Central anterior chamber depth correlated with white-to-white distance in normal, long, and short eyes

PURPOSE

To explore the associations between central anterior chamber depth (CACD) and other anterior segment biometric parameters and to determine the possible determinants of CACD in short, normal, and long eyes.

METHODS

The biometric data of pre-operation patients aged 50-80 years with coexisting cataract and primary angle-closure disease or senile cataract were reviewed. Axial length (AL), CACD, lens thickness (LT), central corneal thickness (CCT), and white-to-white distance (WTW) were measured by Lenstar optical biometry (Lenstar 900). The data of 100 normal eyes (AL = 22 to 26 mm), 100 short eyes (AL ≤ 22 mm), and 100 long eyes (AL ≥ 26 mm) were consecutively collected for subsequent analyses.

RESULTS

The mean age of the subjects was 66.60 ± 7.85 years, with 25.7% of the sample being men. Both CACD and WTW were found to be smallest in short eyes and were smaller in normal eyes than in long eyes (F = 126.524, P < 0.001; F = 28.458, P < 0.001). The mean LT was significantly thicker in short eyes than in normal and long eyes (4.66 mm versus 4.49 mm versus 4.40 mm; F = 18.099, P < 0.001). No significant differences were observed in CCT between the three AL groups (F = 2.135, P = 0.120). Stepwise regression analysis highlighted AL, LT, and WTW as three independent factors associated with CACD in the normal AL group. In the short AL group and long AL group, LT and WTW were independent factors associated with CACD.

CONCLUSIONS

CACD increases as AL elongates and reaches a peak when AL exceeds 26 mm. Furthermore, CACD showed inverse correlation with LT and positive correlation with WTW. A relatively small WTW results in an anteriorly positioned lens, and thus, a decrease in CACD.

[The incidence and time distribution of early transient intraocular pressure elevation after penetrating canaloplasty]

Objective: To report the incidence and time distribution of early transient intraocular pressure (IOP) elevation after penetrating canaloplasty. Methods: Retrospective case series study. Data of patients treated by penetrating canaloplasty for glaucoma in the Eye Hospital of Wenzhou Medical University from June 2015 to March 2020 were collected. Early transient IOP elevation was defined as an increase of IOP to over 21 mmHg on the first week to the third month after surgery followed by a decrease to 21 mmHg or less within 3 months. Main outcome measures included IOP, quantity of medication use, the occurrence time and duration of IOP elevation. Generalized estimating equations were used for statistical analysis, and measurement data with non-normal distribution was represented as M (Q₁, Q₃). Results: A total of 277 patients (315 eyes) achieved 360-degree catheterization of the canal successfully, and 299 eyes (94.9%) completed the postoperative 6-month follow-up. Thirty-four eyes (10.8%) had persistently high IOP, so the surgical treatment failed in them. Consequently, 234 patients (265 eyes) were enrolled in the analyses, including 161 males (184 eyes) and 73 females (81 eyes). The median age was 42 (26, 54) years, the mean preoperative IOP was (37.7±11.1) mmHg, and the mean number of drugs used was 3 (2, 4). The incidence of early transient IOP elevation was 43.0% (114/265) in all enrolled eyes, 42.7% (35/82) in eyes with primary open angle glaucoma, 37.8% (17/45) in eyes with primary angle closure glaucoma, 27.7% (13/47) in eyes with congenital glaucoma and 53.8% (49/91) in eyes with secondary glaucoma. The IOP began to increase on the first to fourth week in 91.2% (104/114) of eyes with early transient IOP elevation and reached the peak [21.3 mmHg to 54.8 mmHg; mean, (32.4±8.2) mmHg] in 88.6% (101/114) on the first to fifth week after surgery. The IOP elevation lasted for no more than 4 weeks in 69.3% (79/114) of eyes. Conclusions: Over 40.0% of patients with penetrating canaloplasty may experience postoperative transient IOP elevation. The incidence is relatively high in secondary glaucoma but low in congenital glaucoma. Most of the elevations and peak IOP occur within 1-4 weeks after surgery.

