Effects of Cataract Surgery on Endothelium in Transplanted Corneal Grafts: Comparison of Extracapsular Cataract Extraction and Phacoemulsification for Complicated Cataract after Penetrating Keratoplasty

Combined versus sequential penetrating keratoplasty and cataract surgery for herpes simplex keratitis: a retrospective study

Purpose

To compare the surgical outcomes of combined penetrating keratoplasty (PK) and cataract surgery with those of sequential surgery (cataract surgery after PK) for herpes simplex keratitis (HSK).

Methods

The medical records of consecutive patients diagnosed with HSK who underwent combined or sequential PK and cataract surgery in active and stable stages between June 2015 and June 2022 were reviewed retrospectively. Complications, graft survival, endothelial cell density (ECD), and final BCVA were compared and analyzed between both surgical methods in each stage.

Results

A total of 171 eyes of 171 patients were enrolled, including active stage (69 combined, 46 sequential) and stable stage (34 combined, 22 sequential). The average follow up was 24.2 ± 15.8 months (range, 3 months - 48 months). The final BCVA had obvious improvement and the postoperative ECD was not different in combined and sequential groups of each stage. In sequential group of active stage, 66.7% of persistent epithelial defects and 50% of HSK recurrence occurred within 3 months after cataract surgery; nevertheless, compared to that in sequential group, capsular rupture (p = 0.021), persistent epithelial defects (p = 0.027), and HSK recurrence (p = 0.035) occurred more frequently in combined group, leading to a lower graft survival rate (p = 0.045); at the last visit, 46.4 and 67.4% of grafts remained clear in combined and sequential groups, respectively. By contrary, 82.4 and 50.0% of grafts remained clear in stable stages of combined and sequential groups at the last visit, respectively, and a higher graft survival rate was observed in combined group (p = 0.030).

Conclusion

Although the postoperative ECD is not different between two surgical groups in each stage, sequential surgery in active stage of HSK seems to have advantages in less complications and higher graft survival rate, whereas combined surgery in stable stage has a better outcome than that in sequential surgery.

An Overview of Corneal Transplantation in the Past Decade

The cornea is a transparent avascular structure located in the front of the eye that refracts light entering the eyes and also serves as a barrier between the outside world and the internal contents of the eye. Like every other body part, the cornea may suffer insult from trauma, infection, and inflammation. In the case of trauma, a prior infection that left a scar, or conditions such as keratoconus that warrant the removal of all or part of the cornea (keratoplasty), it is important to use healthy donor corneal tissues and cells that can replace the damaged cornea. The types of cornea transplant techniques employed currently include: penetrating keratoplasty, endothelial keratoplasty (EK), and artificial cornea transplant. Postoperative failure acutely or after years can result after a cornea transplant and may require a repeat transplant. This minireview briefly examines the various types of corneal transplant methodologies, indications, contraindications, presurgical protocols, sources of cornea transplant material, wound healing after surgery complications, co-morbidities, and the effect of COVID-19 in corneal transplant surgery.

Outcomes of Pseudophakic, Phakic, and Triple DMEK

PURPOSE

To evaluate the outcome of phakic and pseudophakic eyes treated by Descemet membrane endothelial keratoplasty (DMEK) versus DMEK combined with cataract surgery (triple DMEK).

METHODS

Retrospective cohort study based on the prospective Cologne DMEK data base. This study is a single-center analysis of 62 eyes undergoing phakic (age mean ± SD 52 ± 6.43), 518 eyes undergoing pseudophakic (73.5 ± 8.57), and 557 eyes undergoing triple DMEK (67.93 ± 8.57). Outcome measures were changes in best spectacle-corrected visual acuity (BSCVA), central corneal thickness, endothelial cell density (ECD), rebubbling rates within the first year after surgery, and the need for cataract surgery within the first 2 years after phakic DMEK.

RESULTS

The preoperative BSCVA (mean ± SD; logarithm of the minimum angle of resolution) was 0.30 ± 0.22 in the phakic, 0.63 ± 0.45 in the pseudophakic, and 0.44 ± 0.30 in the triple DMEK group (P < 0.001), which changed to 0.09 ± 0.12, 0.14 ± 0.1, and 0.1 ± 0.1 (P < 0.001) 1 year after surgery, respectively. There was no difference in central corneal thickness (P = 0.929) and endothelial cell density (P = 0.606) 1 year postoperatively. Rebubbling rates in DMEK using SF6 20% for anterior chamber tamponade were not significantly different (P = 0.839). After phakic DMEK, 40% of eyes underwent cataract surgery within the second year. However, there was a high loss to follow-up in this group.

