Posterior Ciliary Arteries Research Articles

The dynamics of chorioretinal hemodynamics after courses of preventive care in women at risk for the formation of vascular retinal pathology

Objective:Clinical assessment of chorioretinal hemodynamics in women at risk for vascular retinal pathology before and after long-term courses of preventive care.Methods: 60 women having undergone preeclampsia during pregnancy were exam‑ ined. The 1st group of patients (30 people) got courses of medicamentous correction of endothelial dysfunction: sulodexide, ginkgo biloba (Tanakan), ascorbic acid. The 2nd group (30 women) did not get preventive care. The control group included 30 women having undergone physiological pregnancy (vaginal delivery, without complications). Parameters of chorioretinal hemodynamics were determined 6–8 months later and 3–4.5 years later after delivery.Results: By the end of the follow-up, in the 1st group, the blood flow velocity in the posterior short ciliary arteries statistically significantly increased; the density of the retinal vessels and subfoveolar thickness of the choroid and the area of the avascular zone of the retina decreased.Conclusions: The long-term medicamentous correction of endothelial dysfunction reduces the risk of vascular pathology development in women having undergone preeclampsia during the pregnancy.

Hemodynamics of the temporal and nasal short posterior ciliary arteries in pseudoexfoliation syndrome.

The aim of this study was to investigate blood flow changes in the temporal and nasal short posterior ciliary arteries (SPCAs) in pseudoexfoliation syndrome using color Doppler ultrasonography. This prospective clinical study included 67 eyes of 53 patients scheduled for cataract surgery. Pseudophakic eyes, eyes with traumatic cataract, were excluded. The demographic characteristic of the patients were recorded. Ocular blood flow was measured using 6-10MHz Doppler ultrasound. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (Vm), and resistive index (RI) in the temporal and nasal SPCAs were determined for 39 eyes of 30 patients with pseudoexfoliation syndrome and cataract and a control group comprising 28 eyes of 23 patients with senile cataract. Compared to the control group, patients with pseudoexfoliation syndrome had significantly lower PSV (8.85 ± 2.88cm/s), EDV (3.21 ± 1.12cm/s), and Vm (5.27 ± 1.98cm/s) in the temporal SPCA (PSV P = .001; EDV P = .002; Vm P = .001). There was no difference in velocities in the nasal SPCA. RI of both the temporal and nasal SPCA did not differ statistically between the groups (temporal SPCA P = .517, nasal SPCA P = .752) CONCLUSION: There were significant decreases in temporal SPCA hemodynamic parameters in patients with pseudoexfoliation syndrome. These findings suggest that temporal SPCA ocular blood flow measurements have greater diagnostic value than those of the nasal SPCA.

Plane-Wave Ultrasound Doppler of the Eye in Preeclampsia.

PurposePre-eclampsia (PE) is a serious complication of pregnancy characterized by high blood pressure, proteinuria, compromised fetal blood supply, and potential organ damage. The superficial location of the eye makes it an ideal target for characterization hemodynamics. Our aim was to discern the impact of PE on ocular blood flow.Methods18 MHz plane-wave ophthalmic ultrasound scanning was performed on subjects with PE (n = 26), chronic or gestational hypertension (n = 8), and normal controls (n = 19) within 72 hours of delivery. Duplicate three-second long scans of the posterior pole including the optic nerve were acquired at 6000 images/sec for evaluation of the central retinal artery and vein and the short posterior ciliary arteries. The choroid was scanned at 1000 images/sec. Doppler analysis provided values of pulsatile flow velocity and resistance indexes.ResultsEnd diastolic velocity was higher, and pulsatility and resistive indexes were significantly lower in the choroid, central retinal artery and short posterior ciliary arteries in PE than in controls. Blood pressure was elevated in PE with respect to controls and was negatively correlated with resistance.ConclusionsAlthough vasoconstriction is considered characteristic of PE, we found reduced resistance in the orbital vessels and choroidal arterioles, implying vasodilation at this level. Future studies incorporating optical coherence tomography angiography for characterization of the retina and choriocapillaris in conjunction with plane-wave ultrasound scanning, particularly in late pregnancy, might address this conundrum.Translational RelevanceUse of plane-wave ultrasound scanning for evaluation ocular blood flow in women at risk for PE may offer an avenue towards early detection and clinical intervention.

ROLE OF DILATED SUBFOVEAL CHOROIDAL VEINS IN EYES WITH MYOPIC MACULAR NEOVASCULARIZATION.

