How does Covid-19 affect the choroidal structures at the early post-infectious period?

PURPOSE: To evaluate choroidal thickness (CT) and choroidal vascularity index (CVI) in patients recovered from COVID-19 using enhanced depth imaging optical coherence tomography in the early postinfectious period. METHODS: Sixty-five patients recovered from COVID-19 and 72 healthy subjects were included in the study. A full ophthalmic examination including best-corrected visual acuity (BCVA), slit lamp biomicroscopy, and dilated fundus examination was performed. CT was measured at 3 points as follows: subfoveal, 1000µm nasal and temporal to the fovea. The total choroidal area (TCA), luminal area (LA), stromal area (SA), and CVI were measured with Image-J. RESULTS: The mean age was 39.09±11.27 years in the COVID-19 group and 39.61±11.43 years in the control group. The mean time from the first positive RT-PCR was 49.54±26.82 days (range 18-120) in the COVID-19 group. No statistically significant difference was detected between the groups with regard to axial length, spherical equivalent, and BCVA (all P>0.05). CT was found to be lower in the COVID-19 group compared to the control group in all quadrants, but this difference was not significant (all P>0.05). The mean TCA, LA, and CVI were statistically significantly reduced in the COVID-19 group (all P<0.001); however, SA showed no statistically significant difference (P=0.064). CONCLUSIONS: In asymptomatic or mild COVID-19, CVI and LA decrease significantly, while CT thins in the early postinfectious period but not significantly.

Choroidal changes in Crimean-Congo hemorrhagic fever.

PURPOSE: The goal of this study was to evaluate the effect of Crimean-Congo hemorrhagic fever (CCHF) on choroidal tissue. METHODS: Thirty-two CCHF patients and 34 healthy individuals were included in this cross-sectional study. All subjects were assessed using spectral domain optical coherence tomography and ImageJ software. The choroidal thickness (CT) in the subfoveal, nasal and temporal regions 1 mm from the foveal center was measured. The total choroidal area (TCA), luminal area (LA), stromal area (SA) and choroidal vascularity index (CVI) were calculated. RESULTS: The nasal (P=0.002), subfoveal (P=0.006), and temporal CT (P=0.028) were significantly higher in the CCHF group. The TCA (P=0.021), SA (P=0.001) was significantly higher, and LA/SA (P<0.001) and CVI (P<0.001) were significantly lower in patients with CCHF. Significant negative correlations were found between temporal CT (r=-0.387, P=0.029), TCA (r=-0.461, P=0.008), LA (r=-0.480, P=0.005) SA (r=-0.419, P=0.017) and fibrinogen. Nasal CT, temporal CT, TCA and SA tended to increase with the severity of the disease, while LA/SA tended to decrease when CCHF patients were grouped into mild and moderate stages. CONCLUSIONS: This study demonstrates significant changes in the choroidal structure and vascular characteristics in CCHF patients. These findings may be associated with endothelial damage, vascular leakage, capillary fragility, impaired immune response, and/or inflammation.

Association between lower extremity venous insufficiency and increased choroidal thickness.

PURPOSE: The goal of this study is to investigate the association between the choroid and lower extremity venous insufficiency (LEVI). METHODS: This prospective cross-sectional study includes 56 patients with LEVI and 50 age/sex-similar control subjects. Choroidal thickness (CT) measurements from 5 different points were captured from all participants by optical coherence tomography. In the group with LEVI on physical examination, reflux at the saphenofemoral junction, and the diameter of the great and small saphenous veins were evaluated via color Doppler ultrasonography. RESULTS: The mean subfoveal CT was higher in the varicose group than in the control group (363.04±99.75µm vs. 320.30±73.46µm, P=0.013). In addition, the CTs at the temporal 3mm, temporal 1mm, nasal 1mm, and nasal 3mm distance from the fovea were higher in the LEVI group compared to the controls (for all, P<0.05). There was no correlation between CT and diameter of the great and small saphenous vein in patients with LEVI (for all, P>0.05). However, the great and small saphenous veins of patients with CT above 400µm were observed to be wider in patients with LEVI (P=0.027 and P=0.007, respectively). CONCLUSION: Varicose veins can be a feature of systemic venous pathology. Another component of systemic venous disease may be increased CT. Patients with high CT should be investigated for susceptibility to LEVI.

