Penetrating keratoplasty for keratoconus: complications and long-term success

Clinical Outcomes of Iris-Supported Phakic Toric Intraocular Lenses in Corneal Ectasia

INTRODUCTION

Our aim was to evaluate the visual and refractive outcomes of iris-fixated phakic toric intraocular lenses (IOLs) for visual rehabilitation in eyes with stable corneal ectasia.

METHODS

We conducted a study looking at the clinical outcomes of iris-fixated toric IOLs (Artisan) in 33 eyes of 27 patients diagnosed with mild-to-moderate corneal ectasia at a single center (Queen Victoria Hospital, East Grinstead, UK). The main outcome measures were functional improvement [accuracy of post-operative spherical equivalent (SE), astigmatic correction, topographic parameters, uncorrected and corrected distance visual acuity (UCVA, CDVA)] and safety of the procedure: endothelial cell count and intra- and post-operative complications.

RESULTS

Eighteen males and nine females of mean age 38.85 were included in the study with a mean follow-up of 18 months. All patients had ectasia due to keratoconus except one with post-refractive laser ectasia. Twelve patients had crosslinking, eight had intracorneal rings, and eight had previous keratoplasties. Mean pre-operative logMAR UCVA was 0.75 ± 0.35 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative logMAR CDVA was 0.16 ± 0.17 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative (SE) was - 3.5 ± 3.9 improving to - 2.75 ± 1.39 (p = 0.000) with up to 36-42 months of follow-up. The mean value of endothelial cell density in the overall sample was 2252.54 ± 473.24 cells/mm2 pre-operatively and 2126.75 ± 365.21 cells/mm2 at 24-36 months of follow-up visit. Two patients have intra-operative hyphemia secondary to iris prolapse.

CONCLUSIONS

Implantation of iris-fixated phakic toric IOLs has shown high efficacy and safety in patients with mild-to-moderate astigmatism in corneal ectasia.

Risk factors for corneal graft rejection after penetrating keratoplasty for keratoconus

PURPOSE

To evaluate the association between donor-related factors and the risk of rejection in patients undergoing penetrating keratoplasty (PKP) for keratoconus.

METHODS

A retrospective review was performed of keratoconus patients with no corneal neovascularization who underwent PKP from November 2014 to December 2016 and completed at least two years of follow-up. Preoperative, donor, operative, and postoperative data were collected and analyzed to identify factors leading to corneal graft rejection.

RESULTS

A total of 201 eyes (of 201 patients) that underwent PKP for keratoconus were included. Of these, 22.9% (95% CI 17.6-29.2%) had an episode of graft rejection. The overall graft survival rate was 98.5%. Receipts with a history of corneal transplant in the fellow eye (IRR 1.69, 95% CI 1.01, 2.80; p = 0.044) and those with postoperative stromal neovascularization (IRR 2.51, 95% CI 1.49, 4.21; p = 0.001) had a significantly higher incidence of rejection than those without these features. In univariate analysis, death-to-surgery time and death-to-excision time (DET) showed a weak association with graft rejection (p 0.05 and 0.08 respectively); However, in the multivariable analysis, this significance was lost. Grafts with a death-to-excision time (DET) greater than 8 h had a 0.53X lower risk of rejection compared with grafts with DET within 8 h or less (p = 0.05). Rejection was higher in patients receiving grafts with a preservation time within 7 days or less compared with preservation time greater than 7 days (30.6% vs. 21.2%, respectively, p = 0.291).

CONCLUSION

In the multivariable analysis, none of the donor-related factors were significantly associated with graft rejection; however, short death-to-surgery time may be associated with rejection after PKP. Recipients with a history of PKP in the fellow eye and those who developed corneal neovascularization were also at increased risk of developing rejection after keratoplasty.

Recurrent Keratoconus: Corneal Transplants for Keratoconus Develop Tomographic Ectatic Changes

PURPOSE

The purpose of this study was to evaluate postoperative Scheimpflug imaging changes during the first 5 years after penetrating keratoplasty (PK) in patients with keratoconus (KC).

