Publications

2021

Seto B, Singh M, Lemire C, Arroyo J. Anterior versus posterior endoscopic cyclophotocoagulation: comparison of indications, populations, and outcomes. Int Ophthalmol. 2021;41(9):3021–3028.
PURPOSE: To examine how indications, patient characteristics, and outcomes differ between anterior and posterior approaches of endoscopic cyclophotocoagulation (ECP) in the treatment of glaucoma. METHODS: This is a retrospective chart review of 9 anterior and 20 posterior ECP cases (n = 29). RESULTS: Posterior ECP cases were typically associated with a dramatic increase in intraocular pressure (IOP), whereas the anterior ECP was associated with chronically elevated pressures. The initial IOPs in mm Hg of posterior ECP cases (26.8 non-NVG; 35.2 NVG) were much greater than anterior ECP cases (17.8), and a greater overall reduction in IOP was observed in the posterior versus anterior ECP cases (10.3 posterior non-NVG; 21.3 posterior NVG; 3.6 anterior, P < .001). With procedural success defined as 6-month post-operative IOP falling within normal ranges and a decrease in either IOP or number of prescribed glaucoma medications, the success rate of ECP was 92% for posterior NVG, 89% for anterior and 75% for posterior non-NVG cases (P = .34), similar to the previous literature. Of the four unsuccessful cases, two resulted in a normal IOP but lacked a drop in pressure or reduction in medication burden, one resulted in a 6-point drop in IOP but remained at 23 mm Hg, and one resulted in phthisis bulbi (3%) from an initial pressure above 40 mm Hg. CONCLUSION: Endoscopic cyclophotocoagulation is an effective and safe procedure for severe glaucoma cases from both an anterior and posterior approach. Ophthalmologists should consider this procedure as part of their glaucoma treatment arsenal.
Lonfat N, Wang S, Lee C, Garcia M, Choi J, Park P, Cepko C. Cis-regulatory dissection of cone development reveals a broad role for Otx2 and Oc transcription factors. Development. 2021;148(9).
The vertebrate retina is generated by retinal progenitor cells (RPCs), which produce >100 cell types. Although some RPCs produce many cell types, other RPCs produce restricted types of daughter cells, such as a cone photoreceptor and a horizontal cell (HC). We used genome-wide assays of chromatin structure to compare the profiles of a restricted cone/HC RPC and those of other RPCs in chicks. These data nominated regions of regulatory activity, which were tested in tissue, leading to the identification of many cis-regulatory modules (CRMs) active in cone/HC RPCs and developing cones. Two transcription factors, Otx2 and Oc1, were found to bind to many of these CRMs, including those near genes important for cone development and function, and their binding sites were required for activity. We also found that Otx2 has a predicted autoregulatory CRM. These results suggest that Otx2, Oc1 and possibly other Onecut proteins have a broad role in coordinating cone development and function. The many newly discovered CRMs for cones are potentially useful reagents for gene therapy of cone diseases.
Huang G, Melki S. Small Incision Lenticule Extraction (SMILE): Myths and Realities. Semin Ophthalmol. 2021;36(4):140–148.
The emergence of SMILE in the last decade has provided an alternative to LASIK for patients considering cornea laser refractive surgery. SMILE offers a novel approach using the femtosecond laser to create an intrastromal lenticule that can be removed through a small three to four millimeter incision.The purpose of this study is to review the recent literature on popular SMILE claims - reduced iatrogenic dry eye, better recovery of corneal sensation, and a biomechanically stronger cornea - summarize the published outcomes, and determine which claims are myths versus realities.SMILE is still in its infancy as a refractive technique in the US after recent USFDA approval for its treatment of myopia astigmatism in October 2018. Future randomized controlled studies are needed to compare its outcomes to LASIK, which has well-documented good visual outcomes, rapid postoperative recovery, and good safety profile.
