ALTERATION OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN A PATIENT WITH OCULAR ISCHEMIC SYNDROME

Changes in Outcomes of Macular Optical Coherence Tomography Angiography Following Surgery for Optic Disc Pit Maculopathy

PURPOSE

we aimed to report on the optical coherence tomography angiography (OCTA) outcomes of eight patients with optic disc pit maculopathy (ODP-M) who were treated with 23-gauge pars plana vitrectomy (PPV).

METHODS

We examined sixteen eyes of eight patients-eight eyes with ODP-M and eight healthy fellow eyes. Fundus color photography, fundus autofluorescence, fundus fluorescein angiography, optical coherence tomography (OCT), and OCTA were performed. The vascular density, choriocapillaris blood flow (CCBF), and foveal avascular zone (FAZ) were analyzed using OCTA. Moreover, the correlation between the best-corrected visual acuity (BCVA) and macular OCTA parameters was assessed.

RESULTS

Compared with the healthy fellow eyes, the eyes with ODP-M preoperatively were found to have decreased BCVA, superficial capillary plexus (SCP) vascular density (i.e., total, foveal, parafoveal, and perifoveal), deep capillary plexus (DCP) vascular density (i.e., total, parafoveal, and perifoveal), and CCBF but a significantly increased FAZ (p < 0.05). When the eyes with ODP-M were analyzed pre- and postoperatively at month 12 after surgery, the BCVA, SCP vascular density (i.e., perifoveal), and CCBF had significantly increased, and the FAZ had significantly decreased (p < 0.05). When the eyes with ODP-M were compared with the healthy fellow eyes postoperatively at month 12, the BCVA, SCP, and DCP vascular density parameters had increased, along with CCBF, and the FAZ had decreased in eyes with ODP-M, though not to the levels of the healthy fellow eyes (p < 0.05). Moreover, a positive correlation was found between the postoperative BCVA and SCP total vascular density (p < 0.05).

CONCLUSION

The BCVA and macular OCTA parameters improved in eyes with ODP-M at month 12 following surgery. However, the BCVA and OCTA of the eyes operated on did not reach the levels of the healthy fellow eyes, possibly due to impaired choroidal blood flow (CBF) recovery and the presence of a larger FAZ. In summary, OCTA seems to be useful for assessing qualitative and quantitative perioperative microvascular changes.

Ocular Ischemic Syndrome and the Role of Carotid Artery Revascularization

BACKGROUND

Ocular ischemic syndrome (OIS) is a rare presentation of atherosclerotic carotid artery stenosis that can result in permanent visual loss. This severely disabling syndrome remains under diagnosed and undertreated due to lack of awareness; especially since it requires expedited multidisciplinary care. The relevance of early diagnosis and treatment is increasing due to an increasing prevalence of cerebrovascular disease.

METHODS

The long-term visual and cerebrovascular outcomes following intervention for nonarteritic OIS, remain poorly described and were the objective of this concise review. We conducted a PubMed search to include all English language publications (cohort studies and case reports) between 2002 and 2023.

RESULTS

A total of 33 studies (479 patients) report the outcomes of treatment of OIS with carotid endarterectomy (CEA, 304 patients, 19 studies), and carotid artery stenting (CAS, 175 patients, 14 studies). Visual outcomes were improved or did not worsen in 447 patients (93.3%). No periprocedural stroke was reported. Worsening visual symptoms were rare (35 patients, 7.3%); they occurred in the immediate postoperative period secondary to ocular hypoperfusion (3 patients) and in the late postoperative period due to progression of systemic atherosclerotic disease. Symptomatic recurrence due to recurrent stenosis after CEA was reported in 1 patient (0.21%); this was managed successfully with CAS. None of these studies report the results of transcarotid artery revascularization, the long-term operative outcome or stroke rate.

CONCLUSIONS

OIS remains to be an underdiagnosed condition. Early diagnosis and prompt treatment are crucial in reversal or stabilization of OIS symptoms. An expedited multidisciplinary approach between vascular surgery and ophthalmology services is necessary to facilitate timely treatment and optimize outcome. If diagnosed early, both CEA and CAS have been associated with visual improvement and prevention of progressive visual loss.

[Less Frequent Vascular Disorders of the Retina - Part 1]

This review provides an overview of retinal vascular disorders that are less frequent in Germany and Europe compared to diabetic retinopathy and retinal venous or arterial occlusive disorders. The knowledge of these disorders is important for the differential diagnosis of retinal vascular disorders as well as potentially associated systemic disorders. In the current part one epidemiology, pathophysiology, clinical presentation, and therapy are discussed for hypertensive retinochoroidopathy, ocular ischemic syndrome, retinal alterations in sickle cell disease, Eales disease, radiation retinopathy, peripheral exudative hemorrhagic chorioretinopathy, and retinal disorders associated with pregnancy.

