Stephen J. Smith, MD
Vitreoretinal Surgery Fellow
Byers Eye Institute
Stanford University School of Medicine
One of the perennial favorites at the Retina Society, the surgical section kicked off the afternoon on day 3 of the 50th annual Retina Society Meeting. The session was moderated by Dr. Jonathan Prenner (RETINA Roundup) and Dr. Charlie Barr.
Dr. Mario Romana began the afternoon session with a study looking at fluidics across 6 different vitrectomy platforms (23-, 25-, and 27-gauge with either single blade or double blade cutters). They reported that the fluidics of the 27-gauge double blade system were equivalent to those of the single blade 23- and 25-gauge systems. Across all platforms, double blade systems had higher flow rates on regular vitrectomy mode, which increases safety and functionality. The platforms fluidics of the platforms were approximately equal on shaving mode.
Dr. Susann Binder then gave a timely talk on the importance of primary scleral buckling in the repair of select retinal detachments. As the use of scleral buckling continues to decline, the ability of retina specialists to identify, treat, and support breaks on the buckle takes on greater importance. Dr. Binder introduced the use of a novel device to help in the identification and marking of retinal breaks. These functions enable the user to have a greater chance of surgical success in primary buckling procedures. The device is a depressor that has an internal marker that can be employed when the surgeon has depressed over the break. It can also accommodate an endoscopic light source to help in localization of retinal holes and tears. Using this technology, Dr. Binder and colleagues have successfully treated 15 patients with primary scleral buckles, and have a minimum of 6 month follow up on all these patients. This device may potentially help increase the success rates of primary scleral buckles and also aid in teaching trainees proper primary scleral buckling techniques.
Dr. Charles Barr compared outcomes of pars plana vitrectomy for diabetic patients with vitreous hemorrhage or tractional retinal detachments. Their team specifically carried out a retrospective study comparing outcomes based on the gauge of surgery used, and found no significant correlation between gauge and technical and visual outcomes between 23-, 25-, and 27-gauge surgeries. Over 90% of surgeries were technically successful, but patients with TRD in particular had poor final visual acuity outcomes. However, even in patients with TRDs, approximately 50% gained a minimum of 3 lines of vision. The authors concluded that the gauge of surgery does not seem to correlate with outcomes, and optimal timing of surgery for these patients may be an important factor to improve visual acuity outcomes.
The next talk focused on post-operative inflammation following the use of ICG. Dr. Howard Fine reported the occurrence of both anterior and posterior inflammation in 4 patients who received ICG for ILM-peeling. The first patient presented on post-operative day one with anterior and posterior chamber cell and a hypopyon. Given this presentation, a vitreous tap and injection was performed. Over the ensuing 3 weeks, 3 additional cases presented, and all patients were found to have been treated with ICG sharing the same lot number. High performance liquid chromatography did not definitively implicate ICG, but the facts of the case presentations (different surgeons, scrub nurses, OR days, but same ICG lot number) argue strongly for ICG as the culprit. All patients were ultimately successfully managed with topical steroids, cycloplegics, and topical antibiotics. Inflammation resolved within 3 weeks in all cases, and all patients had final visual acuities in the range that would be expected based on their surgical procedure. This talk highlighted the importance of considering ICG as a cause of inflammation in post-operative patients with the acute onset of anterior and posterior chamber inflammation.
Continuing the theme of inflammation post-vitrectomy, Dr. Sunir Garg and colleagues carried out a randomized, prospective trial comparing plain gut versus 8-0 vicryl suture to close 23-gauge sclerotomies. Their data showed a statistically significant increase in scleral inflammation at post op week 1 and month 1 visits in patients treated with vicryl suture. Patients treated with vicryl suture also had more subjective pain at post op month 1, and this result achieved statistical significance. During question and answer after this talk, several other retina specialists confirmed these findings based on their own clinical experience, and one noted that in addition to better patient outcomes, plain gut suture also happens to be more affordable than vicryl suture.
Dr. Omesh Gupta gave the first of 4 talks on scleral lens fixation. In light of the increasing age of the population, increased time of PCIOL implantation, and increasing occurrence of pseudoexfolation, the number of patients needing scleral supported lenses has continued to increase. Dr. Gupta and colleagues described their experience using the Bausch and Lomb enVista MX60, foldable, hydrophobic, acrylic lens with ab externo gortex suture fixation. Their outcomes in 31 eyes of 31 patients were excellent, with a mean visual acuity improvement from 20/700 preoperatively to 20/45 postoperatively. Perhaps of greater importance, 20 patients received intraocular gas tamponade, with no cases of lens opacification (stay tuned for a talk given by Dr. Ayala Pollack!)
