Findings from a study published in Ophthalmology and Therapy evaluated the protective effect of a rho-associated kinase inhibitor (RKI; ripasudil) on corneal endothelial cells after cataract surgery over the course of 12 months.
Give me some background.
Cataract surgery is the most commonly performed surgical procedure globally and can negatively impact the corneal endothelium—which is critical to maintaining corneal health.
The corneal endothelium lacks significant regenerative ability, making cell loss permanent and emphasizing the need to minimize endothelial cell loss during cataract surgery.
Now bring in rho kinase inhibitors.
Rho kinase inhibitors (also known as ROCK inhibitors) are used to manage glaucoma; however, they have recently gained traction in treating corneal endothelium diseases due to their ability to:
- Promote corneal endothelial cell proliferation
- Increase intercellular adhesion
- Suppress apoptosis
Plus: Previous studies have indicated that ripasudil shows promise in significantly reducing endothelial cell loss after cataract surgery with a regimen of one drop instilled twice daily (BID) for 6 months, starting from the day after surgery.
Now talk about the study.
In this prospective study, researchers included 43 patients divided into two groups:
- Ripasudil group (22 patients, 23 eyes)
- Control group (21 patients, 21 eyes)
All patients had Grade 3 nuclear cataracts and underwent uneventful phacoemulsification with intraocular lens (IOL) implantation.
Tell me more.
In the ripasudil group, one drop of ripasudil hydrochloride hydrate (Glanatec ophthalmic solution 0.4%) was administered three times a day (TID) for 5 days.
Outcome measures included central corneal thickness (CCT) and endothelial cell density (ECD), which were evaluated preoperatively and 12 months postoperatively.
Findings?
The median ECD in both groups at baseline and 12 months postoperatively were as follows:
- Ripasudil group
- Baseline ECD: 2398 cells/mm2 (interquartile range [IQR] 410, 2201-2611)
- 12-month ECD: 2262 cells/mm2 (IQR 298, 2195-2493)
- Control group
- Baseline ECD: 2503 cells/mm2 (IQR 390, 2340-2730)
- 12-month ECD: 2170 cells/mm2 (IQR 324, 2049-2373)
No adverse effects were observed in either of the groups.
Anything else?
Endothelial cell loss (ECL) was 12.8% in the control group and was significantly reduced to 4.5% in the ripasudil group (p=0.001).
Of note: CCT (p=0.042), age (p=0.383), sex (p=0.944), and duration of surgery (p=0.319) were not significant factors in treatment outcomes.
Expert opinion?
While the best-corrected visual acuity (BCVA) outcomes of both groups were comparable, it is well-known that significant ECL can trigger corneal endothelial decompensation and potentially require corneal transplantation.
Thus, the study authors explained, “Ripasudil use may be beneficial in reducing ECL, which could potentially result in a decreased need for corneal transplantation.”
Limitations?
The relatively small sample size and absence of randomization and blinding in the study are limitations that make these findings insufficient to draw robust conclusions.
Take home.
These findings suggest that integrating ripasudil into postoperative management could help maintain corneal endothelial cell integrity and reduce cell loss after cataract surgery—potentially decreasing the need for endothelial transplantation in patients who have undergone intraocular surgeries.
Next steps?
Future research is warranted to determine the optimal dosing, duration, and frequency of ripasudil administration and evaluate the drug’s long-term safety and efficacy.