[Primary intraocular lens implantation can be applied in infants over 7 months of age and young children with adequate consideration].

In recent years, intraocular lenses (IOLs) have been increasingly used in the correction of aphakia after congenital cataract extraction. But IOL implantation in infants and young children, especially under 1 year old, is still controversy. Large-scale, multi-center, randomly controlled clinical observations on this issue have been conducted. The mid-and long-term results have shown that infantile cataract extraction combined with primary IOL implantation can achieve the same or better visual outcome as aphakic contact lens correction. For infants over 7 months of age and young children, primary implantation of IOLs is relatively safe, with a low complication and secondary operation rate. Compared to the way of aphakic contact lens correction, which could be with more inconvenience, high demand of coordination, a higher infection risk, high cost and the need of a secondary IOL implantation surgery, primary implantation of IOLs at over 7 months of age is worth exploring, with appropriate understanding of the surgical indications and adequate surgical techniques. (Chin J Ophthalmol, 2021, 57: 487-491).

Parameters optimization method for the time-delayed reservoir computing with a nonlinear duffing mechanical oscillator.

Reservoir computing (RC) is a recently introduced bio-inspired computational framework capable of excellent performances in the temporal data processing, owing to its derivation from the recurrent neural network (RNN). It is well-known for the fast and effective training scheme, as well as the ease of the hardware implementation, but also the problematic sensitivity of its performance to the optimizable architecture parameters. In this article, a particular time-delayed RC with a single clamped-clamped silicon beam resonator that exhibits a classical Duffing nonlinearity is presented and its optimization problem is studied. Specifically, we numerically analyze the nonlinear response of the resonator and find a quasi-linear bifurcation point shift of the driving voltage with the driving frequency sweeping, which is called Bifurcation Point Frequency Modulation (BPFM). Furthermore, we first proposed that this method can be used to find the optimal driving frequency of RC with a Duffing mechanical resonator for a given task, and then put forward a comprehensive optimization process. The high performance of RC presented on four typical tasks proves the feasibility of this optimization method. Finally, we envision the potential application of the method based on the BPFM in our future work to implement the RC with other mechanical oscillators.

[Several controversial issues in astigmatism correction in cataract surgery].

Cataract surgery has entered the era of refractive surgery, and patients have higher requirements for visual quality. Astigmatism correction in cataract surgery is increasingly valued, but the astigmatism correction results are not ideal, and the principles of corneal astigmatism correction are not well established. In this article, the issues including how to dialectically decide to treat the corneal astigmatism or not, how to choose the corneal astigmatism estimating method and the calculation formula for astigmatism correction, the range of corneal astigmatism suitable for applying multifocal intraocular lens, selection of intraoperative corneal astigmatism correction method, etc., were discussed based on relevant authoritative guidelines, expert consensus and literatures, and corresponding suggestions were given. (Chin J Ophthalmol, 2019, 55: 485-490).

Berry phase in a composite system.

The Berry phase in a composite system with one driven subsystem has been studied in this Letter. We choose two coupled spin-1 / 2 systems as the composite system; one of the subsystems is driven by a time-dependent magnetic field. We show how the Berry phases depend on the coupling between the two subsystems, and the relation between the Berry phases of the composite system and those of its subsystems.