Memories are encoded in a manner that depends on our knowledge and expectations ("schemas"). Consistent with this, expertise tends to improve memory: Experts have elaborated schemas in their domains of expertise, allowing them to efficiently represent information in this domain (e.g., chess experts have enhanced memory for realistic chess layouts). On the other hand, in most situations, people tend to remember abnormal or surprising items best-those that are also rare or out-of-the-ordinary occurrences (e.g., surprising-but not random-chess board configurations). This occurs, in part, because such images are distinctive relative to other images. In the current work, we ask how these factors interact in a particularly interesting case-the domain of radiology, where experts actively search for abnormalities. Abnormality in mammograms is typically focal but can be perceived in the global "gist" of the image. We ask whether, relative to novices, expert radiologists show improved memory for mammograms. We also test for any additional advantage for abnormal mammograms that can be thought of as unexpected or rare stimuli in screening. We find that experts have enhanced memory for focally abnormal images relative to normal images. However, radiologists showed no memory benefit for images of the breast that were not focally abnormal, but were only abnormal in their gist. Our results speak to the role of schemas and abnormality in expertise; the necessity for spatially localized abnormalities versus abnormalities in the gist in enhancing memory; and the nature of memory and decision-making in radiologists.
Chang EK, Gupta S, Chachanidze M, Hall N, Chang TC, Sola-Del Valle D. Safety and efficacy of microinvasive glaucoma surgery with cataract extraction in patients with normal-tension glaucoma. Sci Rep. 2021;11(1):8910.
This study assesses the safety and efficacy of microinvasive glaucoma surgery (MIGS) with cataract extraction in patients with normal-tension glaucoma (NTG). In our sample of 45 NTG patients, mean intraocular pressure (IOP) decreased from 13.7 to 12.3 mmHg at 2.5 years, and mean medication burden decreased from 2.0 to 1.1 at 1.5 years. For success defined as IOP reduction ≥ 30% from baseline IOP with medication burden reduction from preoperative levels, success probability was 5.4% at 1.5 years. For success defined as medication burden reduction with an IOP reaching goal IOP as determined by the glaucoma specialist, success probabilities were 67.2% at 1.5 years and 29.4% at 2.5 years. At the last follow-up visit, eyes with two MIGS procedures with different mechanisms of action achieved successful medication reduction 68.8% of the time versus 35.7% achieved by a single MIGS procedure (p = 0.052). At their last visit, visual acuity was unchanged or improved in all eyes (100%). MIGS with cataract surgery results in modest reductions in IOP and medication burden in NTG patients, which may lead to lower costs and better therapeutic compliance. A combination of two MIGS procedures with different mechanisms of action may potentially be more effective in reducing medication burden than a single MIGS procedure in NTG patients. Further research is necessary to ascertain whether MIGS for NTG patients may help decrease medication burden while helping achieve goal IOP.
Elhusseiny A, VanderVeen D. Early Experience With Ahmed Clear Path Glaucoma Drainage Device in Childhood Glaucoma. J Glaucoma. 2021;30(7):575–578.
PURPOSE: The aim was to evaluate the short-term outcomes of Ahmed clear path (ACP) valveless glaucoma drainage device in childhood glaucoma. METHODS: Retrospective chart review of all patients 16 years or below with childhood glaucoma who had ACP implantation at Boston Children's Hospital from December 2019 to June 2020 with at least 6 months follow-up period. RESULTS: The study included 7 eyes of 5 patients implanted by a single surgeon. The median follow-up was 12 months. The mean intraocular pressure (IOP) was reduced from 36±3.5 mm Hg on a mean of 2.7±0.6 glaucoma medications preoperatively to a mean IOP of 12.4±2.8 mm Hg (P<0.001) on a mean of 0.7±0.8 medications postoperatively at final follow-up (P=0.0009). Complete success was achieved in 4 eyes while qualified success was achieved in 3 eyes. CONCLUSION: The ACP glaucoma drainage device provided good short-term IOP control and technical advantages for implantation for pediatric eyes were observed.
Purpose: Ocular findings such as retinal hemorrhages are common in abusive head trauma (AHT). Binocular indirect ophthalmoscopy has been the standard for assessing the eyes of children who are victims of AHT. However, technological advances have changed our understanding of retinal findings in AHT.Methods: Literature review on AHT - retinal findings, imaging technologies, models of representation, and telemedicine applications.Results: Many studies suggest vitreoretinal traction from repetitive acceleration-deceleration shearing forces during shaking plays an important role in the development of retinal findings in AHT. This is further supported by different imaging modalities [optical coherence tomography (OCT); magnetic resonance imaging (MRI); fluorescein angiography (FA)] and models of representation (animal and mechanical models; finite element analysis).Conclusion: Emerging technologies have augmented our diagnostic abilities, enhanced our understanding regarding the pathophysiology of retinal findings, and strengthened the link between vitreoretinal traction and ocular pathology in AHT. Telemedicine is also starting to play an important role in AHT.