To investigate the dilated choroidal veins (DCVs) at or around myopic macular neovascularizations (MNVs) and to determine whether there is a hemodynamic relationship between them. Fifty-eight eyes of 57 patients with myopic MNVs were examined. Dilated choroidal veins were defined as choroidal veins whose diameter was 2X larger than adjacent veins. Indocyanine green angiography and swept-source optical coherence tomography images were reviewed to detect DCVs that crossed the subfoveal area. The filling sequence of the DCVs and MNVs was determined. Patients' mean age was 71.4 ± 10.6 years. The mean axial length was 29.3 ± 1.8 mm. Dilated choroidal veins below or around the MNV were found in 17 eyes (29.3%). Emissaries of the short posterior ciliary arteries were seen at or around MNVs in 8 of the 17 eyes. In these eyes, the short posterior ciliary artery was filled first or almost simultaneously with the filling of the MNV, followed by a laminar filling of the DCVs. In one eye, afferent arterioles from the short posterior ciliary arteries and efferent venules connected to DCVs were seen. Dilated choroidal veins are present below or around MNVs in about 30% of eyes with myopic MNVs. Our findings suggest that an MNV might be a vascular unit consisting of short posterior ciliary arteries, afferent arterioles, efferent venules, and DCVs.

Inflammation of a Posterior Ciliary Artery in a Naive Cynomolgus Macaque.

This brief communication describes a previously unreported background lesion in the eye of a naive cynomolgus macaque. Inflammation of a posterior ciliary artery was, in this case, morphologically similar to vascular inflammation of other tissues described in naive cynomolgus macaques. However, the available literature does not describe this lesion at this anatomical site. The affected animal did not present with any abnormal clinical signs and ophthalmological examinations were within normal limits. Toxicologic pathologists should be aware of this finding in order to help differentiate it from a test item-related finding.

An Atypical Presentation of Giant Cell Arteritis with Bilateral Choroidal Ischaemia

Background: Giant cell arteritis is an immune-mediated, medium to large vessel vasculopathy affecting individuals over 50 years of age. It can cause sudden, severe and irreversible loss of vision, most commonly from an arteritic posterior ciliary artery occlusion causing anterior ischaemic optic neuropathy. The optic nerve appearance would typically be swollen and chalky white. Visual reduction secondary to choroidal ischaemia is a much less frequent presentation, the signs of which can be more subtle in appearance, making its early recognition potentially more challenging. Case Presentation: A 51-year-old male presented to eye casualty complaining of a one-week history of neck pain, intermittent headaches and jaw claudication, associated with reduced vision in his right eye. Presenting visual acuity was hand movements and 6/5 in the right and left eyes respectively. On examination, he was noted to have a right relative afferent pupillary defect, a pale macular area in the right eye with a possible cherry red spot. There was no optic disc swelling. ESR was 34 and CRP was 46 and he was wrongly diagnosed with a non-arteritic central retinal artery occlusion. He subsequently re-presented 5 weeks later with vision loss in his left eye. Best corrected visual acuity was now 6/60 and 6/12 in the right and left eyes respectively. Dilated fundoscopy showed multiple yellow-white lesions in the posterior pole of the left eye and a retinal cotton wool spot. The right optic nerve was pale, and left was normal. A fundus fluorescein angiogram showed delayed choroidal filling and the temporal artery biopsy was suggestive of GCA. He was started on 110mgs of oral prednisolone. After 4 weeks of steroids his BCVA was 6/36 and 6/6 in the right and left eyes respectively. His neck pain, headaches and jaw claudication had all resolved and his ESR and CRP had returned to normal levels. Conclusion: Our case highlights the need for increased awareness of this uncommon presentation of this potentially blinding disease, to allow prompt and appropriate treatment. Our case is unusual in that despite a delayed diagnosis of 5 weeks, visual acuity initially improved with treatment.

