Posters are always a big draw at any congress – and at the recent American Society of Retina Specialists (ASRS) annual meeting in Chicago, they took center stage with scientific discovery and investigation. Below we share details from a couple that caught our eye at PIE…
Can IOP be predicted by changes in CST?
“In patients with ME due to retinal vascular diseases, early anatomical response was significantly correlated with IOP change after intravitreal DEX.”
Elevated intraocular pressure (IOP) occurs in 1/3 of patients receiving an intravitreal dexamethasone (DEX) implant (Ozurdex, Allergan Inc., Irvine, CA, USA). Therefore, Dong Yoon Kim, MD, PhD, and colleagues investigated whether IOP changes could be predicted by early anatomical response in macular edema (ME) due to retinal vascular diseases treated with the intravitreal DEX implant.
Their results were presented in a poster titled “Association between intraocular pressure change and early anatomical response after dexamethasone implant”. They conducted retrospective review involving patients with diabetic macular edema (DME) or ME due to retinal vein occlusion (RVO), who underwent intravitreal DEX implantation and 3 months follow-up. Eyes were divided into increase (IIOP) or non-increase (nIIOP) of IOP, as well as good (GAR) versus poor anatomical response (PAR). Best corrected visual acuity (BCVA), IOP and central subfield thickness (CST) at baseline, 1 week, 1 month and 3 months were compared between the two groups.
A total of 49 eyes (29 with DME and 20 with ME due to RVO) were included in the study. In total, 18 eyes experienced IIOP, while 31 did not. There was a significant difference in the mean CST reduction at 1 week from baseline between the two groups (-207.11 ± 85.48 in the IIOP group; -140.29 ± 86.19 in the nIIOP group, p = 0.012). Twenty-two eyes were classified as GAR and 27 eyes were PAR. There was a significant difference in the mean IOP elevation at 1 week from baseline after DEX between the two groups (4.00 ± 4.54 GAR, 1.33 ± 2.43 PAR, p = 0.012). The amount of CST reduction from baseline at 1 week had a statistically significant correlation with the amount of IOP change from baseline at 1 week and 1 month after DEX implant (r = 0.443, p = 0.001; r = 0.122, p = 0.001).
These results led the investigators to conclude that “patients with good early anatomical response after DEX should be carefully monitored for IOP elevation”.
Vitrectomy for TRD: Get the timing right for better visual outcomes
“The most common reason for delay was medical risk stratification.”
What is the optimal timeframe for better visual outcomes in patients undergoing vitrectomy for diabetic tractional retinal detachment (TRD)? And what are the reasons for delays?
These are the questions Kathleen A. Regan, MD, from the University of Wisconsin, Department of Ophthalmology and Visual Science, along with colleagues from the University of Florida, Department of Ophthalmology, explored in a poster titled: “Causes and Consequences of Surgical Delay to Vitrectomy for Diabetic Tractional Detachment”.
While waiting to perform vitrectomy for diabetic TRD has been associated with worse visual outcomes, it’s unknown what the ideal timing is for repair. In fact, it’s known that waiting 3 months results in 25% of eyes losing vision.
To investigate contributing factors, and clinical outcomes of surgical delay, a retrospective case series of 130 eyes from 105 patients was conducted. It was found that the primary reasons for delay included: medical risk stratification (n=18); patient preference (n=7); and prior treatment (n=7). Other factors were noted as: loss to follow-up, financial, medical illness, OR scheduling and family/ride.
Dr. Regan utilized a multivariable regression analysis to determine that this delay was associated with a worse visual outcome. Meanwhile, surgical timing of 1-14 days was associated with a better visual outcome than from 15-28 days (p = 0.02). This led the investigators to conclude that vitrectomy within two weeks from the decision for surgery was associated with better visual outcomes.
In addition, they found that surgical timing was associated with the patients’ medical complexity, (including elevated hemoglobin A1C, endocrinology involvement and hemodialysis), and noted that surgeons might consider expedited referrals for better preoperative medical management.
Do patients treated with anti-VEGF for nAMD suffer from increased RRD?
With a reported rate of 0-1%, rhegmatogenous retinal detachment (RRD) is a rare complication from intravitreal anti-VEGF agents – and to date, no study has explored characteristics associated with RRD in patients receiving anti-VEGF treatment for neovascular age-related macular degeneration (nAMD).
