Vitreous mediators in retinal hypoxic diseases.

The causes of retinal hypoxia are many and varied. Under hypoxic conditions, a variety of soluble factors are secreted into the vitreous cavity including growth factors, cytokines, and chemokines. Cytokines, which usually serve as signals between neighboring cells, are involved in essentially every important biological process, including cell proliferation, inflammation, immunity, migration, fibrosis, tissue repair, and angiogenesis. Cytokines and chemokines are multifunctional mediators that can direct the recruitment of leukocytes to sites of inflammation, promote the process, enhance immune responses, and promote stem cell survival, development, and homeostasis. The modern particle-based flow cytometric analysis is more direct, stable and sensitive than the colorimetric readout of the conventional ELISA but, similar to ELISA, is influenced by vitreous hemorrhage, disruption of the blood-retina barrier, and high serum levels of a specific protein. Finding patterns in the expression of inflammatory cytokines specific to a particular disease can substantially contribute to the understanding of its basic mechanism and to the development of a targeted therapy.

Confocal microscopy of corneal nerve plexus as an early marker of eye involvement in patients with type 2 diabetes.

PURPOSE: To measure the thickness and length of corneal nerves and the peri-papillary retinal nerve fiber layer (RNFL) thickness in patients recently diagnosed with diabetes mellitus (DM). METHODS: Twenty-two eyes of 22 patients recently diagnosed with type 2 DM and 22 eyes of 22 healthy individuals were consecutively enrolled. Central corneal sensitivity was measured using a Cochet-Bonnet esthesiometer, and corneal nerve length (CNL) and thickness (CNT) were evaluated through in vivo confocal microscopy. The confocal images were examined using software that could semi-automatically trace the corneal nerve pathway. Spectral domain optical coherence tomography (SD-OCT) was performed to quantify the overall and sectorial RNFL thickness. RESULTS: Mean DM duration was 3.5 ±â€¯1.7 months, whereas the mean glycemia and HbA1c levels were 180.5 ±â€¯73.13 mg/dl and 8.6 ±â€¯1.7% (65.2 ±â€¯19.7 mmol/mol), respectively. Corneal sensation threshold was significantly lower in the DM group compared to control group (p = 0.003). CNL and CNT were reduced in the DM group (p = 0.043 and p = 0.004, respectively). Significant correlations were found between CNT and HbA1c levels (p = 0.04; r = -0.47), and between CNT and the corneal sensation threshold (p = 0.04; r = 0.69). RNFL thickness was significantly reduced in the temporal quadrants, but no correlation was found with CNT and CNL changes (p > 0.05). CONCLUSIONS: CNL and CNT changes are evident even in the early stages of DM, and RNFL reduction was recorded in the temporal quadrants. These findings indicate that, in the eye with diabetes, neuropathy may represent an early marker of the disease.

Influence of retinal vessel printings on metamorphopsia and retinal architectural abnormalities in eyes with idiopathic macular epiretinal membrane.

PURPOSE: To investigate whether the presence of retinal vessel printings (RVPs) in eyes having idiopathic epiretinal membrane (ERM) is associated with a higher degree of metamorphopsia or with more prominent abnormalities in the retinal architecture compared with eyes not having RVPs. METHODS: A cross-sectional study of 36 eyes in 36 patients was conducted. The patients were divided into two groups (18 eyes per group) on the basis of the presence or absence of RVPs on fundus autofluorescence (FAF) imaging. Metamorphopsia was assessed using M-CHARTS. The optical coherence tomography (OCT) and FAF images were recorded using the Spectralis HRA+OCT. The macula was divided into 15 squares, and the areas between the displaced retinal vessels and the corresponding RVPs were calculated. RESULTS: Vertical, horizontal, and average metamorphopsia scores did not differ between the two groups. However, only two patients in the group with RVPs had an average metamorphopsia score of 0.6 or less versus nine patients in the group without RVPs (P = 0.029). There was no correlation between the area of displacement and vertical (P = 0.44), horizontal (P = 0.8), or average (P = 0.38) metamorphopsia scores. The eyes with RVPs manifested a higher degree of irregularity of the external limiting membrane (ELM) and the photoreceptor inner segment/outer segment (IS/OS) lines (P = 0.042 and P = 0.014, respectively). The presence of RVPs was the only independent variable associated with an average metamorphopsia score of 0.6 or higher. CONCLUSIONS: The presence of RVPs in eyes with idiopathic macular ERM is usually associated with an average metamorphopsia score of 0.6 or higher using M-CHARTS and with a higher degree of irregularity of the ELM and IS/OS lines at the fovea.

Long-term results of penetrating keratoplasty using a single or double running suture technique.

BACKGROUND: Corneal astigmatism changes after penetrating keratoplasty (PK) with single running suture (SRS) or double running suture (DRS) were evaluated in this prospective randomized study. METHODS: Sixty-eight consecutive eyes underwent PK: 35 received a SRS and 33 an anti-torque DRS using the same Hanna Suction System. All sutures were removed between 12 and 20 months after surgery. RESULTS: Within the first month after PK, a statistically significant difference was noted, with a lower mean value of astigmatism for the DRS group. The final mean postoperative videokeratographic astigmatism was 3.51+/-1.93 and 3.42+/-1.94 in the SRS and DRS group respectively (36 months' follow-up). CONCLUSIONS: Although the final astigmatism was about the same in the two suture groups, the DRS seems to lead to faster restoration of visual function due to early stability.