[Optical coherence tomography angiography in diagnosis of changes in macular capillary blood flow in chronic ischemic retinopathy]

PURPOSE

Assessment of the indices of macular capillary blood flow and subfoveal choroidal thickness (SCT) using optical coherence tomography angiography in patients with retinal manifestations of ocular ischemic syndrome (RMOIS) associated with atherosclerotic internal carotid artery stenosis.

MATERIAL AND METHODS

The study included 34 patients (68 eyes): 21 men, 13 women with RMOIS in one eye. All patients were divided into 2 groups depending on the severity of atherosclerotic internal carotid artery stenosis and ophthalmoscopic picture of the fundus. To obtain objective information we analyzed the degree of decrease in the main indices characterizing macular microcirculation and SCT depending on the severity of RMOIS.

RESULTS AND DISCUSSION

Analysis of the results showed relationship between the severity of RMOIS and the deficit in macular microcirculation. The macula of the patients with mild RMOIS was characterized by a decrease in the density of superficial vascular plexus (SVP) and the density of deep capillary plexus (DCP) by 13.5% and 10.5% compared to the controls, respectively; in moderate RMOIS - by 19.7% and 14.6%; in severe RMOIS - by 35.9% and 28%, respectively. With an increase in the severity of RMOIS, the area of the foveal avascular zone increased too: in mild degree RMOIS - by 19%, in moderate - by 38.6%, in severe - by 51%. In proportion to the severity of RMOIS, SCT was reduced: in mild degree RMOIS - by only 8%, in moderate - by 22%, and in severe - by 29.8% of the control.

CONCLUSION

The conducted research indicates that pathological changes in RMOIS extend to the entire capillary network of the macula and SCT. With increase in the degree of RMOIS, ischemic changes in all capillary layers of the central parts of the retina proportionally increase in comparison with the control group by 1.15 times in mild degree, by 1.24 times in moderate degree, and by 1.5 times in severe RMOIS.

Retinal Thickness Correlates with Cerebral Hemodynamic Changes in Patients with Carotid Artery Stenosis

Background: We aimed to assess the retinal structural and choroidal changes in carotid artery stenosis (CAS) patients and their association with cerebral hemodynamic changes. Asymptomatic and symptomatic patients with unilateral CAS were enrolled in our study. Material and methods: Swept-source optical coherence tomography (SS-OCT) was used to image the retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), while SS-OCT angiography (SS-OCTA) was used to image and measure the choroidal vascular volume (CVV) and choroidal vascular index (CVI). Computed Tomography Perfusion (CTP) was used to assess the cerebral perfusion parameters; relative perfusion (r) was calculated as the ratio of the value on the contralateral side to that on the ipsilateral side. Results: Compared with contralateral eyes, ipsilateral eyes showed significantly thinner RNFL (p < 0.001), GCIPL (p = 0.013) and CVV (p = 0.001). Relative cerebral blood volume (rCBV) showed a significant correlation with RNFL (p < 0.001), GCIPL (p < 0.001) and CVI (p = 0.027), while the relative permeability surface (rPS) correlated with RNFL (p < 0.001) and GCIPL (p < 0.001). Conclusions: Our report suggests that retinal and choroidal changes have the potential to detect hemodynamic changes in CAS patients and could predict the risk of stroke.

Asymmetric diabetic retinopathy

Increasing prevalence of diabetes mellitus warrants recognition of factors related to asymmetric diabetic retinopathy (DR). This thematic synthesis based on an iterative literature review conducted in Medline and Google Scholar pertaining to diabetes with coexistent asymmetry of retinopathy included 45 original articles, 21 case reports and series, and 18 review articles from 1965 to 2020. Asymmetric DR is defined as proliferative DR (PDR) in one eye and nonproliferative, preproliferative, background, or no DR in the other eye lasting for at least 2 years. It is observed in 5%–10% of patients with PDR. Associated factors can be divided into (i) vascular: carotid obstructive disease, ocular ischemic syndrome, and retinal vascular diseases; (ii) Inflammatory: uveitis, endophthalmitis, and Fuchs’ heterochromic cyclitis; (iii) degenerative: posterior vitreous detachment, high myopia and anisometropia, uveal coloboma, retinal detachment, retinitis pigmentosa, and chorioretinal atrophy and scarring; (iv) cataract surgery and vitrectomy; and (v) miscellaneous: elevated intraocular pressure, glaucoma, amblyopia, retinal detachment, and optic atrophy. The gamut of diagnostic modalities for asymmetric DR includes thorough ocular examination, slit-lamp biomicroscopy, fundus photography, fundus fluorescein angiography, optical coherence tomography, and newer modalities such as ultra-widefield fluorescein angiography and optical coherence tomography angiography, along with a complete systemic evaluation and carotid Doppler studies. The differential diagnosis includes other causes of retinal neovascularization that may present in an asymmetric manner, such as sickle cell retinopathy, retinal vein occlusions, and featureless retina. This review discusses in detail the aforementioned considerations and draws a comprehensive picture of asymmetric DR in order to sensitize ophthalmologists to this important condition.