Quercetin protects against diabetic retinopathy in rats by inducing heme oxygenase-1 expression

Quercetin is a widely-occurring flavonoid that protects against cancer, and improves memory and cardiovascular functions.However, whether quercetin exhibits therapeutic effects in diabetic retinopathy remains unclear.In this study, we established a rat model of streptozocininduced diabetic retinopathy.Seventy-two hours later, the rats were intraperitoneally administered 150 mg/kg quercetin for 16 successive weeks.Quercetin markedly increased the thickness of the retinal cell layer, increased the number of ganglion cells, and decreased the overexpression of the pro-inflammatory factors interleukin-1β, interleukin-18, interleukin-6 and tumor necrosis factor-α in the retinal tissue as well as the overexpression of high mobility group box-1 and the overactivation of the NLRP3 inflammasome.Furthermore, quercetin inhibited the overexpression of TLR4 and NF-κBp65, reduced the expression of the pro-angiogenic vascular endothelial growth factor and soluble intercellular adhesion molecule-1, and upregulated the neurotrophins brain-derived neurotrophic factor and nerve growth factor.Intraperitoneal injection of the heme oxygenase-1 inhibitor zinc protoporphyrin blocked the protective effect of quercetin.These findings suggest that quercetin exerts therapeutic effects in diabetic retinopathy possibly by inducing heme oxygenase-1 expression.This study was approved by the Animal Ethics Committee of China Medical University, China(approval No.2016 PS229K) on April 8, 2016.

Comparison of the femtosecond Laser and mechanical microkeratome for flap cutting in LASIK

· AIM: To compare refractive results, higher-order aberrations(HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis(LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism.·METHODS: In this prospective, non-randomized study,120 eyes with myopia received a LASIK surgery with the Visu Max femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function(CSF) curves,HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery.·RESULTS: At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was113.05 ±5.89 μm(attempted thickness 110 μm), and148.36 ±21.24 μm(attempted thickness 140 μm) in mechanical microkeratome procedure. An uncorrected distance visual acuity(UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in log MAR lines of corrected distance visual acuity(CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant(P 】0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery(P 【0.01). The CSF values of the femtosecond treated eyes were also higherthan those of the microkeratome treated eyes at all space frequency(P 【0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time(TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome treated eyes at postoperative 1, 3mo(P 【0.01).·CONCLUSION: Both the femtosecond laser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF,and longer TBUT.

Clinical features,radiological imaging,and treatment strategies of nonmetallic intraorbital foreign bodies:a retrospective analysis

AIM:To provide comprehensive data on nonmetallic intraorbital foreign bodies(IOFBs)by summarizing and analyzing material types,clinical manifestations,imaging features,and treatment strategies.METHODS:Totally 28 nonmetallic IOFB cases treated at Shengjing Hospital of China Medical University from 2012 to 2020 were retrospectively reviewed.The types of foreign bodies,clinical features,imaging manifestations,and treatment outcomes were analyzed.RESULTS:Among all cases,67.8%(19/28)of the foreign bodies were organic.The top three entrances were the upper eyelid skin(7/28),lower fornix conjunctiva(6/28),and lower eyelid skin(4/28).In most cases(11/28,39.3%),foreign bodies remained in the medial orbits.The major clinical manifestations included eyelid redness and swelling(20/28,71.4%),conjunctival congestion and edema(17/28,60.7%),and ophthalmoptosis(15/28,53.6%).Infection was the main complication,which occurred in 57.1%(16/28)of all cases.Computerized tomography(CT)values differed for different foreign bodies and varied in the different periods after injury.The plant-and grease-derived foreign bodies and the surrounding pus cysts showed different signals on magnetic resonance imaging(MRI).The prognosis varied with different foreign body types,surgery timing,and intraoperative management.CONCLUSION:The majority of nonmetallic IOFBs are organic and often remain in the superior,medial,and inferior areas of the orbit.Clinical manifestations vary owing to their different textures.CT and MRI facilitate the identification of foreign body materials.Plant-derived foreign bodies should be completely removed,and surgical treatment is a complicated process.