The Global Prevalence of Amblyopia in Children: A Systematic Review and Meta-Analysis.

Epidemiological data about the prevalence of amblyopia around the world vary widely among regions and periods. This meta-analysis aimed to determine the global prevalence of amblyopia in children. PubMed, Embase, and the Cochrane Library were searched for prevalence studies published up to 5 November 2021. The outcome was the prevalence of amblyopia, analyzed as pooled estimates with 95% confidence intervals (CI). A total of 97 studies were included, including 4,645,274 children and 7,706 patients with amblyopia. The overall worldwide pooled prevalence of amblyopia was 1.36% (95%CI: 1.27-1.46%). The prevalence of amblyopia was higher in males (1.40%, 95%CI: 1.10-1.70%) than in females (1.24%, 95%CI: 0.94-1.54%) (OR = 0.885, 95%CI: 0.795-0.985, P = 0.025). The results of the meta-regression analysis showed that there were no significant associations between the prevalence of amblyopia and geographical area, publication year, age, sample size, and whether it was carried out in a developed or developing country (all P > 0.05). Begg's test (P = 0.065) and Egger's test (P < 0.001) showed that there was a significant publication bias in the prevalence of amblyopia. In conclusion, amblyopia is a significant vision problem worldwide, and public health strategies of early screening, treatment, and management are important.

Consecutive contralateral comparison of toric and non-toric implantable collamer lenses V4c in vault after implantation for myopia and astigmatism.

AIMS: To compare the vault performance between implantable collamer lens (ICL) V4c and Toric ICL (TICL) V4c after implantation and to investigate the affecting factors. METHODS: Sixty-eight eyes from 34 patients with myopia or myopia astigmatism who underwent implantation of TICL in one eye (group A) and identically sized ICL (group B) in the contralateral eye were included. Mean follow-up time were 7.58 ± 1.63 months (range: 6-10 months). Vault was compared between the two groups and correlations between vault and age, preoperative ocular biometric measurements were analysed. Generalized estimating equation (GEE) model of postoperative vault adjusting for within-patient intereye correlations was performed. RESULTS: The safety indices were 1.27 and 1.35, and the efficacy indices were 1.20 and 1.24 for groups A and B, respectively. Vault of TICL was significantly higher than that of ICL (554.11 ± 219.36 µm vs 449.70 ± 172.47 µm, P < 0.001). The difference between ICL/TICL size and WTW (size-WTW) and STS (size-STS), anterior chamber depth and pupil diameter (PD) were positively correlated with vault. Patient age and clear lens rise measured by Pentacam were negatively correlated with vault. Results of GEE model showed preoperative PD, age, cylindrical power of TICL and size-WTW were influencing factors for postoperative vault. CONCLUSIONS: Vault after TICL implantation is higher than that with ICL. PD, age, cylindrical power of TICL and size-WTW could affect postoperative vault.

A huge lacrimal gland ductule dacryolith with a hairy nucleus: a case report.

BACKGROUND: Dacryoliths in lacrimal gland ductule are a rare condition and an unusual cause of conjunctivitis. Here we report a case with a large lacrimal gland ductule stone with an unique hairy nucleus. CASE PRESENTATION: A 38-year-old female presented with a red left eye for one month. Physical examination revealed an inflammatory granuloma in the lateral canthus and a fistula with purulent secretion. Antibiotics did not ameliorate the symptoms. After we incised the fistula, a huge dacryolith (10 mm × 5 mm × 3 mm) was identified at the end of the dilated lacrimal gland ductule and was removed surgically. Histopathologic examination showed a hairy nucleus surrounded by lamellar structure. The symptoms were resolved in 2 weeks after dacryolith extraction. The formation of the hair-centered dacryolith might be associated with the patient's personal history of being a rabbit raiser for years. CONCLUSION: We should be aware of lacrimal gland ductule dacryolith as a rare cause of conjunctivitis. The relationship between dacryolithiasis and fur-bearing animal raising warrants further investigation.