METHODS

This retrospective, interventional case series includes 31 eyes of 31 patients who underwent their first PK with a history of KC. Postoperative Scheimpflug imaging was performed 3 months after the removal of the last suture (baseline) and then repeated 3 and 5 years after the PK. Demographic data, donor and host trephination diameter, and Scheimpflug imaging (Pentacam HR, Oculus, Germany) parameters indicative of ectasia were analyzed to evaluate postoperative graft changes that occur after PK.

RESULTS

The maximal keratometry (Kmax) progressed significantly between baseline (53.5 ± 6.1 D) and postoperative year 3 and year 5 [56.5 ± 6.1 diopter (D) and 58.8 ± 7.9 D, P < 0.001]. Significant changes were also observed for the anterior best fit sphere and posterior best fit sphere ( P < 0.001 for 3 and 5 years compared with baseline). Kmax increased by at least 2 Ds for 74.2% of patients and up to 7 Ds or more for 25.8% of the patients. A significant inverse correlation was observed for host trephine size and progression of Kmax (r = -0.52, P = 0.01), which indicated that larger host trephination size was associated with a smaller increase in postoperative Kmax.

CONCLUSIONS

Tomographic graft changes indicative of ectasia were observed within 3 to 5 years after PK in patients with KC. These changes were observed more frequently and sooner after corneal transplants than previously reported.

Low-intensity low-frequency ultrasound mediates riboflavin delivery during corneal crosslinking

We employed the mechanical effect from 40 kHz ultrasound (US) to improve the delivery of riboflavin into corneal stroma for collagen crosslinking, which can benefit the treatment of keratoconus and other corneal ectasias. Experiments were conducted, first with porcine corneas ex vivo and then with New Zealand white rabbits in vivo, at varying mechanical index (MI) and sonication time. Results showed that 15 min of US applied on the cornea at MI = 0.8 in the presence of 0.5% of riboflavin solution enabled its delivery to deeper corneal stroma. Excessive heat was removed by a cooling setup to negate the thermal effect. The corneal absorption amount and penetration of riboflavin through cornea as detected by fluorotron, as well as the enhancement of corneal stiffness as measured by Young's modulus, were comparable to the conventional approach that requires complete corneal epithelium debridement. Histological analysis revealed minor exfoliation of superficial cell layers of corneal epithelium and loss of ZO-1 tight junctions immediately after US. Full recovery of the corneal epithelium and restoration of tight junctions occurred in 3-4 days. The study shows that low-intensity low-frequency ultrasound (LILF US) is a less invasive alternative to the conventional epithelium-off method for delivering riboflavin into the corneal stroma.

Impact of vaccination on keratoplasty

PURPOSE OF REVIEW

Corneal graft rejection has been reported after coronavirus disease 2019 (COVID-19) vaccination. The purpose of this review is to evaluate the literature regarding corneal graft rejection after vaccination, including rejection rates and risk factors. We aim to create a framework to identify patients who are at higher risk for graft rejection and may warrant consideration of prophylactic interventions.

RECENT FINDINGS

Graft rejection has been reported following administration of mRNA, viral vector, and inactivated whole-virion COVID-19 vaccines. Most cases had additional risk factors associated with rejection. Vaccination increases circulation of proinflammatory cytokines, CD4+ and CD8+ T-cell responses, and antispike neutralizing antibody, all of which may contribute to graft rejection. Two prospective studies have found no relationship between recent vaccination and rejection but 20% of cornea specialists report to have seen a vaccine-associated rejection and 22% recommend delaying vaccination in certain circumstances. Many specialists recommend prophylactic topical corticosteroids before and after vaccination to mitigate rejection risk but there is no evidence to support this practice on a wider scale.

SUMMARY

Our framework identified 96.8% of penetrating keratoplasty patients with vaccine-associated rejection as higher risk. Further research is needed in order to develop evidence-based guidelines.

