June 1, 2018 Conference

AM - Complications of Emerging Surgical Procedures

Professional Practice Gaps:  Learn about new complications emerging with new techniques.
­Prevention measures associated with a new set of complications.
­Management of new complications not in current armamentarium,

1. To identify complications associated with emerging surgical procedures.
­2. To discuss etiology and prevention of a new set of unfamiliar complications.
­3. To prepare the surgeon to better manage a new set of complications as they embrace new surgical techniques.

The Latest in Corneal Surgery: Climbing the Steep Learning Curve
Joseph M. Williams

The last 25 years has seen both a revolution and evolution of corneal surgery encompassing both corneal modification procedures and corneal replacement procedures.  When compared to the last 100 years this has occurred at a head spinning pace and has resulted in a virtual alphabet soup of abbreviations to describe these new surgical procedures:  PRK, LASIK, LASEK, SMILE, cornea CXL, epi on CXL, epi-off CXL, intrastromal rings/segments, PKP, ALK, ALTK, DALK, DLEK, DSEK, DSAEK, UT-DSAEK, NT-DSAEK, PDEK, DMEK, DSET, DWEK, DSO . The common thread to the evolution of these procedures is standardization of the techniques and minimizing operative and post-operative complications.  Complications may occur intra-operatively or post-operatively and can be broadly grouped as mechanical, inflammatory, and infectious.  Complications specific to these evolving procedures that will be addressed include:  pupillary block; graft preparation, unfolding, orientation; graft adherence/dislocation;  Descemets perforation in DALK; post-operative complications of interface infections; increased incidence of fungal infections.

There are excellent resources on the internet that allow an incredible amount of self-education, discussion, and online debate of these revolutionary and evolutionary techniques with complete surgical videos. While these resources are not peer reviewed they are real time and more current than any print journal.  It is up to each individual ophthalmologist to determine and evaluate the validity of these sources.  The internet blog “kera-net” offers some of the best current information on these evolving corneal surgical procedures.

New Refractive Frontiers: Facing the Unexpected
Jason Brenner, Samir Melki

A case based series of refractive complications will be presented with corneal and ocular imaging as well as surgical video when appropriate. Topics discussed will include corneal haze after presbyopia correcting corneal inlays (Raindrop and Kamra), cataract surgery in the setting of corneal inlays and phakic intraocular lenses (Visian ICL), intraoperative LASIK flap creation issues with the femtosecond laser and enhancement options after small incision lenticule extraction (SMILE). 

Emerging Glaucoma surgery: lower IOP without raising the risk
Susan Liang

In today’s glaucoma treatment paradigm, tube shunts and trabeculectomy continue to be most efficacious in lowering eye pressure.  According to the TVT studies, the 5- year average IOP for tube and trabeculectomy was 14.4 mmHg and 12.6 mm Hg respectively.   Although highly effective, both surgeries carry similar rates of dreaded and potentially vision-threatening complications, like blebitis, endophthalmitis, hypotony maculopathy, and choroidal hemorrhage.  Micro-invasive glaucoma surgery (MIGS) has emerged to provide safer, and less invasive surgical treatment options with modest efficacy.  This presentation will review the safety profile of the most current MIGS that target increasing trabecular, suprachoroidal, and subconjunctival flow, and discuss strategies to manage complications as these new surgeries are implemented in daily practice.


Samuelson TW, et al.  Randomized Evaluation of the trabecular micro-bypass stent with phacoemulsification in patients with glaucoma and cataract.  Ophthalmology 2011; 118(3): 459-467.

Vold S, et al.  Two year COMPASS trial results:  supraciliary microstenting with phacoemulsification in patients with open angle glaucoma and cataract.  Ophthalmology 2016; 123:  2103-2112.

Grover DS,  et al.  Performance and safety of a New Ab Interno Gelatn Stent in Refractory Glaucoma at 12 Months, American Journal of Ophthalmology 2017; 183: 25-36.

Glued IOLs, IOL Scaffold and Other Anterior Segment Acrobatics

Various sticky situations are there in cataract surgery in which implanting an IOL is difficult. In such cases the Glued IOL works well and can restore vision to the patient. In this two scleral flaps are created 180 degrees apart and the three piece PC IOL haptics externalised through the sclerotomies and tucked into intrascleral pockets and the. Glued down using fibrin glue. Marfans syndrome, traumatic cases. PC ruptures all can benefit from this procedure.

