Highlights for Young Ophthalmologists from the 18th EURETINA Congress
This past month YOURS, the committee of Young Ophthalmologists, attended the annual congress of the European Society of Retina Specialists (EURETINA), internationally renowned as the largest retina meeting worldwide. Here are a few particular highlights of the congress which spoke to the issues and focus points for our demographic.
Rita Serra from Eric Souied’s group reported on the long-term evolution of treatment-naïve quiescent choroidal neovascularization (CNV) in intermediate age-related macular degeneration (iAMD).
The study was conducted as a retrospective series of 68 eyes of 68 patients with iAMD with a mean follow-up time of 40 ± 28 months in which multimodal imaging was performed. In addition to fluorescein and indocyanine green angiography and optical coherence tomography (OCT) imaging, OCT angiography (OCTA) images where evaluated where available.
At the last follow-up, 24 of 57 eyes (11 had to be excluded because of poor image quality) converted to exudative AMD, whereas 33 eyes did not develop signs of exudation. With these findings, the authors conclude that in their study, there was a high risk of conversion from iAMD to late exudative AMD.
They discussed that a prevention treatment may be hypothesized, as an early treatment of the lesion before the appearance of exudation signs could be important to preserve as much vision as possible. However, the authors also discussed that preventive treatment of a quiescent CNV is currently not recommended.
X-linked retinitis pigmentosa (RP) is most commonly caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene. With the dawn of clinically applicable gene therapy for hereditary retinal dystrophies, RP caused by this gene is of high interest as a candidate for human gene therapy. Professor Robert MacLaren, principal investigator from the University Eye Hospital in Oxford, presented the results of the XIRIUS study on gene therapy for RPGR-associated RP.
The XIRIUS study is a phase 1/2 open label, single eye dose ranging and escalation study on gene therapy for RPGR-associated RP, using adeno-associated viral vector subretinal gene delivery via a vitrectomy approach.
The study involved 6 cohorts of 3 patients in each cohort, and had a follow-up time of up to 12 months. The study was encouraging, as treatment was shown not only to be well-tolerated, but also showed significant increases in retinal sensitivity on microperimetry in a number of patients. Several patients also reported clear subjective visual field improvements. In some patients in the high-dose cohorts, mild subretinal inflammation was observed that was successfully treated with steroids, but no dose-limiting toxicities or severe treatment-associated adverse events were seen.
These encouraging results have resulted in the planning of the XIRIUS expansion study that will follow at the end of this year, including a group of 30 additional adult and also paediatric patients. In the meantime, the XOLARIS prospective study on the natural history of RPGR-associated RP is performed in a multicentre setting. This study aims to better delineate the anatomical and functional characteristics of the disease.
Kim Drenser Scleral Buckling (SB) is no longer relevant
Dr. Drenser opened up with gory pictures of what she called medieval surgery and argued that SB leads to gross distortion of the eye ball, can cause strabismus (e.g. due to fibrosis or when an oblique muscle is directly affected by a buckle). Additionally, buckles can lead to extrusion of the implant, to infections, ischemia and perforations (which are difficult to control as there is no infusion line to handle the hypotony). An annoying adverse effect can be retained subretinal fluid even after successful SB surgery. Gravity tends to pull the subretinal fluid inferiorly and towards the center of the posterior pole, where it can lead to longstanding distortions in vision. Functionally, the posterior pole is the most important part of the eye and a SB addresses this most important part only indirectly. So, if additional retinal problems exist (which are not always apparent before starting the surgery (e.g. full thickness macula holes or additional breaks), they can elegantly be addressed during vitrectomy, but not during SB surgery. Dr. Drenser then changes gears and explains the evolution of technological advances in vitrectomy instruments and technique, while SB implants and techniques are still ‘stuck in the past and have not seen the same sort of technological advancement’. In case of vitrectomy surgery, these advances include valved trocars and greatly improved fluid dynamics. She said the great historic argument for SB surgery always was that with ppV you will not fully relieve the internal traction at the break and the vitreous base. This is not true anymore as with latest cutter technology one can easily and safely shave all relevant amounts of vitreous. Plus ppV features superior visualization and is simply the more elegant technique.
Finally, surgeons voted with their feet and as less SB surgeries are being done less demand is found for buckling devices. As economy is driven by demand, Dr. Drenser foresees that fewer and fewer choices for SB materials will be provided and the surgical technique of SB will die out as an obsolete and medieval art.
Heinrich Heimann Scleral Buckling (SB) is absolutely relevant
Dr. Heimann opens his argument with a bang and states that “Retinal Detachment Surgery is the only surgical procedure, which featured a better outcome 70 years ago compared to today”. He argues this is because surgeons nowadays do pars plana vitrectomies (ppV) rather than SB surgery.
He argues that technological developments made surgery easier and that we are better today in treating complicated cases. Also, there are more competent retinal surgeons available today. However, eminent figures such as Dr. Custodis had success rate of 80% 70 years ago. While today, Dr. Heimann proclaims, we have poorer visual outcomes because we prefer ppV over SB.
Dr. Heimann cites the SPR study (Heimann H et al. Ophthalmology 2007 114:2142) and explains one headline result: Vitrectomy in pseudophakic patients has a higher anatomical success rate. This evidence was unfortunately taken to argue for ppV in all patients regardless of lens status! Also, because ppV was the easier procedure to teach and to perform, people voted with their feet and just went on to perform vitrectomies.
He then challenges the audience saying “Science is not a democracy – you have to put your arguments forward” and goes back to the same study for another headline result: Phakic patients have better functional outcomes with SB! Interestingly, this is not because SB was done in easier cases. And actually, re-detachment rate is comparable in both groups. However, ppV leads to double the number of adverse events (incl. cataract) even after controlling for risk factors and demographic variables. Another study (Pastor JC et al. BJO 2008) showed that ppV had greater probability of a worse final VA than SB. This finding is also supported by Wong et al. Retina 2015 (35:2552), which shows a 10 letter improvement in SB cases over ppV.
In summary, Dr. Heimann reckons that ppV leads to ok’ish results with a surgery that is much easier. But as SB leads to better functional outcomes with fewer secondary surgeries (especially in phakic patients), we should invest in teaching SB. Because only if we keep the skill of SB alive, will we have the freedom to choose between the two strategies in the future.