Guru Nanak Eye Centre
Maulana Azad Medical College, Delhi, India
The Dissection Room session on retinal detachment surgery was moderated by Dr. Rajeev Jain and Dr. Shashank Rai Gupta and highlighted newer paradigms in retinal detachment repair.
First, Dr. Yoshihiro Yonekawa, from Wills Eye Hospital, USA, presented the results and clinical implications of papers from the Primary Retinal Detachment Outcome (PRO) study, which is a large multicenter study. He condensed 20 PRO studies as 20 lessons from their group over a 10-minute presentation. The following observations were made.
- Primary scleral buckle (SB) alone or combined with pars plana vitrectomy (PPV) had higher single surgery attachment success (SASS) and better visual outcomes overall.
- 360 degree laser did not improve SSAS, but was associated with worse outcomes.
- Contact vs non-contact viewing systems, gauge size (23G vs 25 G), and technique of fixating buckles (suture vs scleral tunnel) did not affect retinal detachment outcomes.
- Eyes with RRD and concurrent full thickness macular hole (FTMH) had worse presenting and final visual outcomes. The holes closed in 100% if ILM was peeled and in 95% even without ILM peeling.
- Prophylactic ILM peeling in primary RD surgery led to better reattachment.
- PPV with SB had a superior outcome compared to PPV alone in RRDs with inferior breaks especially for phakic eyes.
- Elderly patients presented with worse visual acuity and more PVR, and outcomes were worse compared to middle-aged patients. Those who received scleral buckles, despite the older age and pseudophakic status, did better.
- Younger surgeons had better single surgery success rates. Surgeons with a better success rate did more buckles, less 360-degree laser, and used less perfluorooctane.
- At least 10% of patients developed CME post RD surgery. This was more commonly seen in old age, patients with preoperative PVR and post cataract surgery.
- Patients with macula sparing RRD did better with buckle alone than PPV and PPV/SB. Those involving the fovea did better if operated on earlier.
- A machine learning scoring system was developed and validated to predict post-op visual outcomes based on presenting clinical variables.
This landmark study overall highlighted the importance of buckling. Placing a buckle may help improve anatomic outcomes, especially for young patients, patients with pre-operative PVR, and in phakic patients.
Next Dr. Peter Szurman from the Klaus Hoimann Eye Research Institute, Germany, presented his research work on hydrogel vitreous substitutes used as a tamponading agent. These biopolymeric hydrophilic gels resemble the natural refractive index of human vitreous, so they produce no refractive errors. They exhibit viscoelastic properties similar to juvenile vitreous. The metabolic activity, apoptosis and tight junctions of all tested ocular cells were unaffected by these gels in in vitro studies. Long term studies in rabbits showed no signs of photoreceptor toxicity or cataract even at 1 year. We look forward to further advancements.
Third, Dr. Rajeev Muni from St. Michael’s Hospital, Toronto, spoke to us virtually about pneumatic retinopexy (PnR) and retinal displacement. He demonstrated individual steps of performing PnR—namely an anterior chamber paracentesis, intravitreal injection of SF6, followed by laser retinopexy the day after PnR. The results of the PIVOT trial comparing PnR vs PPV for primary RRD were discussed, which showed that PnR offered superior photoreceptor integrity and less retinal displacement with better long-term visual acuity results and less metamorphopsia compared with primary PPV.
Next, Dr. Saumil Seth, from Envision Eye Hospital, Mumbai, discussed his innovative technique of limited vitrectomy with PnR in which no PVD is induced, vitrectomy is done enough to make space for a large gas bubble, subretinal fluid is drained from the primary break, and laser or cryopexy is performed. He advocated this technique for RD in young phakic patients with retinal dialysis or myopia with atrophic holes. This innovative but controversial talk lead to much discussion. We also learned that Dr. Seth and Dr. Muni were former classmates!
Next, Dr. Vinod Kumar, faculty from AIIMS, Delhi, presented his study on anatomical outcomes of supine vs prone positioning in vitrectomy for primary RRD with PVR less than Grade C2. All patients underwent PPV with SF6 gas tamponade. Single surgery reattachment rate was similar in both groups. Complications such as cataract and IOP spikes were interestingly not found to be significant in supine positioning. There was a confounding factor, that, most of the elderly patients were subjected to combined phacoaspiration and intraocular lens implantation along with vitrectomy. However, supine positioning was found a more comfortable alternative for patients who could not maintain prone position for long hours.
Finally, Dr. Yoshihiro Yonekawa, discussed the benefits of extended internal membrane peeling for Grade C PVR. This large international collaborative study compared outcomes of no ILM peeling, ILM peeling within the arcades,vs extended ILM peeling past the arcades. Their results showed that ILM peeling resulted in better anatomical outcomes (significantly higher single surgery success) and better visual outcomes. Additionally, they found that extended ILM peeling was superior to limited ILM peeling.
The session concluded with a lively discussion between the presenters, moderators, panelists, and the audience.