The Role of Alpha-Synuclein Deposits in Parkinson's Disease: A Focus on the Human Retina.

Parkinson's disease (PD) is a neurodegenerative condition characterized by the progressive deterioration of dopaminergic neurons in the central and peripheral autonomous system and the intraneuronal cytoplasmic accumulation of misfolded α-synuclein. The clinical features are the classic triad of tremor, rigidity, and bradykinesia and a set of non-motor symptoms, including visual deficits. The latter seems to arise years before the onset of motor symptoms and reflects the course of brain disease. The retina, by virtue of its similarity to brain tissue, is an excellent site for the analysis of the known histopathological changes of PD that occur in the brain. Numerous studies conducted on animal and human models of PD have shown the presence of α-synuclein in retinal tissue. Spectral-domain optical coherence tomography (SD-OCT) could be a technique that enables the study of these retinal alterations in vivo. The objective of this review is to describe recent evidence on the accumulation of native or modified α-synuclein in the human retina of patients with PD and its effects on the retinal tissue evaluated through SD-OCT.

Choroidal Neovascular Membranes in Retinal and Choroidal Tumors: Origins, Mechanisms, and Effects.

Choroidal neovascularizations are historically associated with exudative macular degeneration, nonetheless, they have been observed in nevus, melanoma, osteoma, and hemangioma involving the choroid and retina. This review aimed to elucidate the possible origins of neovascular membranes by examining in vivo and in vitro models compared to real clinical cases. Among the several potential mechanisms examined, particular attention was paid to histologic alterations and molecular cascades. Physical or biochemical resistance to vascular invasion from the choroid offered by Bruch's membrane, the role of fibroblast growth factor 2 and vascular endothelial growth factor, resident or recruited stem-like/progenitor cells, and other angiogenic promoters were taken into account. Even if the exact mechanisms are still partially obscure, experimental models are progressively enhancing our understanding of neovascularization etiology. Choroidal neovascularization (CNV) over melanoma, osteoma, and other tumors is not rare and is not contraindicative of malignancy as previously believed. In addition, CNV may represent a late complication of either benign or malignant choroidal tumors, stressing the importance of a long follow-up.

Choroidal vascularity index and choroidal thickness: potential biomarkers in retinitis pigmentosa.

Retinitis pigmentosa (RP) is the commonest inherited retinal dystrophy. It is characterized by progressive photoreceptor degeneration and cell death and ongoing neuronal and vascular impairment. In recent years, pathophysiological alterations of the choroid have begun to be appreciated in RP. Thus, representing a potential diagnostic and therapeutic biomarker. In particular, choroidal thickness and the choroidal vascularity index can be used to understand the pathogenesis of disease and evaluate new therapeutic possibilities. Photoreceptor changes seen in eyes with RP are directly correlated to a decrease of choroidal flow, leading to a strong association between relative choroidal ischemia and visual impairment. In this review we analyse the literature on choroidal thickness and choroidal vascularity index in patients with RP and assess whether these markers may reflect progression of disease from an anatomical and functional point of view.

Aqueous Outflow Facility after Periocular Triamcinolone Injection: A Preliminary Evaluation of the Falck Medical Applanation Tonometer.

Aim: To evaluate the Falck Medical Applanation Tonometer 1 (FMAT-1) as a device for measuring intraocular pressure (IOP) and outflow facility (OF) in patients with uveitis after periocular triamcinolone injection in one eye. Materials and methods: Retrospective observational comparison. IOP and OF measurements were recorded and analyzed, comparing Goldmann tonometry and FMAT-1 readings. Records were reviewed for adult patients with uveitis who had undergone recent periocular triamcinolone injection in one eye. Results: A total of 19 patients' records were evaluated. In treated eyes, median IOPs (in mm Hg) by Goldmann and FMAT-1 were 21 and 21.0, respectively, and mean IOPs were 22.21 and 21.15, respectively. In untreated eyes, median IOPs by Goldmann and FMAT-1 were 15 and 15.7, respectively, and mean IOPs were 15.52 and 15.31, respectively. Median OF (in µL/mm Hg) in treated and untreated eyes was 0.17 and 0.22, respectively, and mean values were 0.17 and 0.23, respectively. Pearson correlation showed an inverse relationship between IOP and OF in treated eyes, and linear regression analysis showed that IOP strongly predicted outflow in this group. Conclusion: The FMAT-1 generates IOP results substantially similar to Goldmann and OF readings with greater ease than prior tonography devices. Clinical significance: The mechanism of corticosteroid-induced IOP elevation appears to be a reduction in aqueous OF, and its measurement is tonography. This technique has traditionally been cumbersome. FMAT-1 is a newly launched instrument that measures IOP and OF at the slit lamp simultaneously in a few seconds. How to cite this article: Staso FD, Gaudio PA. Aqueous Outflow Facility after Periocular Triamcinolone Injection: A Preliminary Evaluation of the Falck Medical Applanation Tonometer. J Curr Glaucoma Pract 2023;17(4):197-204.

