Systematic Review and Meta-Analysis of Clinical Outcomes of Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty for Keratoconus

Purpose To conduct a systematic review and meta‐analysis on the levels of oxidative stress markers and antioxidants in keratoconus compared to healthy subject. Method The PubMed, Cochrane Library, Embase, Science Direct and Google Scholar databases were searched on 1st June 2020 for studies reporting oxidative and antioxidative stress markers in keratoconus and healthy controls. Main meta‐analysis was stratified by type of biomarkers, type of samples (tears, cornea, aqueous humour and blood) and type of corneal samples (stromal cells, epithelium and endothelium). Results We included 36 articles, for a total of 1328 keratoconus patients and 1208 healthy controls. There is an overall increase in oxidative stress markers in keratoconus compared with healthy controls (standard mean deviation (SMD) = 0.94, 95% confidence interval (95% CI) 0.55–1.33), with a significant increase in reactive oxygen and nitrogen species (1.09, 0.41–1.78) and malondialdehyde (1.78, 0.83–2.73). There is an overall decrease in antioxidants in keratoconus compared with healthy controls (−0.63, −0.89 to −0.36), with a significant decrease in total antioxidant capacity/status (−1.65, −2.88 to −0.43), aldehyde/NADPH dehydrogenase (−0.77, −1.38 to −0.17), lactoferrin/transferrin/albumin (−1.92, −2.96 to −0.89) and selenium/zinc (−1.42, −2.23 to −0.61). Oxidative stress markers were higher in tears and in cornea of keratoconus than in aqueous humour, and antioxidants were decreased in tears, aqueous humour and blood without difference between sample type. Oxidative stress markers increased in stromal cells and antioxidants decreased in endothelium. Conclusion Oxidative stress markers and antioxidants were dysregulated in keratoconus, involving an imbalance of redox homeostasis in tears, cornea, aqueous humour and blood.

show abstract

“…2018; Song et al. 2019). KC seems to be a multifactorial disease associated with environmental factors, such as atopy (Shajari et al.…”

Section: Introductionmentioning

confidence: 99%

Oxidative and antioxidative stress markers in keratoconus: a systematic review and meta‐analysis

Navel

Malecaze

Pereira

et al. 2020

Acta Ophthalmologica

View full text Add to dashboard Cite

show abstract

“…The refractive cylinder changed from −8.40 ± 4.12 D pre-operatively to −2.86 ± 1.65 D 2 years after surgery ( P < 0.001). The average reported refractive cylinder after DALK for keratoconus may vary among studies between 2.50 and 5.00 D ( 2 , 23 , 24 ). For the moderate and severe keratoconus, the reported post-DALK astigmatism is around 3.50 D but may reach up to 10.00 D ( 11 ).…”

Section: Discussionmentioning

confidence: 99%

A New Pre-descemetic Corneal Ring (Neoring) in Deep Anterior Lamellar Keratoplasty for Moderate-Advanced Keratoconus: A Pilot 2-Year Long-Term Follow-Up Study

et al. 2021

View full text Add to dashboard Cite

Purpose: To assess the outcomes of implanting a new polymethylmethacrylate (PMMA) ring (Neoring; AJL Ophthalmic) in pre-descemet deep anterior lamellar keratoplasty (PD-DALK) procedure for moderate-advanced keratoconus.Methods: This prospective study included 10 eyes of 10 patients with moderate-advanced keratoconus who underwent PD-DALK with Neoring implantation. Neoring was implanted in a pre-descemetic pocket. The post-operative examination included refraction, corrected distance visual acuity (CDVA), corneal tomography, and endothelial cell density (ECD). The root mean squares (RMSs) for coma-like aberrations and spherical aberration were evaluated for a pupil size of 4.5 mm. The junctional graft (Tg) and host (Th) thicknesses were measured. The post-operative follow-up was 24 months.Results: Post-operative CDVA was 0.82 ± 0.14 (decimal scale), 100% of the eyes achieved a CDVA of 0.7 (decimal scale). The refractive cylinder was −2.86 ± 1.65 2-years after surgery. No eyes had a post-operative refractive cylinder ≥5.00 D and in five eyes (50%), it was ≤2.50 D. At the last visit, the mean keratometry was 45.64 ± 1.96 D, the RMS for coma-like aberrations was 0.30 ± 0.15 μm and spherical aberration was 0.22 ± 0.09. The mean ECD remains without changes over the follow-up (P = 0.07). At the last visit, Tg and Th were 679.9 ± 39.0 and 634.8 ± 41.2 μm, respectively. The thickness of the complex (host-Neoring) was 740.6 ± 35.6 μm. In all cases, this thickness was thicker than Tg.Conclusion: The results of this study suggest that PD-DALK along Neoring implantation is a viable, effective, and safe option to optimize the post-operative results for moderate-severe keratoconus.