How do the amblyopic and fellow eyes differ in adults?

OBJECTIVE: To investigate the differences between the amblyopic eye and the fellow eye in adults with anisometropic amblyopia. MATERIALS AND METHODS: Measurements of the central macular thickness [CMT], subfoveal choroidal thickness [SFCT], and retinal nerve fiber layer [RNFL] in patients with anisometropic amblyopia were obtained using optical coherence tomography [OCT]. Axial length [AL], anterior chamber depth [ACD], and central corneal thickness [CCT] were measured with optical biometry. All 12 parameters were compared between the amblyopic eye [Group 1] and the fellow eye [Group 2]. RESULTS: A total of 110 eyes of 55 patients [9 myopic, 46 hypermetropic] were analyzed retrospectively. The ages of the patients ranged from 17 to 55 years, with a mean of 30.8±10.7 years. 56.4% [n=31] of the patients were female, and 43.6% [n=24] were male. The mean spherical equivalent [SE] was 1.96±3.79 in Group 1 and 1.28±2.45 in Group 2. SFCT was 312.00±53.03 in Group 1 and 283.47±51.91 in Group 2. AL was 22.53±1.40 in Group 1 and 22.79±1.18 in Group 2. SE, SFCT, and AL were statistically significantly different between the two groups. There was no difference between the two groups in terms of CMT, RNFL, ACD and CCT values. CONCLUSION: In adults with anisometric amblyopia, the SFCT of the amblyopic eye is greater than that of the fellow eye. The choroid plays an important role in the nutrition of the retinal layers, the development of ocular function and refractive error, and its development may be affected by the refractive error. Since the majority of our patients were hyperopic, the AL was found to be shorter in the amblyopic eye. CMT, RNFL, ACD and CCT values were the similar in both groups. There was no clinically significant relationship between biometric parameters and OCT parameters.

Effect of keratorefractive surgery on choroidal thickness in anisometropic amblyopia.

PURPOSE: To evaluate postoperative change in choroidal thickness (CT) in patients with anisometropic amblyopia undergoing keratorefractive surgery. METHODS: Anisometropic amblyopic patients and nonamblyopic patients who underwent keratorefractive surgery were included in the study. The eyes were divided into three groups. Group 1 consisted of eyes with anisometropic amblyopia, group 2 were the nonamblyopic fellow eyes, and group 3 (control group) were nonamblyopic eyes which had undergone keratorefractive surgery. At the third postoperative month, the CT of these eyes were measured by Enhanced Depth Imaging OCT (EDI-OCT). The choroidal thickness (CT) was measured in the subfoveal area and at 500 micron intervals nasally and temporally. RESULTS: Twenty-three anisometropic amblyopia patients with amblyopic and fellow eyes and 23 control eyes were enrolled. The mean subfoveal choroidal thickness (CT) was 387.3±168.8µm in group 1, 412.2±88.8µm in group 2 and 337.3±99µm in group 3 (P: 0.019). Group 1 and group 2 showed higher choroidal thickness (CT) in the nasal and temporal quadrants than group 3 (P: 0.03, P: 0.04). At the third postoperative month, central foveal choroidal thickness was 356.6±115.5µm in group 1, 375.1±112.5µm in group 2 and 284.4±98.9µm in group 3 (P: 0.071). Choroidal thickness (CT) in the nasal and temporal quadrants at the third postoperative month was also similar (P: 0.210, P: 0.103). CONCLUSIONS: The macular choroid is thicker in amblyopic eyes and non-amblyopic fellow eyes than in the nonamblyopic controls. Improved fixation after refractive surgery may normalize CT.

Effect of 0.01% atropine eye drops on choroidal thickness in myopic children.

