Small Leucine-Rich Proteoglycans (SLRPs) in the Retina.

Retinal diseases such as age-related macular degeneration (AMD), retinopathy of prematurity (ROP), and diabetic retinopathy (DR) are the leading causes of visual impairment worldwide. There is a critical need to understand the structural and cellular components that play a vital role in the pathophysiology of retinal diseases. One potential component is the family of structural proteins called small leucine-rich proteoglycans (SLRPs). SLRPs are crucial in many fundamental biological processes involved in the maintenance of retinal homeostasis. They are present within the extracellular matrix (ECM) of connective and vascular tissues and contribute to tissue organization and modulation of cell growth. They play a vital role in cell-matrix interactions in many upstream signaling pathways involved in fibrillogenesis and angiogenesis. In this comprehensive review, we describe the expression patterns and function of SLRPs in the retina, including Biglycan and Decorin from class I; Fibromodulin, Lumican, and a Proline/arginine-rich end leucine-rich repeat protein (PRELP) from class II; Opticin and Osteoglycin/Mimecan from class III; and Chondroadherin (CHAD), Tsukushi and Nyctalopin from class IV.

Surgical Timing for Congenital Ptosis Should Not Be Determined Solely by the Presence of Anisometropia.

PURPOSE: Timing of surgery in children with congenital ptosis is a critical component of care, and anisometropia is frequently cited as an indication for early intervention. The purpose of this study is to evaluate the change in refractive error following surgery for congenital ptosis to better inform decisions regarding the timing of surgery. METHODS: A retrospective review of clinical records was performed on patients who underwent surgical correction of congenital ptosis in an academic oculoplastic surgery practice from 2002 to 2017. Patients with complete preoperative and postoperative refractive data were included in the study. Changes in refractive error following surgery were analyzed. RESULTS: Among 184 pediatric patients who underwent ptosis surgery during the study period, 56 patients (71 eyes) met inclusion criteria. The mean age at surgery was 5.1 years. Mean refractive error change in all the operated eyes was a 0.82 D decrease in spherical equivalent (p = 0.1920) and a 0.40 D increase in cylinder (p = 0.0255). There were no statistically significant changes in spherical equivalent or cylinder in the control eyes. CONCLUSIONS: The authors data did not show movement toward normalization of refractive error following ptosis surgery. In fact, it showed a statistically significant worsening of astigmatism following surgery. Because refractive error does not improve following surgery, anisometropia should not be the sole indication for early surgery in congenital ptosis.

Foveal Development in Infants Treated with Bevacizumab or Laser Photocoagulation for Retinopathy of Prematurity.

PURPOSE: To characterize and quantify early foveal development in preterm infants and to compare this development between eyes treated with intravitreal bevacizumab or laser photocoagulation (LPC) and untreated eyes. DESIGN: Observational case series. PARTICIPANTS: One hundred thirty-one preterm infants undergoing retinopathy of prematurity (ROP) screenings. METHODS: Handheld OCT imaging was performed longitudinally on all patients. Thickness measurements of the inner and outer retinal layers were obtained at the foveal center and the nasal and temporal foveal rims. Comparisons between treated and untreated eyes were adjusted for age and other confounding variables. MAIN OUTCOME MEASURES: Weekly change in inner and outer retinal thickness and presence of inner retinal layers, ellipsoid zone (EZ), and cystoid macular changes (CMCs). RESULTS: Outer retinal thickness at the foveal center increased by 3.1 µm/week in untreated eyes and 7.2 µm/week in bevacizumab-treated eyes (P = 0.038). Eyes treated with LPC had a lower probability of having all inner retinal layers present at the foveal center (odds ratio, 0.04; P = 0.001) and a lower probability of having the EZ present at the foveal center (odds ratio, 0.07; P = 0.024) compared with untreated eyes. Cystoid macular changes were found in 53% of patients and 22% of imaging sessions. The age-adjusted incidence of CMCs was not correlated with bevacizumab or LPC treatment. CONCLUSIONS: Intravitreal bevacizumab therapy for ROP is associated with more rapid outer retinal thickening at the foveal center, whereas LPC is associated with earlier extrusion of the inner retinal layers and delayed development of the EZ at the foveal center. Long-term follow-up is needed to determine the visual significance of these findings.

Secondary glaucoma after bevacizumab injection in Type-1 retinopathy of prematurity.