Oculoplastics: Risks and Perils of Novel Procedures
John T.H. Mandeville

Novel procedures in the field of ophthalmic plastic surgery tend to fall in one of a few categories:  (1) the application of new materials, (2) alternate anatomic approaches to address pathology, and (3) use of new technology or instruments.  Due to the high success rates of standard oculoplastic techniques, the adoption of novel procedures in oculoplastic surgery may lag behind other ophthalmic specialties.   Complications from these newer procedures are relatively rare and procedure-specific, published as case reports or presented at specialty-specific meetings.  In this discussion, we will review different types of complications that arise from novel oculoplastic techniques, including adverse reactions to implanted materials, migration of implants, hemorrhage and infection, malposition of the lids or globe, and failure to correct the underlying problem.  We will also address diagnosis and management options from the general ophthalmologist’s perspective.Novel procedures in the field of ophthalmic plastic surgery tend to fall in one of a few categories:  (1) the application of new materials, (2) alternate anatomic approaches to address pathology, and (3) use of new technology or instruments.  Due to the high success rates of standard oculoplastic techniques, the adoption of novel procedures in oculoplastic surgery may lag behind other ophthalmic specialties.   Complications from these newer procedures are relatively rare and procedure-specific, published as case reports or presented at specialty-specific meetings.  In this discussion, we will review different types of complications that arise from novel oculoplastic techniques, including adverse reactions to implanted materials, migration of implants, hemorrhage and infection, malposition of the lids or globe, and failure to correct the underlying problem.  We will also address diagnosis and management options from the general ophthalmologist’s perspective.

What’s emerging behind the lens: new retina procedures and associated pitfalls
Archana Seethala

We have seen incredible progress in the field of vitreoretinal disease over the last few decades including but not limited to -  intravitreal injections, OCT/ OCT angiography, and small (27) gauge vitrectomy - which have all changed the scope of how we approach and treat retinal disease. These innovations continue to improve the way we practice, as well provide further options for our patients.

During this presentation we will discuss several of these developments including sutureless scleral fixated IOL’s, Argus II retinal implants, stem cell / gene therapy for dry macular degeneration and hereditary retinal dystrophies .  We will also briefly introduce advanced 3D surgical imaging.

While promising, all of these advancements do have their own respective limitations, complications and concerns.


1. Humayun MS et al. A bioengineered retinal pigment epitheial monolayer  for advanced  dry age related macular degeneration.  2018 Apr 4;10(435)

2. Ameri H. Prospect of retinal gene therapy following commercialization of voretigene neparvovec-rzyl for retinal dystrophy mediated by RPE65 mutation.  2018 Feb 16;30(1)

3. Prenner JL. A novel approach for posterior chamber intraocular lens placement or rescue via a sutureless scleral fixation technique. Retina 2012;32 853-855.

4. Coppola M , et al. Heads up 3D vision systems for retinal detachment surgery. Int J Retina Vitreous 207 Nov 20;3:46

5. Da Cruz L , Dorn JD, Humayun MS , et al . Five – year safety and performance results from the argus II retinal prosthesis system clinical trial. Ophthalmology. 2016 Oct;123(10):2248-54. 

Corneal Transplantation with Pre Descemets Endothelial Keratoplasty and Single Pass 4 Throw Pupilloplasty: Bold and Beautiful

PDEK implants the endothelium Descemets membrane and the pre Descemets later. This is about 25 micron. The biggest advantage is that this can be prepared from any donor age. It has the advantages of both DSEK and DMEK without their disadvantages. Single pass 4 throw pupilloplasty helps open the closed angle glaucoma cases and also helps in cases of bad pseudo phakic bullous keratopathy. This is a simple procedure which can be easily replicated.   


Endocyclophotocoagulation Outcomes for Different Glaucoma Types and Stages
Michael Lin, Abdulrahman Rageh, Angela Turalba, Teresa C. Chen


Minimally invasive glaucoma surgery has traditionally been thought to be less effective for more advanced stages of glaucoma. Endocyclophotocoagulation (ECP, Beaver-Visitec Endo Optiks, Waltham, MA) shrinks ciliary processes and is thought to decrease intraocular pressure (IOP) by opening the drainage angle and reducing aqueous production. Therefore, this study seeks to determine whether angle configuration and glaucoma disease staging affect ECP outcomes for reduction of both IOP and glaucoma medications.


