Directional Optical Coherence Tomography Imaging of Macular Pathology.

PURPOSE: To survey the impact of directional reflectivity on structures within optical coherence tomography (OCT) images in retinal pathology. METHODS: Sets of commercial OCT images taken from multiple pupil positions were analyzed. These Directional OCT (D-OCT) sets revealed directionally reflective structures within the retina. After ensuring sufficient image quality, resulting hybrid and composite images were characterized by assessing the Henle Fiber Layer (HFL), Outer Nuclear Layer (ONL), Ellipsoid Zone (EZ), and Interdigitation Zone (IZ). Additionally, hybrid images were reviewed for novel directionally reflective pathological features. RESULTS: Cross-sectional D-OCT image sets were obtained in 75 eyes of 58 subjects having a broad range of retinal pathologies. All cases showed improved visualization of the ONL/Henle fiber layer interface, and ONL thinning was therefore more apparent in several cases. The EZ and IZ also demonstrated attenuation where a geometric impact of underlying pathology affected their orientation. Misdirected photoreceptors were also noted as a consistent direction-dependent change in EZ reflectivity between regions of normal and absent EZ. CONCLUSION: D-OCT enhances the understanding of retinal anatomy and pathology. This optical contrast yields more accurate identification of retinal structures and possible imaging biomarkers for photoreceptor-related pathology.

A 66-year-old woman with two weeks of distorted vision in the left eye.

PURPOSE: To report a case of concurrent melanoma metastasis to the orbit and MEK inhibitor-associated retinopathy. METHODS: Case report of a 66-year-old female patient undergoing mutation targeted MEK-inhibitor treatment for metastatic melanoma with retinal manifestations. RESULTS: After initiating MEK-inhibitor therapy our patient presented with bilateral blurred vision. Clinical examination and OCT imaging revealed multifocal bilateral serous retinal detachments consistent with MEKAR. Extrafoveal subretinal fluid foci resolved after discontinuation of MEK-inhibitor therapy, but her foveal lesions persisted for over 18 months. Years after her initial evaluation for MEKAR, our patient developed metamorphopsia in the left eye resulting from chorioretinal folds secondary to intraconal orbital metastasis. MRI revealed additional intracerebral and lung metastases, and the patient expired in 2 months. CONCLUSION: We report a case of prolonged MEKAR with concomitant orbital metastasis from melanoma. Multimodal imaging in conjunction with history and clinical features allows for disease identification and monitoring.

Orbital lymphocyte populations in three states of thyroid eye disease.

Purpose: We report histopathologic orbital tissue analysis from three patients with thyroid eye disease (TED) - active, chronic, and post-teprotumumab to better characterize orbital cellular populations in these varying states of TED. Observations: Orbital tissues in TED demonstrate minimal lymphocytic infiltration in fat and Mueller's muscle. Following teprotumumab treatment, the tissues were devoid of lymphocytes with only perivascular cuffs of T-lymphocytes remaining in orbital fat. Conclusions and importance: In active TED, post-teprotumumab treatment, and in quiescent TED, orbital fat may not show significant inflammatory infiltration. More work is warranted to characterize specific cellular effects of teprotumumab and other biologics.

Directional Reflectivity of the Ellipsoid Zone in Dry Age-Related Macular Degeneration.

BACKGROUND AND OBJECTIVE: Ellipsoid zone (EZ) reflectivity on optical coherence tomography (OCT) is affected by the orientation of the scanning beam. The authors sought to determine how directional reflectivity changes in dry age-related macular degeneration (AMD). PATIENTS AND METHODS: Retrospective image analysis included 17 control and 20 dry AMD subjects. Directional OCT (D-OCT) was performed using multiple displaced pupil entrance positions. EZ pixel values and apparent incidence angles were measured. RESULTS: EZ reflectivity decreased in off-axis scans in controls (P < .001), AMD areas between drusen (P < .001), and AMD areas overlying drusen (P < .001). The magnitude of decrement in EZ reflectivity was significantly higher when incidence angles exceeded 10° in controls than in AMD areas between drusen (P = .024). CONCLUSION: EZ reflectivity in dry AMD may vary by incident angle of light less than in controls, possibly indicating alteration of photoreceptor orientation or integrity. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:145-152.].

FINGERPRINT SIGN OF THE HENLE FIBER LAYER.

PURPOSE: To describe the appearance of concentric, fingerprint-like waves within the Henle fiber layer (HFL) using en face optical coherence tomography in patients with tractional pathologies of the retina. METHODS: Retrospective analysis of six eyes of six patients imaged by optical coherence tomography with volumetric slabs positioned at the level of the HFL. RESULTS: Optical coherence tomography data from six patients with tractional vitreoretinal pathology were reviewed. Concentric, fingerprint-like microwaves were visualized through en face optical coherence tomography in all six study eyes at the level of the HFL. This finding resembled the finding of HFL waves previously noted histopathologically from force exerted on this layer. CONCLUSION: In retinal pathologies in which specific physical forces act on the retina, volumetric optical coherence tomography may permit visualization of en face concentric, fingerprint-like hyperreflective rings within the HFL. This "fingerprint sign" may represent a biomechanical consequence of traction on the retina and allow clinical decision making based on improved recognition of the existence of such traction.

Endogenous hypercortisolism inducing reversible ocular hypertension.

