Optical coherence tomography angiography findings in optic disc drusen and idiopathic intracranial hypertension.

PURPOSE: To evaluate the changes in peripapillary microvascularity in idiopathic intracranial hypertension (IIH) and optic disc drusen (ODD) patients, by comparing them with those in healthy individuals, via optical coherence tomography angiography (OCTA). METHODS: Sixty-two eyes of 33 patients with ODD, 58 eyes of 30 patients with IIH, and 70 eyes of 70 healthy people were imaged for 6 × 6-mm optic disc scans on a spectral-domain OCTA. Vascular densities in superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) of ODD, IIH, and healthy eyes were compared with a one-way analysis of variance. Post-hoc analysis was performed with the Gabriel test. RESULTS: There was a significant decrease in peripapillary vessel density in SCP, DCP, and CC in patients with IIH compared to the control group (p < 0.05). In ODD patients, especially peripapillary vessel density in DCP was significantly reduced compared to the control group (p < 0.05). Peripapillary vessel density in DCP was significantly lower in the IIH group than ODD group (p < 0.05). CONCLUSIONS: Peripapillary vascular density may be affected during the course of the disease in both IIH and ODD. Compared to healthy individuals, the decrease in vascular density in these patients and the consequent decrease in perfusion in the peripapillary region may guide the pathogenesis of the complications in the course of these two diseases. Although vascular density in DCP and CC differs significantly between IIH and ODD, case-controlled studies are needed to evaluate the role of OCTA in the differential diagnosis of IHH and ODD.

The extracellular microenvironment in immune dysregulation and inflammation in retinal disorders.

Inherited retinal dystrophies (IRDs) as well as genetically complex retinal phenotypes represent a heterogenous group of ocular diseases, both on account of their phenotypic and genotypic characteristics. Therefore, overlaps in clinical features often complicate or even impede their correct clinical diagnosis. Deciphering the molecular basis of retinal diseases has not only aided in their disease classification but also helped in our understanding of how different molecular pathologies may share common pathomechanisms. In particular, these relate to dysregulation of two key processes that contribute to cellular integrity, namely extracellular matrix (ECM) homeostasis and inflammation. Pathological changes in the ECM of Bruch's membrane have been described in both monogenic IRDs, such as Sorsby fundus dystrophy (SFD) and Doyne honeycomb retinal dystrophy (DHRD), as well as in the genetically complex age-related macular degeneration (AMD) or diabetic retinopathy (DR). Additionally, complement system dysfunction and distorted immune regulation may also represent a common connection between some IRDs and complex retinal degenerations. Through highlighting such overlaps in molecular pathology, this review aims to illuminate how inflammatory processes and ECM homeostasis are linked in the healthy retina and how their interplay may be disturbed in aging as well as in disease.

Complement factor B is critical for sub-RPE deposit accumulation in a model of Doyne honeycomb retinal dystrophy with features of age-related macular degeneration.

EFEMP1 R345W is a dominant mutation causing Doyne honeycomb retinal dystrophy/malattia leventinese (DHRD/ML), a rare blinding disease with clinical pathology similar to age-related macular degeneration (AMD). Aged Efemp1  R345W/R345W knock-in mice (Efemp1ki/ki) develop microscopic deposits on the basal side of retinal pigment epithelial cells (RPE), an early feature in DHRD/ML and AMD. Here, we assessed the role of alternative complement pathway component factor B (FB) in the formation of these deposits. RNA-seq analysis of the posterior eyecups revealed increased unfolded protein response, decreased mitochondrial function in the neural retina (by 3 months of age) and increased inflammatory pathways in both neural retina and posterior eyecups (at 17 months of age) of Efemp1ki/ki mice compared with wild-type littermate controls. Proteomics analysis of eye lysates confirmed similar dysregulated pathways as detected by RNA-seq. Complement activation was increased in aged Efemp1ki/ki eyes with an approximately 2-fold elevation of complement breakdown products iC3b and Ba (P < 0.05). Deletion of the Cfb gene in female Efemp1ki/ki mice partially normalized the above dysregulated biological pathway changes and oral dosing of a small molecule FB inhibitor from 10 to 12 months of age reduced sub-RPE deposits by 65% (P = 0.029). In contrast, male Efemp1ki/ki mice had fewer sub-RPE deposits than age-matched females, no elevation of ocular complement activation and no effect of FB inhibition on sub-RPE deposits. The effects of FB deletion or inhibition on Efemp1ki/ki mice supports systemic inhibition of the alternative complement pathway as a potential treatment of dry AMD and DHRD/ML.

An overview of peripapillary hyperreflective ovoid mass-like structures.

