As another year comes to an end, five members of Ophthalmology Times Europe’s Editorial Advisory Board reflect and share their perspectives on the exciting opportunities that lie ahead for ophthalmologists in 2018, whilst also considering the potential challenges.
Thoughts on glaucoma
Dr Hollo: In the field of glaucoma clinical research and practice, considerable development has been seen in several areas in 2017. In terms of diagnostics and research, optical coherence tomography (OCT) angiography is one such area, and there has also been progression in the understanding of the role of the Bruch membrane opening in optic nerve head OCT imaging.
With regards to surgical treatment, substantial new information has become available on an ab interno implantable microstent for glaucoma filtration surgery, while the popularity of using completely preservative-free topical glaucoma medication, including fixed combinations, has surged. We also see some new molecules in the Rho kinase inhibitor family moving closer to clinical application.
However, when it comes to patient referrals, European research has revealed that using an intraocular pressure (IOP) reading of between 21 and 25 mmHg as a sole criterion for referral to a glaucoma specialist may increase the number of false positive referrals and does not increase the detection of true glaucoma cases.
Although this situation has no direct influence on clinical practice in the upcoming year, I hope that a better or more established referral system will be rolled out in the future, as this will make glaucoma clinics more efficient, allow ophthalmologists to spend more time with those patients who really need it and prevent incorrect glaucoma diagnoses and the negative effect this has on patients.
Dr Augustin: Traditional glaucoma surgery has a significant lowering effect on IOP. However, this approach is not necessary in all patients and leaves patients at risk from several complications that are difficult to manage.
A less traumatic option is micro-invasive glaucoma surgery (MIGS), which is gaining in popularity. This technique uses different devices, allowing the complications seen with traditional techniques to be avoided and giving surgeons the opportunity to reduce IOP more easily and safely.
However, both techniques have advantages and disadvantages, and the major challenge in 2018 will be the decision-making process involved in choosing either MIGS or conventional surgery as the best treatment for the specific patient.
Thoughts on optical coherence tomography angiography (OCTA)
Dr Augustin: Optical coherence tomography angiography (OCTA) is fast becoming an essential tool in the evaluation of retinal diseases. It removes the need to use a dye and provides immediate visualisation of the retinal and choroidal vascular bed. It also helps to visualise the superficial, deep and choroidal vascular network simultaneously. Therefore, by combining dynamic and morphology data the ‘road’ to the diagnosis becomes less complicated.
However, image artifacts, which are common in OCTA and can lead to incorrect interpretations of images, need special attention and require further evaluation. Having a standardised way of evaluating OCTA and a clear listing of all kinds of artifacts to avoid misinterpretation of the results would be helpful.
Dr Hollo: OCTA in the macula area and in the peripapillary region has repeatedly been shown to have good diagnostic accuracy in glaucoma detection. In addition, a case series showed that very significant IOP reduction (at least a 50% reduction to 18 mmHg or less) in high-pressure open-angle glaucoma and ocular hypertension may lead to considerable recovery of the decreased peripapillary circulation.
Another report presented a glaucoma case in which progressive deterioration of the visual field and thinning of the retinal nerve fibre layer was accompanied by progressive reduction of peripapillary perfusion with OCTA.
Thus, OCTA may potentially be applicable in the follow-up of glaucoma patients. Prospective studies addressing this area, however, are not yet available. I hope that the first studies investigating the role of OCT angiography in the detection of glaucomatous progression will be available in 2018.
Thoughts on optical coherence tomography (OCT)
Dr Augustin: The eye is a window to the brain. The relationship between neurodegenerative diseases and ocular structures such as the optic nerve and retina is well established for many disease entities, such as multiple sclerosis (MS).
Optical coherence tomography (OCT) provides an important tool to accurately analyse modifications in the eye that have been induced by inflammation and neurodegeneration. Using the new OCT software platforms we can evaluate every single retinal layer and, above all, ganglion cells layer.
Taking MS as an example, several studies have demonstrated the correlations between GCL and clinical disability in this disease. The value of OCT is currently evaluated in many neurological diseases for both diagnosis and follow-up. The major challenge will therefore be the establishment of a network between neurologists, specialists in internal medicine and ophthalmologists.
Dr Kermani: Cataract and refractive imaging platforms based on swept-source OCT will increase confidence in the measurements, since this technology enables you to actually see what you measure and measure what you see. In 2018 we can expect IOL biometry (including axial length measurement), corneal topography/tomography, anterior segment biometry and anterior segment imaging to be combined in one instrument.
Productivity is one of the central challenges in today’s cataract and refractive world. An important characteristic of the new platforms is the fact that all measurements and analysis are based on high-resolution diagnostic images. This mitigates the effects of confounding factors such as coexisting abnormalities, which often cannot unambiguously be identified without diagnostic imaging.
Processing the ray tracing algorithm with valid patient data is also near to hand. I am sure this will lift us to an even higher level of predictability and success. Such technology should be available in 2018.