Risk Factors of Urrets-Zavalia Syndrome after Penetrating Keratoplasty

Objective: The objective of this study was to analyze the clinical features and risk factors of Urrets-Zavalia syndrome (UZS) after penetrating keratoplasty (PKP). Methods: The medical records of 152 patients who underwent PKP at the Department of Ophthalmology, Tongji Hospital, between January 2014 and December 2016 were retrospectively reviewed. UZS was diagnosed based on pre- and post-operative pupillary findings. The relationships among the primary disease, postoperative intraocular pressure (IOP), and the incidence of UZS were statistically analyzed. The pupillary changes during the follow-up period were studied. Results: Among the 152 included patients, 23 were diagnosed with UZS, with an incidence of 15.13%. The primary diseases of the UZS patients were keratoconus (eight cases, 34.78%), viral keratitis (six cases, 26.08%), leukoma (four cases, 17.39%), fungal corneal ulcer (two cases, 8.70%), corneal endothelial decompensation (two cases, 8.70%), and corneal degeneration (one case, 4.35%). The incidence of UZS in keratoconus patients was higher than that in patients with fungal corneal ulcer (42.11% versus 6.25%, p = 0.003); In addition, the transient postoperative high IOP was not significantly related to the incidence of UZS in keratoconus patients in our study (p = 0.319). Twenty-one patients with UZS were followed up for >6 months, seven of whom (33.33%) recovered spontaneously (within the range of 48 days to 1.5 years). Conclusion: In our study, the incidence of UZS after PKP was 15.13%, and 33.33% of these patients recovered spontaneously. UZS may be more likely to occur in patients with keratoconus. Postoperative transient high IOP may increase the incidence of UZS after PKP for keratoconus.

Comparison of manual and femtosecond astigmatic keratotomy in the treatment of postkeratoplasty astigmatism

PURPOSE

To compare the outcomes of femtosecond astigmatic keratotomy (FSAK) and manual astigmatic keratotomy (AK) in treatment of postkeratoplasty astigmatism.

METHODS

A retrospective, comparative, pairwise-matched case series including 150 patients who underwent either FSAK (n = 75) or manual AK (n = 75) for the treatment of astigmatism (>3.00 D) following penetrating keratoplasty or deep anterior lamellar keratoplasty. Pairwise matching for baseline variables (age, visual acuity and astigmatism) was performed.

RESULTS

Mean age was 57.5 ± 16.0 years. The FSAK group had significantly better postoperative best-corrected visual acuity (BCVA) (p = 0.010), uncorrected visual acuity (UCVA) (p = 0.049), corneal astigmatism (p = 0.020) and manifest astigmatism (p < 0.001) compared with the manual AK group. Gain of ≥3 lines in BCVA (logMAR) was seen in five eyes (6.7%) and 21 eyes (28.0%) in manual AK and FSAK, respectively (p = 0.005). Alpins vector analysis showed lower (closer to 0) index of success (0.50 ± 0.24 and 0.79 ± 0.48, p < 0.001) and higher (closer to 1) correction index (0.94 ± 0.45 and 0.74 ± 0.55, p = 0.020) in FSAK compared with manual AK. Corneal and manifest astigmatism improved significantly in both groups, while BCVA and UCVA improved significantly in FSAK only. Repeat AK rate was 32% (24 eyes) in manual AK and 4% (three eyes) in FSAK (p < 0.001). Overcorrection-related re-suturing rate was 0% in manual AK and 8% (six eyes) in FSAK (p = 0.037). There was one microperforation (1.3%) in FSAK, and there were no occurrences of graft dehiscence, infectious keratitis or graft rejection.

CONCLUSIONS

Both manual AK and FSAK were safe and effective in reducing postkeratoplasty astigmatism. FSAK had superior visual and keratometric outcomes compared with manual AK.

"Corneal Plication" for the Management of Progressive Corneal Graft Protrusion in Patients With Keratoconus: a New Technique

PURPOSE

The purpose of this study was to present a new surgical technique, namely corneal plication, for the management of high astigmatism and progressive corneal graft protrusion after penetrating keratoplasty (PKP) for keratoconus.

METHODS

New surgical approach description.

