Descemet stripping only, revision de casos

Revision sobre DSO

1. Introduction Descemet stripping only (DSO) is a relatively novel treatment for Fuchs endothelial corneal dystrophy (FECD). In this procedure, a central area of Descemet’s membrane and endothelium is removed without the insertion of donor tissue. An advantage of DSO is that it does not utilize donor tissue, which obviates the need for prolonged immunosuppression and eliminates the risk of steroid-related adverse effects, such as cataract and glaucoma. The primary disadvantage of DSO is a longer time to corneal clearance compared to DMEK Currently, we know that DSO can result in corneal clearance and good visual acuity; however, we do not know the longevity or durability of the results.

2. Methods We identified 14 eyes in 12 patients who underwent Descemet stripping only between January 1, 2016, and December 31, 2017. All the patients were treated by a single surgeon. All patients underwent concurrent phacoemulsification. Immediately after placement of the intraocular lens, descemetorhexis was performed to remove the central 4 mm of diseased endothelium. Patients were informed that a topical Rho kinase inhibitor could potentially improve healing after DSO. Five patients chose to order Glanatec (ripasudil 0.4%), which is manufactured in Japan by the Kowa Company. They used it six times per day for 4–6 weeks postoperatively until corneal clearing.

3. Results Corneal clearance and need for subsequent endothelial keratoplasty Twelve of 13 eyes (92%) had complete resolution of corneal edema after DSO. One patient had partial clearance, but persistent mild edema with Descemet folds on examination. Of the 12 eyes that cleared, only two experienced a secondary failure of DSO requiring subsequent DMEK. The time to recurrence of corneal edema was 19 months in both cases and the time to endothelial keratoplasty was 24 months.

4. Results Visual Acuity 10/11 eyes had a visual acuity of 20/40 or better. One patient had decreased vision due to posterior capsule opacification, and a YAG laser capsulotomy was performed. At POM12, 13/13 eyes had a VA of 20/40 or better, and 8/13 eyes had pinhole acuity that was 20/25 or better. At 5 years postoperatively, 9/10 patients who maintained clear corneas had a pinhole acuity of 20/30 or better. Six-year follow up was available for 8 patients, and 6 patients had pinhole acuity of 20/30 or better. The patient with worsening visual acuity experienced progressive vision loss due to age-related macular degeneration.

5. Complications Four patients developed postoperative cystoid macular edema (CME). The average time to the onset of macular edema was 4.25 months. CME resolved with treatment with topical bromfenac , with or without prednisolone. The average time to resolution was 2.38 months. One patient had a central corneal ulcer in the operative eye at POM14. There was no history of contact lens wear, and no organisms were identified on gram stain or corneal cultures. He was treated with fortified tobramycin and cefazolin eye drops and polysporin ointment. The ulcer resolved and the patient achieved a VA of 20/20 −1 at POM24, despite residual paracentral scarring and mild edema. Ultimately, the edema resolved completely by POY3 and the patient did not require endothelial keratoplasty and maintained good visual acuity.

6. Discussion In our series of 13 eyes and 11 patients undergoing DSO, only one patient did not completely clear, yielding an initial success rate of 92%. Of the 12 eyes that had successful corneal clearance, two (17%) had secondary failure at POM19 and required endothelial keratoplasty. They also reported using a scraping technique. We are now aware of the importance of a gentle stripping technique in which the surgeon avoids disrupting the posterior stromal fibers as much as possible, as this can impair the migration of endothelial cells and cause scarring, and has been associated with DSO failure. We now have evidence that Rho kinase inhibitors decrease time to corneal clearance. In our series, patients did not start using a Rho kinase inhibitor until 2017; thus, only five patients were observed on this treatment. Ripasudil was used at a frequency of 6 times per day for a duration of 4–6 weeks. The timeframe for initiating use ranged from the immediate postoperative period to six months after surgery.

7. Introduction ROCK is a serine/threonine-specific protein kinase. It has been demonstrated that the Rho/ROCK pathwayplays a unique role in the trabecular meshwork (TM) by affecting actomyosin cytoskeletal structure and extracellular matrix (ECM) formation. ROCK inhibitors promote relaxation of the TM by attenuating actin cytoskeletal contractility, facilitate nuclear translocation of β-catenin to suppress cellular migration, interfere with ATP-dependent phosphorylation events to inhibit ROCK1 and ROCK2 activity, and prevent the association of Rho GTPases with ROCK . Aqueous humor is known to exit the anterior chamber via TM but also encounter outflow resistance in TM. Increased TM cell contractility and ECM accumulation are observed to narrow intercellular spaces, raising outflow resistance and increasing IOP. ROCK inhibitors are used to relax TM cells and inhibit ECM deposition, thereby facilitating aqueous humor outflow. Ripasudil and netarsudil are two topical ROCK inhibitors approved for glaucoma treatment. Multiple pivotal trials have been conducted to substantiate the IOP-lowering efficacy. Ripasudil was shown to demonstrate significant reductions in IOP compared to the baseline across phase II and III studies in patients with primary open-angle glaucoma (POAG) and ocular hypertension (OHT), both as monotherapy and in combination with timolol or latanoprost

8. Ocular Adverse Effect Conjunctival hyperemia is the most frequently reported side effect associated with ROCK inhibitors, with incidence rates ranging from 37% to 65%—notably higher than those for timolol (8–14%) and latanoprost (9–22%) Peak occurrence typically occurs at 10–15 min post-instillation and resolution is observed within 1–2 h. However, treatment adherence may still be reduced by this side effect In a crossover randomized clinical trial, the severity of hyperemia was significantly reduced in the group receiving the fixed-dose combination of ripasudil and brimonidine compared to the ripasudil monotherapy group. Another notable adverse effect of ROCK inhibitors involves the cornea. Corneal verticillate has been reported in 13–26% of patients receiving ROCK inhibitors, occurring more frequently in those treated with netarsudil than with ripasudil. This phenomenon was absent in non-Rho kinase inhibitor arms in clinical trials. Reticular epithelial corneal edema is less common than corneal verticillata but remains clinically relevant

9. Conclusions Their current use as first-line monotherapy is limited by their modest IOP-lowering efficacy and notable ocular side effects. The emergence of dual kinase inhibitors with improved target selectivity and enhanced efficacy underscores the need for further research. In preclinical studies, superior IOP reduction compared to pure ROCK inhibitors has been demonstrated with dual kinase inhibitors through the modulation of additional cytoskeletal pathways.