Saving Vision, Strengthening Resolve

Cindy* is a 15-year-old Caucasian female who, despite using atropine 0.025% nocte, was still progressing on refraction and axial elongation. The atropine concentration was increased to 0.05% and she was referred to our practice for combination treatment with contact lenses.

I don’t want to be the one to tell them… that they should start learning to manoeuvre the world without depending on their eyes

Vision with her monthly disposable contact lenses of prescription R -13.00DS and L -14.00DS was R 6/18, L 6/24.

Subjective refraction gave R -12.50/-2.00×180 (6/15), L -13.00/-2.00×95 (6/15=).

No improvement could be found with pinhole.

Myopic maculopathy was noted.

Axial lengths were R: 28.30, L: 28.46mm.

Contact lens options were discussed.

While Cindy’s level of myopia was too high to be treated with orthokeratology (OK) alone, there is evidence that partial correction will reduce myopic progression,¹ so partial correction with top-up spectacles for the residual prescription was an option. However, being a teenage girl, she was not keen on wearing spectacles, particularly with considerable edge thickness.

Cindy’s prescription was also outside the range available for MiSight contact lenses, which were only available up to -6.00D when she was seen (since then, CooperVision has increased the MiSight parameter range to -10.00, but this is still too weak for her).

With manifest spherical refraction equivalent at R -13.50, L -14.00, vertex corrected to R -11.75, L -12.00, Cindy was just outside the range of extended depth of focus (EDOF) contact lenses. While this technology has been shown to delay myopia progression,² it would have left her astigmatism uncorrected. Spectacles to correct the astigmatism, in combination with EDOF lenses, would be less thick and unsightly than those used in combination with OK, as the prescription would only entail the astigmatism portion of her prescription.

Consideration was also given to centre-distance multifocal soft contact lenses, for which there is evidence of reducing myopia progression. Unfortunately, Cindy falls outside the ‘normal’ disposable range. Even a made-to-order monthly disposable silicone hydrogel contact lens, recently released by CooperVision, did not suit as the spherical power is only available up to -10.00. CooperVision has a made-toorder monthly disposable Proclear toric multifocal, available in spherical powers of up to -20.00D and cylinder powers up to -5.75D, with centre-near and centre-distance additions available up to +4.00D.

Hybrid multifocal lenses (SynergEyes), also available in centre-distance and centre-near, which correct all corneal astigmatism, are available in powers of up to -20.00DS. The problem for Cindy was her -3.50D corneal astigmatism, which is greater than her refractive cylinder, meaning her residual astigmatism would be uncorrected by the rigid back surface of the lens. Presently, there is no option for front surface cylinder correction using SynergEyes lenses.

Hence, Cindy proceeded with soft toric multifocal monthly disposable lenses. She returned reporting that she was managing reasonably with her vision, but she wanted to know if there could be any improvement. Vision with her lenses was R 6/18=, L 6/24=. We discussed hybrid or EDOF contact lenses with spectacles for the residual astigmatism correction again, but Cindy was adamant she would not wear spectacles. She was advised to sit in the front of the classroom and speak to her teachers about her vision.

LIVING WITH PATHOLOGICAL MYOPIA

Queenie,* a 28-year-old Asian female meteorologist, suffers from pathological myopia, and as a consequence has had episodes of foveal choroidal neovascularisation treated with intravitreal anti-VEGF injections. Her mother is a moderate myope and her father emmetropic. She wears rigid gas permeable (RGP) contact lenses intermittently and, although she finds her vision improved, struggles to tolerate them due to comfort. She complained of difficulty seeing fine print and in dim lighting.

Queenie’s subjective refraction was R -14.00/- 0.75×83 (6/38), L -16.50/-1.00×112 (6/12), near addition +1.00DS.

Axial lengths were R 29.94 L 31.33mm.

Examination revealed significant myopic macular degeneration (MMD) and diffuse chorioretinal atrophy with lacquer cracks (Figures 1 and 2).

Bryan* is a 27-year-old Caucasian high school teacher with emmetropic parents. The only myopia in his family is a myopic paternal aunt. Despite being fit and active, playing tennis and basketball, his myopia had rapidly increased in his youth. He was seeking contact lens options as he was struggling with his vision in his conventional soft contact lenses. He had not been able to tolerate RGP contact lenses in the past.

Subjective refraction was R -13.75/-3.00×20 (6/9), L -16.25/-3.50×135 (6/9).

Examination revealed tilted optic nerves and posterior staphyloma in both eyes, MMD L>R diffuse, multifocal chorioretinal atrophy in both eyes, and Foster-Fuch’s spots (Figures 3 and 4). Bryan’s axial lengths were R: 31.62, L: 33.61mm.

Various options were discussed with both patients.

Queenie was not keen on progressive spectacles as she had always struggled to adapt to any spectacles due to her high prescription. Although her vision improved with contact lenses, due to spectacle minification and peripheral distortion with high minus lenses, she struggled to tolerate contact lenses due to dryness.