RESULTS

A 61-year-old woman with a history of bilateral keratoconus was referred to our institute for the management of progressive corneal graft protrusion in her left eye 25 years after PKP. On presentation, the uncorrected distance visual acuity in the involved eye was counting fingers, whereas slit-lamp examination revealed a clear graft with a crescentic area of thinning in the inferior host cornea, extending from 4 to 9 o'clock that resulted in significant graft protrusion and astigmatism. We proceeded with a novel surgical approach that included "folding" and suturing the thinned, diseased corneal tissue and thus creating a form of corneal plication. No intraoperative or postoperative complications were observed, and uncorrected distance visual acuity was 0.32 6 months after the operation.

CONCLUSIONS

Corneal graft plication may represent a realistic alternative to more invasive procedures, currently used for the management of this long-term post-PKP complication in patients with keratoconus because it is a nonperforating technique that seems to provide satisfactory anatomical and visual outcomes without the need for any tissue excision or regrafting.

Survey of Rejection Prophylaxis Following Suture Removal in Penetrating Keratoplasty in Germany

BACKGROUND

Penetrating keratoplasty (PK) gets more and more reserved to cases of increasing complexity. In such cases, ocular comorbidities may limit graft survival following PK. A major cause for graft failure is endothelial graft rejection. Suture removal is a known risk factor for graft rejection. Nevertheless, there is no evidence-based regimen for rejection prophylaxis following suture removal. Therefore, a survey of rejection prophylaxis was conducted at 7 German keratoplasty centres.

OBJECTIVE

The aim of the study was documentation of the variability of medicinal aftercare following suture removal in Germany.

METHODS

Seven German keratoplasty centres with the highest numbers for PK were selected. The centres were sent a survey consisting of half-open questions. The centres performed a mean of 140 PK in 2018. The return rate was 100%. The findings were tabulated.

RESULTS

All centres perform a double-running cross-stitch suture for standard PK, as well as a treatment for rejection prophylaxis with topical steroids after suture removal. There are differences in intensity (1 - 5 times daily) and tapering (2 - 20 weeks) of the topical steroids following suture removal. Two centres additionally use systemic steroids for a few days.

DISCUSSION

Rejection prophylaxis following PK is currently poorly standardised and not evidence-based. All included centres perform medical aftercare following suture removal. It is assumed that different treatment strategies show different cost-benefit ratios. In the face of the diversity, a systematic analysis is required to develop an optimised regimen for all patients.

Short-term changes in topometric indices after discontinuation of rigid gas permeable lens wear in keratoconic eyes

Purpose:

To estimate the time taken for topometric indices to stabilize in keratoconic corneas following cessation of habitual RGP contact lens wear.

Methods:

A total of 29 eyes of 20 patients, diagnosed with mild to severe keratoconus were included in this prospective observational study. All patients were experienced RGP contact lens wearers (either conventional RGP or Rose K2 lens) with each patient having used these lenses for at least a year. Corneal topography was performed immediately following discontinuation of habitual contact lens wear at baseline and each of four consecutive visits, 1-week apart.

Results:

An overall reduction in the keratometry and thickness values were noted on tomography immediately following cessation of contact lens wear and these indices increased significantly in the 1^st week (P < 0.001). Consecutive visits following the first visit did not show any significant change in the topometric parameters (P > 0.05). Subgroup analysis revealed a similar trend in eyes with “severe” keratoconus and in eyes fitted with the “three-point touch” philosophy. However, eyes with “mild-moderate” keratoconus and those fitted with “apical clearance” fitting philosophy showed marginal differences even within the 1-week period of lens cessation.

Conclusion:

Maximum changes in keratometry and pachymetry values following discontinuation of RGP lens wear stabilize within the 1^st week of cessation of rigid lens wear in a keratoconic cornea. These changes were more pronounced in patients with severe keratoconus and those with an apical bearing fit. This information would be useful for practitioners to assess the progression of keratoconus in RGP lens users before collagen cross-linking.

