Effect of low-degree astigmatism on the objective visual quality.

AIM: To evaluate the effect of low-degree astigmatism on objective visual quality through the Optical Quality Analysis System (OQAS). METHODS: This study enrolled 46 participants (aged 23 to 30y, 90 eyes) with normal or corrected-to-normal vision. The cylindrical lenses (0, 0.5, 0.75, 1.0, and 1.25 D) were placed at the axial direction (180°, 45°, 90°, and 135°) in front of the eyes with the best correction to form 16 types of regular low-degree astigmatism. OQAS was used to detect the objective visual quality, recorded as the objective scattering index (OSI), OQAS values at contrasts of 100%, 20%, and 9% predictive visual acuity (OV100%, OV20%, and OV9%), modulation transfer function cut-off (MTFcut-off) and Strehl ratio (SR). The mixed effect linear model was used to compare objective visual quality differences between groups and examine associations between astigmatic magnitude and objective visual quality parameters. RESULTS: Apparent negative relationships between the magnitude of low astigmatism and objective visual quality were observed. The increase of OSI per degree of astigmatism at 180°, 45°, 90°, and 135° axis were 0.38 (95%CI: 0.35, 0.42), 0.50 (95%CI: 0.46, 0.53), 0.49 (95%CI: 0.45, 0.54) and 0.37 (95%CI: 0.34, 0.41), respectively. The decrease of MTFcut-off per degree of astigmatism at 180°, 45°, 90°, and 135° axis were -10.30 (95%CI: -11.43, -9.16), -12.73 (95%CI: -13.62, -11.86), -12.75 (95%CI: -13.79, -11.70), and -9.97 (95%CI: -10.92, -9.03), respectively. At the same astigmatism degree, OSI at 45° and 90° axis were higher than that at 0° and 135° axis, while MTFcut-off were lower. CONCLUSION: Low astigmatism of only 0.50 D can significantly reduce the objective visual quality.

Thymic Stromal Lymphopoietin-Related Allergic Pathway in Patients With Vernal Keratoconjunctivitis.

PURPOSE: To investigate the expression of thymic stromal lymphopoietin (TSLP) and the relevant signaling pathways in the giant papillae obtained from patients with vernal keratoconjunctivitis (VKC) and to study the potential functional role and molecular mechanism of TSLP. METHODS: Giant papillae from VKC patients and control samples were used to perform immunohistochemical staining and analyze the mRNA expression of TSLP and related pathway by real-time polymerase chain reaction. RESULTS: TSLP was markedly expressed in the epithelial cells and some inflammatory cells of giant papillae, but not in the control conjunctival tissue. TSLP mRNA expression in the giant papillae of VKC was increased by 9.63 ± 0.99 (mean ± SD) fold compared with controls (P < 0.01). CD11c and OX40L immunoreactive cells largely infiltrated the giant papillae as observed by immunohistochemical staining. CD4Th2 cell infiltration was observed through high immunoreactivity of CD4. Th2 cytokines (IL-4, IL-5 and IL-13) and OX40 in the VKC specimens showed increased expression. Augmented gene expression levels of CD4 (6.88 ± 1.84), OX40L (7.60 ± 1.79), OX40 (7.25 ± 1.38), IL-4 (6.89 ± 1.46), IL-5 (8.42 ± 1.55), and IL-13 (9.69 ± 1.94) were significantly different from controls (P < 0.05). CONCLUSIONS: Our observations provide strong evidence that TSLP may be a crucial factor that contributes to the development and progression of allergic conjunctivitis. The results also demonstrated that TSLP activates dendritic cells to prime CD4T cells to differentiate into Th2 type and triggers Th2-dominant allergic inflammation through the TSLP/OX40L/OX40 signaling as part of immunopathogenesis of VKC.

A novel technique of modified continuous blanket suture for amniotic membrane fixation in severe ocular surface diseases.

The purpose of this article is to demonstrate a novel technique using modified continuous blanket suture (MCBS) to fix the amniotic membrane (AM) in different severe ocular surface disease lesions. The MCBS techniques were used to fix the AMs of 5 representative patients with different ocular surface lesions related to severe ocular surface diseases. In all cases, stable adherence of the AM was maintained until the epithelialization of the ocular surface was completed. No early detachment, dissolution, or dislocation of the AM patch was observed. During follow-up, all patients acquired a smooth and acceptable ocular surface without any persistent epithelial defect, infection, or ulceration. The MCBS method achieved good AM fixation on the ocular surface in cases of severe ocular surface lesions and could prevent the early detachment of the AM and promote the epithelialization of the ocular surface.

[Effects of silicone punctal plugs for tear deficiency dry eye patients].

OBJECTIVE: To evaluate the efficacy of silicone punctual plug for treating aqueous tear deficiency dry eye patients. METHODS: Prospective consecutive cases study. Silicone punctal plugs (France Chirurgie Instrumentation) were inserted into lower canaliculus in 65 tear deficiency dry eye patients (65 eyes). The clinical data collected included sex and age of the patients, frequency of lubricant use, the Ocular Surface Disease Index (OSDI) scores, slit lamp microscope examination, Schirmer I test (SIT) (with anesthesia), tear break-up time (TBUT), and ocular surface staining with fluoresce in sodium. All examinations were recorded at baseline, 6 weeks and 6 months after punctal occlusion. RESULTS: There were 41 women and 24 men in this study, and their average age was 41.77 years old. The dry eye symptoms improved in 57 (87.69%) of 65 eyes at 6 months follow-up. The frequency of lubricant use was significantly decreased in these eyes (χ(2) = 81.97, P < 0.01). More importantly, the symptoms disappeared in 25 (38.46%) eyes, which did not need lubricant any more. At baseline, 6 weeks and 6 months after punctal occlusion, OSDI mean score was 37.32 ± 2.41, 19.60 ± 8.07 and 18.17 ± 7.93, respectively (F = 344.10, P < 0.01); mean SIT result was (3.03 ± 0.75) mm, (6.66 ± 2.10) mm and (6.75 ± 2.16) mm, respectively (F = 169.59, P < 0.01); mean TBUT was (2.91 ± 0.76) s, (7.02 ± 2.39) s and (7.57 ± 2.38) s, respectively (F = 242.00, P < 0.01). Compared with the baseline data, hyperemia of conjunctiva grading and ocular surface staining scores were also improved significantly after plug insertion, and all of these differences were statistically significant. Foreign body sensation was the most common complication in our study (12 eyes, 18.46%). Epiphora (4 eyes, 6.15%), partial extrusion (3 eyes, 4.62%), and total extrusion (3 eyes, 4.62%) were the other complications encountered. CONCLUSION: Silicone punctal plug insertion is a stable, effective and safety method for the treatment of tear deficiency dry eye.