Aashraya Karpe, MS
Shroff Eye Centre, New Delhi
The Prove Your Point session at the Delhi Retina Meet showcased the latest innovations and techniques. Retina surgeons presented their new ideas to distinguished retina colleagues and provided evidence in support of their innovation/technique.
First up was Dr. (Col.) Pradeep who spoke about his modified dosage of brolucizumab in DME: Efficacy and safety of Brolucizumab 3.6 mg versus 6 mg. His idea behind this modification was the fact that in the KESTREL study, the treatment outcome in the 3 mg and 6 mg groups was almost similar in terms of efficacy, and a lower dose may cause fewer side effects that have worried many retina specialists. The inclusion criteria were treatment naïve controlled diabetics with HgA1c < 10, NPDR, BCVA < 0.1 on Log MAR and a central macular thickness > 300 microns on SD-OCT. The study showed that CMT progressively improved from week 0 to week 28 in both groups. He concluded that brolucizumab may be used at a lower dosage i.e., 3.6 mg on a PRN basis in DME and was potentially as effective as the 6 mg dosage in terms of CMT reduction and VA improvement.
Dr. Avnindra Gupta then presented his innovative surgical modification of inverted flap macular hole surgery in giant macular holes (base diameter > 1000 microns, MLD > 800 microns) in 6 patients. His technique involved creating and placing an ILM graft over the large macular holes as a scaffold and making the retina elastic by creating a localized detachment at the posterior pole by injecting fluid subretinally with a 40G cannula to mobilize the retina centrally. The fluid drains from the macular hole and after fluid-air exchange, gas or silicone oil or fibrin glue was used to tamponade the hole. With 5 out of 6 holes (hole in which fibrin glue was used remained open) successfully closing with visual improvement, he concluded that his technique was very useful in giant macular holes but needed more cases to provide conclusive evidence. After a brief discussion about the pros and cons of the technique, various surgeons including Dr. Yoshihiro Yonekawa, discussed the technically simpler technique of simply massaging the macula after relieving the tangential traction to mobilize the retina around the hole.
The third presenter, Dr. Mudit Tyagi, presented his take on using glue in macular hole surgeries. He is known to use fibrin glue extensively in retinal detachment surgeries. Dr. Mudit elucidated the cons of using gas tamponade vis-à-vis the role and advantages of using fibrin glue for macular hole surgeries. After obtaining ethical committee clearance, he used this technique in 10 eyes of 10 patients who were unable to maintain post-op prone positioning due to physical limitations. The surgical technique involved conventional ILM peeling followed by placing thick and thin components of fibrin glue to create a fibrin coagulum over the macular hole followed by fluid-air exchange. No positioning was required. The fibrin coagulum is absorbable and dissolves completely in 5-7 days. He demonstrated successful hole closure within a week on OCT and complete resorption of the fibrin in 8 out of 10 cases. The theory behind this technique is that the fibrin glue helps prevent entry of fluid in the hole and contraction of the coagulum may lead to apposition of hole edges resulting in closure. He concluded that this technique demonstrates the use of fibrin glue as an effective adjunct for macular hole surgery in patients unable to maintain prone positioning, thus obviating the problems associated with conventional gas tamponade.
The next presentation was by Dr. Perwez Khan who was working towards use of autologous platelet rich plasma (PRP) for patients with retinitis pigmentosa (RP). His study assessed the electrophysiological and visual parameter changes in RP patients undergoing autologous PRP therapy. According to Dr. Perwez, PRP is rich in growth factors and cell adhesion molecules thus serving as a potential source of growth factors for reactivation of cells in RP. The procedure involved injecting 0.5 ml PRP in the sub-Tenon’s or suprachoroidal space via a specialized needle and was repeated every 15 days for up to 3 injections. The study included patients with BCVA CF close to face and above and excluded those with other pre-existing ocular conditions such as glaucoma. The parameters assessed were VA (ETDRS) before and after each injection and up to 6 weeks from the first injection, mfERG, OCT and perimetry (10-2) before and after each injection. He demonstrated a statistically significant improvement in vision and mfERG waveforms in patients. He concluded that this therapy may serve as a temporizing measure for RP patients until definitive gene therapies become available. However, the small sample size and short duration of follow-up were some of the major drawbacks of the study, and further studies are required.
Dr. Peter Szurman was an invited guest faculty from Germany, (Figure 5) and he demonstrated his groups’ technique of using stem cell therapy for geographic atrophy in dry AMD. He demonstrated an AI-based quantification of ONL degeneration in GA/AMD wherein photoreceptor loss was shown to extend even outside the area of GA. He then showed a promising method of stem cell therapy, where his team harvests autologous pluripotent skin stem cells which are re-differentiated into RPE cells. These cells are then plated on a carrier matrix followed by subretinal implantation in rabbits. This method demonstrated clean integration of the stem cells in the subretinal space in monkeys. This technique is combined with selective RPE cell removal using micropulse lasering of the activated RPE edge in order to prevent a “copy-paste” phenomenon of RPE atrophy, i.e., transplanted RPE cells undergoing degeneration due to existing diseased RPE. He concluded that this novel subretinal injection over laser-ablated RPE is technically easier and demonstrated directional spread of RPE. We look forward to further advances in this promising research.