With heavy hearts, Malaysia spent the 100th day anniversary of the disappearance of Malaysian Airline MH 370 in prayers and support for families and friends of the missing passengers and air crews. It also happened to be on this day that the Malaysian Academy of Optometry held its first specialty and advanced contact lens seminar in Kuala Lumpar.
The programme included lectures by Professor Pauline Cho (Hong Kong Polytechnic University), workshops conducted by Dr Stan Isaacs (president of The Singapore Contact Lens Society and of the Society of Orthokeratology), and a panel discussion on the topic of trouble-shooting in orthokeratology (OK).
Myopia studies
Professor Pauline Cho presented an analysis of the Retardation of Myopia In Orthokeratology (ROMIO) study, a randomised longitudinal study on myopic control using OK. The 2012 study had shown that orthokeratology treatment slowed the progression of myopia by about 43 per cent. Another randomised study, High Myopia – Partial Reduction Orthokeratology (HM-PRO) published in 2013, showed slower myopic progression in the OK group by about 63 per cent.
HM-PRO only partially corrected the high myopes in the OK group. Although it was a randomised study, the sample size of the study was relatively small. A randomised clinical trial with a larger sample size is warranted to confirm the effect of partial reduction OK, suggested Cho. The Toric Orthokeratology-Slowing Eyeball Elongation (TO-SEE) study, published in 2013, showed a slower myopic progression rate of 53 per cent in OK-treated eyes.
In recent years, there has been a lot of interest in peripheral (off axis) refraction and how it may be a cause of myopic progression. Results of a just-completed PhD study at HKPU do not appear to support the potential role of peripheral hyperopic defocus in myopic progression. Further studies are currently being planned to investigate the mechanism of myopic retardation in OK. The next to look out for, the Discontinuation of Orthokeratology on Eyeball Elongation (DOEE) study, which aims to investigate the growth of axial length when children undergoing OK treatment stopped wearing the lenses, has just been completed. Data analyses are being conducted and we may expect the results to be out soon.
An interesting point was made in the post-lecture discussion from one audience member who reported that in a study of retinopathy of prematurity in premature babies in a private hospital in Kuala Lumpur, follow up result indicated that most of them suffered from high myopia later on in life.
The myopia theme was further developed by Dr Stan Isaacs who reminded the audience that myopic progression is multi-factorial. We know blur is one major factor and peripheral blur is a major factor as well, as shown by the animal work of Professor Earl Smith.
Professor Cho added that some practitioners take pride in the amount of myopia that they could reduce in their patients. Practitioners are warned to be careful with higher myopic reduction with OK. There is no competition to achieve the highest myopic reduction and practitioners are reminded to keep an eye on the treatment zone and the quality of vision of such patients.
In the lively discussion that ensued, one question from the floor concerned what is the safe age to start OK fitting for children, and what other factors do practitioners consider for appropriate fitting? Isaacs suggested that it depends on the 3 ‘Ms’, that is maturity of the child, maturity of the parents and maturity of the practitioner. The age of the child is not important if the parents are mature, he suggested, and are sensible enough to assist their child and, if the child is co-operative enough, for the mature and well prepared practitioner to do the fitting.
One delegate related that their youngest OK patient was four years old and eight years later, the child is still wearing the OK lenses successfully. ‘I usually spend one hour in the initial consultation talking to the child and parents, explaining the principles of the fitting, maintenance and care, and compliance issues. Parents and children will think ab
out it and discuss between themselves before they confirm whether or not to go ahead.’
Another delegate explained how they used to turn down children under the age of 12 but now believe in early intervention. ‘The immune system of each child must be stable and the child must be quite mature in handling compliance issues’ they added.
Professor Cho continued: ‘When a myopic child is 12 years old, there is not much one can do to slow myopic progression. Our ROMIO study has shown a better effect of myopa retardation in younger children. When 6-7-year-old children become myopic, the progression of myopia is usually very fast and it is therefore important to intervene at an early age.’ Dr Isaacs added: ‘It is good to start a dialogue with the myopic child without the presence of the parents nearby at the beginning of the fitting and then again at each aftercare. It is important for children to establish a trusting relationship with us, their practitioners, so that they will tell us mishaps that they will not tell their parents, for example, chipping their lenses and continuing wearing them for fear of getting a good scolding. Communication with the children is very important, for the practitioner and the parents.’
With regard to this, Cho suggested practitioners need to be careful, as some overly-concerned parents may pressurise their children to continue wearing the lenses overnight even when they are suffering from flu or colds. ‘This should not be happening,’ she went on. It is therefore important for the practitioner to talk to the child alone for a few minutes at each after-care session without the presence of the parents.
? Monica Lau is a practising optometrist based in Malaysia