Retrospective chart review of eyes that underwent ECP, with or without concurrent cataract extraction, between October 2010 and December 2016 at one institution. Exclusion criteria included not having follow-up at 1 year after surgery. Based on the Hodapp-Parrish-Anderson staging system, patients were divided into mild, moderate, and advanced glaucoma. Outcome measures were degree of IOP reduction and change in number of glaucoma medications.


There were 118 eyes of 97 patients that had at least 1 year of follow-up. Of these, 105 had concurrent cataract extraction. Eyes undergoing standalone ECP had greater IOP reduction than eyes undergoing ECP with concurrent phacoemulsification, but not greater medication reduction (9.1 vs 2.9 mmHg, p=0.001; 0.9 vs 0.6 medications, p=0.36). Glaucoma severity was mild in 39 eyes, moderate in 34, and advanced in 26. At 1 year, there was no difference in IOP reduction or medication reduction for eyes with mild, moderate, or advanced glaucoma (decrease of 3.0, 3.4, and 2.0 mmHg, respectively, p=0.56; decrease of 0.5, 0.8, and 0.7 medications, respectively, p=0.49). Greater pre-operative IOP was directly correlated with greater IOP reduction (R2=0.69). The 30 eyes with chronic angle closure glaucoma (CACG) had greater IOP reduction and medication reduction than the 55 eyes with open angle glaucoma (5.5 vs 1.9 mmHg, p=0.01; 1.1 vs 0.2 medications, p=0.0001).


In this study, eyes with CACG were more responsive to ECP than eyes with other types of glaucoma. Stage of glaucoma was not associated with degree of IOP reduction or medication reduction after ECP.


ECP can reduce IOP and medication use, particularly in CACG, and it can be employed for all stages of glaucoma.


1. Morales J, Al Qahtani M, Khandekar R, Al Shahwan A, Al Odhayb S, Al Mobarak F, Edward DP. Intraocular Pressure Following Phacoemulsification and Endoscopic Cyclophotocoagulation for Advanced Glaucoma: 1-Year Outcomes. J Glaucoma. 2015;24(6):e157-62.
2. Francis BA, Berke SJ, Dustin L, Noecker R. Endoscopic cyclophotocoagulation combined with phacoemulsification versus phacoemulsification alone in medically controlled glaucoma. J Cataract Refract Surg. 2014 Aug;40(8):1313-21.

Doxorubicin (DXR) & HIF-1 Inhibitor (HIF-1I) polymer conjugates in Choroidal (CNV) and Retinal Neovascularization (RNV) models
Rishi Chadha

Ocular neovascularization is a huge cause of vision loss in individuals throughout the world. The two main types are retinal (RNV) and choroidal neovascularizaion (CNV). RNV occurs in ischemic retinopathies such as diabetic retinopathy, the most common cause of moderate to severe vision loss in working class Americans. CNV occurs in diseases such as age related macular degeneration (AMD) and is the leading cause of vision loss in people ages 50 and over. While there are treatments, many have limited efficacy thus requiring consistent treatment which can lead to reduced patient compliance. Doxorubicin (DXR) and HIF-1 Inhibitor (HIF-1I) targets HIF-1, a master regulator of angiogenesis. This study will evaluate whether DXR and HIF-1I are effective treatment options for RNV and CNV. We used CNV and oxygen-induced retinopathy (ROP) generated mice models and conducted intraocular injections of both the DXR and HIF-1I particles as well as controls. Flat mounts of the choroid and retina were taken and neovascularization was measured using fluorescence microscopy and image analysis. Intraocular injection of 1µg of HIF-1I in the ROP mice model resulted in a 37% in NV while the injection of 1µg of DXR2 resulted in a 28% reduction. Intraocular injection of 1µg of HIF-1I immediately after rupture of Bruch’s membrane resulted in a 44% reduction in CNV while the injection of 1µg of DXR2 resulted in a 38% reduction. Both of these particles showed significant reduction in neovascularization in both CNV and ROP model mice. Future studies may include attempting suprachoroidal injections in rat CNV models. Suprachoroidal injections as this would allow the drug to be in a location where it is needed as well as reduce the risk of many complications such as vitreous hemorrhage, retinal detachment and floaters. 