Anatomic study on safe insertion of acupuncture needle in Qiuhou (EX-HN7) acupoint

To explore the anatomical structure of acupuncture point Qiuhou (EX-HN7) area for safe insertion of acupuncture needle. A total of 28 orbital specimens of adult corpses (14 men and 14 women) were randomly selected to be observed by anatomical sectioning and layering methods. The acupoint EX-HN7, located at the junction between the 1/4 of the outer boundary and 3/4 of the inner boundary of the infraorbital margin according to the "Standardization of Acupoint Position" implemented by the People's Republic of China, and marked first with a color pen, followed by cutting the head into horizontal sections along the cross line by using a cadaver cutter and measuring the distance between the skin and blood vessels and main nerves with a digimatic caliper. When the anatomic hierarchy was performed, the blood vessels and nerves in the orbit, the morphological characteristics of the structure around the needle body were particularly focused. When an acupuncture needle was vertically inserted into EX-HN7 region, the tissues through which the needle passes are skin, subcutaneous tissue, orbicularis muscle, orbital adipose body, inferior oblique muscle and inferior orbital wall, respectively. When an acupuncture needle was inserted obliquely upward and along the inferior orbital wall to a depth of (26.5±1.7)mm, the needle tip met the posterior ciliary artery; when to a depth of (41.4±1.3)mm, it reached the superior ophthalmic vein. When inserted to a depth of (40.4±1.5)mm, the needle tip may damage the ophthalmic artery and optic nerve. When the acupuncture needle was inserted inferiorly and closely along the orbital inferior wall to a depth of (13.2±1.4)mm, the infraorbital artery in the suborbital sulcus would be hurt. It is recommended that when insert vertically into a depth of 12.0 mm in EX-HN7, the acupuncture needle tip should be slightly inclined inward and posterior-upward, and the depth should not exceed 26.0 mm.

Initial experience with the Scepter Mini dual-lumen balloon for transophthalmic artery embolization of anterior cranial fossa dural arteriovenous fistulae

BackgroundPrecise delivery of liquid embolic agents (LEAs) remains a challenge in the endovascular treatment of dural arteriovenous fistulae (dAVFs) and cerebral arteriovenous malformations (cAVMs). Despite significant advances in the past...

Compressive Retinal Degeneration Due to a Large Lacrimal Gland Tumor

A 64-year-old man presented with painless, progressive proptosis of the OS that lasted for several years. Clinical examination revealed severe downward deviation of the eyeball and a firm palpable mass above the eyeball (Fig. 1A). Visual acuity was “hand motion,” and the fundus could not be observed because of hypermature cataract. B-scan ultrasound revealed severe compression of the upper eyeball by the orbital mass (Fig. 1B), and MRI revealed a 3.5 cm-sized well-defined round mass above the eyeball (Fig. 1C,D).FIG. 1.: Preoperative findings of the patient and surgical specimen of the removed orbital mass. A, External photograph shows severe downward deviation of the left eye. B, B-scan ultrasound shows compression of the upper eyeball by the orbital mass. C, D, Magnetic resonance imaging (MRI) shows a 3.5-cm, well-defined, relatively homogeneous enhanced mass in the left superior orbit with severe inferior displacement of the eyeball. E, Gross specimen photograph of the well-encapsulated firm mass after complete excisional biopsy.Complete excisional biopsy of the mass was performed and diagnosed as pleomorphic adenoma of the lacrimal gland (Fig. 1E). Cataract surgery was performed after 2 months, and a degenerative retinal change was observed in the superior retina at the site of previous tumor compression (Fig. 2A). The optic disc showed no sign of optic atrophy (Fig. 2B). Optical coherence tomography (OCT) revealed dense sub-retinal pigment epithelium (RPE) material (red asterisk) and choroidal thinning (arrow heads) which were more prominent on the affected superior side (red dashed arrow) than inferior area (green dashed arrow, Fig. 2C). Choroidal thickness in the opposite eye was normal (Fig. 2D).FIG. 2.: Fundus photography and OCT images taken 8 months after orbital mass removal and 6 months after cataract surgery. A, Fundus photography shows well-demarcated retinal degeneration in the superior retina, previously compressed by the tumor (white dashed arrow: OCT scan location shown in Figure 2C). B, OCT evaluation of retinal nerve fiber layer shows retinal nerve fiber layer thickness within normal range. C, Vertical OCT scan of the left eye shows diffuse sub-RPE deposit in the superior retina (red asterisk); Choroidal thinning (arrow heads) is observed more than the opposite eye (D, arrow heads); Choroidal thinning seen prominently in the superior area (red dashed arrow) as compared to the inferior area (green dashed arrow). G, general; INT, inferior; N, nasal; NAS, nasal; NI, nasal inferior; NS, nasal superior; RNFLT, retinal nerve fiber layer thickness; SUP, superior; T, temporal; TI, temporal inferior; TMP, temporal; TS;temporal superior.The possibility of retinal degeneration by other etiologies cannot be completely ruled out. However, given the fact that degenerative retinal changes have been observed at previous tumor compression sites, the possibility of retinal degeneration by long-term compression can also be assumed. The possible pathophysiology is that the large orbital tumor mainly compresses the posterior ciliary arteries and affects choroidal circulation, while relatively conserving the central retinal artery traversing inside the optic nerve. Choroidal blood flow compromised over a long period can cause choroidal thinning and induce outer retinal and RPE degeneration. The diffuse sub-RPE deposits could be due to the outer retinal metabolite clearance failure caused by RPE dysfunction.

