Hong Liang Lin

Excessive uric acid (UA) is associated with age-related cataract. A previous study showed that a high UA level in the aqueous humor stimulated the senescence of lens epithelial cells (LECs), leading to cataract progression. To better understand the underlying mechanisms, we investigated UA-driven senescence in human lens tissue samples obtained during surgery, rat lens organ cultures, and in vivo experiments, using senescence-associated β-galactosidase (SA-β-gal) staining, electronic microscopy, Western blotting, and histological analyses. Initially, we identified markedly higher expressions of NLRP3 and caspase-1 in the lens capsules of hyper-uricemic patients compared to normo-uricemic patients. This increase was accompanied by a significant rise in the SA-β-gal positive rate. We next built a cataract model in which rat lenses in an organ culture system were treated with an increasing dosage of UA. Notably, opacification was apparent in the lenses treated with 800 μM of UA starting on the fifth day. Mechanistically, UA treatment not only significantly induced the expression of NLRP3, caspase-1, and IL-1β, but also upregulated the levels of SA-β-gal and the senescence regulators p53 and p21. These effects were fully reversed, and lens opacification was ameliorated by the addition of MCC950, a selective NLRP3 antagonist. Moreover, an in vivo model showed that intravitreal UA injection rapidly induced cataract phenotypes within 21 days, an effect significantly mitigated by co-injection with MCC950. Together, our findings suggest that targeting the UA-induced NLRP3 inflammasome with MCC950 could be a promising strategy for preventing cataract formation associated with inflammageing.

Purpose . To evaluate the clinical outcome of the three‐random‐point (TRP) marking method for toric intraocular lens (IOL) alignment using the iTrace aberrometer (Tracey Technologies Corp., Houston, TX). Setting . Department of Ophthalmology, Guangdong Eye Institute, Guangdong Academy of Medical Sciences, Guangdong Provincial People’s Hospital, Guangzhou, China. Design . Prospective, randomized comparative trial. Method . Thirty eyes of 30 patients undergoing cataract surgery with coexisting corneal astigmatism of over 1.0 D were included in this study. All patients were prospectively randomized into the TRP marking group or slit‐lamp horizontal meridian (SHM) marking group. TRP marking involved marking three points randomly in the corneal limbus of the patients and accurately marking the horizontal meridian was not required. The follow‐up duration was 3 months after cataract surgery. Results . Fifteen eyes of 15 patients were in the TRP marking group and 15 eyes of 15 patients in the SHM marking group. There was no statistically significant difference in BCVA, UDVA, preexisting corneal astigmatism, or residual astigmatism between the groups before or after surgery ( P > 0.05). The mean toric IOL misalignment was lesser but without significance in the TRP marking group than in the SHM marking group after 3 postoperative months (2.66° ± 1.42° versus 3.29° ± 1.67°; P = 0.295). Conclusion . The TRP marking method using the iTrace aberrometer is simple and accurate for preoperative marking of toric IOLs. It can eliminate the potential systematic errors resulting from varying head positions during the preoperative keratometry measurement and from manual marking.

Importance: Age‐related cataract is the leading cause of blindness worldwide. The pathological mechanisms causing this disease remain elusive.Background: To examine the involvement of uric acid (UA) in the pathogenesis of posterior subcapsular cataract (PSC).Design: Retrospective study and experimental investigation.Participants: A total of 180 patients with PSC or non‐PSC were included.Methods: Samples obtained from the patients were used to analyse content of UA and for histochemical examinations. The effects of UA on human lens epithelial cells were also investigated.Main Outcome Measures: Aqueous humour UA and urate deposits.Results: The results showed a significant increase of aqueous humour UA in patients with PSC. After adjustment for potential confounders, elevated aqueous humour UA (odds ratio [OR] = 1.45) showed a stronger association with PSC than serum UA (OR = 1.10). Gomori methenamine silver staining revealed in PSC an intense deposit of urates in the lens fibres in equatorial regions, and in subcapsular fibres in posterior regions of the lens. Such staining was not detected in the lens with non‐PSC. Treatment with UA‐induced senescence and apoptosis in human lens epithelial cells in a dose dependent manner. Our results suggest that the elevated level of UA in aqueous humour causes a deposition of urates in human lens epithelium, which could possibly lead to dysfunction of these cells that generates opacification in PSC.Conclusions and Relevance: These findings indicate the local action of excessive UA in the pathogenesis of PSC. Control of serum UA level could delay the progression of PSC.

BackgroundTo compare clinical characteristics of lens subluxation between eyes with or without acute angle closure (AAC).MethodsThis is a retrospective and case control study. Thirty-four cases with lens subluxation were recruited from 2015 to 2017. Patients with acute angle closure were assigned to the AAC group (n=17 eyes) and those without AAC were in the non-AAC group (n=17 eyes). Quantitative anterior segment was evaluated by ultrasound biomicroscopy (UBM). Axial length (AL) was measured with IOL master. All patients underwent lens extraction surgery and were followed up for 6 months. ResultsThe history of blunt trauma was accounted for 11 (64.7%) cases in the AAC group and 14 (82.3%) cases in the non-AAC group. Nine (52.9%) patients in the AAC group had LPI or SPI treatment history, and high intraocular pressure was recurred. The UBM analysis showed that the average central ACD of affected eyes in the AAC group was 1.75 mm, which was significantly shallower than the fellow eyes (2.39 mm, P < 0.05) or both eyes in the non-AAC group (affected eye 3.24mm vs fellow eye 3.81mm). Lens vault and AOD500 also showed a remarkable difference between affected eye than fellow eye (P < 0.001) in the AAC group. The both eyes in the AAC group presented a shorter AL and shallower anterior chamber, comparing with those in the non-AAC group. Besides, the affected eyes in the AAC group presented significantly higher LV. ConclusionsThe crowded anterior chamber structure and shorter AL might be an anatomic basis for the eye with lens subluxation induced AAC. Quantitative evaluation of these ocular structures to identify zonular compromise, increased LV and shorter AL are valuable for the diagnosis of lens subluxation induced AAC.

To report a case of femtosecond laser-assisted removal of an intracorneal chestnut. A chestnut was obliquely protruding to the stroma of cornea and it was localized at the paracentral region on the left eye of a 32-year-old man. The best-corrected visual acuity (BCVA, in decimal values) was 0.6 in the injured eye. The white ulcers with feathery edges or satellite infiltrates were not observed in the lesion, and the anterior chamber was deep and quiet. Anterior segment optical coherence tomography (AS-OCT) demonstrated that the original entry path of the foreign body had been sealed, spanning a thickness of approximate 152 μm. In view of location of the intraocular chestnut at the paracentral region, femtosecond laser was applied according to the procedures of IntraLase Enabled Keratoplasty (IEK) to create an anterior lamellar flap rapidly and precisely. The lamellar flap was easily separated with a flap lifter, and the chestnut was removed entirely using a pair of forceps. In 3 days after surgery, the patient complained of mild pain and blurred vision. These symptoms were relieved after treatment with the eyedrops. At three-month follow-up, the corneal wound was healed well, and the BCVA was greatly improved to 1.2 in the left eye. A dot-like haze was observed corresponding to the scar at the site of foreign body removal. No surgical induction of corneal astigmatism was found in the corneal topography. Without induction of a visually significant scar and corneal astigmatism, the IEK procedure of femtosecond laser is of particular interest as it provides a unique method for removal of intracorneal foreign bodies impinging on the visual axis.