Factors Associated With Improvement in Vision Following Femtosecond Astigmatic Keratotomy in Post-Keratoplasty Keratoconus Patients

PURPOSE

To evaluate factors associated with improvement in vision following femtosecond astigmatic keratotomy (FSAK) in patients with keratoconus post-keratoplasty.

DESIGN

Retrospective, interventional case series.

METHODS

The study took place in an institutional setting. This was a retrospective study that included patients with keratoconus who underwent FSAK for astigmatism following penetrating (PKP) or deep anterior lamellar keratoplasty (DALK). Success was defined as improvement in 3 Early Treatment Diabetic Retinopathy Study lines (doubling of the visual angle) of uncorrected distance visual acuity (UDVA) or best spectacle-corrected visual acuity (BSCVA).

RESULTS

A total of 56 eyes in 56 patients with keratoconus were included. Following FSAK, there was a significant improvement in UDVA (1.30 ± 0.49 to 0.87 ± 0.58 logarithm of minimal angle of resolution [logMAR]; P < .001), BSCVA (0.40 ± 0.26 to 0.27 ± 0.29 logMAR; P <.001), and corneal astigmatism (8.69 ± 2.72 to 3.92 ± 2.13 diopter [D]; P < .001). Success was achieved in 60.7% (34/56) of cases, and this group had a higher proportion of previous PKP (73.5% vs 45.5%; P = .03), worse preoperative UDVA (1.42 ± 0.47 vs 1.11 ± 0.47 logMAR; P = .03), and a greater preoperative manifest cylinder (7.56 ± 2.26 vs 5.72 ± 2.12 D; P = .01). In multiple regression analysis, PKP (vs DALK) (odds ratio [OR]: 8.52; P = .009), worse preoperative UDVA (OR: 9.08, P = .02), and greater preoperative cylinder (OR: 1.51; P = .04) were independently associated with success, and, when combined, led to a sensitivity and specificity of 84.6% and 93.8%, respectively, in predicting success. The optimal cutoff predicting success with a preoperative cylinder was a cylinder >6.75 D.

CONCLUSION

Approximately 60% of patients with keratoconus post-keratoplasty experience doubling of the visual angle following FSAK. Patients with previous PKP and a greater cylinder are more likely to benefit from this procedure. Separate nomograms for DALK and PKP patients may be warranted.

Penetrating Keratoplasty for Keratoconus in Vietnamese Patients

BACKGROUND

Keratoconus is an ectatic corneal disorder that can impair the visual acuity. Up to now, penetrating keratoplasty (PK) remains the most common surgical procedure to treat severe keratoconus. In Vietnam, most keratoconus patients come to visit doctor at severe stage and were treated by PK, so we conduct this study.

AIM

To evaluate the results of PK for keratoconus in Vietnamese patients.

METHODS

This was a retrospective study of 31 eyes with keratoconus who underwent PK in VNIO from January 2005 to December 2014.

RESULTS

The average visual acuity was 0.86 ± 0.37 logMAR (20/145). In the group of patients without amblyopia, best spectacle-corrected visual acuity of 20/60 or better was recorded in 75.9% of eyes and 93.1% of eyes achieved a best corrected visual acuity with hard contact lenses of 20/40 or better. Mean postoperative corneal power was 43.8 ± 4.5D. Mean corneal astigmatism was 5.9 ± 2.7D. 94.6% of grafts remained clear. Posterior subcapsular cataract developed in 22.6% of eyes. Graft rejection was recognized in 12.9% of eyes.

CONCLUSION

PK is an effective procedure with high rate of graft survival for keratoconus patients. However, patients should be aware of the necessary of optical correction to gain the best VA after surgery.

