Descemet Membrane Endothelial Keratoplasty in Aphakic, Aniridic, and Vitrectomized Eyes: A Review

PURPOSE

The aim of this review is to examine the techniques, complications, and outcomes of Descemet membrane endothelial keratoplasty (DMEK) in aphakic, aniridic, and vitrectomized eyes.

METHODS

A literature search was conducted in the MEDLINE database (via PubMed), using as keywords "(DMEK) AND (aphakia OR aniridia OR vitrectomy OR vitrectomized)." The research was limited to 10 years (January 2014-March 2024), in view of lack of literature before 2014. Articles, including case reports and case series, were included.

RESULTS

Twenty articles were included. No randomized controlled trials were found nor comparative studies with more than 1 technique used. Mean rebubbling rate in complex eyes was 29%, whereas mean endothelial cell loss at 6 months was 37%. The mean postoperative visual acuity improved from 1.47 logarithm of the minimal angle of resolution to 0.7 logarithm of the minimal angle of resolution.

CONCLUSIONS

Despite being more challenging, compared with the techniques reported in literature, DMEK can be considered a valid option for the management of endothelial decompensation in complex eyes, with rebubbling rate and endothelial cell loss at 6 months, which are similar to non-complex eyes.

Clinical Outcomes of Transscleral-Sutured Intraocular Lens Combined With Descemet Membrane Endothelial Keratoplasty

PURPOSE

The aim of the study was to report clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) combined with transscleral-sutured intraocular lens (IOL) compared with DMEK combined with phacoemulsification and posterior chamber IOL (Phaco-DMEK).

METHODS

A retrospective chart review of all patients who underwent DMEK combined with transscleral-sutured intraocular lens fixation or combined with phacoemulsification for Fuchs endothelial corneal dystrophy from 2016 to 2021 at the Toronto Western Hospital or the Kensington Eye Institute (Toronto, ON, Canada) and had at least 18 months of follow-up was performed. Main outcomes were postoperative distance-corrected visual acuity, rebubbling rate, graft survival rate, and complications.

RESULTS

Twenty-one cases of DMEK combined with transscleral-sutured IOL (DMEK-TSS-IOL) and 44 cases of Phaco-DMEK were evaluated. Twelve eyes (57.15%) had a foldable acrylic 3-piece IOL (AR40E) and 9 (42.85%) had a single-piece polymethylmethacrylate (PMMA) IOL (CZ70BD). LogMAR distance-corrected visual acuity improved significantly from 1.48 ± 0.62 (SD) to 0.86 ± 0.82 ( P = 0.01) 12 months after DMEK-TSS-IOL and from 0.41 ± 0.29 logMAR to 0.11 ± 0.11 logMAR ( P < 0.0001) after Phaco-DMEK. No statistically significant differences were observed in donor ( P = 0.97) or 1-year postoperative endothelial cell density ( P = 0.11) between the groups. Rebubbling was necessary in 33.33% of eyes in DMEK-TSS-IOL compared with 25% of Phaco-DMEK eyes ( P = 0.55). Graft survival rate was 76.19% in the DMEK-TSS-IOL group compared with 90.90% in the Phaco-DMEK group ( P = 0.13).

CONCLUSIONS

Transscleral-sutured IOL combined with DMEK is an option for the management of endothelial diseases in aphakic eyes or those which require IOL exchange for the experienced surgeon. However, when compared with routine Phaco-DMEK, there are higher complication and lower survival rates at 18 months.

Descemet Membrane Endothelial Keratoplasty with cornea press technique and implantation of a Carlevale scleral-fixated intraocular lens

Purpose

We describe a combined Descemet Membrane Endothelial Keratoplasty (DMEK) using the Cornea-press (C-Press) technique, with implantation of a new sutureless, scleral fixated intraocular lens (IOL) (Carlevale, Soleko), in a case of bullous keratopathy and IOL mispositioning.

Observations

Two scleral pockets were created along two scleral radial incisions, 180° apart, followed by two 23 G sclerotomies at the pockets' sites. After removal of the dislocated IOL through a corneoscleral incision, posterior vitrectomy was completed. The Carlevale IOL was injected into the anterior chamber (AC) and placed above the iris. The haptics were then externalized using opening distal forceps through the sclerotomies, and the plugs were secured in the scleral pockets. DMEK was then performed using the "C-press" technique, where corneal indentation allowed to artificially shallow the AC to ensure successful graft unrolling. Fifteen months postoperatively, the cornea was clear, the Carlevale IOL well positioned, and the patient's vision improved.

