Aakriti Garg

Reticular pseudodrusen in early age-related macular degeneration are associated with choroidal thinning.

PURPOSE To compare choroidal thickness (CT) measurements in early AMD between patients with and without reticular pseudodrusen (RPD) using spectral-domain optical coherence tomography (SD-OCT). METHODS This cross-sectional study examined 84 age- and sex-matched AMD patients (40 RPD [63 eyes], 44 non-RPD [75 eyes]). Fundus photographs and scanning laser ophthalmoscopy images were graded to identify RPD and non-RPD groups by three retinal specialists (MO, SY, SB) who were masked to corresponding SD-OCTs. CT at the fovea and 2400 to 3000 μm superior and inferior to the fovea was measured on SD-OCT by a grader (AG) and reviewed by a retinal specialist (SB). Only images with a clear posterior choroidal margin were analyzed (six eyes excluded due to poor image quality), and enhanced depth imaging SD-OCT was used when available (20 of 138 eyes). Greatest retinal thickness (RT) on horizontal foveal SD-OCT was also recorded. RESULTS Mean CTs in the superior, foveal, and inferior macula in RPD (191.3 μm ± 57.9 SD, 176.3 μm ± 60.5 SD, 179.7 μm ± 56.24 SD) were significantly less than that of non-RPD (228.0 μm ± 66.1 SD, 216.5 μm ± 70.3 SD, 224.4 μm ± 71.9 SD; P = 0.0010, P = 0.0005, P = 0.0001, respectively), as was greatest RT (P = 0.0301). CONCLUSIONS CT was thinner throughout the macula in the RPD group as compared with the non-RPD group. The current analysis supports an association between RPD and a thinned choroidal layer and is consistent with a choroidal etiology of RPD. CT may be integral to understanding RPD, and may be helpful in stratifying AMD progression risk.

Stem Cell Therapies in Retinal Disorders

Stem cell therapy has long been considered a promising mode of treatment for retinal conditions. While human embryonic stem cells (ESCs) have provided the precedent for regenerative medicine, the development of induced pluripotent stem cells (iPSCs) revolutionized this field. iPSCs allow for the development of many types of retinal cells, including those of the retinal pigment epithelium, photoreceptors, and ganglion cells, and can model polygenic diseases such as age-related macular degeneration. Cellular programming and reprogramming technology is especially useful in retinal diseases, as it allows for the study of living cells that have genetic variants that are specific to patients’ diseases. Since iPSCs are a self-renewing resource, scientists can experiment with an unlimited number of pluripotent cells to perfect the process of targeted differentiation, transplantation, and more, for personalized medicine. Challenges in the use of stem cells are present from the scientific, ethical, and political realms. These include transplant complications leading to anatomically incorrect placement, concern for tumorigenesis, and incomplete targeting of differentiation leading to contamination by different types of cells. Despite these limitations, human ESCs and iPSCs specific to individual patients can revolutionize the study of retinal disease and may be effective therapies for conditions currently considered incurable.

Choroidal and Retinal Thickening in Severe Preeclampsia

PURPOSE To compare choroidal thickness and retinal macular volume (RMV) among three groups of women: severe preeclampsia postpartum, normotensive postpartum, and normotensive nongravid. While visual disturbances often accompany severe preeclampsia, the underlying choroidal and retinal changes responsible for these symptoms have not been described. METHODS This case-control study was based on 15 severe preeclampsia cases and 15 ethnicity- and parity-matched normotensive controls recruited during the postpartum hospital stay. A reference group of 19 age-matched, nongravid, normotensive women was also studied. Choroidal thickness and RMV were measured by using enhanced depth imaging spectral-domain optical coherence tomography. Two retinal specialists, one of whom was masked to the case-control status, reviewed all images. RESULTS Severe preeclampsia cases demonstrated greater mean choroidal thickness (425 ± 90 μm vs. 354 ± 140 μm; P = 0.021) and RMV (9.0 ± 0.4 mm(3) vs. 8.7 ± 0.5 mm(3); P = 0.006) than controls. In contrast, control and reference groups were similar with respect to choroidal thickness (354 ± 140 μm vs. 363 ± 82 μm; P = 0.764) and RMV (8.7 ± 0.5 mm(3) vs. 8.8 ± 0.4 mm(3); P = 0.870). Follow-up imaging of two severe preeclampsia cases within 3 months of delivery revealed decreasing choroidal thickness. CONCLUSIONS Our results demonstrate subclinical retinal and choroidal thickening in the setting of severe preeclampsia. This is the likely source of its associated visual phenomena and may reflect rising levels of vascular endothelial growth factor. Retinal and choroidal markers could serve as novel predictive markers of severe preeclampsia.

Bilateral Orbital Abscesses After Strabismus Surgery.

Infectious orbital complications after strabismus surgery are rare. Their incidence is estimated to be 1 case per 1,100 surgeries and include preseptal cellulitis, orbital cellulitis, subconjunctival and sub-Tenons abscesses, myositis, and endophthalmitis. This report describes the case of an otherwise healthy 3-year-old boy who underwent bilateral medial rectus recession and disinsertion of the inferior obliques. A few days after surgery, the patient presented with bilateral periorbital edema and inferotemporal chemosis. A series of CT scans with contrast revealed inferotemporal orbital collections OU. The patient immediately underwent transconjunctival drainage of fibrinous and seropurulent collections in the sub-Tenons space and experienced rapid improvement a few days later. The patient is reported to be in stable condition in a follow-up examination performed more than a year after the reported events.