Regional Vessel Caliber, Retinal Oximetry and Predominantly Peripheral Diabetic Retinal Lesions as Surrogate Markers of Nonperfusion on Ultrawide Field Angiography in Diabetic Eyes
Alex Pisig, Konstantina Sampani, Paolo Silva, Jennifer K. Sun, L. Paul Aiello

Methods: Vessel diameters, ETDRS diabetic retinopathy (DR) severity and presence of PPL were evaluated on UWF 200 degree images. Retinal oximetry and UWF-FA were obtained at the same visit. Vessel calibers at 1 disc diameter (DD, inner-AVR) and 3.5 DD (outer-AVR) from the center of the disc were measured using a customized semiautomated computer program. Retinal NP (mm2) was measured from UWF-FA images. Venous oxygen saturation (VO2, %) and arteriovenous difference (A-V, %) were calculated within a 2 DD ring centered on the optic disc.
Results: A total of 39 eyes from 20 subjects with mean age 40.7±10.7 yrs, diabetes duration 21.1±10.4 yrs, HbA1c 7.7%±1.1, 65.0% male and 75.0% type 1 diabetes were evaluated. DR severity was no DR 10.3%(4 eyes), mild nonproliferative DR (NPDR) 48.7%(19), moderate 20.5%(8), severe 10.3%(4), and proliferative DR 10.3%(4). PPL were present in 56.4%(22) of eyes and associated with increasing DR severity (p=0.006) as well as increasing NP & VO2, and decreasing A-V. In all eyes, NP was associated with increasing DR severity (r=0.60, p<0.0001) and increasing outer venular diameters (r=0.46,p=0.03). In eyes with PPL (N=22), increasing NP was correlated with increasing inner-AVR (r=0.43, p=0.04) and larger differences between outer- and inner-AVR (r=0.44, p=0.04). In eyes without PPL (N=17), NP was correlated with increasing inner (r=0.45, p=0.0370) and outer (r=0.68, p=0.0021) venular diameters. Correlation between inner and outer AVR was present only in eyes with no PPL (r=0.50, p=0.03) suggesting differences between inner and outer zones in eyes with PPL (r=0.29, p=0.18).
Conclusions: In this cohort, increasing NP was associated with increasing DR severity, venular dilation, increased VO2 and decreased A-V, suggesting greater areas of retinal ischemia, presence of venous shunting and reduced retinal oxygen utility. In eyes with PPL, regional differences in vessel caliber were correlated with increasing peripheral NP and provide further evidence that the risk of progression with PPL is driven by retinal ischemia.

Role of OCT in Monitoring for Ethambutol Induced Optic Neuropathy
Sona Chaudhry, Crandall Peeler


Toxic optic neuropathy is a rare but serious complication of ethambutol use. The incidence of optic neuropathy increases with sustained periods of the drug’s standard loading dose (25 mg/kg/day). To date, there are no known strategies for detecting subclinical ethambutol-induced toxicity, which if detected early may be reversed upon stopping the drug. We assess the utility of ocular coherence tomography (OCT) in detecting subclinical ethambutol-induced optic neuropathy.


We present a prospective case series of seven patients started on ethambutol and referred to the ophthalmology clinic for monthly screening while on the medication. Visual acuity, color vision, automated perimetry, and OCT of the optic nerve head with retinal nerve fiber layer (RNFL) analysis were obtained and analyzed. Progression analysis from the Heidelberg OCT was utilized to track the RNFL thickness over time. Statistical significance was defined as a p-value <0.05.


All seven patients had a baseline BCVA of 20/20, full color vision, and normal RNFL thickness on OCT. All but one patient had full baseline visual field testing. Ethambutol doses ranged from 12.5mg/kg/day to 26.0mg/kg/day.  Mean follow up was 5.6 months from initial screening (Range 1-12 months). No patients in the cohort developed afferent visual dysfunction but three of seven cases showed an upward trend in RNFL thickness, although not statistically significant (p-value 0.57 to 1.0).


We demonstrate an upward trend in RNFL thickness in patients following initiation of ethambutol therapy.  We hypothesize that this thickening results from subclinical optic nerve toxicity, manifest as subtle axonal swelling that may precede the development of frank optic atrophy.  Larger studies are required to determine whether a “threshold” value of thickening exists that is associated with clinical changes in afferent visual function. 