Conclusions and importance

DMEK using the C-Press technique, combined with a sutureless, scleral-fixated IOL such as the Carlevale in a single procedure, may be a safe and effective option to restore vision in case of bullous keratopathy and dislocated IOL.

Efficacy and safety of UT-DSAEK combined with Carlevale's sutureless scleral fixation IOL

PURPOSE

To evaluate a novel surgical combination of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and sutureless scleral fixation for Carlevale intraocular lens (SSF-Carlevale IOL) implantation to manage corneal endothelial decompensation when there is a concomitant need for secondary IOL fixation.

METHODS

Clinical data collected from 10 eyes of 9 patients with bullous keratopathy (BK) who underwent combined UT-DSAEK and SSF-Carlevale IOL implantation in a single procedure were retrospectively analyzed. Anterior chamber IOL (4 cases), aphakia (4 cases, 1 of which associated with PEX), and previous trauma (2 cases) were the conditions responsible for BK. Corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), central corneal thickness (CCT), graft thickness (GT) and complications were recorded over a 12-month follow-up period.

RESULTS

In 90% (9/10) of eyes graft clarity was maintained during follow-up. The mean CDVA improved significantly (p < 0.0001) from 1.78 ± 0.76 logMAR preoperatively to 0.53 ± 0.3 logMAR at 12 months. ECD on average decreased from 2575 ± 125.3 cells/mm2 (donor tissue) to 1697 ± 133.3 cells/mm2 in 12 months. The mean CCT decreased from 870 ± 200 µm to 650 µm ± 9 at 12 months (ANOVA, p = 0.0005).

CONCLUSIONS

Combined UT-DSAEK and SSF-Carlevale IOL implantation was associated with good corneal graft survival and IOP control, with few complications. These findings suggest that this surgical approach is a practical option for patients requiring both treatment for corneal endothelial dysfunction and secondary IOL implantation.

Temporary Pupil Occlusion and Retrolenticular Air Bubble Injection for Descemet Membrane Endothelial Keratoplasty in Vitrectomized Unicameral Eyes

PURPOSE

The aim of this study was to describe a surgical method that can be easily and safely performed during Descemet membrane endothelial keratoplasty in patients who had previously undergone pars plana vitrectomy with transscleral fixation of the intraocular lens.

METHODS

This report reviewed 2 Descemet membrane endothelial keratoplasty procedures performed in patients with vitrectomized unicameral eyes. The proposed technique is characterized by the temporary suture of the pupillary aperture to block the forward flow of vitreous humor and prevent the abrupt loss of air tamponade due to backward movement of the air bubble into the vitreous cavity. At the same time, another air bubble is injected behind the scleral-fixated intraocular lens to induce forward movement of the iris-intraocular lens diaphragm through buoyancy. Thus, the depth of the anterior chamber is reduced, allowing easier unscrolling of the Descemet membrane endothelial keratoplasty lenticule.

RESULTS

Pupil closure and buoyancy of the air bubble allow the anterior chamber to be separated from the inflow of vitreous cavity fluid and maintained adequately shallow. During the keratoplasty, the graft is then easily unscrolled without the support of the capsular diaphragm. Postoperatively, the air bubble is maintained in the anterior chamber for a sufficient period. Nd:YAG laser suture lysis is performed after complete absorption of the air bubble during outpatient follow-up.

CONCLUSIONS

Temporary pupil occlusion and retrolenticular air bubble injection provide a stable surgical approach in challenging cases of postvitrectomized unicameral eyes.

Concomitant sutureless scleral fixation of intraocular lens with keratoplasty: Review of surgical techniques

Sutureless scleral fixation of intraocular lens (sSFIOL) is a commonly employed method of optical rehabilitation of aphakic patients with deficient capsular support, and corneal transplant surgeries can be simultaneously combined with sSFIOL to handle aphakic corneal opacities. A single-stage procedure circumvents the need for repeat intraocular procedures and carries lower risk of graft endothelial damage, endophthalmitis, and macular edema associated with sequential surgeries. However, it mandates surgical expertise and increases the chances of postoperative inflammation. A basket of options is available with the corneal surgeons regarding the manner of host and donor preparation as well as the approaches to scleral fixation and certain intraoperative modifications along with postoperative vigilance may enhance the surgical outcomes. Most of the studies pertaining to keratoplasty with sSFIOL categorize to case reports/series, surgical techniques, and retrospective studies with very limited prospective data available currently. The purpose of the present review is to consolidate all available literature on concomitant sSFIOLs and keratoplasty procedures.