Purpose: The authors report three separate cases of type 1 retinopathy of prematurity (ROP) treated with intravitreal bevacizumab before, or at 34 weeks postmenstrual age (PMA), with subsequent development of secondary glaucoma. Observations: All three cases involve patients born ≤24 weeks and meeting the American Academy of Pediatrics criteria for ROP screening. Prior to treatment, each patient was noted to have normal anterior chamber structures with no signs of glaucoma. Each patient developed type 1 ROP and was treated with intravitreal bevacizumab, which was administered at or before 34 weeks PMA. Following the administration of intravitreal anti-vascular endothelial growth factor (VEGF), each patient developed a suspected open-angle glaucoma (OAG) within an approximate 4-week time frame. In these cases, the presentation of glaucoma differed from those that have been previously reported in the literature. Conclusion and importance: Based on similar timing of glaucoma development following intravitreal bevacizumab injections, we hypothesize that the administration of anti-VEGF agents to very premature infants (≤24 weeks) at or before 34 weeks PMA, may predispose them to the development of secondary glaucoma through an unknown and possibly novel pathway.

In Vivo Assessment of Retinal Phenotypes in Axenfeld-Rieger Syndrome.

Purpose: Axenfeld-Rieger syndrome (ARS) is characterized by ocular anomalies including posterior embryotoxon, iridocorneal adhesions, corectopia/iris hypoplasia, and developmental glaucoma. Although anterior segment defects and glaucoma contribute to decreased visual acuity, the role of potential posterior segment abnormalities has not been explored. We used high-resolution retinal imaging to test the hypothesis that individuals with ARS have posterior segment pathology. Methods: Three individuals with FOXC1-ARS and 10 with PITX2-ARS completed slit-lamp and fundus photography, optical coherence tomography (OCT), OCT angiography, and adaptive optics scanning light ophthalmoscopy (AOSLO). Quantitative metrics were compared to previously published values for individuals with normal vision. Results: All individuals demonstrated typical anterior segment phenotypes. Average ganglion cell and inner plexiform layer thickness was lower in PITX2-ARS, consistent with the glaucoma history in this group. A novel phenotype of foveal hypoplasia was noted in 40% of individuals with PITX2-ARS (but none with FOXC1-ARS). Moreover, the depth and volume of the foveal pit were significantly lower in PITX2-ARS compared to normal controls, even excluding individuals with foveal hypoplasia. Analysis of known foveal hypoplasia genes failed to identify an alternative explanation. Foveal cone density was decreased in one individual with foveal hypoplasia and normal in six without foveal hypoplasia. Two individuals (one from each group) demonstrated non-foveal retinal irregularities with regions of photoreceptor anomalies on OCT and AOSLO. Conclusions: These findings implicate PITX2 in the development of the posterior segment, particularly the fovea, in humans. The identified posterior segment phenotypes may contribute to visual acuity deficits in individuals with PITX2-ARS.

Subclinical macular findings in infants screened for retinopathy of prematurity with spectral-domain optical coherence tomography.

OBJECTIVE: To evaluate subclinical macular findings in premature patients at risk of retinopathy of prematurity (ROP) with the use of handheld spectral-domain optical coherence tomography (SD-OCT). DESIGN: Prospective, observational case series. PARTICIPANTS: Forty-nine prematurely born neonates. METHODS: Forty-nine infants were imaged using a handheld SD-OCT. Images were acquired in nonsedated infants in the neonatal intensive care unit (NICU). Some patients were followed and reimaged over the course of several weeks. A total of 300 total images were acquired and evaluated for cystoid macular edema (CME) and persistence of inner retinal layers. MAIN OUTCOME MEASURES: In vivo determination of foveal retinal lamination, image analysis, and clinical observation. RESULTS: A total of 241 (80%) of the images from 46 patients were usable (defined as having scans passing through the fovea with clearly identifiable retinal layers). Persistence of 1 or more inner retinal layers was seen in 43 of the patients with usable images (93%). Of the patients with at least 1 persistent layer, 17, 4, 8, 12, and 1, had a maximum ROP stage of 0, 1, 2, 3, and 4A, respectively. Cystoid macular edema was seen in 25 of the 46 patients (54%) during 1 or more imaging sessions. Cystoid macular edema was present in 9, 1, 5, 9, and 1 patient with maximum ROP stage of 0, 1, 2, 3, and 4A, respectively. CONCLUSIONS: Our data suggest there is persistence of inner retinal layers in premature infants regardless of maximal ROP stage. Subclinical CME is seen in premature infants; however, CME does not appear to be correlated with ROP stage. This suggests that there may be other causes for the CME seen in this patient population. Hand-held SD-OCT imaging is a viable technique for evaluating subclinical macular findings in premature infants, although larger datasets are needed from multiple centers to further evaluate the generalizability of these findings. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Association between myopia progression and quantity of laser treatment for retinopathy of prematurity.