show abstract

“…In ALK, the anterior diseased layers of the recipient's cornea are replaced (15); in EK, a posterior lamellar keratoplasty technique, the diseased corneal endothelium of the recipient is replaced (16). These two "lamellar" keratoplasty techniques, have been shown to achieve lower risks of immunological graft rejection and improved graft survival rates (9,(17)(18)(19)(20)(21)(22). With these advantages, lamellar keratoplasties have thus gradually been adopted as preferred corneal transplantation techniques in various institutions (2,9,13).…”

Section: Introductionmentioning

confidence: 99%

“…In ALK, the recipient's own Descemet membrane (DM) and corneal endothelium are retained. As endothelial graft rejection is the most commonly encountered form of immunological rejection following corneal transplantations, the observed rates of graft rejection in ALK are therefore significantly lower compared to PKP or EK (9,19,22,44). Despite being less common, immunological rejections, namely epithelial, subepithelial, or stromal rejections, still do occur following ALK (22).…”

Section: Introductionmentioning

confidence: 99%

The Effects of Donor-Recipient Age and Sex Compatibility in the Outcomes of Deep Anterior Lamellar Keratoplasties

et al. 2022

View full text Add to dashboard Cite

PurposeCorneal transplantations are the commonest allogenic transplant surgeries performed worldwide. Transplantable grade donor cornea is a finite resource. There is thus an impetus for eye banks to optimize the use of each harvested cornea, and clinicians to minimize the risks of graft rejection and failure. With better survival and lower rejection rates, anterior lamellar keratoplasty has gained popularity as an alternative technique to full-thickness penetrating keratoplasty, for the treatment of corneal stromal diseases. This study evaluated the effects of donor-recipient age- and sex-matching on the outcomes of eyes that had undergone deep anterior lamellar keratoplasty (DALK) surgeries.DesignObservational cross-sectional study (national corneal graft registry data).SubjectsAll DALK surgeries performed in a tertiary ophthalmic hospital over an 11-year period.MethodsTo analyse the effects of donor-recipient sex-matching, transplantations were classified as “presumed H-Y incompatible” (male donor to female recipient) or “presumed H-Y compatible” (all other donor-recipient sex combinations). For age-matching, differences in donor and recipient ages were calculated. Cox proportional hazards regressions were used to evaluate the influence of donor-recipient sex-matching and age-matching on graft failure and rejection.Main Outcome MeasuresRates of graft failure and rejection within each group.Results401 eyes were included. 271 (67.6%) transplants were presumed H-Y compatible. 29 (7.2%) grafts failed and 9 (2.2%) grafts rejected. There were trends of lower hazard ratios (HRs) in graft failure and rejection in the presumed H-Y compatible group [HRs: 0.59 (95% CI 0.20–1.77, p = 0.34) and 0.93 (95% CI 0.22–3.89, p = 0.926), respectively]. Median difference in age between recipients and donors was 15.0 years (IQR −2.8–34.3). The HRs of graft failure and rejection were not influenced by donor-recipient age [HRs per 1-year increase in age difference: 0.995 (95% CI 0.98–1.01, p = 0.483) and 1.01 (95% CI 0.99–1.03, p = 0.394), respectively].ConclusionIn eyes that had undergone DALK surgeries, no significant influence of donor-recipient sex- or age-matching on graft rejection and failure was observed. Without strong evidence and the limitations of obtaining sample sizes required for an adequately powered study, the benefits of sex- and age-matching of donors and recipients during graft allocation for DALK surgeries is currently inconclusive.

show abstract

Systematic Review and Meta-Analysis of Clinical Outcomes of Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty for Keratoconus

Cited by 38 publications

References 39 publications

Oxidative and antioxidative stress markers in keratoconus: a systematic review and meta‐analysis

Oxidative and antioxidative stress markers in keratoconus: a systematic review and meta‐analysis

A New Pre-descemetic Corneal Ring (Neoring) in Deep Anterior Lamellar Keratoplasty for Moderate-Advanced Keratoconus: A Pilot 2-Year Long-Term Follow-Up Study

The Effects of Donor-Recipient Age and Sex Compatibility in the Outcomes of Deep Anterior Lamellar Keratoplasties

Contact Info

Product

Resources

About