Effect of Changing Heart Rate on the Ocular Pulse and Dynamic Biomechanical Behavior of the Optic Nerve Head.

PurposeTo study the effect of changing heart rate on the ocular pulse and the dynamic biomechanical behavior of the optic nerve head (ONH) using a comprehensive mathematical model.MethodsIn a finite element model of a healthy eye, a biphasic choroid consisted of a solid phase with connective tissues and a fluid phase with blood, and the lamina cribrosa (LC) was viscoelastic as characterized by a stress-relaxation test. We applied arterial pressures at 18 ocular entry sites (posterior ciliary arteries), and venous pressures at four exit sites (vortex veins). In the model, the heart rate was varied from 60 to 120 bpm (increment: 20 bpm). We assessed the ocular pulse amplitude (OPA), pulse volume, ONH deformations, and the dynamic modulus of the LC at different heart rates.ResultsWith an increasing heart rate, the OPA decreased by 0.04 mm Hg for every 10 bpm increase in heart rate. The ocular pulse volume decreased linearly by 0.13 µL for every 10 bpm increase in heart rate. The storage modulus and the loss modulus of the LC increased by 0.014 and 0.04 MPa, respectively, for every 10 bpm increase in heart rate.ConclusionsIn our model, the OPA, pulse volume, and ONH deformations decreased with an increasing heart rate, whereas the LC became stiffer. The effects of blood pressure/heart rate changes on ONH stiffening may be of interest for glaucoma pathology.

Variations in anterior segment vasculature of the eye and their implication in ophthalmologic surgical procedures

ObjectiveAnterior segment ischemia (ASI) is a complication of strabismus surgery and other ocular procedures. The aim of this study is to determine anatomic variability of the vessels involved in the greater arterial circle of iris including short posterior ciliary arteries (SPCA), the long posterior ciliary artery (LPCA) and anterior ciliary arterial (ACA) anastomosis. Understanding these variations may help decrease the incidence of ASI in patients following strabismus surgery and other ophthalmologic procedures.MethodsA total of 126 preserved cadaveric eyeballs from Kansas City University, Nebraska Medical Center, and Creighton University were dissected. The dissection was performed through an anterior approach following removal of the orbital contents. All further dissection was performed, and photographs taken, using a Zeiss Meditech AG dissection scope. Choroid was exposed by making an incision in the sclera 1–2 cm from the limbus, followed by removal of overlying sclera to a point 2–3 cm proximal to the insertion point of the four rectus muscles.Short posterior ciliary arteries were counted as they entered the major arteriolar circle of iris and their locations were mapped in relation to the vertical and horizontal axes. Long posterior ciliary arteries were located, isolated, and cut prior to removal of the choroid. Distances were measured from the penetration point of the LPCA through the sclera in relation to the optic nerve and the vertical and horizontal axes.The number and location of SPCAs that contribute to the major arteriolar circle of iris and LPCAs as they pierce the sclera was determined. Comparisons were also made to determine if there were significant differences between right and left eyes as well as between males and females.ResultsSpecific locations of SPCAs were determined and mapped to identify their contribution to the anterior segment and generate surgical safe zones during various ophthalmologic procedures. The specific location and number of the LPCAs was also determined and mapped to clarify their contribution to the LPCA – ACA anastomosis, highlighting their importance as the sole source of blood flow following incision of the rectus muscles and corresponding anterior ciliary arteries during strabismus surgery. Surgical safe zones were created using the location where LPCA pierces the sclera which can be used to avoid damage to this artery during invasive ophthalmologic procedures.ConclusionsAs far as the investigators are able to determine, this is the first cadaveric study that uses an anterior approach to map SPCAs and LPCAs as they enter the greater arteriolar circle of iris. The findings of the study enabled the investigators to identify a surgical safe zone for invasive ophthalmologic procedures involving the extraocular muscles, sclera, choroid, and retina. This information should be beneficial to physicians performing strabismus surgery, choroidal effusion drainage, placement of ocular devices, subretinal fluid drainage and other procedures near these vessels. These findings should help surgeons avoid anterior segment ischemia, hemorrhage, and other important complications during invasive ophthalmologic procedures.