PURPOSE: To describe the clinical findings of two patients with reversible ocular hypertension secondary to endogenous hypercortisolism. DESIGN: Retrospective, observational case series. SUBJECTS: A 65-year-old man (patient 1) and a 21-year-old woman (patient 2) were both found to have Cushing's syndrome after presentation to our clinic with elevated intraocular pressures (IOP). METHODS: Clinical histories, ophthalmic examinations including IOP measurements, optical coherence tomography of the retinal nerve fiber layer, visual field testing, magnetic resonance imaging and computerized tomography of two patients were reviewed between 2007 and 2019. OBSERVATIONS: Patient 1 demonstrated elevated IOP (maximum 26 mmHg OD and 22 mmHg OS) and bilateral disc edema. Following diagnosis of Cushing's syndrome, the patient underwent two pituitary resections and bilateral adrenalectomy, with subsequent resolution of his hypercortisolism and ocular hypertension (OHT). Patient 2 presented with blurred vision and found to have OHT (maximum 32 mmHg OU). Following diagnosis of Cushing's disease and two resections of her adrenocorticotropic hormone (ACTH) producing pituitary adenoma, her IOPs normalized. Both patients maintained normal IOPs after resolution of their endogenous hypercortisolism and discontinuation of topical IOP-lowering medication. CONCLUSIONS AND IMPORTANCE: Ocular hypertension induced by endogenous hypercortisolism is, in some cases, fully reversible following normalization of cortisol levels. These findings suggest that the physiologic changes to the trabecular meshwork induced by endogenous hypercortisolism may be fully reversible.

Loss of Foveal Cone Structure Precedes Loss of Visual Acuity in Patients With Rod-Cone Degeneration.

Purpose: To assess the relationship between cone spacing and visual acuity in eyes with rod-cone degeneration (RCD) followed longitudinally. Methods: High-resolution images of the retina were obtained using adaptive optics scanning laser ophthalmoscopy from 13 eyes of nine RCD patients and 13 eyes of eight healthy subjects at two sessions separated by 10 or more months (mean 765 days, range 311-1935 days). Cone spacing Z-score measured as close as possible (average <0.25°) to the preferred retinal locus was compared with visual acuity (letters read on the Early Treatment of Diabetic Retinopathy Study [ETDRS] chart and logMAR) and foveal sensitivity. Results: Cone spacing was significantly correlated with ETDRS letters read (ρ = -0.47, 95%CI -0.67 to -0.24), logMAR (ρ = 0.46, 95%CI 0.24 to 0.66), and foveal sensitivity (ρ = -0.30, 95%CI -0.52 to -0.018). There was a small but significant increase in mean cone spacing Z-score during follow-up of +0.97 (95%CI 0.57 to 1.4) in RCD patients, but not in healthy eyes, and there was no significant change in any measure of visual acuity. Conclusions: Cone spacing was correlated with visual acuity and foveal sensitivity. In RCD patients, cone spacing increased during follow-up, while visual acuity did not change significantly. Cone spacing Z-score may be a more sensitive measure of cone loss at the fovea than visual acuity in patients with RCD.

Relationship Between Foveal Cone Structure and Visual Acuity Measured With Adaptive Optics Scanning Laser Ophthalmoscopy in Retinal Degeneration.

Purpose: To evaluate foveal function in patients with inherited retinal degenerations (IRD) by measuring visual acuity (VA) after correction of higher-order aberrations. Methods: Adaptive optics scanning laser ophthalmoscopy (AOSLO) was used to image cones in 4 healthy subjects and 15 patients with IRD. The 840-nm scanning laser delivered an "E" optotype to measure AOSLO-mediated VA (AOSLO-VA). Cone spacing was measured at the preferred retinal locus by two independent graders and the percentage of cones below the average density of 47 age-similar healthy subjects was computed. Cone spacing was correlated with best-corrected VA measured with the Early Treatment of Diabetic Retinopathy Study protocol (ETDRS-VA), AOSLO-VA, and foveal sensitivity. Results: ETDRS-VA significantly correlated with AOSLO-VA (ρ = 0.79, 95% confidence interval [CI] 0.5-0.9). Cone spacing correlated with AOSLO-VA (ρ = 0.54, 95% CI 0.02-0.7), and negatively correlated with ETDRS letters read (ρ = -0.64, 95% CI -0.8 to -0.2). AOSLO-VA remained ≥20/20 until cones decreased to 40.2% (CI 31.1-45.5) below normal. Similarly, ETDRS-VA remained ≥20/20 until cones were 42.0% (95% CI 36.5-46.1) below normal. Cone spacing z scores negatively correlated with foveal sensitivity (ρ = -0.79, 95% CI -0.9 to -0.4) and foveal sensitivity was ≥35 dB until cones were 43.1% (95% CI 39.3-46.6) below average. Conclusions: VA and foveal cone spacing were weakly correlated until cones were reduced by 40% to 43% below normal. The relationship suggests that VA is an insensitive measure of foveal cone survival; cone spacing may be a more sensitive measure of cone loss.

Microhabitat Selection and Eyefluke Infection Levels in the Western Mosquitofish (Gambusia affinis).

Several trematode species infect the eyes of fish as second intermediate hosts. In most cases the definitive host is a piscivorous bird. Studies of a few species have shown an increase in transmission due to decreased visual acuity of the fish host. However, this may vary depending on trematode microhabitat choice within the eye. Some trematode species are found in the lens, some are found in the vitreous humor, and others have been reported from the retina. Here we report 3 genera of eyeflukes in 3 locations of the eye in the intermediate fish host, Gambusia affinis . Clinostomum metacercariae were found attached to the outer sclera within the eye orbit, and Diplostomum metacercariae were found in the lens. Posthodiplostomum metacercariae were confirmed by histology to reside between the choroid and pigmented retina. Posthodiplostomum metacercariae were found in both eyes of all 20 fish examined and in high intensities (up to 27 metacercariae per eye). High trematode intensities between the choroid and pigmented retina found in this study may disrupt vision in this fish host. Our study is the first to document the microhabitat of all 3 trematode metacercariae within the eye of G. affinis .