PURPOSE OF REVIEW: The purpose of this review is to provide an overview of the ophthalmic findings associated with peripapillary hyperreflective ovoid mass-like structures (PHOMS) in both adult and pediatric patients. RECENT FINDINGS: PHOMS have recently been identified in a number of different ophthalmic disease entities ranging from nonpathologic to pathologic, including but not limited to anatomic abnormalities (tilting in myopia), optic nerve head drusen, optic disc edema from inflammation (optic neuritis, white dot syndromes), vascular insults (ischemic optic neuropathy, retinal vascular occlusion), and papilledema. The mechanism underlying the formation of PHOMS has not been fully elucidated although it has been hypothesized that PHOMS occur secondary to axoplasmic stasis from crowding at the optic nerve head. SUMMARY: Although the clinical significance of the presence of PHOMS remains unclear, PHOMS are associated with several disease processes. Understanding the mechanism behind their formation and their impact on optic nerve head structure and visual function may be relevant in patients with optic nerve head pathology. The presence of PHOMS may also correlate with disease severity and duration. Future studies to evaluate whether the formation of PHOMS may be useful as an early indicator of disease or a prognostic tool are warranted.

The second Japanese family with Malattia Leventinese/Doyne honeycomb retinal dystrophy.

PURPOSE: To describe the clinical and genetic findings of patients in the second Japanese family with Malattia Leventinese/Doyne honeycomb retinal dystrophy (ML/DHRD). METHODS: Two patients (a 41-year-old male proband and his third son) underwent comprehensive ophthalmic examinations, including full-field and multifocal electroretinography (ERG). Sanger sequencing was performed to detect an EFEMP1 gene variant (p.Arg345Trp), which was identified as the only causative pathogenic variant. RESULTS: Genetic analysis revealed that both patients carried the heterozygous variant, but the other unaffected family members did not. Although the proband exhibited innumerable radially distributed drusen in both the posterior poles and good visual acuity at initial presentation, bilateral choroidal neovascularization (CNV) developed during the 15-year follow-up. The proband received 15 intravitreal anti-vascular endothelial growth factor (VEGF) injections in the left eye (LE) and two injections in the right eye (RE). At 56 years of age, his decimal best-corrected visual acuity was 0.1 and 1.2 in the LE and RE, respectively. Full-field ERG showed that while the rod and combined responses were within normal amplitudes, the cone and 30-Hz flicker responses had slightly decreased amplitudes. Multifocal ERG revealed attenuated central responses in the LE and decreased temporal responses in the RE. In the 20-year-old son, multifocal ERG showed normal responses in both eyes. CONCLUSION: This is the first report of ML/DHRD in a patient who developed bilateral CNV and received anti-VEGF treatment in both eyes. Although multifocal ERG exhibited worsening of macular function, the generalized photoreceptor function was preserved until middle age.

Effects of Zinc Acetate Hydrate Treatment on Serum Oxidative Stress Markers in Patients with Macular Drusen.

Purpose: To measure the serum levels of the oxidative stress markers superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPx) and compare them before and after zinc supplementation in patients with early age-related macular degeneration (AMD). Methods: We measured serum zinc levels in 65 patients with early AMD. Of these, 29 patients with macular drusen and a serum zinc level <80 µg/dL received oral zinc acetate dihydrate (50 mg/day). Serum trace metal levels (zinc and copper) and oxidative stress marker levels (SOD, MDA, and GPx) were measured at baseline and 12 weeks after the treatment. The macular drusen areas and best-corrected visual acuity were evaluated in 24 participants who attended the 3-month follow-up. Results: MDA level was significantly decreased from baseline to 12 weeks after zinc administration (170.5 ± 100.9 vs. 148.3 ± 57.9 pmol/mL, P = 0.03), while SOD was significantly increased from baseline to 12 weeks after zinc intake (4.2 ± 0.9 vs. 4.6 ± 0.9 U/mL, P = 0.03). The serum zinc level was significantly correlated with the MDA level (P = 0.03, ρ = -0.26). The area of soft drusen was significantly decreased after zinc treatment (1,936,654.9 ± 1,348,267.6 vs. 966,883.9 ± 719,938.1 µmm2, P = 0.04). Conclusions: The levels of oxidative stress markers MDA and SOD decreased and increased, respectively, after oral zinc administration to 24 patients with AMD. The therapeutic effect of zinc treatment on drusen area might differ depending on the drusen phenotype in early AMD.

First reported case of Doyne honeycomb retinal dystrophy (Malattia Leventinese/autosomal dominant drusen) in Scandinavia.