Obstructive sleep apnea in the pathogenesis of ocular vascular diseases

Respiratory changes caused by obstructive sleep apnea (OSA) syndrome increase the risk of ocular vascular diseases. Hypoxia, hypercapnia, endothelial dysfunction associated with OSA syndrome, promote local impairment of fibrinolysis, cause hypercoagulation and vasospasm, creating conditions for retinal vein occlusions as well as for those of posterior ciliary arteries. 91,5 % patients with retinal vein occlusions and 75 % patients with nonarteritic anterior ischemic optic neuropathy have moderate-to-severe OSA. OSA timely diagnosis and treatment prevent acute vascular pathology of the retina and optic nerve.

Association Study of MTHFR Polymorphisms with Nonarteritic Anterior Ischemic Optic Neuropathy in a Spanish Population

Introduction: Nonarteritic anterior ischemic optic neuropathy (NAION), painless loss of central and/or peripheral vision, is a multifactorial disease caused by insufficient blood flow through the posterior ciliary arteries to the optic nerve head. Mutations in the methylenetetrahydrofolate reductase (MTHFR) gene, triggering hyperhomocysteinemia as a consequence of a decreased activity of the codified enzyme, have been considered to be among the risk factors of NAION. Objective: The main aim was to study the association of the most common MTHFR genetic polymorphisms C677T and A1298C with NAION in a Spanish population. Methods: In this case-control study, the association of the most common MTHFR polymorphisms was investigated in 94 unrelated native Spanish patients diagnosed with NAION and 204 healthy controls. Two single nucleotide polymorphisms located in the MTHFR gene, C677T (rs1801133) and A1298C (rs1801131), were analyzed by DNA sequencing and TaqMan assays. Results: The allelic and genotypic frequencies of the MTHFR variants obtained in the NAION group were not significantly different when compared with the control group. A higher frequency of the C677T/A1298C genotype, codifying the nonmutated MTHFR form, was obtained in control subjects (11.27%) compared to NAION patients (4.26%), suggesting a protective effect of the wild-type protein, although this result was not conclusive considering the obtained confidence interval (CI) (95% CI: 0.13–1.06). Study of additional clinical factors including hypertension, diabetes mellitus, and dyslipidemia showed no association with a higher risk of NAION. Conversely, the clinical history of heart or cerebrovascular diseases was significantly higher in NAION patients compared to controls. Over the world, risk variants of the MTHFR gene are highly frequent, excluding African black populations, indicating a racial influence. Conclusions: The MTHFR variants did not significantly increase the risk of suffering from NAION. However, considering that individuals with at least one of the risk variants have the MTHFR enzyme with decreased activity, it cannot be ruled out that these mutations are relevant for the development of NAION in a subgroup of the population with other specific characteristics. These may include high plasma levels of homocysteine along with nutritional deficiencies including low folate or vitamin B12 and the combination of systemic and local risk factors.

Abnormal retrobulbar blood flow variables in central serous chorioretinopathy.

To evaluate if the retrobulbar blood flow variables were deteriorated in central serous chorioretinopathy (CSC) patients. We included 25 CSC patients and 25 healthy subjects. We used color Doppler ultrasonography to assess the ophthalmic artery (OA), the central retinal artery (CRA), and the posterior ciliary arteries (PCA) for peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI). Mean ages of the patients and controls were 42.3 ± 8.5 and 41.3 ± 9.4 years, respectively (P = .853). There were no significant differences between the two groups with regard to the values of PSV, EDV, and RI of CRA (P = .406, P = .627, P = .227) and PCA (P = .785, P = .403, P = .935, respectively). The PSV and EDV of OA were lower in the CSC patients (P = .005, P = .024, respectively). Whereas the RI of OA was not significantly different (P = .729). Submacular choroidal thickness (SCT) was greater in CSC patients (P < .001). There was a negative correlation between SCT and PSV of PCA (P = .022, r = -0.457) and between SCT and EDV of PCA (P = .004, r = -0.560) in CSC patients. Hemodynamic changes in OA and a negative correlation between PCA values and SCT suggest ocular circulatory dysfunction in patients with CSC.