Bryan, on the other hand, could not tolerate wearing spectacles due to spectacle distortion, and his present contact lenses were resulting in hypoxic changes, i.e. limbal neovascularisation. His corneas were too large and flat for SynergEyes contact lenses, and he was not keen to retry corneal RGP contact lenses, so scleral lenses were prescribed.

Refractive surgery was not an option – both patients were far too high for laser refractive therapy and surgeons are hesitant to operate on such myopic eyes given the risk of retinal detachment. Very few spectacle lens manufacturers can even make their prescriptions.

With Cindy, we were running into dead-ends trying to find myopia control options. With Queenie and Bryan, we were struggling to find options to allow them to see at all.

Regardless of the solutions we came up with, we knew they would be temporary. In reality, the most tragic part of managing patients like these – who are in the prime of their lives – is that because they are so young with such advanced disease, they are ticking time bombs and will only get worse. Reality bites.

MAKING THE MOST OF THE OPTIONS

Managing myopia can, at times, feel a bit repetitive – we have the same lengthy conversations with overbearing parents who demand answers and exact percentages. An exam that could be a quick refraction check and an easy dispense may open a can of worms, turn into a drawn-out consultation, and involve education on myopia and its implications, with detailed discussion on the various options.

When the appointment book is completely full, it can be tempting to avoid these conversations for fear of running behind. A part of me almost misses my early days of practice when OK, with the most robust clinical evidence, was our only option – there were no alternatives to explain.

Yet despite these challenges, I am excited about the options we have today, about the increasing research, and our expanding knowledge as we try to fight this myopic epidemic. Because, as we all know, one size does not fit all, and the young person in your chair is not a figure or a percentage; they are an individual. That means we need to provide what is best for them, and ‘best for them’ is not limited to their ocular factors but also their lifestyle and personality.

HOLD THE HORSES

Patients like Cindy, Queenie and Bryan are a glaring reminder of the ‘why’. At 15, 28 and 27 years of age, they already have myopic maculopathy with reduced vision, and they will go blind – it is not a matter of ‘if ’ but ‘when’.

I don’t want to be the one to tell them they should be choosing occupations where vision is not crucial; that they should start learning to manoeuvre the world without depending on their eyes.

Whenever I see patients like these, I feel deeply saddened for them as I know the end of their story and it’s not happy. Unfortunately, their future is dark.

I saw these three patients in the same fortnight. I know the demographics of my practice may be ‘unique’ but these patients appear to be getting younger and more frequent, and I hope we don’t see the day when they are commonplace.

Some may argue that the ‘horse has already bolted’ for these individuals, however we need to make sure that the horse does not continue any further along its journey. We know that with increasing levels of myopia and axial length, the risk of visual impairment increases –not in a linear relationship but in an exponential one, as shown by Tideman (Figure 5).³

Bullimore also showed that for every dioptre of myopia, an individual has a 67% increased risk of developing myopic macular degeneration.⁴

There is also the misconception that nothing can be done because they are genetically programmed to become this way. Perhaps they were, but these three patients did not have significant family history of myopia, two were Caucasian and from a rural location.

Parents often ask, “How do we know if the myopia management technique we have employed is working?”. Well, we don’t. We can only know when it doesn’t – when their myopia progresses, their axial length increases and when it does we can’t reverse it.

We don’t know which people with hypertension will go on to have complications, such as stroke and heart attacks, but we do know they are at greater risk – so we lower their blood pressure. Will we know if we save their life? We certainly will if we don’t.

*Patients’ names changed for anonymity. 

Jessica Chi is the director of Eyetech Optometrists, an independent speciality contact lens practice in Melbourne. She is the current Victorian, and a past national president of the Cornea and Contact Lens Society, and an invited speaker at meetings throughout Australia and beyond. She is a clinical supervisor at the University of Melbourne, a member of Optometry Victoria Optometric Sector Advisory Group and a Fellow of the Australian College of Optometry, the British Contact Lens Association and the International Academy of Orthokeratology and Myopia Control. 

References 

1. Charm J, Cho P. High myopia–partial reduction ortho-k: a 2-year randomized study. Optom Vis Sci 2013;90:530–9
2. Sankaridurg P, Bakaraju RC, Naduvilath T, et al. Myopia control with novel central and peripheral plus contact lenses and extended depth of focus contact lenses. Two year results from a randomised clinical trial. Ophthalmic Physiol Opt. 2019 Jul;39:294-307
3. Tidermann JWL et al. Association of Axial Length With Risk of Uncorrectable Visual Impairment for Europeans With Myopia. JAMA Ophthalmol. 2016;134(12):1355-1363. 
4. Bullimore MA, Brennan NA. Myopia Control: Why Each Diopter Matters. Optom Vis Sci. 2019 Jun;96(6):463-465. doi: 10.1097/OPX.0000000000001367. PMID: 31116165.