PURPOSE: To examine the effects of low-dose atropine on the choroidal thickness (CT) of young children in Shanghai, China, as well as the ocular biometrics of myopic patients. METHODS: A total of 59 eyes of 35 myopic children had subfoveal CT and ocular biometry measurements taken before and after 2weeks, 4weeks, and 8weeks of treatment with 0.01% atropine. All eyes were measured using swept-source optical coherence tomography. CT and changes in it were also recorded. RESULTS: The choroid exhibited significant and continuous thickening under the fovea after patients were treated with 0.01% atropine. The magnitude of change in CT varied with the location and with the duration of treatment. The greatest change was observed in the fovea. There was no significant relationship between changes in subfoveal CT and axial length. CONCLUSIONS: Using 0.01% atropine eye drops significantly increased CT in eyes of young myopic children, by variable magnitude depending upon location.

The effect of silicone oil presence time on macular and choroidal thickness with macula-off rhegmatogenous retinal detachment.

OBJECTIVE: To investigate the effects of silicone oil (SiO) on macular thickness (MT) and subfoveal choroidal thickness (SFCT) in patients with macula-off rhegmatogenous retinal detachment (RRD) undergoing pars plana vitrectomy (PPV). MATERIAL AND METHODS: In this prospective study, 70 eyes of 70 patients who received SiO tamponade for the treatment of macula-off RRD were treated with PPV and a 5000-cSt SiO endotamponade followed by subsequent SiO removal. MT and SFCT were measured 1 day before and 3 months after SiO removal using spectral-domain optical tomography (SD-OCT) and enhanced depth imaging optical tomography (EDI-OCT). The patients were divided into 3 groups according to the length of time that the SiO was present: group 1 (3-6 months), group 2 (6-9 months), and group 3 (9-18 months). RESULTS: A total of 70 eyes of 70 patients with a mean age of 57.22±9.83 years (range: 30 years to 75 years) were included in the SiO (5000-cSt) study. SiO was extracted after a mean duration of 8.67±5.33 months (range, 3-18 months) after PPV. In the 1st group, BCVA increased from 1.83±0.32 log MAR before PPV to 0.85±0.41 log MAR at 3 months after silicone removal (P<0.001). In the 2nd group, BCVA increased from 1.76±0.38 log MAR before PPV to 0.86±0.48 log MAR at 3 months after silicone removal (P<0.001). In the 3rd group, BCVA increased from 1.89±0.28 log MAR before PPV to 1.08±0.63 log MAR at 3 months after SiO removal (P=0.001). There was no statistically significant change in MT in the difference values of each group. As the length of SiO presence in the eye increased, significant thinning was observed on measurement of SFCT. Differences in the SFCT values were -14.91µm, -18.76µm, and -51.50µm in groups 1, 2, and 3 respectively (P=0.004). CONCLUSIONS: A significant decrease in macular and choroidal thicknesses after SiO removal was observed. Presence of SiO endotamponade for 9 months was associated with subfoveal choroidal thinning and decreased final visual acuity in eyes undergoing RRD surgery. SD-OCT and EDI-OCT may be recommended for the treatment and follow-up of patients with complications caused by the use of SiO tamponade.

Evaluation of changes in retinal and choroidal thickness using spectral domain optical coherence tomography in unilateral non granulomatous acute anterior uveitis.

PURPOSE: To assess retinal and choroidal thickness changes in eyes with a first episode of unilateral non granulomatous acute anterior uveitis (AU). METHODS: Thirty-one patients with acute unilateral non granulomatous AU who had undergone spectral domain optical coherence tomography (SD-OCT) of both eyes were included in this retrospective study. Retinal thickness (RT) as defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) and subfoveal choroidal thickness (SFCT) obtained by SD-OCT were recorded. Healthy fellow eyes of the patients served as the control. RESULTS: A significant thickening in 1mm of ETDRS subfield and in subfoveal choroid was observed in eyes with acute AU when compared with the unaffected fellow eyes (P=0.005 and P<0.00001, respectively). RT and SFCT of affected eyes did not show a significant difference in terms of HLA-B27 antigen presence or absence (P>0.05, for all). CONCLUSIONS: Significant posterior segment changes were detected in eyes with acute unilateral non granulomatous AU.

