A Chinese family with Axenfeld-Rieger syndrome: report of the clinical and genetic findings.

AIM: To describe a Chinese family affected by a severe form of Axenfeld-Rieger syndrome (ARS) and characterize the molecular defect in PITX2 in the family. METHODS: Patients presented with typical ARS from a Chinese family were investigated. We performed genome-wide linkage scan and exome sequencing to identify the pathogenic mutations. Candidate mutations were verified for co-segregation in the whole pedigree using Sanger sequencing. Real-time polymerase chain reaction (RT-PCR) and Western blotting were performed to verify the expression of the pathogenic gene. RESULTS: Genome-wide linkage and exome sequencing analyses showed PITX2 as the disease candidate gene. A>G substitution at position -11 of 3'ss of exon 5 (IVS5-11A>G) that co-segregated with the disease phenotype was discovered in the family. The PITX2 messenger ribonucleic acid and protein levels were about 50% lower in patients with ARS than in unaffected family members in the family. CONCLUSION: Our findings implicate the first intronic mutation of the PITX2 gene in the pathogenesis of a severe form of ARS in a Chinese family. This study highlights the importance of a systematic search for intronic mutation in ARS cases for which no mutations in the exons of PITX2 have been found.

Visual performance with accommodating and multifocal intraocular lenses.

AIM: To compare the visual functional outcomes with accommodating and multifocal intraocular lenses (IOLs). METHODS: Our retrospective comparative study included 51 patients (60 eyes) received implantation of an accommodating IOL (Tetraflex; 16 patients, 20 eyes), a refractive multifocal IOL (ReZoom; 18 patients, 20 eyes), or a diffractive multifocal IOL (ZMA00; 17 patients, 20 eyes). Subjective refraction, visual acuity, contrast sensitivity (CS), intraocular aberration, and subjective photic phenomena were detected at 3mo after surgery. RESULTS: The spherical equivalent in the three groups was -0.38±0.54 D, 0.14±0.56 D, and 0.35±0.41 D, respectively. No statistically significant differences were found in uncorrected and corrected distance visual acuity and uncorrected intermediate visual acuity among the groups (P=0.39). The ReZoom group had significantly better distance-corrected intermediate visual acuity than the ZMA00 group (P=0.003). The ZMA00 group had significantly better near visual acuity than the other groups (P<0.05). Better contrast sensitivity values were observed in the Tetraflex group under most of the spatial frequencies conditions (P=0.025). The total aberration was lowest in the ZMA00 group (P=0.000), and the spherical aberration was highest in the Tetraflex group (P=0.000). The three groups had similar frequency of ghosting and glare, and the Tetraflex group had a low rate of halos (P=0.01). CONCLUSION: Both accommodating and multifocal IOLs can successfully restore distance and uncorrected intermediate visual acuities. Tetraflex accommodating IOLs perform better in CS and with less halos of photic phenomena. ReZoom refractive multifocal IOLs have better performance in distance-corrected intermediate visual acuity than ZMA00 diffractive multifocal IOLs, and the latter achieved better near visual acuity and efficiently decreased the optical aberration.

[Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 µm from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment.

[Pseudo-accommodation with accommodating intraocular lens in patients at different ages].

OBJECTIVE: To compare the clinical performances of patients in different ages with implantation of a accommodating IOLs. METHODS: It was a retrospective study. Forty-seven eyes (47 patients) were enrolled in 3 groups for phacoemulsification and a accommodating IOL implantation. According to their ages, they were divided into 3 groups: ≤ 45 years, 46 - 59 years, and ≥ 60 years. Parameters analyzed after more than 3 months postoperation were uncorrected distance, best-corrected distance, uncorrected near, and distance-corrected near visual acuities; changes of anterior chamber depth(ACD) during accommodative measured using the ultrasound biomicroscopy (UBM);changes of ACD by instilling 2% pilocarpine using the A-ultrasonic scan; and the amplitude of accommodation using the pushing-up test. RESULTS: No significant difference was observed between distance and near visual acuities of IOL groups. The mean changes of ACD measured with UBM in the group of ≤ 45 years [(0.16 ± 0.12) mm] was significantly higher than the other age groups [46 - 59 years, (0.06 ± 0.06) mm, P = 0.00; ≥ 60 years, (0.07 ± 0.05) mm, P = 0.008)]. The mean changes of ACD stimulated by pilocarpine measured with A-ultrasonic scan in the group of ≥ 60 years [(0.17 ± 0.14) mm] was significantly lower than the other age groups [≤ 45 years, (0.68 ± 0.44) mm, P = 0.00; 46 - 59 years, (0.43 ± 0.20) mm, P = 0.00]. The accommodative amplitude of the ≥ 60 years groups ((2.32 ± 0.88) D) was lower than the group of ≤ 45 years [(2.87 ± 0.52) D, P = 0.005]. CONCLUSIONS: The accommodative amplitude of patients implanted with accommodating IOLs stepped down following the increase of age. However, no statistical differences were found in distance and near visual acuities between the different age groups.

