Hongfei Ye

Noninvasive Keratograph assessment of tear film break-up time and location in patients with age-related cataracts and dry eye syndrome:

Objective To investigate tear-film break-up time and spatial distribution via noninvasive Keratograph 4 in patients with cataracts and dry eye syndrome (DES). Methods Noninvasive first break-up time (NIKf-BUT) and average break-up time (NIKav-BUT) were evaluated via Keratograph 4 in patients with age-related cataracts and DES. The location and size of tear break regions were recorded and the distribution of first break-up areas was summarized. Patients also underwent conventional break-up time assessments (TBUT test and Schirmer’s test). Results A total of 43 left and 43 right eyes were examined. There was no significant difference between TBUT and NIKav-BUT. NIKf-BUT was significantly shorter than TBUT. Both NIKf-BUT and NIKav-BUT correlated positively with TBUT. In both the left and right eye, the most common first break-up areas were the peripheral domain of the inferior precorneal surface and the central domain of the superior portion. Conclusions The Keratograph 4 appears to provide an effective noninvasive method for assessing tear film, enabling effective preoperative evaluation of tear film break-up regularity, informing the location of the incision and reducing the probability of postoperative DES.

LOXL1 Hypermethylation in Pseudoexfoliation Syndrome in the Uighur Population

PURPOSE High prevalence of pseudoexfoliation syndrome (PEX) occurs in the Uighur population. This study investigated DNA methylation of the lysyloxidase-like 1 (LOXL1) gene in Uighur PEX patients with cataracts. METHODS The research involved 10 lens capsule specimens from Uighur PEX patients with cataracts and 10 lens capsule specimens from Uighur control patients with age-related cataract (ARC) alone. All specimens were freshly collected during cataract surgery. Methylation status of the CpG islands was analyzed using pyrosequencing. The mRNA levels of LOXL1 were evaluated by quantitative real-time PCR, and protein levels were evaluated by Western blot assay. RESULTS For all the six chosen CpG islands of the LOXL1 gene promoter, hypermethylation was found in the PEX with cataracts compared to the age-matched ARC group. At the same time, the expression level of LOXL1 mRNA was significantly reduced in the PEX with cataracts group than that in the ARC group, and the expression level of the LOXL1 protein product demonstrated a similar tendency. CONCLUSIONS The susceptible PEX gene LOXL1 undergoes DNA hypermethylation in its promoter region in Uighur PEX with cataracts patients. This indicates that epigenetic regulation might play roles in PEX pathogenesis.

αA Crystallin May Protect against Geographic Atrophy—Meta-Analysis of Cataract vs. Cataract Surgery for Geographic Atrophy and Experimental Studies

Background Cataract and geographic atrophy (GA, also called advanced “dry” age-related macular degeneration) are the two major causes of visual impairment in the developed world. The association between cataract surgery and the development of GA was controversial in previous studies. Methods/Principal Findings We performed a meta-analysis by pooling the current evidence in literature and found that cataract is associated with an increased risk of geographic atrophy with a summary odds ratio (OR) of 3.75 (95% CI: 95% CI: 1.84–7.62). However, cataract surgery is not associated with the risk of geographic atrophy (polled OR = 3.23, 95% CI: 0.63–16.47). Further experiments were performed to analyze how the αA-crystallin, the major component of the lens, influences the development of GA in a mouse model. We found that theαA-crystallin mRNA and protein expression increased after oxidative stress induced by NaIO3 in immunohistochemistry of retinal section and western blot of posterior eyecups. Both functional and histopathological evidence confirmed that GA is more severe in αA-crystallin knockout mice compared to wild-type mice. Conclusions Therefore, αA-crystallin may protect against geographic atrophy. This study provides a better understanding of the relationship between cataract, cataract surgery, and GA.

Changes of corneal higher-order aberrations after cataract surgery.

Purpose To demonstrate the time-dependent changes in corneal aberrations after cataract surgery and to analyze the effects of incision location on corneal aberrations. Methods The patients were divided into two groups: group 1 consisted of patients (32 right eyes) who underwent corneal incision at 9 o’clock and paracentesis incision at 3 o’clock; group 2 consisted of patients (30 left eyes) who underwent corneal incision at 3 o’clock and paracentesis incision at 6 o’clock. Corneal high-order aberrations were measured before surgery and 1 day, 3 days, 2 weeks, 1 month, and 2 months after surgery. The changes in corneal aberrations were compared between the two groups. The modulation transfer function and the Strehl ratio were also measured to evaluate visual function after surgery. Results Corneal aberrations on the anterior surface were less affected by cataract surgery than those on the posterior surface, which changed almost in parallel with the total corneal surface aberrations over time. Total higher-order aberrations on the posterior and total corneal surfaces increased significantly at 1 day after surgery compared with the baseline values (p = 0.005 and p < 0.001, respectively, for group 1; p = 0.004 and 0.038, respectively, for group 2) but gradually returned to the baseline by 2 months after surgery (p > 0.05 for both groups). The changes in horizontal coma were in different directions for the two groups. Statistically significant differences were observed in the changes of fourth-order aberrations (p = 0.045) and horizontal coma (p < 0.001) in the posterior corneal surface between the two groups. No statistically significant differences were found for either the modulation transfer function or the Strehl ratio between the two groups. Conclusions After cataract surgery, changes in corneal aberrations occurred mainly on the posterior surface. The location of the corneal incisions affected the changes in corneal aberrations but did not significantly affect the long-term visual quality.

Tilt, Decentration, and Internal Higher-Order Aberrations of Sutured Posterior-Chamber Intraocular Lenses in Patients with Open Globe Injuries

Purpose To evaluate the tilt, decentration, and internal higher-order aberrations (HOAs) of sutured posterior-chamber intraocular lenses (IOLs) in patients with open globe injuries. Methods 46 consecutive patients (47 eyes) who underwent transsclerally sutured IOL implantation were enrolled in this prospective cohort study. Nineteen eyes had a history of open globe injury. The tilt and decentration of the IOLs and the visual quality were measured 1 month after surgery. Results The horizontal tilt and decentration of the IOLs in the open-globe-injury group were significantly higher than those in the control group (both P < 0.05). In the open-globe-injury group, the horizontal decentration was significantly greater in the limbus-sclera-involved group (n = 11) than in the only-cornea-involved group (n = 8, P = 0.040). The internal coma, 3rd-order, and total HOA values at pupil sizes of 4 mm (P = 0.006) and 6 mm (P = 0.013) were significantly higher in the open-globe-injury group than in the controls. Consequently, the optical quality data for the modulation transfer function and the Strehl ratio (all P < 0.05) were significantly poorer in the open-globe-injury group. Conclusions Open globe injuries damage the structural integrity of the eyeball, resulting in more-misaligned sutured IOLs and poorer visual quality.