Chromatic and achromatic visual fields in relation to choroidal thickness in patients with high myopia: A pilot study.

PURPOSE: To analyse the relationship between the choroidal thickness and the visual perception of patients with high myopia but without retinal damage. METHODS: All patients underwent ophthalmic evaluation including a slit lamp examination and dilated ophthalmoscopy, subjective refraction, best corrected visual acuity, axial length, optical coherence tomography, contrast sensitivity function and sensitivity of the visual pathways. RESULTS: We included eleven eyes of subjects with high myopia. There are statistical correlations between choroidal thickness and almost all the contrast sensitivity values. The sensitivity of magnocellular and koniocellular pathways is the most affected, and the homogeneity of the sensibility of the magnocellular pathway depends on the choroidal thickness; when the thickness decreases, the sensitivity impairment extends from the center to the periphery of the visual field. CONCLUSIONS: Patients with high myopia without any fundus changes have visual impairments. We have found that choroidal thickness correlates with perceptual parameters such as contrast sensitivity or mean defect and pattern standard deviation of the visual fields of some visual pathways. Our study shows that the magnocellular and koniocellular pathways are the most affected, so that these patients have impairment in motion perception and blue-yellow contrast perception.

Choroidal thickness in healthy eyes using enhanced depth imaging optical coherence tomography and comparison with cases of retinitis pigmentosa.

INTRODUCTION: The goal of this study was to measure by spectral domain optical coherence tomography (SD-OCT) with EDI the choroidal thickness in healthy subjects and to compare these parameters with those of patients with retinitis pigmentosa (RP). METHODS: Data were obtained from 60 healthy patients without history or family history of retinal or choroidal disease or glaucoma. A case-control study was also conducted on 40 eyes of 20 patients with RP and 40 eyes of 20 healthy refraction- and age-matched controls, selected from among the 60 healthy patients. OCT was used with the EDI protocol. The primary outcome measure was choroidal thickness. RESULTS: Among healthy patients, the overall choroidal thickness was 287.7µm. Mean choroidal thickness was lower on the nasal side (236.6µm at 2000µm from the fovea) compared with the temporal side (262.3µm at 2000µm, P=0.002). It also varied according to age, being highest among 20-29-year-old patients and decreasing thereafter with increasing age. Choroidal thickness was significantly higher in healthy patients than in RP patients, regardless of the location (P<0.001). CONCLUSION: This observational study confirms that choroidal thickness varies with age and location. It decreases in subjects with RP and is related to worsening of retinal damage, independently of age-related thinning. Further studies are needed to understand whether choroidal vascular alteration is a cause or a consequence of the degenerative pathology.

Prevalence of macular complications associated with high myopia by multimodal imaging.

PURPOSE: To describe the prevalence of macular complications in patients with visual acuity decrease related to high myopia (HM). To establish correlations between these complications and demographic or anatomical characteristics. MATERIALS AND METHODS: Cross-sectional observational study including HM patients undergoing best-corrected visual acuity (BCVA), fundus examination, macular SD-OCT, and fluorescein angiography in the case of suspicion of choroidal neovascularization (CNV). The presence of anatomical criteria (staphyloma, subfoveal choroidal thickness [CT]) and macular complications (CNV, lacquer cracks, central chorioretinal atrophy, dome-shaped macula with serous retinal detachment [SRD], retinal foveoschisis, macular hole and epiretinal membrane) was investigated. RESULTS: A total of 87 eyes of 47 patients were included (39 eyes without macular complication and 48 eyes with macular complications). In the case of macular complications, decrease in BCVA was related to CNV in 33%, macular hole in 25%, chorioretinal atrophy in 19%, foveoschisis in 11%, lacquer crack in 6%, to a dome-shape macula with serous retinal detachment in 4% and epiretinal membrane in 2%. After adjusting for interocular correlation and degree of myopia, staphyloma (P=0.0023), choroidal thinning (P=0.0036), and extrafoveal chorioretinal atrophy (P=0.042) were significantly associated with macular complications. CONCLUSIONS: High myopic patients with staphyloma or choroidal thinning should undergo regular comprehensive retinal screening for retinal complications.