[Analysis of patients with extraction of open-loop anterior chamber intraocular lenses].

OBJECTIVE: To analyze the cause of flexible open-loop anterior chamber intraocular lenses (AC-IOL) extraction and to evaluate the safety of these lenses implantation. METHODS: This retrospective study comprised 28 patients (28 eyes) who had received open-loop AC-IOL extraction from 1999 to 2009 in our hospital. Several factors of these patients were analyzed, including the type of AC-IOL, primary disease, the intraocular duration of AC-IOL, the cause of AC-IOL extraction and therapeutic result. RESULTS: All of the AC-IOL used were modern flexible open-loop AC-IOL. Twenty one patients were implanted AC-IOL because of ocular trauma; the average intraocular duration of the AC-IOL was (6.1 ± 3.1) years. In the causes of AC-IOL extraction, bullous keratopathy was the most common cause, accounted for 42.9% (12/28); secondary glaucoma, retinal detachment and lens dislocation accounted for 32.1% (9/28), 17.9% (5/28) and 7.1% (2/28), respectively. In the 12 cases with bullous keratopathy, 6 cases just received AC-IOL extraction and the others received penetrate corneal transplantation. Six cases with secondary glaucoma received AC-IOL extraction combined with trabeculectomy. CONCLUSIONS: Bullous keratopathy and secondary glaucoma are the two most common causes for open-loop AC-IOL extraction. The patients who will receive AC-IOL implantation need an adequate selection and must be followed properly.

RNAi-mediated silencing of ezrin gene reverses malignant behavior of human gastric cancer cell line SGC-7901.

OBJECTIVE: To investigate the effects of ezrin targeting gene of RNA interference (RNAi) on human gastric cancer cell line SGC-7901 in vitro. METHODS: The highly metastatic human gastric cancer cell line SGC-7901 transfected with a small interfering (siRNA) lentivirus vector was selected for this research study. Expressions of ezrin mRNA and ezrin protein in the SGC-7901 cells were detected using RT-PCR and Western blot. Cell apoptosis was observed using flow cytometry. Transwell invasion and the cell adhesion test were used to verify the effect of RNAi on ezrin expression in the human gastric cancer cell line SGC-7901 in vitro. RESULTS: Ezrin gene targeting via a RNAi-mediated lentivirus vector had obvious inhibitory effects on ezrin expression in the human gastric cancer cell line SGC-7901. The results of the RT-PCR show the obvious inhibition of ezrin mRNA expression in Eai and Ebi groups (0.22 +/- 0.01 vs 0.95 +/- 0.04, P < 0.05; 0.31 +/- 0.01 vs. 0.95 +/- 0.04, P < 0.05). Western blot analysis revealed a 72.35 +/- 3.74% reduction of the ezrin protein level after interference with the ezrin targeting gene. Moreover, the inhibition of ezrin expression clearly inhibited SGC-7901 cell migration and invasion, and improved cell adhesion as well as increased sensitivity to camptothecin-induced apoptosis. CONCLUSION: Ezrin gene targeting by RNAi can inhibit the metastatic growth and migration of SGC-7901 human gastric cancer cells.

[Experimental study of low molecular weight heparin drug delivery system for prevention of posterior capsular opacification in rabbit eyes].