Mechanisms of Collagen Crosslinking in Diabetes and Keratoconus

Collagen crosslinking provides the mechanical strength required for physiological maintenance of the extracellular matrix in most tissues in the human body, including the cornea. Aging and diabetes mellitus (DM) are processes that are both associated with increased collagen crosslinking that leads to increased corneal rigidity. By contrast, keratoconus (KC) is a corneal thinning disease associated with decreased mechanical stiffness leading to ectasia of the central cornea. Studies have suggested that crosslinking mediated by reactive advanced glycation end products during DM may protect the cornea from KC development. Parallel to this hypothesis, riboflavin-mediated photoreactive corneal crosslinking has been proposed as a therapeutic option to halt the progression of corneal thinning by inducing intra- and intermolecular crosslink formation within the collagen fibrils of the stroma, leading to stabilization of the disease. Here, we review the pathobiology of DM and KC in the context of corneal structure, the epidemiology behind the inverse correlation of DM and KC development, and the chemical mechanisms of lysyl oxidase-mediated crosslinking, advanced glycation end product-mediated crosslinking, and photoreactive riboflavin-mediated corneal crosslinking. The goal of this review is to define the biological and chemical pathways important in physiological and pathological processes related to collagen crosslinking in DM and KC.

Stepwise Combination of Femtosecond Astigmatic Keratotomy With Phacoemulsification and Toric Intraocular Lens Implantation in Treatment of Very High Postkeratoplasty Astigmatism

PURPOSE

To report the outcomes of stepwise combined femtosecond astigmatic keratotomy (FSAK) and phacoemulsification with toric intraocular lens (IOL) implantation in the treatment of very high astigmatism after either penetrating keratoplasty or deep anterior lamellar keratoplasty.

METHODS

This is a retrospective, interventional case series including 8 eyes of 6 patients with very high astigmatism [≥8.00 diopter (D)] after either penetrating keratoplasty or deep anterior lamellar keratoplasty who underwent FSAK, followed by phacoemulsification and toric IOL implantation. Outcome measures were corneal and manifest astigmatism and uncorrected and best spectacle-corrected visual acuity (UCVA, BSCVA).

RESULTS

The average age was 58.9 ± 5.1 years. The average follow-up time was 40.9 ± 43.8 months. Outcome measure changes after both FSAK and toric IOL implantation were: corneal astigmatism improved from 13.56 ± 4.81 D to 4.48 ± 2.83 D (P < 0.001), manifest astigmatism improved from 9.15 ± 3.86 to 1.46 ± 0.88 D (P = 0.011), UCVA improved from 1.69 ± 0.45 LogMAR (Snellen equivalent ∼20/980) to 0.23 ± 0.11 LogMAR (Snellen equivalent ∼20/33, P < 0.001), and BSCVA improved from 1.01 ± 0.71 LogMAR (Snellen equivalent ∼20/200) to 0.19 ± 0.11 LogMAR (Snellen equivalent ∼20/30, P = 0.015). BSCVA and UCVA at the last follow-up were 20/40 or better in all patients. All procedures were uneventful. Two eyes underwent photorefractive keratectomy after FSAK to regularize and further reduce astigmatism before toric IOL implantation. One patient underwent temporary compression suturing because of FSAK overcorrection.

CONCLUSIONS

Combined stepwise use of FSAK and phacoemulsification with toric IOL implantation was an effective and apparently safe approach in patients with very high postkeratoplasty astigmatism. Additional treatment using photorefractive keratectomy may be beneficial in some cases.

Efficacy of Different Procedures of Intra-Corneal Ring Segment Implantation in Keratoconus: a Systematic Review and Meta-Analysis

Purpose

To evaluate the efficacy of the functional, keratometric, and refractive postoperative parameters of intracorneal ring segment (ICRS) implantation in keratoconus and its association with collagen cross-linking (CXL), photorefractive keratectomy (PRK), and intraocular lenses (IOLs).

Methods

We conducted a systematic review and meta-analysis on case series published between 2007 and 2017.