Therefore, Danny A. Mammo, MD, from the University of Minnesota Department of Ophthalmology and Alexander Ringeisen, MD, and D. Wilkin Parke III, MD, from Vitreoretinal Surgery P.A. in Minneapolis, hypothesized that “RRD in patients undergoing anti-VEGF treatment for nAMD may experience an increased rate of detachments in the area of the injection site, as well as a decrease in postoperative injection frequency due to the presumed increased anti-VEGF clearance in the virectomized eye”.
Their results were presented in a poster called “Rhegmatogenous retinal detachment in active neovascular age-related macular degeneration”.
The investigators conducted a single-center retrospective, consecutive review of all nAMD patients with RRD while receiving bevacizumab, ranibizumab or aflibercept between 1/1/2014 to 30/10/2018, with outcome measures including the quadrant of the retinal break(s), visual acuity (VA) at the time of RRD and final follow-up, as well as pre-op and post-op injection frequency.
They found that the superotemporal quadrant was the most frequently involved in known retinal breaks; while the 21.1 days was the average between last injection and RRD onset. The average VA at time of RRD was 20/230, and at last follow-up at 34 months it was 20/220. Additionally, 64.7% of patients either increased their injection interval or required no post-op injections (n=4), while 5 patients had decreased injection intervals and one patient maintained similar intervals.
This led Dr. Mammo and colleagues to conclude that “the quadrant involved in patients with RRD while receiving intravitreal injections for nAMD does not seem to differ from the normal reported distribution of retinal breaks in in all eyes with RRD”. Additionally, this study found that the majority of nAMD patients required fewer injections postoperatively, which may be due to increased oxygenation of the vitreous after PPV, which reduces VEGF expression.
Surgical outcomes of 23-gauge PPV after phaco: Is smaller better for outcomes?
“Findings of this study suggest that managing post-cataract surgery retained lens fragments with 23-gauge PPV is safe and efficient.”
Dislocated lens material into the vitreous cavity is a well-recognized complication of phacoemulsification surgery – and pars plana vitrectomy (PPV) remains the sole effective strategy to definitively eradicate the lens matter.
In the past 25 years, major studies have reviewed the outcomes of PPV for dislocated lens fragments performed with 20-gauge instruments . . . however, surgical outcomes of 23-gauge PPV remain uncertain.
Therefore, Elizabeth Yang and colleagues from Moorfields Eye Hospital, London, United Kingdom, explored outcomes and predictive factors of 23-gauge PPV in a poster titled: “Visual Outcomes and Prognostic Factors of 23-Gauge Vitrectomy for Retained Lens Fragments after Phacoemulsification”.
A retrospective, non-interventional cohort study including 291 consecutive eyes of 291 patients with dislocated lens material managed with PPV from 2012 to 2017 at Moorfields Eye Hospital was conducted. The investigators collected baseline demographic and clinical data, intra-operative factors and postoperative complications, including BCVA. They used univariate and multivariate logistic regression to characterize the impact of clinical factors on achieving better than 20/40, or worse than 20/200 vision.
They found that from 0.73 ± 0.70 (before cataract surgery), logMAR VA improved to 0.46 ± 0.63 (p < 0.001). At 6 months, 183 (62.9%) achieved BCVA better than 20/40, while 45 patients (15.5%) had a BCVA worse than 20/200. Final VA of 20/40 or better was associated with better pre-cataract surgery VA, age <75 years and absence of diabetic or persistent CME (p < 0.05). Meanwhile, poorer VA before cataract surgery, a delay of more than 2 weeks before PPV and aphakia, were the only factors predictive of 20/200 or worse VA at 6 months (p < 0.05).
Results also showed that the most frequent complications were de novo ocular hypertension (10%) and transient cystoid macular edema (CME; 8.6%); the retinal detachment rate was 3.1%.
These findings led the investigators to conclude that managing post-cataract surgery retained lens fragments with 23-gauge PPV is safe and efficient. They also suggested that VA outcomes were not adversely affected, as long as PPV is performed up to two weeks after cataract surgery. Timing or technique of the IOL placement also did not affect outcomes. In addition, the investigators noted that appropriate and prompt management of CME may improve outcomes.