Topical treatment of dupilumab-associated refractory conjunctivitis and keratitis.

PURPOSE: To report 3 cases of severe dupilumab-related conjunctivitis and keratitis topical treatment. OBSERVATION: Description, management, and outcomes of dupilumab-related refractory conjunctivitis associated with punctate keratitis.Three patients with atopic dermatitis (AD) experiencing severe ophthalmic complications following dupilumab treatment were referred to us when conventional management methods failed. We treated them topical and external pimecrolimus 10 mg/g cream to the eyelids. The patients showed substantial clinical remission within 10 days. CONCLUSIONS AND IMPORTANCE: Those cases are remarkable as a drug applied externally to the eyelid skin successfully treated underlying conjunctivitis and punctate keratitis. The complete clinical remission suggests that pimecrolimus applied topically to the eyelid skin is a safe and effective delivery route. The resolution of the keratitis and conjunctivitis presumably represents either a contiguous effect of the improvement of the cutaneous inflammation, or the effect of transcutaneous pimecrolimus penetration through the eyelid.Further studies are needed to support the use of this drug for dupilumab-associated conjunctivitis.

Treatment of Capecitabine Corneal Side Effects With Autologous Blood-derived Serum Eye Drops.

BACKGROUND/AIM: To describe the clinical progress and management of ocular side effects in a 35-year-old patient with metastatic breast cancer who underwent oral chemotherapy with capecitabine and lapatinib. MATERIALS AND METHODS: Slit lamp evaluation revealed bilateral perikeratic hyperemia, perilimbal conjunctival edema associated with corneal marginal infiltrates and epithelial and anterior stromal defects in both eyes. Slit lamp examination, in vivo confocal microscopy and anterior-segment optical coherence tomography were highly suggestive for limbal stem cell deficiency. The decision to administer autologous blood- derived serum eye drops was made. RESULTS: Following administration of autologous blood-derived serum eye drops, corneal marginal infiltrates, epithelial and stromal defects significantly regressed in both eyes after only 10 days. Chemotherapy was resumed and serum eye drops were prescribed simultaneously. CONCLUSION: Autologous blood-derived serum eye drops may be an adequate therapeutic choice for bilateral corneal lesions detected as ocular side effects of capecitabine.

Human amniotic membrane patch and platelet-rich plasma to promote retinal hole repair in a recurrent retinal detachment.

PURPOSE: To present a modified surgical technique, based on a combination of human amniotic membrane (hAM) patch and autologous Platelet-rich plasma (PRP) in a case of recurrent retinal detachment (RRD) due to a perivascular retinal hole over an area of staphyloma in an eye with pathologic myopia. METHODS: Presenting the surgical technique with the disposal of surgical video. After performing 23-gauge pars plana vitrectomy (PPV) the hAM patch was inserted under the neuroretina through the perivascular hole and PRP was injected on top to speed up the closure of the hole. To complete the surgical procedure High Viscosity Silicon oil (5000cst) was used as tamponade. The patient was prescribed to maintain a face-down position for the first 3 days after the operation. Follow-up was evaluated through Optical coherence tomography (OCT) scans. RESULTS: The 3 days postoperative OCT showed a flat retina with the filling of the myopic staphyloma. The hAM patch was well positioned and the retinal hole could not be identified. At 6 weeks from intervention, the site of the retinal hole at OCT scan was covered by new tissue. Silicone oil was removed 3 months later with no recurrence. CONCLUSION: hAM transplantation is a novel technique in case of retinal detachment recurrences to seal retinal holes over high myopic chorioretinal atrophy. The adjunctive use of PRP and high viscosity silicon oil allows to reducing the standard face-down positioning timing, representing a valid solution for elderly patients who have difficulties maintaining the position for long periods.

Treatment of refractory conjunctivitis associated to dupilumab with topical pimecrolimus applied to the eyelid skin.