BACKGROUND: Doyne honeycomb retinal dystrophy (DHRD)/malattia leventinese (ML) is an autosomal dominant, progressive retinal disorder characterized by massive central retinal drusen often partly coalescent forming a characteristic honeycomb-like pattern. Debut of vision loss often occurs in early to mid-adulthood, and the degree varies. A single variant in EFEMP1: c.1033C>T (R345W) has been identified as the cause in all cases. METHODS: Following DNA isolation, exome sequencing was performed in seven genes associated with flecked retina. Direct sequencing was used for variant verification. RESULTS: We report the first Scandinavian case of molecular genetically verified DHRD/ML: a 57-year-old woman debuting with vision loss and metamorphopsia. On both eyes, ophthalmological findings included massive hard drusen in the macular region and nasal to the optic disc as well as macular hyperpigmentation. Secondary choroidal neovascularizations were identified on both eyes, and anti-vascular endothelial growth factor was administered, without effect. CONCLUSION: Molecular genetic investigation revealed heterozygosity for the known pathogenic missense variant in EFEMP1: c.1033C>T (R345W) previously reported in relation to DHRD/ML. Family history revealed no other cases of similar visual impairment suggesting a de novo mutation. Furthermore, there was no correlation between the unique DHRD/ML haplotypes reported in the literature and our patient.

Clinically-identified C-terminal mutations in fibulin-3 are prone to misfolding and destabilization.

Distinct mutations in the secreted extracellular matrix protein, fibulin-3 (F3), have been associated with a number of ocular diseases ranging from primary open angle glaucoma to cuticular age-related macular degeneration to a rare macular dystrophy, Malattia Leventinese (ML). The R345W F3 mutation that causes ML leads to F3 misfolding, inefficient secretion and accumulation at higher intracellular steady state levels in cultured cells. Herein, we determined whether fifteen other clinically-identified F3 mutations also led to similar levels of misfolding and secretion defects, which might provide insight into their potential pathogenicity. Surprisingly, we found that only a single F3 variant, L451F, presented with a significant secretion defect (69.5 ± 2.4% of wild-type (WT) F3 levels) and a corresponding increase in intracellular levels (226.8 ± 25.4% of WT F3 levels). Upon follow-up studies, when this conserved residue (L451) was mutated to a charged (Asp or Arg) or bulky (Pro, Trp, Tyr) residue, F3 secretion was also compromised, indicating the importance of small side chains (Leu, Ala, or Gly) at this residue. To uncover potential inherent F3 instability not easily observed under typical culture conditions, we genetically eliminated the sole stabilizing N-linked glycosylation site (N249) from select clinically-identified F3 mutants. This removal exacerbated R345W and L451F secretion defects (19.8 ± 3.0% and 12.4 ± 1.2% of WT F3 levels, respectively), but also revealed a previously undiscovered secretion defect in another C-terminal variant, Y397H (42.0 ± 10.1% of WT F3 levels). Yet, glycan removal did not change the relative secretion of the N-terminal mutants tested (D49A, R140W, I220F). These results highlight the uniqueness and molecular similarities between the R345W and L451F variants and also suggest that previously identified disease-associated mutations (e.g., R140W) are indistinguishable from WT with respect to secretion, hinting that they may lead to disease by an alternative mechanism.

Blood flow disturbances in the central retinal artery in patients with bilateral optic disc drusen.

To evaluate retrobulbar hemodynamics in patients with optic disc drusen (ODD) by color Doppler imaging. A prospective study included 52 patients with bilateral ODD and 50 age-matched controls. Blood flow in the central retinal artery (CRA) in both eyes was evaluated. Peak-systolic velocity (PSV), end-diastolic velocity (EDV), and the resistivity index (RI) were measured. Mean values of the blood flow Doppler parameters were compared between the patients with ODD and the controls. Both PSV and EDV in the CRA were significantly lower in patients with ODD than in the controls (p < 0.001). The RI in the CRA of ODD patients was significantly higher than in the controls (p < 0.001). Women with ODD presented with significantly lower values of PSV and EDV than men (p = 0.05 and p = 0.03, respectively). Arterial hypertension, cigarette smoking and location of ODD in the left or right eye did not exert a significant effect on the blood flow in the CRA. Blood flow in the CRA is considerably disturbed in patients with ODD. This disturbance might result from mechanical stenosis of the vascular wall caused by the drusen. Color Doppler ultrasound is a useful method in the assessment of retrobulbar hemodynamics in ODD.

Prevalence and histopathological signatures of optic disc drusen based on microscopy of 1713 enucleated eyes.