Effect of Limbal relaxing incisions during implantable collamer lens surgery.

BACKGROUND: The limbal relaxing incisions (LRIs) technique is a safe and an inexpensive procedure, which is simple for experts to perform. It can effectively reduce astigmatism and result in a rapid visual rehabilitation. But there are few reports about reducing pre-existing corneal astigmatism by LRI in ICL surgery. Our research was aimed to study the effect of limbal relaxing inci sions during implantable collamer lens (ICL) surgery. METHODS: A prospective analysis reviewing consecutive cases of corneal astigmatism that had either independent ICL surgery (control group) or combined with LRIs (LRIs group). The study population consisted of 45 patients, 85 eyes, with high myopia and regular corneal astigmatism more than 0.50 diopter (D) and less than 3.00 D. The first group received ICL surgery combined with LRIs (limbal relaxing incisions); the control group received only ICL surgery alone. The outcomes considered were uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BCVA), refraction, keratometry, slit lamp biomicroscopy, indirect ophthalmoscopy, corneal topography, corneal astigmatism, endothelial cell count, and patient satisfaction. The follow-up period covered 12 months. RESULTS: The mean uncorrected distance visual acuity (UDVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up period, the UCVA was statistically better for the patients with LRIs compared with those underwent ICL surgery alone. The LRIs group showed significant reduction in the mean topographic astigmatism from 1.48 ± 0.35 D preoperatively to 0.37 ± 0.14 D postoperatively (P < .0001) after one month. The control eyes did not show a statistically significant change (P > 0.05). The mean magnitude of the surgically induced astigmatism (SIA) read 1.10 ± 0.35 D,1.13 ± 0.34D,1.13 ± 0.34D,1.11 ± 0.35D by the end of the 1st, the 3rd, the 6th and the 12th month postoperatively in LRIs group, which was slightly lower than the target-induced astigmatism (TIA). The difference in SIA between the LRI and the control group was statistically significant by the end of the 1st, the 3rd, the 6th and the 12th month postoperatively (P < 0.001). The mean correction index (CI) was less than 1, which indicated undercorrection effect of limbal relaxing incision. No difference was observed in the postoperative endothelial cell count between the two groups. There was no intraoperative and postoperative ocular or systemic complication. CONCLUSION: Limbal relaxing incision is an effective method in reducing corneal astigmatism during implantable collamer lens surgery. TRIAL REGISTRATION: The trial was retrospectively registered in 14 April 2017. (NO: ChiCTR-ONR-17011147 ).

[Agreement and repeatability of central corneal thickness measurement using the Pentacam and ultrasound pachymetry].

OBJECTIVE: To compare the agreement and repeatability of the OCULUS Pentacam (a new Scheimpflug-based imaging system) with ultrasound pachymetry in the measurement of central corneal thickness (CCT). METHODS: Central corneal thickness was measured in 112 subjects (112 eyes) separately by two examiners, first using the Pentacam instrument, then using an ultrasonic pachymetry. Measurements were repeated 3 times for each pachymetry. RESULTS: Mean values of CCT for each instrument were (538.63 ± 31.55) µm and (541.02 ± 30.45) µm using the Pentacam and the ultrasonic pachymeter, respectively. The difference is significant between the two instruments (t = -3.414, P = 0.001), the mean value of the difference is (-2.39 ± 7.42) µm. The Bland-Altman Plots displayed relatively good agreement (limits of agreement were -16.93 µm to 12.15 µm) between the two instruments. The intraclass correlation coefficient (ICC) of the two devices showed high repeatability (Separately 0.86 and 0.88). CONCLUSIONS: The agreement between the Pentacam instrument and the ultrasonic pachymetry was good, and the repeatability was also good for both instruments independently, however it is needed to increase measure times to improve the repeatability of the Pentacam which is a promising new instrument for anterior eye evaluation.