Ocular blood flow and choroidal thickness changes after carotid artery stenting

To evaluate changes in ocular blood flow and subfoveal choroidal thickness in patients with symptomatic carotid artery stenosis after carotid artery stenting. We included 15 men (mean age, 63.6 ± 9.1 years) with symptomatic carotid artery stenosis and 18 healthy volunteers (all men; mean age, 63.7 ± 5.3 years). All participants underwent detailed ophthalmologic examinations including choroidal thickness measurement using enhanced depth-imaging optic coherence tomography. The patients also underwent posterior ciliary artery blood flow measurements using color Doppler ultrasonography before and after carotid artery stenting. Patients lacked ocular ischemic symptoms. Their peak systolic and end-diastolic velocities increased to 10.1 ± 13.1 (p=0.005) and 3.9 ± 6.3 (p=0.064) cm/s, respectively, after the procedure. Subfoveal choroidal thicknesses were significantly thinner in patients with carotid artery stenosis than those in the healthy controls (p=0.01). But during the first week post-procedure, the subfoveal choroidal thicknesses increased significantly (p=0.04). The peak systolic velocities of the posterior ciliary arteries increased significantly after carotid artery stenting (p=0.005). We found a significant negative correlation between the mean increase in peak systolic velocity values after treatment and the mean preprocedural subfoveal choroidal thickness in the study group (p=0.025, r=-0.617). In patients with carotid artery stenosis, the subfoveal choroid is thinner than that in healthy controls. The subfoveal choroidal thickness increases after carotid artery stenting. Carotid artery stenting treatment increases the blood flow to the posterior ciliary artery, and the preprocedural subfoveal choroidal thickness may be a good predictor of the postprocedural peak systolic velocity of the posterior ciliary artery.

Evaluation of retrobulbar circulation in type 2 diabetic patients using color Doppler imaging.

Purpose:To investigate the retrobulbar circulatory parameters in type 2 diabetes mellitus patients with color Doppler imaging (CDI) and compare the results with nondiabetic controls.Methods:This prospective study included 50 type 2 diabetic patients and 50 age-matched controls. Seven field stereo fundus photography was used to diagnose and classify diabetic retinopathy (DR). Diabetic patients were further divided into two: Group 1, consisted of patients with no DR, mild and moderate non-proliferative DR (n = 36); Group 2, severe nonproliferative and proliferative DR (n = 14). CDI was performed using Philips iU22 xMATRIX ultrasound. The peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI) and pulsatile index (PI) of ophthalmic (OA), posterior ciliary artery (PCA), and central retinal artery (CRA) along with central retinal vein (CRV) were recorded.Results:RI in the ophthalmic artery was significantly higher in both DR groups than the control group (P = 0.000). Diabetic Group 1 had decreased blood flow velocity (PSV and EDV) in PCA compared to controls (P = 0.046 and P = 0.010, respectively). Group 2 DR had significantly reduced EDV and increased RI in CRA compared to Group 1 (P = 0.015). Binary logistic regression analysis revealed glycosylated hemoglobin and RI of OA to be independent risk factors of DR.Conclusion:Significant changes in resistivity index and flow velocities were observed in the retrobulbar vessels, especially in ophthalmic artery in diabetics compared to controls. CDI with results of increased resistance or decreased flow could be useful to predict individuals at higher risk for developing severe DR.

The role of retinal microcirculation disorders in the progression of glaucomatous optic neuropathy