Efficacy of Goniosurgery for Newborn versus Infantile Primary Congenital Glaucoma
Helen Yeung, David S. Walton

     This is a retrospective review of patient records with newborn PCG and infantile PCG who underwent initial goniosurgery. Newborn PCG were those children with PCG diagnosed within the first 1 month of age and infantile PCG were those children with PCG diagnosed later, between 1 and 13 months of life. Complete success was defined as intraocular pressure (IOP) less than 23, qualified success as IOP less than 23 with medications, and failure as IOP greater than 23 requiring other types of glaucoma surgery.
     For the newborn PCG group, there was a total of 38 patients with 72 eyes. 92% (66 of 72 eyes) failed in controlling IOP after goniosurgery while 8% (6 of 72 eyes) achieved either qualified or complete success. The interval of goniosurgery to failure was 0.75 years (range: 3 days – 11 years). For the infantile PCG group, there were a total of 142 patients with 220 eyes. 97% (213 of 220 eyes) achieved complete success in controlling IOP while 3% (7 of 220 eyes) failed. The average postoperative interval follow-up was 10.5 years (range: 8 months – 40 years).
     Careful gonioscopy and inspection of the irides are imperative to determine the correct PCG diagnosis and the severity of the related filtration angle anomalies in order to select the appropriate surgical technique to perform for the proper subtype of PCG. Goniosurgery is not successful in all forms of PCG. It is highly successful in controlling IOP in the infantile PCG group compared to newborn PCG. Therefore, these results and the correct diagnosis of children with PCG are important in determining the appropriate glaucoma surgery for these young patients.

Gelatin-based Hydrogel as a Vehicle for Retinal Progenitor Cell Transplantation
Jeayoung Park

One of the current limitations of retinal transplantation of stem cells as well as other cell types is loss of cells and low graft survival. Gelatin-Hydroxyphenylpropionic acid (Gtn-HPA) is a biodegradable hydrogel that can undergo gelainization in vivo, which can preserve injected cells. We tested the hypothesis that Gtn-HPA hydrogel supports survival and integration of RPC transplantation. In vitro biocompatibility of Gtn-HPA with human RPCs (hRPCs) as well as in vivo survival of xenografted GFP+ pig RPCs (pRPCs) in rats were characterized with immunocyto/histochemistry. hRPCs showed equivalent % viability when cultured in a thin layer of Gtn-HPA compared to fibronectin-coated cover slides (control group). Caspase-3 Staining showed minimal apoptotic cells by day 4, and Ki-67 staining demonstrated proliferating cells in all days in culture. Transplanted pRPCs were found in tighter clusters in the subretinal space when injected with Gtn-HPA compared to saline control. GFP+ cell population was roughly equivalent in numbers between the hydrogel and liquid vehicle groups. Subretinal grafts showed no visible immune cell infiltration when stained with CD45. Gtn-HPA shows promise as an injectable and biodegradable polymer vehicle for subretinal stem cell transplantation. 

Direct-to-Consumer Virtual Visits: Feasibility of a Next-Generation Health Care Delivery System in Ophthalmology
Marissa Lynn, Heather Meyers, Caitlin Schumann, Christina Brown , Dylan Cahill , Aaron Farber-Chen , Jane Patrick , Molly Porter, Mary Whitman, Gordon Massey , David G. Hunter, Ankoor Shah

Methods: Retrospective review of ophthalmology VVs conducted at Boston Children’s Hospital on a custom-designed, device-agnostic, secure video platform. Primary outcome was provider-defined visit efficacy as measured by provider-facing surveys. Secondary outcomes were provider and patient metrics obtained via surveys and comprehensive chart review. Cost savings were calculated with a subset of assumptions for economic modeling of clinical business development used across BCH. 

Results: In 13 months, 3 providers conducted 57 VVs with 91% of encounters rated as effective. Patient satisfaction was 90% overall with benefits of convenience (100%), efficiency (82%), and improved access (73%). Providers saw post-operative (26), return (26), and new (5) visits with 37 strabismus, 7 orbital, and 13 ocular surface diagnoses. No negative outcomes were encountered. In comparison to the consumer expense of in-person visits, VVs saved patients ~$18,686 and >179 hours of travel and wait time.

Conclusions: VVs can provide high patient/provider satisfaction. While there were no negative outcomes, prospective comparisons will be required to evaluate quality and safety. Additionally, VVs offered significant time and cost savings for patients. Provider-sided economics does need to be estimated next to understand if there is similar savings before the economics of VVs is fully understood.