BACKGROUND: Previous studies found that infants with retinopathy of prematurity (ROP) who were treated for more posterior disease with a greater number of laser spots developed higher myopia. These studies included multiple physicians with variations in laser density. In treatments by a single physician, laser spot count is a better surrogate for area of avascular retina and anterior-posterior location of disease, so that the relationship with myopia can be better assessed. METHODS: Our retrospective study included infants treated with laser for ROP by a single surgeon at a single center. Exclusion criteria were irregularities during laser and additional treatment for ROP. We assessed correlation between laser spot count and change in refractive error over time using a linear mixed effects model. RESULTS: We studied 153 eyes from 78 subjects treated with laser for ROP. The average gestational age at birth was 25.3±1.8 weeks, birth weight 737±248 grams, laser spot count 1793±728, and post-treatment follow up 37±29 months. Between corrected ages 0-1 years, the mean spherical equivalent was +0.4±2.3 diopters; between ages 1-2, it was -1.3±3.2D; and ages 2-3 was -0.8±3.1D. Eyes that received more laser spots had significantly greater change in refractive error over time (0.30D more myopia per year per 1000 spots). None of the eyes with hyperopia before 18 months developed myopia during the follow-up period. CONCLUSIONS: Greater myopia developed over time in infants with ROP treated by laser to a larger area of avascular retina.

Decorin Concentrations in Aqueous Humor of Patients with Diabetic Retinopathy.

Diabetic retinopathy (DR) is a microvascular complication of diabetes in the retina. Chronic hyperglycemia damages retinal microvasculature embedded into the extracellular matrix (ECM), causing fluid leakage and ischemic retinal neovascularization. Current treatment strategies include intravitreal anti-vascular endothelial growth factor (VEGF) or steroidal injections, laser photocoagulation, or vitrectomy in severe cases. However, treatment may require multiple modalities or repeat treatments due to variable response. Though DR management has achieved great success, improved, long-lasting, and predictable treatments are needed, including new biomarkers and therapeutic approaches. Small-leucine rich proteoglycans, such as decorin, constitute an integral component of retinal endothelial ECM. Therefore, any damage to microvasculature can trigger its antifibrotic and antiangiogenic response against retinal vascular pathologies, including DR. We conducted a cross-sectional study to examine the association between aqueous humor (AH) decorin levels, if any, and severity of DR. A total of 82 subjects (26 control, 56 DR) were recruited. AH was collected and decorin concentrations were measured using an enzyme-linked immunosorbent assay (ELISA). Decorin was significantly increased in the AH of DR subjects compared to controls (p = 0.0034). AH decorin levels were increased in severe DR groups in ETDRS and Gloucestershire classifications. Decorin concentrations also displayed a significant association with visual acuity (LogMAR) measurements. In conclusion, aqueous humor decorin concentrations were found elevated in DR subjects, possibly due to a compensatory response to the retinal microvascular changes during hyperglycemia.

Survey of practice patterns for the management of ophthalmic genetic disorders among AAPOS members: report by the AAPOS Genetic Eye Disease Task Force.

To better understand AAPOS member pediatric ophthalmologists' knowledge and needs regarding genetic eye disorders, the AAPOS Genetic Eye Disease Task Force developed a 16-question survey that was circulated to national and international AAPOS members. Responses to questions on practice patterns, baseline knowledge, and educational interests regarding patients with suspected ophthalmic genetic disorders were collected. A majority of respondents (93%) evaluate patients with suspected genetic disorders. Knowledge gaps were present in heritability of certain conditions, genetic testing strategies, and referral to clinical trials. Most respondents expressed interest in further education in these areas. A model for care is proposed as a first step in the education process.

Findings in Persistent Retinopathy of Prematurity.

