Clinical observations of EVO-ICL implantation and changes in corneal astigmatism using a modified technique

Clinical observations of EVO-ICL implantation with single incision without viscoelastic agent

BACKGROUND

To investigate the safety and effectiveness of non-viscoelastic agent technique for EVO-ICL implantation.

METHODS

A total of 181 myopia eyes that underwent non-toric ICL without viscoelastic agent through single incision from Beijing Tongren Hosipital were included. An analysis was conducted on the quantity of haptics that were initially implanted intraoperatively into the posterior chamber. Intraocular pressure (IOP) was evaluated at before and 2 h,24 h,1week,6month after surgery. Anterior chamber volume(ACV), anterior chamber depth(ACD), anterior chamber angle(ACA), pupil diameter(PD) and corneal densitometry density (ECD) were evaluated at before and 24 h postoperatively. Refractive outcomes were investigated at before, 24 h ,7 days and 6months. Vault was evaluated at 24 h ,7 days and 6months.

RESULTS

The efficacy and safety indices were 1.30 ± 0.32 and 1.31 ± 0.32, respectively. Of 181 eyes, 99 eyes received 4 haptics on the first attempt without any adjustment, and 72 eyes received lens alignment without an viscoelastic agent. The success rate of the viscoelastic agent free procedure was 94.5%. Two hours postoperatively, IOP was 17.41 ± 3.77 mmHg, which was significantly higher than baseline value (t = 8.930, P < 0.000), however there was no significant difference between preoperative IOP and IOP at 1 day ,1 week and 6 months postoperatively. The ECD changed from 2895.52 ± 253.73 cells/mm2 preoperatively to 2873.66 ± 244.17 cells/mm2 at 1 day and 2882.63 ± 239.97 postoperatively, and the difference was not statistically significant (t = 1.811, P = 0.072). The ACA was narrowed by 42% on the first day.

CONCLUSION

The pure viscoelastic agent free technique is an efficient and safe way for ICL implantation. It can be a safer method of ICL implantation because of it reduces the risk of complications associated with ocular hypertension at the early postoperative stages.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2000036335) at August 20, 2020.

The effect of irrigation and aspiration on the corneal endothelial cell density in patients undergoing Implantable Collamer Lens with a central hole implantation for myopia correction

PURPOSE

In the conventional technique, viscoelastic agents are typically rinsed away with balanced salt solution (BSS), but it may lead to a series of complications such as viscoelastic residue, anterior chamber instability and intraoperative TICL rotation. The utilization of irrigation and aspiration (I/A) has been shown to be effective in maintaining anterior chamber stability, reducing the incidence of postoperative high intraocular pressure, and minimizing postoperative fundus complications. However, there is a lack of previous studies investigating the impact of I/A on corneal endothelial cells during ICL implantation. The objective of this study was to examine the effect of I/A on corneal endothelial cells in patients undergoing myopia correction through implantation of Implantable Collamer Lens with a central hole (V4c ICL).

METHODS

A retrospective selection was made of 344 eyes from 172 patients who underwent V4c ICL implantation and I/A to remove viscoelastic agent from the anterior chamber between 2021 and 2022. The intraocular pressure (IOP) was measured at 1 h, 2 h and 3 h after surgery. Corneal endothelial cell density (ECD), coefficient of variation in cell size (CV), standard deviation of cell area (SD), and percentage of hexagonal cells (HEX) were evaluated at 1 week postoperatively to assess corneal endothelial cells. The first two represent polymegethism or morphological variation, while the third parameter represents the degree of polymorphism of the corneal endothelial cells. Electronic medical records were utilized for data collection purpose.

RESULTS

All surgeries proceeded without complications. The IOP was 16.50 ± 3.42 mmHg (range: 11.5-22.3 mmHg) prior to surgery and increased to 21.25 ± 5.61 mmHg (range: 9.5-34.8 mmHg), 19.85 ± 5.18 mmHg (range: 11.4-36.2 mmHg) and finally settled at an average of 18.81 ± 4.57 mmHg (range: 10.1-38.8 mmHg) at the respective time points of 1 h, 2 h and 3 h after surgery. The preoperative ECD was recorded as being approximately 3004 ± 295 cell/mm2, which exhibited a marginal decreased of 1.17% postoperatively, resulting in an average ECD value of 2969 ± 303 cell/mm2 one week after surgery (P = 0.12). Similarly, the preoperative CV was determined as 31.10 ± 3.78%, and it experienced a slight reduction with an average CV value of 30.74 ± 3.77% at week after surgery (P = 0.21). And, the preoperative SD was reported as 104.76 ± 17.26, and it remained virtually unchanged with an average SD value of 104.85 ± 18.75 at one week after surgery (P = 0.95). The preoperative HEX was calculated as 55.38 ± 8.94%, and it remained its stability with an average HEX value of 55.45 ± 8.73% one week after surgery (P = 0.92).

CONCLUSION

The utilization of I/A led to a slight decrease in postoperative ECD when compared to conventional surgical techniques. Nevertheless, the reduction in ECD remained within acceptable limits, taking into accout the avervantaged it offered, such as stabilization of the anterior chamber and decreased occurrence of viscoelastic residue after surgery. It is challenging to anticipate the long-term safety of corneal endothelial cells based on current short-term studies. However, this study provides a valuable reference indicating that neither anterior chamber irrigation nor I/A aspiration have an adverse impact on the safety of corneal endothelial cells in the short term. Further research is imperative to enhance our understanding of their effects over an extended period.