Optical Coherence Tomography Angiography (OCTA) Visibility of Diabetic Microaneurysms (MAs): associations with wall characteristics and blood flow parameters.
Konstantina Sampani, Omar Abu-Qamar, NIlesh Raval, Yang Lu, Miguel Bernabeu, Ward Fickweiler, Lloyd Paul Aiello, Jennifer K. Sun

Purpose: OCTA does not successfully image all MAs, yet it is unclear what determines MA OCTA visibility. Our goal was to identify diabetic MA wall characteristics on adaptive optics scanning laser ophthalmoscopy (AOSLO) as well as blood flow parameters estimated by computational fluid dynamics (CFD) modeling that are correlated with OCTA MA visibility.

Methods: Retinal MAs in diabetic eyes were imaged by AOSLO and OCTA (Optovue, software ver 2017.1.0.149) at the same visit. AOSLO images were graded for wall hyperreflectivity (WH), wall deformability (WD), cross-sectional area, clot presence, perfusion percentage and morphology. On OCTA, MAs were assessed as fully visible (FullVis), partially visible (PartVis) or not visible (NoVis). Multimodal images for each MA were registered. CFD modeling estimated shear rate drop (SRD) and wall shear stress drop (WSSD) within a subset of MAs. Statistical analyses adjusted for correlations between follow-up images of individual MAs.

Results: A total of 162 MAs (45 eyes) were imaged (259 sessions, 97 MAs with >1 follow-up). On OCTA, MAs were 58.7% (N=152) FullVis , 21.2% (55) PartVis and 20.1% (52) NoVis. FullVis MAs had greater perfusion percentage (FullVis mean±SD: 71.4±29.9%, PartVis: 52.8±32.3% NoVis: 41.5±36.4%, p<0.0001) and were also more likely to exhibit WD (WD in 29.8% FullVis vs 13.2% in PartVis or NoVis MAs, p=0.006). No relationship was identified between OCTA visibility and MA WH, area or clot presence. Within MAs that were fusiform or saccular (N=212), FullVis MAs were less likely to be saccular (FullVis: 76.0%, PartVis or NoVis: 90.1%, p=0.01). Of 16 MAs that underwent CFD modeling, FullVis MAs had lower SRD and WSSD than PartVis or NoVis MAs (SRD: 54.0±57.2 vs 59.0±68.6, p<0.0001; WSSD: 19.5±15.5 vs 28.6±24.5, p<0.0001).

Conclusions: In this study, over 40% of MAs present on AOSLO were not fully visible in superficial or deep capillary plexus OCTA images. OCTA visibility appeared to be more dependent on MA perfusion than size. Thus, OCTA evaluation of MA may particularly underestimate MAs with limited perfusion. Computational modeling may help identify MAs with slower blood flow that may be less visible on OCTA. These data support future investigations to determine the implications of MA OCTA visibility for predicting local neural retinal pathology and visual dysfunction in the diabetic eye.

Outcomes in Resident-performed Cataract Surgeries with Iris Challenges: Results from the PCIOL Study
Giannis Moustafa, Durga Borkar, K. Matthew McKay, Emily Eton, Nicole Koulisis, Carolyn Kloek

Purpose: To assess the outcomes of resident-performed cataract surgeries with iris challenges and to compare these outcomes to similar surgeries performed by attending physicians.

Setting: Massachusetts Eye and Ear Infirmary, Harvard Medical School.

Design: Retrospective chart review.

Methods: All cases of cataract extraction by phacoemulsification with intraocular lens insertion performed by comprehensive ophthalmologists between January 1 and December 31, 2014, were reviewed, and cases with pre- or intraoperative miosis, iris prolapse, and floppy iris syndrome (IFIS), were included. Visual outcomes and the rate of perioperative untoward events were compared for resident and attending cases. Factors predicting untoward events were also assessed.

Results: In total, 1931 eye cases of 1434 patients were reviewed, and 65 resident and 168 attending cases were included. Mean logMAR best-corrected visual acuity was better in the resident group one month after surgery (0.051±0.10 versus 0.132±0.30, p=0.03), but the difference was eliminated when controlling for macular disease. Mean operative time was 43.8±26.5 and 30.9±12.6 minutes for cases performed by resident and attending surgeons, respectively (p<0.0001). Residents utilized supplemental pharmacologic dilation or retraction more frequently than attendings (98% versus 87% of cases, p=0.008). The overall rate of untoward events was no different between residents and attendings (p=0.16). Dense nuclear sclerosis predicted untoward events in cataract cases with iris challenges (adjusted odds ratio=1.86, p=0.001, 95% confidence interval 1.17-2.94).