Thoughts on cataract & refractive surgery
Dr Kermani: Quality and safety in cataract and refractive surgery is better today than ever before. Femtosecond laser-assisted cataract surgery (FLACS) and premium IOLs are my gold standard now. Usually, I can perform what I have promised to my patients and this is a real game changer. However, the number of patients is significantly increasing and so the main challenge ahead, beside consolidation of results, is improving the perioperative set-up at all levels.
With challenges come opportunities and some of the new therapeutic technologies that have recently been introduced promise to revolutionise surgery. For example, the company Avedro, which develops corneal crosslinking (CXL) products, has developed the ‘Mosaic’ technology, which offers both customised remodeled vision (CuRV) and photorefractive intrastromal crosslinking (PiXL).
CuRV is a procedure that allows advanced cross-linking options to be offered to keratoconus patients. This treatment is customised to a patient’s specific corneal topography. Clinical studies have demonstrated that the CuRV procedure can result in greater flattening of K-max, improved corneal regularisation and reduced epithelial healing responses, compared with standard CXL.
The PiXL procedure applies cross linking to a selective part of the cornea to flatten the cornea. It results in the cornea being reshaped, thus having the potential to provide non-invasive vision improvement.
Dr Fazio: In my practice, I have only had two ectasia cases: one after LASIK and the other after photorefractive keratectomy (PRK). Each patient was around 30-years-old and neither was showing an abnormal topography; the amount of refractive error was in the mid-range. In my eyes, it is evident that the Randlemann rule is largely inadequate to protect patient and surgeons from late complications after refractive excimer treatments.
Tomography software claims to give useful clues. Lately, the Corvis instrument (Oculus) has been proposed as a means to analyse corneal biomechanics in order to rule out patients at risk of ectasia. We are in need of strongly validated ways to decide if a patient is truly a good candidate for LASIK or PRK.
There are also challenges with toric IOLs. Since the advent of toric IOLs, astigmatic correction of the refractive error after lens replacement has seemed possible. However, even though they are a very powerful means of correcting astigmatism, a certain degree of disappointment still weighs on the procedure.
Despite the eventual acknowledgement of the role of the posterior corneal curvature on the amount of corneal astigmatism, the goal of a consistent precise astigmatism correction remains elusive.
There are three reasons for this: firstly, unlike optical or laser correction of refractive error, which relies on a subjective test or precise wavefront analysis, astigmatic correction via toric IOLs rely on shape analysis of the cornea and effective lens position in terms of antero-posterior shift as well as centration. Believe it or not, shape analysis of the central anterior and posterior cornea is still an art to refine.
Secondly, even if the surgeon has determined axis and amount of toric correction, perfect alignment of the lens is a far from easy. And techniques using automated surface recognition or even intraoperative wavefront analysis seem to offer no more precision than manual techniques.
Finally, toric IOLs occasionally exhibit a tendency to rotate. I personally believe that anterior capsule fixation, instead of capsular fornix fixation, is worth exploring in order to ensure better IOL stability and centration.
Another challenge in 2018 and in the years to come is achieving emmetropia in 100% of postoperative cases. Both with laser vision correction and refractive or cataract lens exchange, this is often achieved. However, something is missing in our anatomical analysis of the eye.
Moreover, effective lens position, that is to say, where exactly your artificial lens will decide to sit into the eye of your patient, is still guess work. The impact strategy of our excimer laser has yet to be improved.
In a setting of premium surgery, 0.50D of emmetropia is considered a failure. The challenge is to reduce such a small error to zero, every time.
Dr Alio: Multifocal trifocal IOLs have shown excellent results, becoming the gold standard for the majority of patients receiving a multifocal lens after refractive lens exchange (RLE) or cataract surgery, due to its better defocus curve for intermediate vision (nowadays critical) and greater tolerance.
It is now a common treatment option for all hyperopic patients of >45-years-old who ask for refractive surgery. Knowing this, is it coherent to perform LASIK in a 40-year-old patient with +6D of sphere considering that this option will preclude him from receiving multifocal lenses in the future? Many surgeons decide to wait until presbyopia appears in those patients before performing an RLE, but does it make sense to wait?
On the other hand, where should we place the cut-off age limit? With the current performance of new multifocal lenses, this age limit will probably change, although we still do not know what adverse events might appear with such lenses in the very long term (for example, 30 years’ time). We might see glistening and opacification, for example.
Age limits for multifocal lenses probably need to be redefined today, although not forgetting the expected long survival of these lenses in such young patients.
Meanwhile, many extended depth-of-focus (EDOF) lenses are currently being launched. These lenses offer the theoretical advantage of reduced adverse visual symptoms compared with the usual diffractive lenses. However, we will have to define where such EDOF lenses fit in our clinical practice and be sure on their supposed advantages (it has been reported with some models that they can still induce significant halos and equivalent visual symptoms). Their safety and efficacy for post-refractive surgery patients (either myopic or hyperopic) still needs to be properly defined.