CONCLUSIONS

Phakic and triple DMEK procedures tend to have a better 1-year BSCVA than pseudophakic DMEK, with no differences in all other parameters analyzed. However, patients from the pseudophakic DMEK group were older and already had worse BSCVA before surgery.

Phacoemulsification After Descemet Membrane Endothelial Keratoplasty: Incidence and Influence on Endothelial Cell Density

PURPOSE

To analyze the incidence of cataract extraction after Descemet membrane endothelial keratoplasty (DMEK) in phakic eyes and to evaluate the effect of phacoemulsification after DMEK on the donor endothelial cell density (ECD).

METHODS

The clinical data of phakic patients with DMEK were examined. From this cohort, all patients who subsequently underwent phacoemulsification after DMEK were reviewed. Data from a prospectively collected dataset were analyzed, including demographic profile, ECD, corrected distance visual acuity (CDVA), central corneal thickness (CCT), and complications.

RESULTS

From a series of 261 phakic patients with DMEK, 35 eyes (13.4%) required cataract surgery within the mean follow-up period of 54.2 ± 28 months. The mean time from DMEK to phacoemulsification was 18 ± 13 months (range: 3 to 69 months). The probability of cataract extraction after DMEK was 0.06 (95% CI: 0.03 to 0.09) at 1 year and 0.17 (95% CI: 0.12 to 0.22) at 10 years, respectively. ECD decreased from 1,314 ± 524 cells/mm² before phacoemulsification to 1,167 ± 443 cells/mm² (-11%) at 1 to 6 months postoperatively (P = .333). CDVA improved from 0.27 ± 0.13 logMAR preoperatively to 0.07 ± 0.12 logMAR at 1 to 6 months postoperatively. CCT before phacoemulsification was 532 ± 46 µm and remained stable at 539 ± 56 µm at 1 to 6 months after phacoemulsification. Phacoemulsification did not elicit DMEK graft detachment in any of the eyes studied.

CONCLUSIONS

The incidence and 10-year projection of cataract extraction in phakic eyes with DMEK was relatively low. Phacoemulsification after DMEK provided excellent CDVA outcomes, did not induce graft detachment, and was associated with an acceptable decrease in ECD. [J Refract Surg. 2021;37(2):119-125.].

The effect of phacoemulsification fluid flow on the corneal endothelium: An experimental study in rabbit eyes

PURPOSE

To quantify the damage to the corneal endothelium from the flow of balanced salt solution during phacoemulsification.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Experimental Study.

METHODS

Twelve New Zealand white rabbits received bilateral surgery. Six eyes served as controls with no irrigation (incision only). In 18 eyes, the Intrepid Balanced tip of the Centurion (Alcon) Ozil handpiece was inserted into the anterior chamber for continuous irrigation at 50mL/minute with either 250 mL or 500 mL of balanced salt solution (BSS). After euthanasia and enucleation, the corneas were removed, stained with trypan blue/alizarin red, and photographed in a standardized manner (X400 photographs from 5 specific areas, and 1 overview photograph from each corneal button). The ImageJ program was used to evaluate cell damage and loss in the photographs obtained from each cornea.

RESULTS

Analysis of the X400 photographs showed no statistical differences between control, 250 mL, and 500 mL groups in the percentage of intact, damaged, or lost cells (P= 0.896, 0.851, and 0.972 respectively). For the overview photos, the differences in areas of intact and damaged cells among the groups were statistically significant, likely due to the peripheral areas of damage related to touches between the phaco tip and the endothelium during irrigation.

CONCLUSION

The volume of BSS flow alone does not appear to be a major contributing source of endothelial cell damage and loss, providing further insight on mechanisms of corneal endothelium damage during phacoemulsification.

Review of anaesthetic management for cataract surgery in transplant recipients

The prevalence of transplantation is on the increase worldwide. Corneal transplantation is the most common form of human donor transplantation. Transplantation of other organs and bone marrow is established treatment for various end-organ failure and many haematological conditions, respectively. Success and survival of these patients have increased with advances in immunosuppression. Unfortunately, these patients are susceptible to cataract formation as a consequence of immunosuppressive therapy and accelerated progression of several diseases. Topical anaesthesia and regional ophthalmic blocks are ideal for cataract surgery in cooperative adults. General anaesthesia may be required in children, for extremely anxious or claustrophobic adults and for complex surgery such as simultaneous cataract and corneal transplantation. The perioperative anaesthetic management of cataract surgery in a transplant recipient is no different to a standard technique in a healthy adult, but additional challenges are posed by the underlying pathology necessitating transplantation, function of the transplanted organ, physiological and pharmacological problems of allograft denervation, side-effects of immunosuppression, risk of infection and potential for rejection. This narrative review summarises optimal anaesthetic management in transplant recipients undergoing cataract surgery.