Conclusions: Although requiring a longer operative time and more surgical manipulation, resident-performed cataract surgeries with iris challenges achieve outcomes comparable to those performed by attending surgeons, and residents should be given the opportunity to operate on these cases.

The effect of epiretinal membrane on drusen volume as quantified by SD-OCT
Emily Li, Omar Shakir, James Kempton, Patrick Coady

Background: Macular drusen is a characteristic feature of age-related macular degeneration (AMD), a common disease affecting one in ten adults 75 years and older.1 The pathophysiology behind drusen accumulation remains uncertain, and there is no known treatment to decrease drusen load, though there have been reports of spontaneous drusen resorption and drusen regression after laser photocoagulation, rhegmatogenous retinal detachment, intravitreal anti-vascular endothelial growth factor injection, and vitrectomy with internal limiting membrane peeling.2,3 Select cases from our clinical context suggest there may be an unexplored relationship between the macular drusen present in non-exudative AMD and epiretinal membranes (ERM).

Objective: We aimed to quantitatively investigate the relationship between presence of ERM and macular drusen volume in patients with non-exudative AMD.

Methods: We retrospectively searched records from January 1, 2007 to December 31, 2016 to identify patients who have concurrent diagnoses of macular drusen or non-exudative AMD and ERM using ICD-9 and ICD-10 billing codes. Exclusion criteria included age under 18 years and history of trauma, intravitreal injection, exudative AMD, retinal laser photocoagulation, vitreoretinal surgery, and diabetes mellitus. Of the 163 patients identified, 8 met the inclusion criteria of having macular drusen in both eyes and ERM in one eye, as well as available Heidelberg spectral domain optical coherence tomography (SD-OCT) imaging. Our primary outcome was macular drusen volume in a 6 mm-diameter macular area on SD-OCT, obtained using Heidelberg segmentation software. We derived the drusen volume between Bruch’s membrane (BM) and the retinal pigment epithelium (RPE) by first removing automated segmentation of each retinal layer. We manually outlined BM and the RPE such that there was space between the two lines only when drusen was present and obtained volume through Heidelberg segmentation software. Two investigators independently performed this task and average volumes between the two data sets were used in analysis. The Yale University Institutional Review Board approved this study.

Result: The averaged drusen volume was higher in the eye without an ERM compared to the ERM eye in eight out of eight patients. The eyes without an ERM had a mean drusen volume of 0.256 mm3 [+/- 0.153 mm3] while the fellow eyes with an ERM had a mean drusen volume of 0.188 mm3 [+/- 0.063 mm3]. A two-tailed paired t-statistic test yielded a p-value of 0.150.

Conclusion: Our cohort of non-exudative AMD patients with concurrent bilateral macular drusen and unilateral ERM had lower drusen volumes in the ERM eye compared to the fellow eye, as measured by manual segmentation on Heidelberg SD-OCT. Although this difference was not statistically significant in our sample, all eight patients conformed to this trend. Findings warrant further investigation in the relationship between ERM and drusen accumulation with a larger study size. Elucidating a better understanding of macular drusen deposits, a finding present in various vision-threatening diseases including AMD, may benefit global comprehension of their pathophysiology and the driving forces behind the disease processes in which they manifest.

Optimization of the Diagnosis and Management of Retrobulbar Hemorrhages in the Adult Emergency Room Setting: A Residents-Educating-Residents Initiative
Emily Li, Venkatesh Brahma, Andrew Pouw, Russell Levine, Julie Cho, Jessica Chow

Background: Retrobulbar hemorrhages are one of the most serious ophthalmological emergencies often presenting first to the emergency room setting. Prompt diagnosis and rapid intervention—lateral canthotomy and cantholysis—are crucial to visual prognosis. Given this urgency, it is fundamental to optimize the efficiency and efficacy of recognition and intervention. In the Yale-New Haven Hospital (YNHH) Adult Emergency Department (ED), emergency room providers are almost always the first responders to patients with retrobulbar hemorrhages, followed subsequently by ophthalmology residents. It is unknown whether a formalized curriculum for emergency medicine residents would enhance the preparation of providers to recognize and treat patients with retrobulbar hemorrhages presenting to the YNHH Adult ED.