OBJECTIVE: To investigate the safety and efficacy of low-molecular-weight heparin drug delivery system (LMWH DDS) for prevention of posterior capsular opacification (PCO) in rabbit eyes. METHODS: (1) To prepare the LMWH DDS by freeze-drying way with Polylactic-co-glycolic acid (PLGA) as the carrier, and evaluate its release properties in vitro. (2) Fifty New Zealand albino rabbits (50 eyes) undergoing phacoemulsification were equally divided into five groups: receiving normal saline eye drops (group A), 3 different dose (1 mg, 0.5 mg and 0.25 mg) of LMWH DDS respectively implanted into the posterior chamber (group B, C and D), and a carrier DDS implanted into the posterior chamber (group E). All the 50 eyes were examined by slit-lamp microscopy. The low-molecular-weight heparin levels in aqueous humor were measured, and the wet posterior capsules were weighed. RESULTS: The LMWH DDS prepared with a freeze-dried way has high encapsulation efficiency, and the equation of 49-day release curve fitting in vitro were were similar to zero order. The fibrin exudation in group B, C and D were lower than in Group A and E during the first postoperative day. There were 10, 2, 3, 9 and 10 eyes that developing PCO in the group A, B, C, D and E, respectively. The mean wet-weight of the posterior capsule were (114.59 +/- 14.58) mg, (24.14 +/- 6.08) mg, (39.23 +/- 17.13) mg, (99.35 +/- 29.37) mg, (115.29 +/- 19.87) mg respectively in 5 trial groups. There were stable and high concentration of low molecular weight heparin in aqueous of group B and C during the 4 weeks (> 20 mg/L), while a instable and lower concentrations in group D. The result of optical microscopy and electron microscopy examination indicated that fibroblast proliferation was quite active in groups A, D and E, but inactive in group B and C. Neither infiltration of inflammatory cells at the cornea, iris, trabecular meshwork and ciliary body nor retinal degeneration or necrosis was found in any group at 12 weeks. There was no intraocular bleeding in all the five groups in the following 12 weeks. CONCLUSIONS: The LMWH DDS prepared by freeze-drying way with PLGA as the carrier has good slow-release and biological tolerance. Implantation of LMWH DDS into the posterior chamber of experimental animals can significantly reduce postoperative fibrin exudation, and can safe and effective prevent the occurrence of PCO, and also there were some dose-effect relationship.

[Study of different methods in reducing conjunctival bacteria before cataract surgery].

OBJECTIVE: To study the conjunctival bacteria flora in eyes of patients undergoing cataract surgery and determine the efficacy of reducing conjunctival bacteria with different methods. METHODS: A total of 135 eyes of 135 patients scheduled to undergo cataract surgery were randomized into 3 groups (45 each). They received topical prophylactic treatment with three different kinds of antibiotics (0.5% levofloxacin, 0.3% levofloxacin and 0.3% tobramycin). Each group was randomized into one-day group and three-day group. All the eyes underwent irrigation of fornices with 2.5% povidone-iodine (PVI) before surgery. Conjunctival cultures were obtained at various time points. RESULTS: The total positive rate of conjunctival cultures was 66.7%. The eliminating rate of conjunctival bacteria in one-day groups were 72.7%, 72.7% and 61.1% (P = 0.667) while 70.0%, 70.0% and 55.5% in the three-day groups respectively (P = 0.751). Immediately after PVI irrigation, the eliminating rate in one-day groups added up to 86.4%, 77.3% and 88.9% (P = 0.564) as compared with 90.0%, 80.0% and 66.7% in the three-day groups respectively (P = 0.749). And there was no statistically significant difference between one-day groups and three-day groups in the eliminating rate of conjunctival bacterial after the topical antibiotic application. The MIC test revealed that the antibiotic sensitivity of Gram-positive cocci (G(+)C) to levofloxacin was 94.8% versus 74.1% to tobramycin (P = 0.000) while the antibiotic sensitivity of Gram-negative bacillus (G(-)B) to levofloxacin was 94.4% versus 83.3% to tobramycin (P = 0.289). CONCLUSION: G(+)C accounts for the most among the conjunctival bacteria flora in eyes of patients undergoing cataract surgery and there is no statistically significant difference in the efficacy of reducing conjunctival bacteria between the application of topical antibiotic for one day and for three days. Both G(+)C and G(-)B retain a high sensitivity to levofloxacin. Topical antibiotic in combination with 2.5% PVI irrigation further reduces conjunctival bacteria.

[Intraocular lens power calculations following keratorefractive surgery].

Intraocular lens power calculation after corneal refractive surgery is complicated. It is common to have a great postoperative deviation with the traditional method. The reasons for IOL power calculation error after corneal refractive surgery are analysed and many solutions are listed in this article, which we hope could provide basis for these patients.