Secondary Intraocular Lens Implantation After Simultaneous Penetrating Keratoplasty and Cataract Extraction for Coexisting Corneal and Lens Opacities

PURPOSE

To report the results of a new approach to the 2-stage surgical management of coexisting visually significant corneal opacities and cataract.

METHODS

A retrospective analysis of eyes with corneal opacities and cataract that were surgically treated with simultaneous penetrating keratoplasty and cataract surgery, followed by secondary intraocular lens (IOL) implantation after removal of corneal sutures, was conducted. The parameters used for assessment were the following: mean percentage of graft endothelial cell loss after IOL implantation, deviation of the postoperative mean spherical equivalent from the target refraction, and mean uncorrected distance visual acuity (UDVA).

RESULTS

Twenty-nine eyes were included in the study. The mean baseline UDVA was 1.94 ± 0.46, and the mean baseline best-corrected distance visual acuity was 1.56 ± 0.42. The mean interval between the 2 surgical interventions was 13.3 ± 2.2 months. Just before secondary IOL implantation, the mean endothelial cell density was 2198 ± 311 cells. The mean percentage of corneal endothelial cell loss was 7.3% at 6 months after IOL implantation (P = 0.16). Before IOL implantation, the mean spherical equivalent was +11.75 ± 3.38 D. After IOL implantation, the mean spherical equivalent improved to -0.19 ± 0.93 D (P = 0.003) at 6 months. The mean UDVA improved to 0.34 ± 0.18 (P = 0.017), whereas the mean corrected distance visual acuity improved to 0.18 ± 0.29 at 6 months (P = 0.016). All grafted corneas maintained their clarity until the final follow-up visit.

CONCLUSIONS

Postponing IOL implantation some months after simultaneous penetrating keratoplasty and cataract extraction has a negligible effect on the corneal graft endothelium and achieves near postoperative target refraction with significant improvement in UDVA.

Cataract surgery and lens implantation

PURPOSE OF REVIEW

This review aims to introduce recent updates in cataract surgery and lens implantation.

RECENT FINDINGS

Compared to phacoemulsification, femtosecond laser-assisted cataract surgery (FLACS) may offer benefit for cataract patients with other complicated ocular diseases, such as corneal disease and vitreous abnormalities. Meanwhile, several types of novel intraocular lenses (IOLs) have been introduced to the market, and each of them has particular features in improving patients' visual acuity. In addition, based on a series of studies, multifocal IOL is superior to monofocal IOL when it comes to providing a better visual correction at different distances. Furthermore, a research group has introduced a new approach for cataract surgery - all laser surgery (FLACS band with nanolaser emulsification), which can effectively reduce iatrogenic trauma to the cornea. Also, a novel technique designed for children can lessen damage from cataract surgery.

SUMMARY

Based on previous studies, we summarize the new proceedings in FLACS and the indications for applying multifocal or toric IOL. In addition, we briefly introduce a new approach to cataract surgery - all laser surgery (FLACS band with nanolaser emulsification), and a less invasive surgical procedure used in pediatric cataract patients.

Femtosecond laser-assisted cataract surgery after penetrating keratoplasty: a case report

BACKGROUND

Cataract surgery after penetratingkeratoplasty (PKP) is often challenging due to changes in the integrity of the cornea caused by PKP. For example, corneal endothelial cell (CEC) loss and corneal edema commonly occur after traditional phacoemulsification cataract surgery in patients that previously had successful PKP. Recent studies have reported that femtosecond laser-assisted cataract surgery (FLACS) significantly reduces the need for ultrasound energy minimizing mechanical damage to the cornea and results in a reduction of CEC loss and corneal edema.

CASE PRESENTATION

We report a case in which FLACS was used in a patient with previous PKP.

CONCLUSION

This case supports the suggestion that the use of the femtosecond laser improves the surgical outcome of cataract surgery after PKP. This improvement may be result of the precise incision, controlled capsulorhexis, and reduced lens fragmentation experienced with the femtosecond laser which helps to reduce potential complications of cataract surgery after PKP.