Thoughts on corneal disease
Dr Augustin: In recent years, developments in corneal surgery have increasingly been directed towards lamellar keratoplasty instead of penetrating surgery, especially for diseases involving the endothelium of the cornea.
Nowadays, Descemet membrane endothelial keratoplasty (DMEK) enables surgeons to transplant just a part of the corneal tissue (the Descement membrane and endothelium), which is proving to offer better postoperative visual acuity and also reduces the risk of graft rejection.
DMEK enables patients’ vision to recover more quickly after surgery and, therefore, patient satisfaction has grown, while surgeons have access to a fast, effective option. Thus, this type of surgery has been revolutionary for both surgeons and patients.
A further improvement might come from the opportunity to have pre-cut donor flaps. However, this technique is not easy to learn. In addition, tissue preparation requirements mean that new facilities will be needed.
Dr Kermani: Dry eye is a real problem in refractive and premium cataract surgery. It needs to be seriously addressed. Today there are many ways to do so and we are building up the armamentarium both in diagnostics and therapy. We are not letting dry eyes spoil our surgical results. We will fight back and we will prevail.
Thoughts on management of presbyopia
Dr Alio: Surgical management of presbyopia is both innovative and challenging and is constantly being renewed. However, there are many factors in the development of presbyopia, making it difficult to adequately manage it.
Most surgical techniques that have been proposed for the surgical correction of this age-related disease are based on the acquirement of pseudoaccommodation. Accommodative intraocular lenses would be the ideal solution for presbyopia, having the power to resolve the inconvenience of the disease and the side effects produced by current surgical options.
However, despite many attempts to restore accommodation via the use of IOLs, none of the lenses have demonstrated sufficient long-term efficacy, even though they initially created a stir in the scientific community. Some new models and ideas are arriving and we should pay attention to their first clinical results, but we should do so carefully to avoid repeating the same mistakes of the past.
Dr Fazio: Presbyopia will probably remain the number one ophthalmic challenge in the refractive area for many years to come. These days the debate is about the new category of extended-depth-of-focus (EDOF) IOLs.
These lenses claim to make it possible for patients to have a continuous or almost continuous range of focus, from far to intermediate, without (or almost without) visual disturbances. Lenses competing in the increasingly crowded EDOF market include Symfony (Technis), Lara (Zeiss) and the Mini WELL IOL (SIFI Medtech).
With these lenses, worse near correction is traded for better far vision. But the question remains: how much worse does the near vision become and how big are the improvements to far vision?
If these lenses could really compete shoulder to shoulder with a standard aspheric lens in order of far quality of vision, that would be really good. However, since even an EDOF IOL manipulates the incoming light, a certain amount of visual disturbance is to be taken into account.
Thoughts on small-incision lenticule extraction (SMILE)
Dr Alio: Treatment of hyperopia remains challenging for refractive surgeons. Hyperopic small-incision lenticule extraction (SMILE) performed using a proprietary femtosecond laser has recently been proposed and developed as a new treatment option. Clinical data from the first clinical trials are now being reported, bringing the technique closer to the clinic.
However, although encouraging results have been seen and will likely lead to a change in hyperopia management in the near future, there are still some important concerns, such as central haze, that need to be addressed. Further light might be shed on this in the coming year, as long-term outcomes and regression rate data become available.
Dr Alio: There are still some concerns regarding the available surgical options for SMILE enhancements. Important evidence has recently been published regarding the efficacy and safety of photorefractive keratectomy (PRK) after SMILE.
Visual recovery takes a little longer with SMILE (sometimes longer than acceptable) than with LASIK, and to convert into LASIK by opening the interface is not always feasible. We should be aware of future SMILE improvements such as cyclotorsion control to improve astigmatic outcomes; reSMILE standardisation to improve enhancement outcomes; and software optimisations to reduce the tissue comsumption per diopter.
Dr Fazio: SMILE is a relatively new treatment that has been proposed as a means to overcome the troubles encountered with the old and trusty LASIK and PRK. But will it be able to honour this promise?
SMILE has its limitations, including a slower recovery time compared with LASIK; difficult hyperopia treatment; and complications such as retained lenticule fragments. Moreover, it is not an open technique; it is a machine-linked procedure requiring the surgeon to use a femtosecond laser system (for example, Zeiss’ Visumax) if he or she wants to embrace the philosophy within.
Since there is not yet a validated way to analyse the biomechanical impact of a SMILE procedure compared with a PRK- or LASIK-guided procedure, the jury is still out. It is true that corneal analysis by the Corvis ST (Oculus) reveals a lesser impact of SMILE on the stiffness of the cornea but it is not yet clear if Corvis ST’s results can powerfully predict eventual ectasia.
One more thing...
Dr Kermani: An ongoing challenge is knowing when to take a break! I am not a workaholic but I recognise that I have to take care not to burn out by the enthusiasm I have of my work.
Every now and then I have to reflect on my work-life balance. In Germany, they say “you live to work” and in France they say “you work to live”. I want to do both with the same passion and attention. This is my personal challenge for 2018.