Full-vision maintenance in extra-high myopia from implantable collamer lens to trifocal intraocular lens implantation

Dear Editor,I am Dr.Ye Shen from the Department of Ophthalmology,the First Affiliated Hospital,College of Medicine,Zhejiang University,Hangzhou,China.I write to share my experience of full-vision maintenance in patient with extrahigh myopia from implantable collamer lens （ICL） to trifocal intraocular lens （IOL） implantation.

Increased aquaporin-1 levels in lens epithelial cells with primary angle-closure glaucoma

AIM： To determine the levels of aquaporin-1（AQP-1） in the lens epithelial cells（LECs） of primary glaucoma and to clarify its correlation with lens thickness.METHODS： This study comprised 64 eyes of 64 patients with primary glaucoma, who were divided into 3 groups： 25 eyes of 25 patients with acute primary angle-closure glaucoma（APACG）, 19 eyes of 19 patients with chronic primary angle-closure glaucoma（CPACG） and 20 eyes of 20 patients with primary open angle glaucoma（POAG）. This study also included 12 eyes of 12 patients with senile cataract as controls. The levels of AQP-1 in LECs were examined by real-time quantitative polymerase chain reaction（RT-q PCR） and immunohistochemistry. The lens thickness was measured by A-scan ultrasonography. RESULTS： The AQP-1 m RNA levels of LECs were 0.84±0.27, 0.69±0.34, 0.44±0.19 and 0.51±0.21 in APACG, CPACG, POAG and senile cataract group, respectively. The levels of AQP-1m RNA were significantly higher in PACG groups compared with those in senile cataract and POAG group（all P〈0.05）. The immunohistochemistry showed the AQP-1 expression were strong-positive in PACG groups, but weak-positive in senile cataract and POAG group. A positive correlation was found between AQP-1 m RNA levels and the lens thickness（r=0.645, P〈0.001）. CONCLUSION： These findings show that the higher expression of AQP-1 in LECs may contribute to increased lens thickness, which might be associated with the occurrence and development of PACG.

Preloaded and non-preloaded intraocular lens delivery system and characteristics: human and porcine eyes trial

AIM： To compare characteristics of preloaded and nonpreloaded intraocular lens（IOL） delivery systems during IOL delivery procedures. METHODS： Total 101 human eyes were included in this prospective observational case series. Delivery characteristics of 5 types of IOLs including i Sert250 NC60（NC60）, En Vista MX60（MX60）, Acry Sof IQ SN60 WF（SN60 WF）, TECNIS ZCB00（ZCB00）, and TECNIS PCB00（PCB00） were investigated. NC60 and PCB00 were injected via preloaded delivery systems and other IOLs were injected via nonpreloaded systems. In the human trial, time taken from IOL loading to completion of implantation was measured in all eyes undergoing conventional cataract surgery. Using 4 excised porcine eyes, dynamics of ophthalmic viscosurgical device（OVD） between an IOL injector and a porcine eye was analyzed using fluorescein sodiumstained OVD. RESULTS： The average time for IOL implantation was 22.0 s for NC60, 43.2 s for MX60, 32.3 s for SN60 WF, 41.4 s for ZCB00, and 14.6 s for PCB00 respectively. The number of cases with IOL manipulation with a second instrument was 6 for MX60, 2 for ZCB00, 0 for SN60 WF, NC60, and PCB00. Amount of OVD pushed into a porcine eye was smaller with a preloaded system than with non-preloaded systems. CONCLUSION： IOL delivery with preloaded systems is faster and more predictable. Moreover, a preloaded delivery system shows relatively less OVD pushed into a porcine eye than non-preloaded systems.

The BL Lac Object PKS 0537-441: A Lens or Being Lensed?

We present and discuss deep high resolution images taken with the ESO NTT as well as spectra taken with the ESO VLT in the field of the BL Lac object PKS 0537 441. We could neither detect the host galaxy nor a galaxy along the line of sight to the BL Lac as claimed from previous observations. We found 4 nearby companion galaxies which could be a splitted and magnified image of a distant background galaxy. Our VLT spectra, however, rule out this possibility. All 4 companions have similar redshifts as the BL Lac and may (at least in part) trigger the enormous activity in this source. PKS 0537 441 might be located in a galaxy cluster as rich as Abell 1. Alternatively, the BL Lac could also be located in the outskirts of a galaxy cluster or even be projected on a large scale structure as indicated by spectra of 30 galaxies in the field. Either lensing hypothesis (lens or being lensed) is considerably weakened by our observations.

OPTICAL OPTIMIZATION FOR LIQUID CRYSTAL TEST BY LASER-CCD SYSTEM

For the narrowband of liner charge-coupled device （CCD） receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can concentrate on a strip facula, Considered the effective CCD length and selection of lens parameters, the system can be optimized. Correspondingly to the CCD pixels, the ray is composed of much angle information. By widening the parallel ray or increasing the lens aperture, luminous flux can be ensured when oblique incidence. Meanwhile, the effective working range can also be improved. Based on the experimental data, cylindrical system could be applied in accurate angle measurement. It has been proved feasible that the cylindrical system can be used in anchor behavior study for liquid crystal （LC） case. The low-power He-Ne laser cylindrical system can carry out the previous effect in high power laser spherical system.