To assess the progression of primary open-angle glaucoma (POAG) and to study the role of retinal microcirculation in its progression. In this 2-year prospective study, the rate of POAG progression was determined using perimetry (ROP1) and spectral domain optical coherence tomography (SD-OCT) by thinning of retinal nerve fiber layer (RNFL) (ROP2) and ganglion cell complex (GCC) (ROP3). The vessel density of parafoveal superficial plexus (VD parafovea) and peripapillary retina (VD ppr) was assessed using OCT angiography, peripheral resistance index (RI), and blood flow velocity in the posterior short ciliary arteries (PSCA) and central retinal artery (CRA) with the use of color Doppler mapping. The predictive properties of each parameter were calculated using the area under receiver operating curve (AUC). Progression was detected in 9.8% cases by perimetry and in 19.7% cases by OCT. The combination of these two methods increased the detection up to 32.8%. Circulatory parameters - VD parafovea (AUC 0.70±0.07), VD ppr (0.715±0.07), PSCA RI (0.801±0.12), CRA RI (0.798±0.11) - had similar high predictive properties as IOP max (0.79±0.05), corneal hysteresis (0.755±0.07), thickness of inner parafoveal layers (0.728±0.07) and RNFL (0.692±0.06). The study revealed the following correlations: ROP1 with maximum IOP (p=0.01), ROP2 with blood flow velocity in PSCA (p=0.01), VD parafovea with corneal hysteresis (p=0.01), and GCC thickness with ocular perfusion pressure (p=0.01). The obtained data demonstrates the importance of combining perimetry with OCT for detecting the progression of glaucoma and indicates its relationship with reduced ocular hemoperfusion.

A Color Doppler Imaging Study of Ocular Haemodynamic Parameters in Primary Open Angle Glaucoma (POAG)

Aims: To study retrobulbar haemodynamics in primary open angle glaucoma (POAG) patients. Methods: It was a hospital based cross-sectional study carried out in Medical College Out Patient Department (OPD). A total of 26 patients with newly diagnosed POAG and 23 controls were randomly selected for the study. The haemodynamic parameters i.e. Peak systolic velocity (PSV), End diastolic velocity (EDV) and resistivity index (RI) were studied in ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) measured using Color Doppler imaging (CDI). Mean, standard deviation (SD) and Independent t- test was applied to compare the results between the two group. Results: The mean intraocular pressure (IOP) for the POAG group and control group was 26.31±4.51 mmHg and 17.04±1.26 mmHg, respectively (P < 0.001). The mean PSV for both OA and CRA, the mean EDV for all OA, CRA and SPCA were significantly lower whereas the mean RI in the CRA and SPCA were significantly higher in POAG than controls. Conclusions: Retrobulbar blood flow was significantly lower in POAG as compared to controls, thereby suggesting the importance of measuring the retrobulbar blood flow in POAG patients.

Temporal Arteritis Related Arteritic Anterior Ischemic Optic Neuropathy

Temporal arteritis (Giant cell arteritis) is an autoimmune systemic disease affecting the elderly population characterized by granulomatous vasculitis involving the mid-large size vessels. Classical systemic symptoms include headache, skin sensitivity in the temporal region, and jaw fatigue. Inflammation involving the posterior ciliary arteries leads to arteritic anterior ischemic optic neuropathy which causes sudden vision loss. Temporal artery biopsy is the gold standard for diagnosis and should be applied to all patients suspected of the disease. As early diagnosis and treatment are of vital importance in terms of improvement of visual loss and prevention of other ocular involvement, Optic neuropathy is considered to be a neuro-ophthalmologic emergency. The gold standard in treatment is steroids. There is no consensus in the literature regarding the optimal therapeutic approach in cases with steroid resistance. Biological agents, especially tocilizumab, are promising in refractory cases. Up-to-date steroids are the first step in the treatment algorithm, tocilizumab is recommended in the second line; however, in cases with progression, abatacept, ustekinumab, and anakinra are recommended as last-line treatments.

Unraveling the Enigma of Nonarteritic Anterior Ischemic Optic Neuropathy.

Non-arteritic anterior ischemic optic neuropathy (NAON) is the second most common optic neuropathy in adults. Despite extensive study, the etiology of NAION is not definitively known. The best evidence suggests that NAION is caused by an infarction in the region of the optic nerve head (ONH), which is perfused by paraoptic short posterior ciliary arteries (sPCAs) and their branches. To examine the gaps in knowledge that defies our understanding of NAION, a historical review was performed both of anatomical investigations of the ONH and its relevant blood vessels and the evolution of clinical understanding of NAION. Notably, almost all of the in vitro vascular research was performed prior our current understanding of NAION, which has largely precluded a hypothesis-based laboratory approach to study the etiological conundrum of NAION. More recent investigative techniques, like fluorescein angiography, have provided valuable insight into vascular physiology, but such light-based techniques have not been able to image blood vessels located within or behind the dense connective tissue of the sclera and laminar cribrosa, sites that are likely culpable in NAION. The lingering gaps in knowledge clarify investigative paths that might be taken to uncover the pathogenesis of NAION and possibly glaucoma, the most common optic neuropathy for which evidence of a vascular pathology also exists.