PURPOSE: Optic disc drusen (ODD) are calcified optic nerve head deposits. Objectives of this study were to examine the prevalence of ODD in eyes removed by enucleation and to describe related histopathological signatures of ODD and surrounding tissues. METHODS: The study was a retrospective observational case series study assessing and re-evaluating enucleated eyes in Denmark from 1980 to 2015 by microscopy. Individual ODD were described based on size, number and location (superficial and/or deep) within the optic nerve. Optic nerve heads with ODD were assessed for elevated discs, retinal nerve fibre layer (RNFL) thickness, oedematous axons and presence of localized peripapillary axonal distension (LPAD) equivalent to the peripapillary hyperreflective ovoid mass-like structures seen on optical coherence tomography. RESULTS: Microscopy of 1713 eyes revealed ODD in 31 eyes equivalent to a prevalence of 1.8%. Optic disc drusen (ODD) were seen as circular shapes of different sizes and varying number. Elevated discs were present in 15 (54%) of the cases. Thickening of the superficial RNFL was present in eyes with large deeply located ODD. For more superficial ODD of approximately same size, the RNFL was thinner. Oedematous axons were present in three eyes. Localized peripapillary axonal distension (LPAD) was seen in five eyes. CONCLUSIONS: Prevalence of ODD in this study of histopathological signatures was higher than the prevalence found in clinical studies. Our results suggest that large, deep ODD might cause crowding and herniation of axons in the optic nerve head leading to a thickened superficial nerve fibre layer, pseudopapilledema and LPAD.

A study of optic nerve head drusen in 38 pseudoxanthoma elasticum (PXE) patients (64 eyes). Location of optic nerve head drusen in PXE.

PURPOSE: To investigate the prevalence and location of optic nerve head drusen and their potential association with other PXE-related ophthalmic abnormalities. MATERIALS AND METHODS: Thirty-eight of the 155 patients (57 male and 98 female aged 49±17 years) included in this retrospective study had optic nerve head drusen. All of the patients underwent a comprehensive ophthalmic examination, including color images using red-free, blue and red filters, autofluorescence imaging and late-phase ICG frames. Comparative analysis of both groups (optic nerve head drusen or not) was conducted using R statistical software. RESULTS: The prevalence of optic nerve head drusen in our cohort was 24.5%. In this study, no evidence of a significant link between optic nerve head drusen and other fundus abnormalities was detected. They were more commonly located in the nasal sector than in the temporal sector of the optic disc (P<0.001). They were more frequently situated superonasally than inferonasally (P<0.004), superotemporally (P<0.001) or inferotemporally (P<0.03). No central visual field defect was observed in OND+ patients who were unaffected by macular disorders. DISCUSSION: We hypothesized this predominantly nasal primary location may result from greater sensitivity in the nasal optic nerve fibers which follow a much more angular path once they arrive in the scleral canal, accounting for accumulation of axoplasmic debris. CONCLUSION: In PXE, optic nerve head drusen are mostly located in the superonasal quadrant, causing progressive optic nerve invasion but probably no central visual field defects.

Paediatric case of peripapillary choroidal neovascularisation associated with optic disc drusen treated with aflibercept.

Peripapillary choroidal neovascularisation (PPCNV) associated with optic disc drusen is a rare complication that can result in severe vision impairment in children. We report the first case of paediatric PPCNV secondary to optic disc drusen successfully treated with intravitreal aflibercept. A 6-year-old girl presented with a one week history of reduced vision in her right eye with best-corrected visual acuity of 20/500. Fundus examination revealed bilateral elevated discs with a peripapillary pigmentary lesion in the right eye. Optical coherence tomography of the right eye showed marked subfoveal fluid. Both B-scan ultrasonography and fundus autofluorescence demonstrated findings consistent with optic disc drusen. Diagnosis of PPCNV was further confirmed on fluorescein fundus angiography. The child received three intravitreal aflibercept injections with complete resolution of the subfoveal fluid. Her visual acuity improved to 20/25 with no recurrence at a 16-month follow-up. No adverse side effects were reported.

Factors associated with visual field defects of optic disc drusen.

