Choroidal macrovascular and capillary alterations in eyes with idiopathic epiretinal membranes.

PURPOSE: To evaluate the choroidal vascular alterations and effect of surgical treatment in the setting of idiopathic epiretinal membranes. METHODS: The structure of the choroid was studied in 33 patients with unilateral idiopathic epiretinal membrane using optical coherence tomography with enhanced depth imaging and optical coherence tomography angiography. Eyes with epiretinal membrane underwent 25-gauge vitrectomy with epiretinal membrane and internal limiting membrane peeling. The choroidal vascularity index, Haller layer/choroidal thickness ratio, and choriocapillaris flow density were used to evaluate changes in choroidal structure after surgery and compare with the healthy fellow eyes. RESULTS: The choroidal vascularity index and Haller layer/choroidal thickness ratio of the eyes with epiretinal membrane were higher than those of the fellow eyes at baseline (p=0.009 and p=0.04, respectively) and decreased postoperatively compared with preoperative values (p=0.009 and p=0.001, respectively). The choriocapillaris flow of eyes with epiretinal membrane was lower than that of the fellow eyes at baseline (p=0.001) and increased after surgery compared with the preoperative value (p=0.04). The choroidal vascularity index, Haller layer/choroidal thickness ratio, and choriocapillaris flow values of the healthy fellow eyes were comparable at baseline and final visit. In eyes with epiretinal membrane, the final choroidal vascularity index correlated with the final choriocapillaris flow (r=-0.749, p=0.008) in the multivariate analysis. CONCLUSION: Idiopathic epiretinal membrane appears to affect the choroidal structure with increased choroidal vascularity index and Haller layer/ choroidal thickness ratio and decreased choriocapillaris flow. These macrovascular (choroidal vascularity index and Haller layer/choroidal thickness) and microvascular (choriocapillaris flow) alterations appear to be relieved by surgical treatment of the epiretinal membranes.

Choroidal macrovascular and capillary alterations in eyes with idiopathic epiretinal membranes

ABSTRACT Purpose: To evaluate the choroidal vascular alterations and effect of surgical treatment in the setting of idiopathic epiretinal membranes. Methods: The structure of the choroid was studied in 33 patients with unilateral idiopathic epiretinal membrane using optical coherence tomography with enhanced depth imaging and optical coherence tomography angiography. Eyes with epiretinal membrane underwent 25-gauge vitrectomy with epiretinal membrane and internal limiting membrane peeling. The choroidal vascularity index, Haller layer/choroidal thickness ratio, and choriocapillaris flow density were used to evaluate changes in choroidal structure after surgery and compare with the healthy fellow eyes. Results: The choroidal vascularity index and Haller layer/choroidal thickness ratio of the eyes with epiretinal membrane were higher than those of the fellow eyes at baseline (p=0.009 and p=0.04, respectively) and decreased postoperatively compared with preoperative values (p=0.009 and p=0.001, respectively). The choriocapillaris flow of eyes with epiretinal membrane was lower than that of the fellow eyes at baseline (p=0.001) and increased after surgery compared with the preoperative value (p=0.04). The choroidal vascularity index, Haller layer/choroidal thickness ratio, and choriocapillaris flow values of the healthy fellow eyes were comparable at baseline and final visit. In eyes with epiretinal membrane, the final choroidal vascularity index correlated with the final choriocapillaris flow (r=-0.749, p=0.008) in the multivariate analysis. Conclusion: Idiopathic epiretinal membrane appears to affect the choroidal structure with increased choroidal vascularity index and Haller layer/choroidal thickness ratio and decreased choriocapillaris flow. These macrovascular (choroidal vascularity index and Haller layer/choroidal thickness) and microvascular (choriocapillaris flow) alterations appear to be relieved by surgical treatment of the epiretinal membranes.

Evaluation of Central and Peripheral Retinal Vascular Changes in the Fellow Eyes of Patients with Unilateral Retinal Vein Occlusions

Objectives: To evaluate the subtle peripheral retinal and macular vascular changes in the fellow eyes of patients with unilateral retinal vein occlusion (RVO). Materials and Methods: This retrospective study included 53 patients with unilateral RVO and 44 age-matched controls. The frequency of peripheral retinal vascular pathologies in both eyes was evaluated using high quality ultra-wide field fluorescein angiography (UWFFA). Macular vascular density, flow area, and foveal avascular zone measurements from optical coherence tomography angiography (OCTA) were analyzed together with laser flare photometry values in patients and controls. Results: Peripheral retinal vascular pathologies were detected on UWFFA in the fellow eyes of 36 (67.9%) patients. No significant central vascular pathologies were detected on OCTA and there was no significant difference in OCTA parameters between the fellow eyes and the controls. Flare values did not differ significantly between the control and the fellow eyes. Conclusion: Two thirds of the fellow eyes of unilateral RVO patients had subtle peripheral retinal vascular changes, while there was no significant microvascular change detected with OCTA in the macula. This suggests that vascular changes caused by systemic vascular disorders probably first start in the peripheral retina of the fellow eyes of patients with RVO.