BACKGROUND AND OBJECTIVE: To determine whether retinopathy of prematurity (ROP) that persists beyond a postmenstrual age (PMA) of 45 weeks has abnormalities that can be documented by fundus photography or fluorescein angiography (FA). PATIENTS AND METHODS: Fundus photographs and FAs were reviewed for all premature infants who underwent FA for persistent ROP after 45 weeks PMA. RESULTS: Of the 487 infants who were screened for ROP, 16 (3.3%) demonstrated ROP beyond 45 weeks. Seven (43.8%) infants received prior treatment with intravitreal bevacizumab (IVB) for Type 1 ROP. FAs were obtained in eight cases; four subjects were previously treated with IVB. Leakage at the vascular-avascular border was demonstrated in seven subjects (87.5%). Shunt vessels, posterior retinal nonperfusion, and absence of the foveal avascular zone was limited to the IVB group. CONCLUSIONS: There are persistent vascular abnormalities among infants with ROP beyond 45 weeks. Findings that may be missed by RetCam fundus photographs were highlighted with FA. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:497-503.].

Histopathological analysis of retinopathy of prematurity after intravitreal bevacizumab.

We report the case of a premature infant with end-organ failure who developed high-risk retinopathy of prematurity (ROP) bilaterally and was treated with intravitreal bevacizumab (IVB) injection therapy with regression noted on follow-up clinical examination. The infant died 3 weeks after IVB injection therapy. Histopathological analysis was conducted on bilateral globes and revealed persistent preretinal vessels.

ATTENUATION OF THE GANGLION CELL LAYER IN A PREMATURE INFANT REVEALED WITH HANDHELD SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To report on subclinical retinal abnormalities shown through handheld spectral domain optical coherence tomography on a premature infant. METHODS: Case report. RESULTS: The initial and follow-up exams on a premature infant revealed severely attenuated ganglion cell and nerve fiber layers. There was cystoid macular edema in both eyes at the initial visits, which resolved by the 1-year follow-up. DISCUSSION: Optical coherence tomography can reveal significant retinal abnormalities in premature infants which are not detectable through funduscopic exam. Documenting such findings may be useful for the comprehensive management of vision problems in children with a history of premature birth.

Relationship between foveal cone specialization and pit morphology in albinism.

PURPOSE: Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. METHODS: We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. RESULTS: We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. CONCLUSIONS: Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue.

Evaluation of normal human foveal development using optical coherence tomography and histologic examination.

OBJECTIVE: To assess outer retinal layer maturation during late gestation and early postnatal life using optical coherence tomography and histologic examination. METHODS: Thirty-nine participants 30 weeks' postmenstrual age or older were imaged using a handheld optical coherence tomography system, for a total of 102 imaging sessions. Foveal images from 16 participants (21 imaging sessions) were normal and evaluated for inner retinal excavation and the presence of outer retinal reflective bands. Reflectivity profiles of central, parafoveal, and parafoveal retina were extracted and were compared with age-matched histologic sections. RESULTS: The foveal pit morphologic structure in infants was generally distinguishable from that in adults. Reflectivity profiles showed a single hyperreflective band at the fovea in all the infants younger than 42 weeks' postmenstrual age. Multiple bands were distinguishable in the outer retina at the peri fovea by 32 weeks' postmenstrual age and at the fovea by 3 months' postterm. By 17 months' postnatal, the characteristic appearance of 4 hyperreflective bands was evident across the foveal region. These features are consistent with previous results from histologic examinations. A "temporal divot" was present in some infants, and the foveal pit morphologic structure and the extent of inner retinal excavation were variable. CONCLUSIONS: Handheld optical coherence tomography is a viable technique for evaluating neonatal retinas. In premature infants who do not develop retinopathy of prematurity, the foveal region seems to follow a developmental time course similar to that associated with in utero maturation. CLINICAL RELEVANCE: As pediatric optical coherence tomography becomes more common, a better understanding of normal foveal and macular development is needed. Longitudinal imaging offers the opportunity to track postnatal foveal development among preterm infants in whom poor visual outcomes are anticipated or to follow up treatment outcomes in this population.

Dural Fistulas.

The treatment of dural fistulas is varied and complex. Treatment decisions require consideration of the nature of the symptoms, the location of the lesion, the complexity of the angioarchitecture, and the risk of progression. Standard treatment modalities include compression therapy, endovascular embolization, neurosurgery, and radiosurgery. Complex lesions will often require multiple different interventions. Because dural fistulas may present with a variety of neurologic and ophthalmologic problems, a team of neurologists, neuro-ophthalmologists, neuroradiologists, and neurosurgeons should develop a comprehensive treatment plan.