Oxidative stress affects all the structures of the human eye, particularly the retina and its retinal pigment epithelium (RPE). The RPE limits oxidative damage by several protective mechanisms, including the non-enzymatic antioxidant system zinc-metallothionein (Zn-MT). This work aimed to investigate the role of Zn-MT in the protection of RPE from the oxidative damage of reactive oxygen intermediates by analytical and biochemical-based techniques. The Zn-MT system was induced in an in vitro model of RPE cells and determined by elemental mass spectrometry with enriched isotopes and mathematical calculations. Induced-oxidative stress was quantified using fluorescent probes. We observed that 25, 50 or 100 μM of zinc induced Zn-MT synthesis (1.6-, 3.6- and 11.9-fold, respectively), while pre-treated cells with zinc (25, 50, and 100 μM) and subsequent 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH) treatment increased Zn-MT levels in a lesser extent (0.8-, 2.1-, 6.1-fold, respectively), exerting a stoichiometric transition in the Zn-MT complex. Moreover, AAPH treatment decreased MT levels (0.4-fold), while the stoichiometry remained constant or slightly higher when compared to non-treated cells. Convincingly, induction of Zn-MT significantly attenuated oxidative stress produced by free radicals’ generators. We conclude that the stoichiometry of Zn-MT plays an important role in oxidative stress response, related with cellular metal homeostasis.

PurposeTo assess visual and refractive results after bilateral implantation of a trifocal intraocular lens (IOL) in patients with hyperopia.MethodsIn a retrospective nonrandomized study, 196 eyes of 98 patients had bilateral implantation of a trifocal IOL. The Barrett Universal II formula was used for IOL power calculation. Eyes were divided into two groups for their analysis: low-moderate, with IOL power ranging from 22 to 26 D, and high, with IOL power ranging from 25 to 34 D. Refractive error was used to assess predictability, and corrected distance visual acuity (CDVA) and uncorrected distance visual acuity values were used to assess efficacy and safety of the surgery.ResultsSix months postoperatively, our results revealed a Snellen decimal CDVA of 0.97±0.05 and 0.94±0.09, for the low-moderate and high groups, respectively. The low-moderate hyperopia group showed a 75.23% of eyes with 20/20 of CDVA and 100% of eyes with 20/25 of CDVA, and the high hyperopia group showed 60.95% and 94.29% for these values of visual acuity, respectively. The mean postoperative spherical equivalent was −0.25±0.36D and −0.24±0.42D for low-moderate and high hyperopia groups, respectively. In the case of low-moderate hyperopia group, 81% of eyes were within ±0.50D and 99% within ±1.00D. These values were 78% and 95%, respectively, for the high hyperopic eyes.ConclusionBilateral implantation of a trifocal IOL in hyperopic eyes provided good visual and refractive outcomes. The Barrett Universal II formula was accurate in predicting the IOL power in hyperopic eyes.

Background: The purpose of this study is to evaluate the utility and safety of plasma rich in growth factors immunosafe eye drops (is-ePRGF) in the postoperative treatment of non-penetrating deep sclerectomy (NPDS). Methods: This is a case–control study in patients with open-angle glaucoma. Group one (control) was not treated with is-ePRGF, while group two (is-ePRGF) was treated (four times a day for four months). Postoperative evaluations were performed at one day, one month, three months and six months. The main outcomes were: intraocular pressure (IOP), microcysts in blebs with AS-OCT and the number of hypotensive eye drops. Results: Preoperatively, group one (n = 48 eyes) and group two (n = 47 eyes) were similar in age (71.5 ± 10.7 vs. 70.9 ± 10.0 years; p = 0.68), IOP (20.6 ± 10.2 vs. 23.0 ± 9.0 mmHg; p = 0.26) and number of hypotensive drugs (2.7 ± 0.8 vs. 2.8 ± 0.9; p = 0.40). The IOP at six months dropped to 15.0 ± 8.0 mmHg (IOP reduction: −27.2%) and 10.9 ± 4.3 mmHg (IOP reduction: −52.6%) for group one and group two, respectively (p < 0.01). At six months, blebs with microcysts were 62.5% (group one) and 76.7% (group two). Postoperative complications were observed in 12 eyes (25%) for group one and in 5 eyes (11%) for group two (p = 0.06). No specific complications related to the use of is-ePRGF were identified. Conclusions: Topical is-ePRGF seems to reduce IOP and the rate of complications in the medium term after NPDS, so it can be considered as a possible safe adjuvant to achieve surgical success.