Clinical characteristics and the treatment modalities of Graves' orbitopathy in a tertiary referral center in Turkey: changes over two decades.

PURPOSE: To evaluate the changes in demographics, clinical findings, and treatment modalities in Graves' orbitopathy (GO) patients at a tertiary referral center in Turkey over the last two decades. METHODS: The clinical data of 752 GO patients were evaluated retrospectively. Patients were divided into 2 groups according to the first ophthalmic examination date; Group 1(n:344) between January 1998 and December 2007 and Group 2(n:408) between January 2008 and December 2017. RESULTS: The number of nonsmokers was significantly higher in Group 2 (44.0 vs. 26.5%, p < 0.001). The time from the diagnosis of thyroid dysfunction and referral to our center was 32.4 months in Group 1 and 34.8 months in Group 2, (p = 0.166). The most common treatment of hyperthyroidism was antithyroid medications. Radioiodine ablation treatment rate was significantly lower in Group 2 (14.8 vs. 9.1%, p < 0.001). The time between the diagnosis of thyroid disease and orbital involvement was 22.0 vs. 26.6 months in Groups 1 and 2, respectively (p = 0.009). The time elapsed between the diagnosis of orbital disease and referral to our clinic was 21.0 months vs. 22.4 months in Group 1 and 2, respectively (p = 0.068). Orbital disease was most commonly mild, and inactive. Mild and moderate to severe GO and the mean Clinical Activity Score significantly increased, and the rate of sight-threatening disease and orbital decompression surgery significantly decreased in Group 2 (p = 0.042; p < 0.001, respectively). CONCLUSIONS: Mild and inactive orbital disease was the most common form of GO. The severity of GO is declining over the last two decades in Turkey.

Iontophoresis Corneal Cross-linking With Oxygen Supplementation in Ovine Eyes.

PURPOSE: To evaluate the biomechanical changes and advanced oxidation protein products (AOPP) production after different corneal cross-linking (CXL) protocols with or without oxygen supplementation. METHODS: Ovine eyes in the study were equally distributed to five groups as control, standard Dresden protocol, diluted alcohol- and iontophoresis-assisted CXL (DAI-CXL), and 0.1% and 0.2% riboflavin-mediated iontophoresis-assisted CXL with oxygen supplementation (I-CXL). Corneas that received CXL were divided into two equal parts, one part was used for uniaxial tensiometry and one part was used for AOPP measurement. RESULTS: All treatment groups showed higher Young's modulus and stiffness compared to the control group (P < .05). Both oxygen-assisted I-CXL groups with 0.1% and 0.2% riboflavin concentrations had higher corneal Young's modulus (P = .009 and .006, respectively) and stiffness (P = .009) values, whereas the DAI-CXL group had lesser Young's modulus and stiffness values (P = .032) compared to the Dresden protocol group. All treatment groups showed higher AOPP concentrations compared to the control group (P < .05). DAI-CXL and I-CXL groups showed similar AOPP formation compared to the Dresden protocol (P = .673). CONCLUSIONS: When the epithelium is intact, the desired increase in corneal stiffness might not be achieved. However, increasing the oxygen in the environment might provide a sufficient increase in stiffness in cases undergoing epitheliumon I-CXL, which might be promising in terms of shortening the CXL therapy and decreasing the complications. [J Refract Surg. 2022;38(10):674-681.].

Singlet oxygen formation during accelerated and hyperaccelerated corneal cross-linking: in vitro study.

BACKGROUND: To evaluate the singlet oxygen (1O2) production of oxygen assisted %0.1 riboflavin and ultraviolet-A (UVA) crosslinking therapy (with and without oxygen assistance), in combination with standard, accelerated and hyper-accelerated procedures via an important quantitive marker of 1O2 which is the photo-oxidation of 1,3 diphenylisobenzofuran (DPBF). METHODS: %0.1 riboflavin-containing wells were irradiated with UVA light (365-nm wavelength) with or without 2-4-6-8 L/min oxygen flow assistance. Measurements of decrease in absorbance of DPBF were made in 30 mW (hyper-accelerated), 9 mW (accelerated), and 3 mW UV-A (standard) applications, and with additional 2-4-6-8 L/min oxygen flow in 30 mW and 2 L/min oxygen flow in 9 mW. A total of 8 different UV-A irradiance with and without oxygen supplementation groups were formed. RESULTS: 2 L/min oxygen assisted accelerated UV-A irradiance group has shown a greater decrease in DPBF absorbance compared to Dresden protocol. (p = 0.014) Also, Dresden protocol has shown a greater decrease in DPBF compared to all groups except accelerated crosslinking with 2 L/min oxygen. (p < 0.001) Oxygen assisted hyper-accelerated crosslinking groups were showed greater reduction in DPBF absorbance compared to standard crosslinking without oxygen groups. (p < 0.001). CONCLUSION: Oxygen supplementation may increase the singlet oxygen generation to the similar levels of Dresden Protocol's in accelerated group. Also, more singlet oxygen generation with oxygen supplementation compared to standard UV-A application might be considered to be promising in terms of shortening the crosslinking therapy.