Associations Between β-Peripapillary Atrophy and Reticular Pseudodrusen in Early Age-Related Macular Degeneration

Purpose Choroidal thinning has been associated with reticular pseudodrusen (RPD) and β-peripapillary atrophy (β-PPA), which have been linked to normal-tension glaucoma (NTG). This analysis sought to determine whether RPD are independently associated with β-PPA in early AMD patients. Secondary outcomes included the association of RPD and preexisting diagnosis of glaucoma, cup-to-disc ratio (CDR), subfoveal choroidal thickness (SFCT), and IOP. Methods This prospective cross-sectional study examined 78 age- and sex-matched early AMD patients: 43 RPD patients (63 eyes) and 35 non-RPD patients (64 eyes). Exclusion criteria included advanced AMD, high myopia, and vitreoretinal conditions/surgery. RPD and non-RPD groups were identified by confocal scanning laser ophthalmoscopy. β-PPA as well as CDR were graded on digital, nonstereoscopic fundus photos. SFCT was measured on spectral-domain optical coherence tomography for 69 patients (35 RPD and 34 non-RPD). IOP and glaucoma diagnosis were extracted from charts. Results β-PPA had a greater prevalence in RPD than non-RPD (44% vs. 19%, P = 0.002); however, this relationship was not significant when SFCT was added to the model (P = 0.150). A preexisting diagnosis of glaucoma (P = 0.156), CDR (P = 0.176), and IOP (P = 0.98) was not different between groups. Conclusions RPD in early AMD are associated with presence of β-PPA, but choroidal thickness is a confounder in this relationship. Because β-PPA is a common finding in NTG, focusing on a potential shared pathway between RPD and NTG could improve the understanding of pathophysiology and expand therapies for each condition.

Using Anterior Segment Optical Coherence Tomography to Monitor Disease Progression in Peripheral Ulcerative Keratitis

We report two cases of peripheral ulcerative keratitis (PUK) imaged with anterior segment optical coherence tomography (AS-OCT). The first patient had prolonged nonsteroidal anti-inflammatory drug use, while the second had inflammatory arthritis by laboratory findings without any systemic findings as well as possible concurrent tuberculosis. In both patients, AS-OCT demonstrated corneal thinning at the onset of the disease with improvement six months after initiation of intensive medical therapy. Our cases highlight the need for a multidisciplinary approach and careful monitoring in PUK cases, especially with objective measures such as corneal thickness assessed with AS-OCT.

PROPHYLACTIC PREOPERATIVE LASER RETINOPEXY DOES NOT REDUCE THE OCCURRENCE OF RHEGMATOGENOUS RETINAL COMPLICATIONS IN MACULAR SURGERY.

Purpose: Knowledge on the utility of prophylactic 360° laser retinopexy before pars plana vitrectomy in the absence of peripheral retinal pathology is limited. This study compares the occurrence of rhegmatogenous events in the setting of small-gauge pars plana vitrectomy with and without prophylactic preoperative laser. Methods: Our multicenter, retrospective case–control analysis reviewed patients who underwent epiretinal membrane removal or macular hole repair through 23- or 25-gauge pars plana vitrectomy: 205 controls who did not receive prophylactic laser and 176 cases who received preoperative prophylactic laser retinopexy anterior to the equator. Main outcome measures were the rate and characteristics of postoperative retinal tears and detachments. Patients with previous pars plana vitrectomy or significant retinal disease were excluded. Results: Of those patients with prophylactic laser and those without, there was no significant difference in the number of retinal breaks (1.7% vs. 0.49%, respectively; P = 0.339) or retinal detachments (0% vs. 0.49%, respectively; P = 1.00). Of the lasered group, there was one sclerotomy-related retinal break and two non–sclerotomy-related retinal breaks. Of the nonlasered group, there was one non–sclerotomy-related retinal break and one sclerotomy-related retinal detachment. Conclusion: Preoperative prophylactic peripheral laser retinopexy does not seem to offer an added benefit in the prevention of intraoperative and postoperative rhegmatogenous events.

Peripapillary sparing in RDH12-associated Leber congenital amaurosis

ABSTRACT Background: Peripapillary sparing is a characteristic that is traditionally described as pathognomonic for Stargardt disease. Materials and methods: We present a multimodal assessment of four Leber congenital amaurosis (LCA) cases with congenital macular atrophy and severely attenuated electroretinogram findings caused by bilallelic mutations in RDH12. Results: Fundus autofluorescence imaging revealed a general loss of retinal pigment epithelium across the macula except for the peripapillary region in both eyes of all patients. Spectral domain-optical coherence tomography confirmed relative preservation in this area along with retinal thinning and excavation throughout the rest of the macula. LCA was diagnosed based on clinical exam and retinal imaging, and subsequently confirmed with genetic testing. Conclusions: Peripapillary sparing is a novel phenotypic feature of RDH12-associated LCA.