Results

We included 95 case series with a total of 4560 patients. We included 64 studies of the ICRS procedure, 20 studies of ICRS+CXL, 9 studies of ICRS+CXL+PRK, and 5 studies of ICRS+IOL. We demonstrated an overall improvement of all parameters in all procedures. Cylinder was decreased with an overall effect size (ES) of −1.15 (−1.36 to −0.95; I² = 93.7%). Corrected distance visual acuity was improved with an overall ES of 0.89 (0.78 to 1.00; I² = 81.9%). Maximal keratometry was decreased with an overall ES of 0.98 (0.85 to 1.11; I² = 78.9%). ICRS+IOL is the best procedure to improve spherical equivalent and uncorrected distance visual acuity (P < 0.05) compared with other procedures. ICRSs versus ICRS+CXL are similar in all parameters except for corrected distance visual acuity. ICRS+CXL+PRK is better than ICRS alone in all parameters except for the correction of spherical equivalent.

Conclusions

Although the quality and strength of the data are questionable, ICRS implantation is an effective strategy to preserve visual function in keratoconic patients. Particularly, ICRS+CXL+PRK could be a low invasive procedure to propose to young keratoconic patients.

Translational Relevance

To propose an overview of postoperative parameters on each ICRS procedure on keratoconus.

Long-term safety outcome of systemic immunosuppression in pig-to-nonhuman primate corneal xenotransplantation

BACKGROUND

Safety concerns exist for corneal recipients under immunosuppression. We report long-term safety results of porcine corneal xenotransplantation under immunosuppression in nonhuman primates.

METHODS

Systemic monitoring data from 49 Chinese rhesus macaques that received pig corneal transplant between 2009 and 2018 were retrospectively reviewed. The recipients were divided into 4 groups depending on the systemic immunosuppressants used: (a) conventional steroid group; costimulation blockade groups ([b] anti-CD154 antibody, [c] anti-CD40 antibody); and (d) commercially available immunosuppressants (anti-CD20 antibody, tacrolimus, basiliximab) group. We compared results of general condition monitoring; hematologic, biochemical, and electrolyte tests; and Rhesus Cytomegalovirus infection monitoring.

RESULTS

All recipients recovered from early weight loss. White blood cell counts significantly decreased at 6 months in the steroid and anti-CD154 groups. Abnormal liver and kidney function and electrolyte imbalance were not observed in all groups. The mean value of Rhesus Cytomegalovirus DNA copies was consistently lower than 200 copies/mL, and antibody titers did not change over time in all groups. Tacrolimus-associated thrombotic microangiopathy was developed in one case, which resolved after discontinuation of tacrolimus. In 2017, a simian varicella virus outbreak led to clinical signs in 5 that received immunosuppressive therapies, of which 3 died.

CONCLUSION

Costimulatory blockade-based and anti-CD20 antibody/tacrolimus-based immunosuppressive therapies seem to be comparably safe with steroid therapy in nonhuman primates receiving corneal xenotransplantation, as they did not reactivate Rhesus Cytomegalovirus and maintained manageable systemic status. Although reactivation is rare, antiviral prophylaxis for simian varicella virus should be considered in immunocompromised hosts.

[Influence of the donor age on graft survival : Is the demographic change also important for corneal tissue donation?]

The success of corneal transplantation highly depends on the quality of the used graft. Various factors play a crucial role such as a perfect stroma without optically relevant, centrally located cloudiness or changes (e. g. scars) or an adherent Descemet membrane. One of the most important parameters is the quality of the endothelial cell layer with a sufficiently large endothelial cell count. An open question is so far whether the donor age affects corneal quality and therefore has an impact on the success of transplantation. A comprehensive review of the available literature revealed that a large amount of scientific data on the influence of donor age exist to answer this question. In a variety of studies, no significant dependence of graft quality of donor age could be detected. Rather the studies prove that graft survival depends primarily on the state of the endothelial cell layer, and postoperative endothelial cell loss must be considered as a major cause of graft failure. Extensive quality assurance procedures in tissue preparation and cornea processing in the eye banks in Germany (Europe) ensures that only corneas with tested high quality are allocated for transplantation regardless of the donor age. Against the background of an aging population, the use of grafts from older donors should not be waived.

Corneal Collagen Cross-Linking in the Management of Keratoconus in Canada: A Cost-Effectiveness Analysis

PURPOSE

To use patient-level microsimulation models to evaluate the comparative cost-effectiveness of early corneal cross-linking (CXL) and conventional management with penetrating keratoplasty (PKP) when indicated in managing keratoconus in Canada.