Choroidal vascularity index and choriocapillary changes in retinal vein occlusions.

PURPOSE: To evaluate the changes in the choroidal structure in the setting of retinal vein occlusion (RVO). METHODS: Changes in the structure of the choroid were studied in sixty-four eyes with unilateral central or branch RVO using optical coherence tomography (OCT) with enhanced depth imaging and OCT-angiography (OCT-A). Choroidal vascularity index (CVI), Haller layer/choroidal thickness (H/C) ratio, and choriocapillaris flow density were used to compare the structural characteristics of the choroid with fellow eyes and the eyes of thirty-four age-, gender-, and systemic co-morbidity-matched controls. RESULTS: Eyes with RVO had a higher H/C ratio but a lower choriocapillaris flow density compared to both fellow and control eyes (p < 0.001). CVI was significantly lower in both eyes of the patients with RVO compared with control eyes (p < 0.05) with a more robust decrease in the eye that had developed RVO (p < 0.001). The H/C ratio (r = 0.303 p < 0.001), CVI (r = - 0.268, p = 0.001), and choriocapillaris flow density (r = - 0.237, p = 0.003) were all correlated with logMAR visual acuity, and other clinical features. CONCLUSION: Retinal vein occlusions alter the hemodynamic properties of the choroid leading to structural changes. These changes may be secondary to a compensatory mechanism to supply oxygen to hypoxic retina.

Real-life comparison of the viewing angle and the image quality of two commonly used viewing systems for vitreoretinal surgery

Background/aim: To compare the clinical use, image quality and viewing angle of a commonly used contact wide angle viewing (WAV) system (Advanced Visual Instruments (AVI) Panoramic Imaging Systems, NY, USA) with a commonly used noncontact WAV system (Leica RUV800, Leica Microsystems, Switzerland). Materials and methods: Images of 42 consecutively operated eyes were obtained with both systems at the same surgical stages and were compared for image quality using the Imatest Master 4.5.13 (Imatest LLC, Boulder, USA) software. The viewing angles of the images were calculated using the optic disc sizes measured from the OCT and infrared fundus images. The 68-degree AVI lens was compared with the 90-dioptre (D) Leica RUV800 lens, while the 130-degree AVI lens was compared with the 132-D Leica RUV800 lens. The surgical assistants were asked to grade the difficulty of holding the lens in place from 1 to 10, 1 being the easiest and 10 being the most difficult. Results: The contact system provided wider viewing angles with higher quality compared to the noncontact system both under fluid and air media. The difference was clinically significant in eyes with impaired corneal clarity, very high myopia, or small pupil. The difficulty of holding the lens in place ranged from 4 to 7, and decreased gradually with practice. Conclusions: Both WAV systems provided high image quality and adequate viewing angles in most cases. However, the contact system appeared to provide a superior image quality and/or a wider viewing angle in more challenging situations. The difficulty of holding the contact lens in place was found to be moderate.

Effect of Riboflavin/Rose Bengal-Mediated PACK-CXL on Acanthamoeba Trophozoites and Cysts in Vitro.

PURPOSE: To evaluate the antiamoebic properties of photo-activated chromophore for keratitis (PACK)-corneal cross-linking (CXL) (PACK-CXL), in combination with riboflavin (0.1 and 0.25%) or rose bengal (0.1 and 0.2%), for treatment of Acanthamoeba trophozoites and cysts. MATERIALS AND METHODS: Cultures of Acanthamoeba castellanii were grown in a fluid medium at a concentration of 2.7 × 105 cell/ml. PACK-CXL was used on A. castellani cells in combination with either riboflavin (0.1 and 0.25%) or rose bengal (0.1 and 0.2%). Riboflavin-containing wells were irradiated with ultraviolet-A (UVA) light (365-nm wavelength). Rose bengal-containing wells were irradiated with green light (523-nm wavelength). A power density of 9 mW/cm2 for 10 min and total irradiation dose of 5.4 J/cm2 was used for both riboflavin and rose bengal. After UVA and green light irradiation, cell viabilities were evaluated, and percentage of dead cells calculated. RESULTS: No significant amoebicidal activity was observed following PACK-CXL/riboflavin at either concentration. PACK-CXL/rose bengal, however, was observed to be highly effective in eradicating Acanthamoeba cells at either concentration, with no significant difference observed between the two concentrations. The percentage of dead cells was 63% following treatment at either rose bengal concentration. CONCLUSION: PACK-CXL with rose bengal demonstrated pronounced antiamoebic activity against A.castellanii. Further in vitro and in vivo studies are needed to confirm this finding.