Endodiathermal Tautening of Floppy or Irregular Iris in Endothelial Keratoplasty (Iridodiathermy)

ABSTRACT

Floppy or irregular irides may be seen during endothelial keratoplasty in complex cases or in eyes with damaged irides and may cause uneven air fill, retro-pupillary air escape, anterior bowing of iris, forward movement of lens-iris diaphragm, shallowing of anterior chamber (AC), bellowing and floppiness of iris, uneven AC depth, difficulty in inserting and opening graft, iris trauma, intraoperative bleeding, and iridodialysis. We present a technique of iridodiathermy for tautening and flattening such irides. With continuous irrigation using AC maintainer, the bipolar endodiathermy probe tip is applied in localized spots to midperipheral iris in the affected area with power and duration adjusted to induce mild localized shrinkage and tightening of iris stroma. Such iris tautening decreases its floppiness and prevents anterior bowing, excessive mobility, irido-corneal touch, and peripheral anterior synechiae formation. It provides a stable AC with regular depth and improved, uniform, and nonmigratory air fill, thus decreasing intraoperative challenges.

Scleral fixation of intraocular lenses

PURPOSE OF REVIEW

To review current, effective and more popular techniques for scleral fixation of intraocular lens (IOLs) and IOL-capsular bag complex.

RECENT FINDINGS

Scleral fixation of IOLs became popular, originally with sutured scleral fixated IOLs and later the Scharioth technique of intrascleral haptic fixation. This was further developed as the Glued IOL technique which enjoys widespread adoption all over the world. Recently the Yamane technique has also become popular and is being widely adopted as well.

SUMMARY

Scleral fixated IOLs have evolved in the last 2 decades with technical modifications, extended indications and improvised instrumentation. Though sutured and sutureless techniques have been growing equally, the sutureless scleral fixation techniques have attracted special interest. Reduced suture-related complications, technical ease and high-quality functional outcomes may be possible reasons. Sutureless capsular bag fixation also has distinct advantages.

Double-infusion cannula technique for glued fixation of intraocular lens with endothelial keratoplasty

OBJECTIVE

To describe double-infusion cannula technique (DICT) that involves the placement of 2 infusion cannulas in a combined surgical approach of glued intrascleral haptic fixation of intraocular lens (glued IOL) with endothelial keratoplasty (EK) in patients with aphakic bullous keratopathy.

DESIGN

Prospective, single-centre, interventional study.

PARTICIPANTS

Five eyes of 5 patients.

METHODS

The first cannula placed for fluid infusion at pars plana stabilises the globe and facilitates vitrectomy with the glued IOL procedure. Secondary IOL fixation compartmentalises the eye into anterior and posterior chamber and a continuous posterior fluid infusion prevents globe collapse in an already vitrectomized eye. The second cannula is placed at the level of limbus for pressurised air infusion that facilitates an EK procedure. When the donor graft is being unfolded, air infusion is stopped and fluid from the posterior infusion pushes up the iris IOL diaphragm and facilitates graft unfolding.

RESULTS

The mean follow-up was 14 ± 5 months (range 9-21 months). The donor age ranged from 35-57 years, and the mean percentage of endothelial cell loss calculated at 9 months follow-up was 27.32% ± 3.65%. The mean preoperative and postoperative best-corrected visual acuity was 1.02 ± 0.164 and 0.276 ± 0.173 logMAR, respectively (p = 0.000). No incidence of primary graft failure, graft rejection, or retinal detachment was reported during the entire follow-up period in any of the eyes.

CONCLUSION

DICT prevents hypotony and intraoperative pressure fluctuations, assists graft unrolling, promotes adherence to the recipient bed tissue, and prevents seepage of air into the vitreous cavity and loss of air tamponade in the anterior chamber.

Use of Pressurized Air Infusion For Pre Descemet's Endothelial Keratoplasty (PDEK) - The Air Pump Assisted PDEK Technique

Purpose:

To assess the advantages offered by the air pump assisted PDEK technique that utilizes pressurized Anterior Chamber (AC) air infusion.

Methods:

Pressurized air infusion was provided through an anterior chamber maintainer connected to the fluid air exchange system of a posterior vitrectomy machine during surgery.

Results:

Pressurized air infusion within the AC helped perform Descemetorhexis, prevented bleeding during Peripheral Iridectomy (PI) and synechiolysis, prevented oozing of blood from peripheral corneal neovascularization into the AC and thus helped maintain a non-fibrinous AC environment. In addition, it helped in precise graft manipulation, centration, edge unfolding and unwrinkling after it was floated against the stroma as well as faster graft adhesion. It also prevented AC depth fluctuations during intra-cameral maneuvers and prevented intra-operative as well as post-operative graft detachment.

