Retention of silicone oil droplets from ophthalmic viscosurgical devices in the drainage angle of 2 eyes

Phacoemulsification and nucleic acid-enriched aerosol: considerations from an eye model of cataract simulation

Purpose

The purpose of this study is to investigate whether phacoemulsification can generate aerosolized single-stranded RNA (ssRNA) and retain sequence integrity using an artificial eye model for experimental cataract surgery.

Methods

A simulation of cataract surgery was performed using an anterior chamber eye model filled with an ssRNA probe at different scalar dilutions (kanamycin positive control ssRNA). A plastic conical cage was built over the artificial eye surface of the mock-up. A total of 24 tests (twice reproduced) were performed, and five nitrocellulose strips were placed 15 cm from the artificial surface of the mock-up and used to collect aerosol particles, from each experiment. Phaco-activity was mimicked using a phacoemulsification equipped with a 2.75-mm tip, and strips were removed at the end of the procedure. RNA extraction, reverse transcription, and agarose gel electrophoresis were performed and compared.

Results

Strips collected aerosol droplets enriched with ssRNA, mainly at the higher concentrations tested, compared to related untouched standard solutions. Complementary DNA (cDNA) synthesis confirmed the presence of intact ssRNA fragments. As observed from densitometric analysis of resolved RNA in extracted samples and cDNA bands after retro-transcription, lower concentrations of ssRNA were also detected.

Conclusions

As the main output of the study, the phaco-generated aerosol can deliver an intact ssRNA sequence. Since the aerosol can potentially reach the operator’s face, any biological agent (virus/bacteria) potentially inside the anterior chamber of a patient undergoing cataract surgery, eventually escaping from biomolecular checks, can be potentially infective for operators. The data reported herein suggest that collective versus individual protective countermeasures should always be encouraged in ocular surgery and should not be restricted to coronavirus disease emergencies.

Intraocular lens dystrophic calcification after trans-scleral diode laser treatment for a cyclodialysis cleft

Purpose

To describe a case of intraocular lens (IOL) dystrophic calcification as a complication of trans-scleral diode laser successfully used to treat a post-trabeculectomy cyclodialysis cleft.

Observations

A 76-year-old male with primary open angle glaucoma and pseudophakia (+19.0D Akreos M160L, Bausch & Lomb) was evaluated for vision impairment 4 months post-trabeculectomy complicated by a cyclodialysis cleft of his right eye. The patient was successfully treated with trans-scleral diode laser. After this treatment IOL opacification developed. Slit lamp examination and color photography of the anterior segment was performed prior to exchange of the opacified IOL. The explanted IOL underwent star testing, macroscopic imaging, phase contrast and scanning electron microscopy in addition to energy dispersive x-ray spectroscopy.

Confluent IOL deposits developed 4 months after trans-scleral diode laser treatment requiring IOL exchange. Star optical testing of the explanted IOL showed disruption of the diffraction image. An asymmetric pattern of deposition was congruent with the laser treatment quadrant. The subsurface location and discrete nature of the deposits were seen on phase contrast and electron microscopy. Energy dispersive x-ray spectroscopy demonstrated a predominance of calcium/phosphate in the deposits. We are unaware of previous reports in the literature of IOL dystrophic calcification occurring as a complication of trans-scleral diode laser treatment for a post-trabeculectomy cyclodialysis cleft.

Conclusion and importance

Delayed postoperative IOL dystrophic calcification in our case may have been from a combination of IOL biomaterial susceptibility to diode laser energy; damaged IOL material providing a nidus for calcific nucleation; and blood ocular barrier breakdown altering aqueous composition. We suggest that pseudophakia should influence the consideration of diode laser as treatment of a cyclodialysis cleft.

Intraocular lens implantation without the use of ophthalmic viscosurgical device

The purpose of this study was to determine whether single-piece hydrophilic acrylic intraocular lens can be safely implanted without the use of ophthalmic viscosurgical devices. This retrospective study comprised 100 eyes having phacoemulsification and intraocular lens implantation without the use of ophthalmic viscosurgical device. 80 eyes with the use of a viscosurgical device are used as control group. In this intraocular lens implantation technique, the anterior chamber was maintained with an irrigation cannula and intraocular lens was implanted with a lens injector. Visual acuity, corneal clarity and edema, intraocular pressure, and corneal endothelial cell count were evaluated preoperatively and postoperatively at days 1, 7, and 30. Corneal endothelial cell count was repeated 2 weeks after surgery. Complications of this technique were also evaluated. No significant complications of this intraocular lens implantation technique, such as posterior capsule rupture, intraocular lens buttonholing, zonular dialysis, Descemet's tear/detachment, occurred. On the seventh postoperative day, 90 % of eyes achieved 20/20 or better vision. There was no difference in corneal endothelial cell loss between viscoelastic device-used and not-used cases (p = 0.356). When implanting intraocular lens without the use of ophthalmic viscosurgical device, significant intraoperative complications did not occur. The possible advantages are shortened surgery time, avoidance of postoperative IOP spike from ocular viscosurgical device (OVD) remnant, and reduced cost.