Minus 5 Diopter centers with plano periphery and Plus and Minus 5 Diopter periphery with plano centers. Each combination had 5 different center diameters. It was found that the peripheral power lenses induced more eye growth and refractive changes than the central power lenses. The +5 Diopter peripheral lens inhibited eye growth which "opens the possibility that appropriately designed concentric lenses may control the progression of human myopia."Blacker, Adam; Mitchell, G Lynn; Bullimore, Mark A.; Long, Bill; Barr, Joseph T.; Dillehay, Sally M.; Bergenske, Peter; Donshik, Peter; Secor, Glenda; Yoakum, John; Chalmers, Robin L. (2009) Myopia Progression During Three Years of Soft Contact Lens Wear. (FULL TEXT) Optom Vis Sci. October 2009 - Volume 86 - Issue 10 - pp 1150-1153 doi:10.1097/OPX.0b013e3181bab365
MyopiaPrevention.org comment: A study to see if soft lens material can affect myopia progression. Lenses that transmit less oxygen and younger patients were both risk factors for progression. The difference between low and high oxygen lenses was .41 D over three years. If children are to wear soft lenses, a high oxygen material is best.JEFFREY J. WALLINE, MARJORIE J. RAH.(2009) Soft Bifocal Contact Lenses for Myopia Progression. (FULL TEXT) Contact Lens Spectrum March 2009 Document 160 Retrieved May 29, 2010
MyopiaPrevention.org comment: A brief review of peripheral hyperopia driving myopic progression and how bifocal soft contact lenses could stop the process.Tarrant, J, Severson, H, Wildsoet, C (2008). Accommodation in emmetropic and myopic young adults wearing bifocal soft contact lenses. (FULL TEXT) Ophthalmic Physiol Opt. 2008 January; 28(1): 62–72.
MyopiaPrevention.org comment: Bifocal soft contact lens patients, both emmetropes and myopes, over-accommodated; in other words had a lead of accommodation instead of a lag of accommodation. If lag of accommodation helps to drive myopic progression, then bifocal soft lenses may be beneficial in slowing the process.Aller TA, Wildsoet C. (2008) Bifocal soft contact lenses as a possible myopia control treatment: a case report involving identical twins. (ABSTRACT) Clin Exp Optom. 91(4): 394-9
MyopiaPrevention.org comment: In a report of two twins with esophoria, myopia progressed rapidly in a 12 year old twin wearing regular soft contact lenses but did not in the twin wearing a soft bifocal contact lens. During the second year of the report, both twins wore soft bifocal contact lenses and neither significantly progressed.Aller TA, Wildsoet CF. (2006). International Myopia Conference, Singapore. Results of a one-year prospective clinical trial (CONTROL) of the use of bifocal soft contact lenses to control myopia progression.(ABSTRACT) (1.0 M pdf download) Ophthalmic Physiol Opt 2006 26 (Suppl.1):8-9 (F003)
MyopiaPrevention.org comment: 78 children ages 8-18 with near esophoria were divided into two groups, one fitted with bifocal soft contact lenses and the other a control of single vision soft lenses. Over a one year period the bifocal lens patients averaged a -.10 increase in myopia while the controls averaged -.75 of change, an 87% reduction of progression the first year. Axial lengths increased by .05 in the treatment group and .24 in the control group. This abstract indicates that bifocal soft lenses were successful in reducing myopia progression, at least for those with a near esophoria for one year.Jeffrey J. Walline, OD, PhD; Lisa A. Jones, PhD; Donald O. Mutti, OD, PhD; Karla Zadnik, OD, PhD, (2004) A Randomized Trial of the Effects of Rigid Contact Lenses on Myopia Progression. (FULL TEXT) Arch Ophthalmol Vol 122, Dec 2004;122:1760-1766
MyopiaPrevention.org comment: Report of the Contact Lens and Myopia Progression (CLAMP) Study. Rigid contact lenses (RGP) reduced myopia progression by .63 D over three years compared to soft lens wearers, but most of the effect was the first year (.40) and could be attributed to corneal changes expected to reverse if the lens treatment stopped. No difference in axial length, a strong indicator of actual myopic progression, was noted between the RGP and soft lens group. The evidence indicates RGP lenses slow myopic progression but the effect was not uniform over time, slowing progression 34% the first year but only averaging 12% per year over the next 2 years. The authors did not feel the effect was strong enough to recommend rigid contact lens wear as a myopia control treatment but the results were worthy of discussion with potential patients.Thomas Aller, David Grisham (2000). Myopia Progression Control Using Bifocal Contact Lenses. Optometry and Visual Science. Vol 77: Issue 12s. Dec. 10, 2000 Poster #92, Annual Meeting of the American Academy of Optometry
MyopiaPrevention.org comment: (No link found) A retrospective study of 84 myopes, ages 9-40 with progressive myopia and esophoria at near were followed for six years with four interventions: Single vision spectacle or single vision soft contact lenses progressed -.50/year; progressive addition spectacles progressed -.37/year; bifocal soft contact lenses progressed -.08/year. Bifocal soft contact lenses were found to effectively halt myopic progression in those with near esophoric findings.