Conclusions:

This technique makes several steps of surgery easier and improves graft adhesion.

Glued intrascleral haptic fixation of an intraocular lens

Glued intrascleral haptic fixation of an intraocular lens (glued IOL) has evolved as a technique with various modifications that are adopted and practiced by several surgeons. With adequate and appropriate haptic tuck, glued IOL imparts a stable IOL fixation and is a secured method of secondary IOL placement with no pseudophacodonesis.

Young donor-graft assisted endothelial keratoplasty (PDEK/DMEK) with epithelial debridement for chronic pseudophakic bullous keratopathy

OBJECTIVE

The aim of this study was to describe the applicability and report visual outcomes for the treatment of subepithelial fibrosis and anterior stromal scarring in cases of chronic pseudophakic bullous keratopathy (PBK) with epithelial debridement and endothelial keratoplasty (EK) (pre-Descemet endothelial keratoplasty [PDEK]; Descemet membrane endothelial keratoplasty [(DMEK]) using young donor tissue.

DESIGN

Prospective, single-centre, interventional study.

PARTICIPANTS

6 cases with chronic PBK (> 1 year duration).

METHODS

Case 1 underwent PDEK with glued intraocular lens (IOL) as a single-stage procedure, whereas cases 2 and 3 underwent glued IOL followed by DMEK and PDEK, respectively, as a second-stage procedure. Cases 4 and 6 underwent PDEK, whereas case 5 underwent DMEK. Epithelial debridement was performed in all cases at the time of EK, and young donor grafts were used. The main outcome measures were best spectacle-corrected visual acuity, clearance of corneal scar and haze, central corneal thickness (CCT), specular microscopy, and endothelial cell count (ECC).

RESULTS

Postoperatively, all cases demonstrated significant improvement in visual acuity. The mean value of depth of subepithelial haze was 121±71.7 µm and 25.3 ± 19.8 µm in the preoperative and postoperative periods, respectively (p = 0.028). At the 1-month follow-up, the mean preoperative CCT of 676 ± 92.7 µm was reduced to 534.6 ± 21.1µm. At the 6-month follow-up, the mean ECC loss resulting from the procedure was 36.5 ± 10.4%.

CONCLUSIONS

EK with epithelial debridement performed for the treatment of chronic PBK resulted in significantly improved visual acuity to a functional level, with the clearance of subepithelial fibrosis and anterior stromal scar, in most patients.

Intrascleral IOL Fixation

Intrascleral sutureless intraocular lens (IOL) fixation utilizes direct haptic fixation within the sclera in eyes with deficient capsular support. This has advantages of long-term stability, good control of tilt and decentration, and lesser pseudophakodonesis. This review summarizes various techniques for intrascleral haptic fixation, results, complications, adaptations in special situations, modifications of the technique, combination surgeries, and intrascleral capsular bag fixation techniques (glued capsular hook).

Glued Intrascleral Fixation of Intraocular Lens With Pupilloplasty and Pre-Descemet Endothelial Keratoplasty: A Triple Procedure

PURPOSE

To describe a surgical approach of glue-assisted intrascleral fixation of an intraocular lens (IOL) with pupilloplasty and pre-Descemet endothelial keratoplasty as a single-stage procedure.

METHODS

Glue-assisted intrascleral fixation of an IOL is performed initially because it helps to secure the IOL fixation, followed by pupilloplasty that imparts stability to the anterior chamber and prevents air diversion into the vitreous cavity, thereby facilitating the pre-Descemet endothelial keratoplasty procedure that is performed to complete the surgical repair.

RESULTS

The procedure was performed in 5 eyes of 5 patients, and the donor age ranged from 9 months to 65 years. There was a significant change in the uncorrected (P = 0.034) and corrected (P = 0.043) distance visual acuities in the postoperative period. The mean graft size was 7.6 ± 0.4 mm (range, 7-8 mm). The mean preoperative and postoperative specular endothelial counts were 2788 ± 204 cells per square millimeter and 1898 ± 90 cells per square millimeter, respectively. No incidence of primary graft failure or graft rejection during the entire follow-up period was reported in any of the eyes.

CONCLUSIONS

The combined procedure serves as an effective method in select cases of endothelial decompensation that require a secondary IOL implantation or an IOL exchange with good postoperative results.