[Effect of traditional Chinese medicine on osseointegration and bone absorption of implants]

Implantation of the base bone in the implant after effective and rapid bone binding and prevention and treatment of bone resorption, to ensure the success of planting surgery is of great significance. This article reviews the mechanism of traditional Chinese medicine promoting bone integration and the etiopathological mechanism of bone resorption, and expounds the influence of traditional Chinese medicine on osseointegration and bone resorption.

Mitochondrial tRNALeu(CUN) A12307G variant may not be associated pancreatic cancer

Mitochondrial DNA mutations that lead to mitochondrial dysfunction have long been proposed to play important roles in the development of pancreatic cancer. Of these, alterations to mitochondrial tRNA genes constitute the largest group. Most recently, a variation at position 12307 in the gene encoding tRNA(Leu(CUN)) has been reported to be associated with this disease. However, the molecular mechanism underlying this relationship remains poorly understood. To assess this association, we evaluated this variant by evolutionary conservation analysis, measurements of allelic frequencies among control subjects, and use of several bioinformatic tools to estimate potential structural and functional alterations. We found this residue to have a high conservation index; however, the presence of the A12307G variation in control subjects revealed by a literature search suggested it to be common in human populations. Moreover, RNAfold results showed that this variant did not alter the secondary structure of tRNA(Leu(CUN)). Through the application of a pathogenicity scoring system, this variant was determined to be a "neutral polymorphism," with a score of only 4 points based on current data. Thus, the contribution of the A12307G variant to pancreatic cancer needs to be addressed in further experimental studies.

miR-499A>G rs3746444 and miR-146aG>C expression and hepatocellular carcinoma risk in the Chinese population

We conducted a case-control study of a possible association of miR-499A>G rs3746444 and miR-146aG>C rs2910164 with risk of hepatocellular carcinoma. Samples from 172 hepatocellular carcinoma patients and 185 cancer-free controls were collected from October 2008 to December 2011. PCR-RFLP analysis was performed to determine the polymorphisms in each individual. The MAFs of miR-146aG>C and miR-499A>G in controls were similar to that known from the SNP database, and frequencies of genotypes in controls were in line with Hardy-Weinberg equilibrium. We found that miR-499 AG was significantly associated with decreased risk for hepatocellular carcinoma when compared with miR-499 AA genotype (adjusted odds ration = 0.74, 95% confidence interval = 0.24-0.96). However, subjects carrying miR-146a GG had a non-significant 0.62-fold decreased risk of hepatocellular carcinoma. We did not find a significant association of miR-146aG>C rs2910164 and miR-499A>G rs3746444 polymorphisms with hepatocellular carcinoma risk in the Chinese population. Further investigations are warranted to clarify the relationship between miRNA polymorphisms and susceptibility to hepatocellular carcinoma risk in various ethnic populations.

The effect of dilution and prolonged injection time on dexamethasone-induced perineal pruritus

Dexamethasone has been widely used before general anesthesia induction. However, previous studies have found that a pre-induction bolus dose of dexamethasone sometimes causes perineal pruritus. We hypothesized that an appropriate prolongation of the injection time might suppress dexamethasone-induced perineal pruritus. Four hundred patients requiring general anaesthesia were randomly allocated into four groups: group I receiving 2 ml dexamethasone (5 mg/ml); group II receiving 4 ml dexamethasone (2.5mg/ml); group III receiving 10 ml dexamethasone (1 mg/ml); and group IV receiving 20 ml dexamethasone (0.5 mg/ml). Dexamethasone was diluted with 0.9% sodium chloride. The injection time of dexamethasone was 5s in groups I, II and III; while the injection time of dexamethasone was 30s in group IV. Occurrence of perineal pruritus was significantly reduced in Group IV (0% vs 38%, 32% and 12% in Groups I, II and III, respectively, p < 0.05). The incidence was higher in females than in males (p < 0.05). The duration of perineal pruritus was longer in females than in males in groups I, II and III (p < 0.05). We conclude that the dilution of dexamethasone to 0.5 mg/ml with 0.9% sodium chloride combined with prolonged injection time to 30 s eliminates dexamethasone-induced perineal pruritus.