[Laser-induced damage to the cornea after YAG laser surgery of anterior segment structures]

Laser photodestruction (LPD) of tissues is the basis of modern laser reconstructive surgery in ophthalmology. The most common laser technologies based on LPD mechanisms include YAG laser capsulotomy (discission) (LD) of secondary cataract and YAG laser iridectomy (LIE) for glaucoma. Laser reconstructive interventions for secondary cataract, as well as LIE, have a number of advantages over traditional surgery, but at the same time are associated with the risk of complications, including in the cornea. Corneal endothelium is the most susceptible to laser damage, while Descemet's membrane and corneal stroma are injured less often. This review describes cases of iatrogenic perforation and purulent inflammation of the cornea. In the long-term, laser interventions can lead to bullous keratopathy and corneal graft rejection. At this time, the most popular and available among the methods for assessing the cornea after YAG laser interventions is the method of specular microscopy. Ultrasound biomicroscopy is used less commonly. The modern method of corneal confocal microscopy is practically not used for this purpose, and taking into account the risks of developing laser-induced injuries, it indicates its relevance and the need for further research.

Impact of primary posterior capsulorhexis on regeneratory after-cataract and YAG laser rates with an acrylic micro-incision intraocular lens with plate haptics: 1-year and 3-year results

Purpose

To evaluate the posterior capsule opacification (PCO) and YAG laser capsulotomy (YAG‐LCT) rates with a plate‐haptic acrylic micro‐incision intraocular lens (IOL) and the impact of primary posterior capsulorhexis.

Methods

A total of 97 patients scheduled for immediate sequential bilateral cataract surgery underwent a randomized, prospective intraindividual comparison with the ZEISS Asphina 409MV plate‐haptic acrylic IOL with the eyes receiving an additional primary posterior capsulorhexis (PPCR) or not. YAG‐LCT and PCO rates were evaluated at 1 and 3 years. Three‐year PCO rates were calculated with a 3‐scenario method for eyes that underwent YAG‐LCT between 1 and 3 years.

Results

A total of 56 patients were seen at 1 year, and 57 at 3 years. For the eyes without and with PPCR, YAG‐LCT rates were 14.3% and 0% at 1 year, and 59.7% and 3.5% at 3 years, respectively. Opacification rates at 1 year were 0.55 ± 0.99 and 0.05 ± 0.21 for the central 2‐mm optic zone. A total of 42 patients completed both the 1‐ and 3‐year follow‐up. Three‐year opacification rates for the group without PPCR were 1.99 ± 2.20, 2.26 ± 2.66 and 3.66 ± 3.61 for the central 2‐mm zone and 2.57 ± 2.07, 3.13 ± 3.03 and 4.09 ± 3.34 for the 4.5‐mm zone for the best, extrapolated and worst‐case scenarios, respectively.

Conclusion

The ZEISS Asphina 409MV plate‐haptic acrylic IOL exhibited unusually high YAG‐LCT and PCO rates with standard in‐the‐bag implantation. PPCR was safe and effective in preventing central opacification and the need for YAG laser treatment.

A new technique for Nd:YAG laser posterior capsulotomy

AIM

To investigate the effects of a new opening pattern in neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy on visual function.

METHODS

This technique was conducted along a circular pattern. The energy ranged between 0.8 and 1.2 mJ/pulse was consumed and mean total energy levels were 74±21 mJ (mean±standard deviation: SD, from 40 to 167) and laser shots aimed at 150 µm away behind a datum point and went along an imaginary line which extends 0.5 mm inside from optic margin and into the circular en bloc pattern. Vitreous stands were attached with fragment and then they were cut off by the laser after circular application. The circular fragment was completely separated from vitreous, and then this fragment was quickly sunk in intravitreal space.

RESULTS

The follow-up period ranges from at least a week to 40mo, making 15.8mo on average. The procedural outcome showed 96% (74 eyes out of the 77 eyes) enhancement in patients' visual acuity. Cystoid macular edema or retinal detachment was not observed in any of the patients during follow-up periods.

CONCLUSION

This new technique is expected to improve the weaknesses that the conventional procedures have by adding the process to cut off vitreous stands attached with the fragment by the laser to the circular application.