Methods: We conducted a prospective interventional study to investigate the effect of implementing a formalized resident-teaching-residents curriculum on the preparation of emergency department residents. Our intervention consisted of a 45-minute lecture designed to educate emergency medicine residents on the recognition and treatment of retrobulbar hemorrhages. Our primary outcome measure was the difference in scores from a one-paged written assessment given prior to and after the intervention. The evaluation consisted of five prompts that measured subjective comfort level and objective knowledge base. We asked each resident to disclose their post-graduate year (PGY) and the number of lateral canthotomy and cantholysis procedures they performed prior to our intervention. We used paired t-test to compare scores from before and after our intervention and analysis of variance (ANOVA) to compare scores among the PGY cohorts. We used a two-tailed p-value cutoff of <0.1 to indicate statistical significance.

Results: A total of 21 emergency department residents—six PGY-1, seven PGY-2, two PGY-3, and seven PGY-4—were included in the study. Of these, two residents indicated they each have performed one lateral canthotomy and cantholysis procedure before the study intervention. The mean score was 1.86 prior to intervention and 3.55 after intervention (p <0.0001). We did not perform subgroup analysis within each PGY cohort given their lower n-values do not provide enough statistical power. There was no statistically significant difference in scores among the three PGY cohorts (p = 0.64).

Conclusion: Retrobulbar hemorrhages are sight-threatening emergencies that require prompt recognition and management through the performance of a lateral canthotomy and canthoysis to prevent permanent vision loss. We implemented a peer education initiative that significantly improved the preparation of YNHH emergency medicine residents to be able to provide appropriate care for patients with retrobulbar hemorrhages in the YNHH ED.

THBS1 polymorphism associated with increased risk of pterygium and altered thrombospondin-1 expression
Vinny Keshav, Lilla Simon, Connor Baharozian, Rebecca Regan, Sharmila Masli, Hyunjoo Lee

Purpose: The pathogenesis of pterygium and its associated risk factors, beyond that of UV exposure, are poorly understood. A thrombospondin 1 gene (THBS1) single nucleotide polymorphism (SNP) (rs1478604) was previously found to confer increased risk of post-LASIK dry eye syndrome (DES) and was associated with decreased ocular surface glycoprotein thrombospondin 1 expression.

Our aims were to determine if rs1478604 is also associated with an increased risk of pterygium formation and whether the associated decreased THBS1 expression on the ocular surface can also be observed in peripheral blood.

Methods: This research followed the tenets of the Declaration of Helsinki. The institutional review board of the Boston Medical Center approved the study protocol. All patients gave informed written consent.

Portions of pterygium tissue were obtained from 42 patients undergoing pterygium excision. Genomic DNA was isolated for each subject, and THBS1 SNP rs1478604 was genotyped. The rs1478604 genotypes were compared between pterygium and normal subjects according to a recessive model as above. Groups were compared using a student’s T test.

Peripheral blood was obtained from 34 normal subjects without pterygium. RNA was isolated from peripheral blood samples and qRT-PCR was performed in a standard fashion. The normal subjects were divided by rs1478604 genotype according to a recessive model (TT+TC vs CC), and the relative expression of THBS1 mRNA was compared between the 2 groups using relative quantification. Groups were compared using a Student’s unpaired T test with Welch’s correction.

Results: The minor allele of THBS1 SNP rs1478604 was associated with increased odds of having pterygium. Using a recessive model, the frequency of minor allele (CC) homozygosity was 35% in subjects with pterygium, compared to 7.6% in normal subjects (odds ratio [OR] = 6.667; 95% confidence interval [CI] = 1.752-25.37; p = 0.003)

There was also a significant difference in decreased peripheral blood THBS1 mRNA expression in subjects carrying the minor allele of rs1478604. (25.67 + 5.125 in TT+TC vs 8.924 ± 1.540 in CC; p = 0.0037)

Conclusions: The minor allele of THBS1 SNP rs1478604 was associated with an increased risk of pterygium formation and decreased THBS1 mRNA expression in peripheral blood.

Based upon our current study, the THBS1 SNP rs1478604 may be related to increased risk of pterygium formation. Based on previous studies, the minor allele of rs1478604 is related to decreased ocular surface expression and our current study suggests a more universal association. This SNP may also serve as a potential peripheral marker for ocular surface inflammation.