Differentiating Degenerative from Vascular Dementia with the Help of Optical Coherence Tomography Angiography Biomarkers.

Alzheimer's disease and vascular dementia account for the majority of cases of cognitive decline in elderly people. These two main forms of dementia, under which various subtypes fall, are often overlapping and, in some cases, definitive diagnosis may only be possible post-mortem. This has implications for the quality of care and the design of individualized interventions for these patients. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality used to visualize the retinal layers and vessels which shows encouraging results in the study of various neurological conditions, including dementia. This review aims to succinctly sum up the present state of knowledge and provide critical insight into emerging patterns of OCTA biomarker values in Alzheimer's disease and vascular dementia. According to the current literature, vessel density seems to be a common biomarker for both forms; inner retinal layer thickness might represent a biomarker preferentially affected in degenerative dementia including Alzheimer's, while, in contrast, the outer-layer thickness as a whole justifies attention as a potential vascular dementia biomarker. Radial peripapillary capillary density should also be further studied as a biomarker specifically linked to vascular dementia.

The Contribution of Ocular Biomarkers in the Differential Diagnosis of Alzheimer's Disease versus Other Types of Dementia and Future Prospects.

With dementia becoming increasingly prevalent, there is a pressing need to become better equipped with accurate diagnostic tools that will favorably influence its course via prompt and specific intervention. The overlap in clinical manifestation, imaging, and even pathological findings between different dementia syndromes is one of the most prominent challenges today even for expert physicians. Since cerebral microvasculature and the retina share common characteristics, the idea of identifying potential ocular biomarkers to facilitate diagnosis is not a novel one. Initial efforts included studying less quantifiable parameters such as aspects of visual function, extraocular movements, and funduscopic findings. However, the really exciting prospect of a non-invasive, safe, fast, reproducible, and quantifiable method of pinpointing novel biomarkers has emerged with the advent of optical coherence tomography (OCT) and, more recently, OCT angiography (OCTA). The possibility of analyzing multiple parameters of retinal as well as retinal microvasculature variables in vivo represents a promising opportunity to investigate whether specific findings can be linked to certain subtypes of dementia and aid in their earlier diagnosis. The existing literature on the contribution of the eye in characterizing dementia, with a special interest in OCT and OCTA parameters will be reviewed and compared, and we will explicitly focus our effort in advancing our understanding and knowledge of relevant biomarkers to facilitate future research in the differential diagnosis between Alzheimer's disease and common forms of cognitive impairment, including vascular dementia, frontotemporal dementia, and dementia with Lewy bodies.

Management of Pseudophakic Malignant Glaucoma in Sunset Syndrome: A Case Report and Literature Review.

To present an interesting case of pseudophakic malignant glaucoma in sunset syndrome, which potentially points to a correlation between a posterior chamber intraocular lens (PCIOL) subluxation and development of aqueous misdirection. Furthermore, we underlined the effectiveness of YAG-laser hyaloidotomy as a first line treatment for malignant glaucoma. This is a case report and literature review. A 76-year-old male with primary open angle glaucoma (POAG) with a history of left monocular diplopia due to inferior dislocation of the PCIOL (sunset syndrome), presented with a sudden onset of pain in the left eye and decreased visual acuity with corrected distance visual acuity (CDVA) of 20/60, seven years after an uneventful left phacoemulsification. The anterior chamber (AC) was shallow, the intraocular pressure (IOP) elevated and the PCIOL extruded in AC. Aqueous misdirection was diagnosed and treated with YAG laser hyaloidotomy. A gush of fluid emerged with simultaneous deepening of the AC and the IOP dropped immediately to 24 mmHg and later to 9 mmHg. A prophylactic YAG peripheral iridotomy was also performed. An IOL exchange surgery with anterior chamber IOL placement was performed a few days later resulting in a final CDVA of 20/30. We argue that postoperative subluxation of a PC IOL is likely to be an initiating event for aqueous misdirection.