The Inflammatory and Cytological Effect of Repeated Povidone-Iodine Application in Patients Receiving Intravitreal Injections.

OBJECTIVE: To investigate the effect of repeated povidone-iodine (PVI) application on the ocular surface parameters of patients who received intravitreal injections. MATERIALS AND METHODS: In this prospective study, 52 eyes of 52 patients with age-related macular degeneration who underwent unilateral intravitreal injection at least three times in the last 1 year (intravitreal injection [IVI] group), 52 fellow eyes with no previous intravitreal injection (NIVI group), and 51 eyes of 51 healthy subjects (control) were included. Tear break-up time (TBUT), the Schirmer test, the Oxford staining score, the Ocular Surface Disease Index questionnaire, conjunctival impression cytology, and tear inflammatory cytokine levels (interleukin [IL]-1ß and IL-6) were analyzed in all participants. RESULTS: The IVI group had lower TBUT and higher Oxford staining score than the NIVI and control groups ( P <0.05). No significant difference was found between the groups in the Schirmer test ( P =0.161). Conjunctival impression cytology analysis revealed that the IVI group had a significantly lower goblet cell count and significantly higher Nelson staging result than the NIVI and control groups ( P <0.05). As a result of tear cytokine analysis, although IVI and NIVI groups had higher IL-1ß and IL-6 levels than the control group ( P <0.05), there was no difference between NIVI and IVI groups ( P ≥0.05). CONCLUSIONS: Repeated PVI application caused cytotoxic injury to the ocular surface, resulting in goblet cell loss and squamous metaplasia of epithelial cells. As a result, the stability of the tear film layer was found to be impaired and ocular surface-related symptoms developed in patients.

Regional analysis of segmented-macular structure in patients with myopic anisometropia.

PURPOSE: To compare intraretinal layers between the eyes in patients with myopic anisometropia, and evaluate the relationship between the layers with spherical equivalent (SE) and axial length (AL). METHODS: In this retrospective study, the more myopic (MM) and fellow (F) eyes of 41 patients with myopic anisometropia, and 38 emmetropic (± 0.50 diopter) control (C) eyes were inclueded. Intraretinal layer segmentation was performed by optical coherence tomography. Global volumes of retinal layers and their thicknesses in nine macular regions were compared. Correlation analysis was used to determine the relationship with SE and AL in each layer. RESULTS: Total retinal, ganglion cell (GCL), inner nuclear (INL), and outer plexiform (OPL) layer volumes in MM eyes were less than in C eyes, while INL and OPL were less than in F eyes. There was no difference in the fovea, except for the retinal pigment epithelium. In MM eyes, only INL and OPL were thin in at least one perifoveal and parafoveal quadrant compared to F eyes. Only INL and OPL thicknesses were significantly correlated with both SE and AL in all perifoveal quadrants. In contrast to the thinning found in MM eyes, the only layer in which thickening was detected to compare to C eye was nerve fiber layer (NFL), which correlated positively with SE and negatively with AL. CONCLUSION: While the fovea is less affected by myopia, thinning becomes remarkable in the perifoveal quadrants. Despite thinning in many layers, especially INL and OPL, NFL thickening may be seen due to myopia.