PURPOSE: To investigate the prevalence and risk factors for visual field defect in patients with optic disc drusen (ODD). METHODS: We assessed the visual field status of patients with ODD whose diagnosis were confirmed by spectral-domain optical coherence tomography (SD-OCT). Visual field defects were classified as normal, enlarged blind spot, or other defects. ODD were classified into either type 1 (without hyperreflective border and heterogenic internal reflectance) or type 2 (with hyperreflective border and lower internal reflectance). The prevalence and risk factors for each visual field defect was analyzed using logistic regression analysis and classification and regression tree (CART) modeling. RESULTS: Of the 40 eyes with ODD, 33 (83%) eyes were categorized as type 1 and 7 (17%) eyes were categorized as type 2 ODD. Regarding the visual field defects, 19 (48%) eyes showed normal visual field, 11 (28%) eyes showed enlarged blind spot, and 9 (24%) eyes showed other defects. The latter was more frequent in type 2 ODD (P = 0.001). Logistic regression analysis revealed that the factor associated with other defects was the thinning of the average retinal nerve fiber layer (RNFL) (per 10 µm decrease, OR = 3.436, P = 0.004), and the factor associated with enlarged blind spot was the height of ODD (per 100 µm increase, OR = 3.956, P = 0.023). CART modeling revealed that the average RNFL thickness lesser than 85.5 µm, and then the ODD height larger than 348 µm were the best split-up factors for predicting the type of visual field defects. CONCLUSIONS: In this study, one-quarter of ODD patients showed abnormal visual field defect other than enlarged blind spot. These other visual field defects appeared to be associated with the axonal loss in the eyes with type 2 ODD.

RETINAL FINDINGS IN A CASE OF PRESUMED CUTIS MARMORATA TELANGIECTATICA CONGENITA.

PURPOSES: To correlate the clinical picture and fundus fluorescein angiography findings in case of presumed cutis marmorata telangiectatica congenita. METHODS: A 41-year-old woman with presumed cutis marmorata telangiectatica congenita who is a known case of hypothyroidism for the last 6 years and has bilateral peripheral retinal vascular abnormalities, peripheral retinal nonperfusion on fluorescein angiography and bilateral optic disk drusen. RESULT: A patient presented with blurring of vision in both eyes for last 6 months. On examination, livedo reticularis skin lesions in both upper and lower extremities were noted. Best-corrected visual acuity in the right eye was 6/18 and left eye was 6/36. Slit-lamp examination revealed posterior subcapsular cataract in the right eye. Fundus examination showed bilateral optic disk drusen, tortuous blood vessels, and peripheral fan-shaped sclerosed neovascularization. Fundus fluorescein angiography showed peripheral retinal nonperfusion. She underwent peripheral laser photocoagulation of the left eye and cataract surgery in the right eye. After 2 years of follow-up, her best-corrected visual acuity was 6/9 in both eyes. Her fundus examination and fundus fluorescein angiography findings were stable in both eyes. CONCLUSION: Presumed cutis marmorata telangiectatica congenita is a rare cutaneous vascular disorder that can manifest with nonprogressive retinal vascular abnormality and optic disk drusen.

Optical Coherence Tomography Angiography in Optic Nerve Drusen.

AIM: To determine the efficacy of optical coherence tomography angiography (OCT-A) in diagnosing optic nerve head flow impairment in patients with optic nerve drusen. METHODS: Patients affected by optic-nerve head drusen (ONHD) attending the Eye Clinic of the Federico II University of Naples were enrolled in this prospective case series between October 2015 and October 2016. Each patient underwent evaluation of best corrected visual acuity (BCVA), Goldman applanation tonometry, slit-lamp biomicroscopy, fundus examination, standard visual-field testing (perimetry), spectral domain (SD)-OCT and OCT-A. RESULTS: Thirteen patients (6 females and 7 males with a mean age of 22.05 ± 7.54 years) with ONHD (19 eyes) were enrolled. Mean BCVA was 0.16 ± 0.21 LogMar and mean intraocular pressure was 15.68 ± 1.66 mm Hg. The control group constituted 16 individuals (24 eyes). Both ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) parameters were lower in patients than in controls. Similarly, the flow index (U = 134, p = 0.021) and vessel density (U = 90, p = 0.001) were significantly lower in eyes affected by ONHD than in normal eyes. Visual-field parameters did not differ between the 2 groups. GCC parameters were significantly correlated with OCT-A parameters (p < 0.05). No correlation was found between RNFL and OCT-A parameters. CONCLUSIONS: Our data suggest that OCT-A could be an objective method, helpful in the analysis of flow changes in patients with ONHD.

Multicolor imaging in optic disc swelling.

Differentiating optic disc edema (ODE) from pseudo optic disc edema (PODE) continues to pose a diagnostic dilemma. Current report highlights the role of multicolor imaging (MC) in differentiating ODE from PODE. Composite multicolor images of the disc in ODE show greenish hyperreflectance that extends beyond the optic disc margins with irregular blurry margins and obscured disc vasculature whereas PODE shows a greenish hyperreflectance with clear and distinct margins and well delineated disc vasculature. MC imaging adds to the present armamentarium of imaging modalities obviating needless neurological evaluation mandatory in a case of true disc edema.