The next talk was given by one of the pre-eminent authorities on posterior scleral IOL fixation, Dr. Jonathan Prenner. He presented data on 6 patients who underwent vitrectomy and 3-piece IOL fixation via a thin walled 30-gauge needle with thermal haptic deformation. One of the primary advantages of this technique is the use of the Aaren Scientific EC3 Pal IOL. This lens has nearly unbreakable haptics, and the material allows for thermal deformation of the haptic to secure the haptic in place in the scleral tunnel. Securing the second haptic in the vitreous enables greater freedom to operate and helps reduce the technical challenge of fixating the second haptic. Complications in this small case series were minor, including IOL capture in 1 patient and corneal edema in 1 patient. These were addressed in the office. All patients had excellent visual acuity outcomes with follow up of up to 3 months.
Dr. Jeremy Wolfe presented data from one of the largest cohorts of patients undergoing sutureless intrascleral IOL fixation. 122 patients were included, with mean follow up of just shy of 2 years. All patients had a centered IOL at last follow up with -0.57D SE refraction. Vitreous hemorrhage was the most common complication, occurring in 14.8% of patients, with most resolving spontaneously. UBM was carried out in certain patients and several cadaveric eyes were also studied to assess the position of these lenses after fixation. These studies further confirmed excellent lens position, with minimal stretching at the haptic-optic junction and IOL rotation. This report highlighted the good outcomes that are possible with the utilization of this technique.
As promised, we now present data related to IOL opacification following gas injection. The main concern around the use of hydrophilic lenses relates to concern about lens opacification with exposure to intraocular gas. This has been reported in the literature, particularly in patients undergoing endothelial keratoplasty with gas bubble placement. Dr. Ayala Pollack and colleagues described 4 patients who underwent PPV (1 for macular hole, 3 for RD repair) who subsequently developed IOL opacification requiring IOL explanation. Interestingly, the opacification did not occur until 6 months to 1.5 years after PPV. Dispersive x-ray spectroscopy of the lens opacification demonstrated the presence of calcium and phosphorus. In the question and answer session, Dr. Barr asked how many retina specialists have seen opacification of the Akreos lens, and >30 hands were raised. In vivo studies of these lenses have not demonstrated opacification in all Akreos lenses exposed to gas, and the cause for opacification of some hydrophilic lenses exposed to gas is still not completely understood.
We then pivoted away from scleral fixated lens cases, and moved to a long-term assessment of outcomes following 27-gauge PPV. Dr. Ali Khan presented data on 371 patients, with a mean follow up of approximately 2 years. Outcomes of this multi-center, retrospective interventional case series demonstrated that 27-gauge PPV was well tolerated and with favorable rates of post-operative complications across varied surgical indications. No cases required intra-operative conversion to 23- or 25-gauge. Rates of postoperative hypertension (10.8%) were almost double that of hypotony (5.6%). 82 eyes underwent additional surgery, with almost half of these for cataract extraction. There was an 89% success rate in primary RRD repair, with a 77% success rate in recurrent retinal detachment cases. While operating time wasn’t directly reported, Dr. Khan stated anecdotally that it compared favorably to 23-gauge vitrectomy. Limitations of this study included the use of one operating platform (alcon), surgeon choice of instrumentation, and lack of visual acuity outcome data on all patients. However, it provided additional support for the value of the 27-gauge platform for a variety of surgical indications.
The final talk of the surgical session was given by Dr. Jerry Sebag. He looked at outcomes among patients who underwent limited vitrectomy for vitreous opacities. He began his talk by talking about the impact that floaters have on patients’ quality of life. Dr. Sebag presented data that showed a marked reduction in contrast sensitivity in patients with symptomatic floaters, including patients with PVD. Ultrasound studies have also showed that greater vitreous density results in lower contrast sensitivity. Dr. Sebag noted that his evaluation of patients with floaters involves both ultrasound and contrast sensitivity, and he will not perform PPV on patients with floaters who normal contrast sensitivity. He presented data on 190 surgeries performed on 140 patients. VFQ showed a 30% improvement in vision in patients post-operatively. Mean visual acuity improved from approximately 20/30 to 20/25, and this was statistically significant. Dr. Sebag concluded that limited pars plana vitrectomy appears to have a place in the treatment of symptomatic floaters, particularly in patients with reduced contrast sensitivity.
The afternoon session continues with late breaking abstracts and a second surgical session, followed by the gala dinner.