Patients with atopic dermatitis commonly experience ophthalmic complications, and a higher incidence of conjunctivitis has been observed during treatment with dupilumab. We present the case of a 49-year-old woman with persistent severe atopic dermatitis who complained of refractory conjunctivitis associated with dupilumab. Ocular examination showed features of atopic conjunctivitis for which an external topical application to the eyelids of pimecrolimus 10 mg/g cream was prescribed. The patient showed substantial clinical remission after only 12 days. This case was remarkable as the medication applied externally to the eyelid skin was effective in treating the conjunctival involvement possibly due to penetration of pimecrolimus through the eyelid layers. Further studies are needed to support the use of this drug for dupilumab-related conjunctivitis.

Optical Coherence Tomography of Choroid in Common Neurological Diseases.

The choroid is involved directly and indirectly in many pathological conditions such as age-related macular degeneration, myopia-related chorioretinal atrophy and central serous chorioretinopathy. Optical coherence tomography (OCT) has gradually become a fundamental part of modern resources in the hands of ophthalmologists. The enhanced depth imaging technique and swept-source OCT make a great contribution to conventional in vivo choroid assessment. This review focuses on the most common neurological conditions in which choroid assessment by OCT may provide help in early diagnosis and be used as an interdisciplinary follow-up tool. In order to avoid evaluation biases and misdiagnosis, the main and most common physiological and para-physiological conditions in which the choroid may show alterations are also reviewed.

Diagnostic capability of optic nerve head rim width and retinal nerve fiber thickness in open-angle glaucoma.

PURPOSE: This study was performed to test the diagnostic capability of the minimum rim width compared to peripapillary retinal nerve fiber layer thickness in patients with glaucoma. METHODS: A case control, observer masked study, was conducted. Minimum rim width and retinal nerve fiber layer thickness were assessed using the patient-specific axis traced between fovea-to-Bruch's membrane opening center axis. For both minimum rim width and retinal nerve fiber layer thickness, the regionalization in six sectors (nasal, superior-nasal, superior-temporal, temporal, inferior-temporal, and inferior-nasal) was analyzed. Eyes with at least one sector with value below the 5% or 1% normative limit of the optical coherence tomography normative database were classified as glaucomatous. The area under the receiver operator characteristic curve, the accuracy, sensitivity, specificity, and predictive positive and negative values were calculated for both minimum rim width and retinal nerve fiber layer thickness. RESULTS: A total of 118 eyes of 118 Caucasian subjects (80 eyes with open-angle glaucoma and 38 control eyes) were enrolled in the study. Accuracy, sensitivity, and specificity were 79.7%, 77.5%, and 84.2%, respectively, for minimum rim width and 84.7%, 82.5%, and 89.5% for retinal nerve fiber layer thickness. The positive predictive values were 0.91% and 0.94% for minimum rim width and retinal nerve fiber layer thickness, respectively, whereas the negative predictive values were 0.64% and 0.70%. The area under the receiver operator characteristic curve was 0.892 for minimum rim width and 0.938 for retinal nerve fiber layer thickness. CONCLUSION: Our results indicated that the sector analysis based on Bruch's membrane opening and fovea to disk alignment is able to detect glaucomatous defects, and that Bruch's membrane opening minimum rim width and retinal nerve fiber layer thickness showed equivalent diagnostic ability.

In Vivo Laser Scanning Confocal Microscopy of Human Meibomian Glands in Aging and Ocular Surface Diseases.

Meibomian glands (MGs) play a crucial role in the ocular surface homeostasis by providing lipids to the superficial tear film. Their dysfunction destabilizes the tear film leading to a progressive loss of the ocular surface equilibrium and increasing the risk for dry eye. In fact, nowadays, the meibomian gland dysfunction is one of the leading causes of dry eye. Over the past decades, MGs have been mainly studied by using meibography, which, however, cannot image the glandular structure at a cellular level. The diffusion of the in vivo laser scanning confocal microscopy (LSCM) provided a new approach for the structural assessment of MGs permitting a major step in the noninvasive evaluation of these structures. LSCM is capable of showing MGs modifications during aging and in the most diffuse ocular surface diseases such as dry eye, allergy, and autoimmune conditions and in the drug-induced ocular surface disease. On the other hand, LSCM may help clinicians in monitoring the tissue response to therapy. In this review, we summarized the current knowledge about the role of in vivo LSCM in the assessment of MGs during aging and in the most diffuse ocular surface diseases.