DESIGN

Cost-utility analysis using individual-based, state-transition microsimulation models.

PARTICIPANTS

Simulated cohorts of 100 000 individuals with keratoconus who entered each treatment arm at 25 years of age. Fellow eyes were modeled separately. Simulated individuals lived up to a maximum of 110 years.

METHODS

We developed 2 state-transition microsimulation models to reflect the natural history of keratoconus progression and the impact of conventional management with PKP versus CXL. We collected data from the published literature to inform model parameters. We used realistic parameters that maximized the potential costs and complications of CXL, while minimizing those associated with PKP. In each treatment arm, we allowed simulated individuals to move through health states in monthly cycles from diagnosis until death.

MAIN OUTCOME MEASURES

For each treatment strategy, we calculated the total cost and number of quality-adjusted life years (QALYs) gained. Costs were measured in Canadian dollars. Costs and QALYs were discounted at 5%, converting future costs and QALYs into present values. We used an incremental cost-effectiveness ratio (ICER = difference in lifetime costs/difference in lifetime health outcomes) to compare the cost-effectiveness of CXL versus conventional management with PKP.

RESULTS

Lifetime costs and QALYs for CXL were estimated to be Can$5530 (Can$4512, discounted) and 50.12 QALYs (16.42 QALYs, discounted). Lifetime costs and QALYs for conventional management with PKP were Can$2675 (Can$1508, discounted) and 48.93 QALYs (16.09 QALYs, discounted). The discounted ICER comparing CXL to conventional management was Can$9090/QALY gained. Sensitivity analyses revealed that in general, parameter variations did not influence the cost-effectiveness of CXL.

CONCLUSIONS

CXL is cost-effective compared with conventional management with PKP in the treatment of keratoconus. Our ICER of Can$9090/QALY falls well below the range of Can$20 000 to Can$100 000/QALY and below US$50 000/QALY, thresholds generally used to evaluate the cost-effectiveness of health interventions in Canada and the United States. This study provides strong economic evidence for the cost-effectiveness of early CXL in keratoconus.

Penetrating Keratoplasty for Keratoconus With and Without Resolved Corneal Hydrops: Long-term Results

PURPOSE

To evaluate the long-term risk of endothelial rejection, graft survival, and associated factors following penetrating keratoplasty (PK) for keratoconus, with and without prior resolved corneal hydrops.

DESIGN

Retrospective cohort study.

METHODS

Primary outcome measures were endothelial rejection-free survival and failure-free survival. Secondary outcome measures were corneal neovascularization following hydrops and complications following PK.

RESULTS

A total of 245 eyes underwent PK for keratoconus with mean follow-up of 5.6 ± 3.6 years. Eyes with prior hydrops (n = 74) had lower endothelial rejection-free survival rates compared with eyes without prior hydrops: 86.5% ± 4.0% vs 86.5% ± 2.6% at 1 year, 61.0% ± 6.2% vs 76.9% ± 3.3% at 5 years, and 45.8% ± 10.1% vs 70.9% ± 4.3% at 10 years, respectively (P = .023). Multivariate analysis identified factors associated with endothelial rejection as age ≤25 years (P = .017), corneal neovascularization (P = .001), donor trephination size >8 mm (P = .017), and poor clinic attendance (P = .015). There was no difference in the failure-free survival rates with and without prior hydrops: 98.6% ± 1.3% vs 97.1% ± 1.3% at 1 year, 97.3% ± 1.9% vs 95.1% ± 1.9% at 5 years, and 97.3% ± 1.9% vs 92.2% ± 2.7% at 10 years, respectively (P = .42). Corneal neovascularization was present at the time of PK in 44.6% of eyes with prior hydrops and 7.6% without prior hydrops (P < .001).

CONCLUSIONS

Corneal neovascularization, a frequent complication of corneal hydrops, was associated with increased risk of endothelial rejection following PK. However, allograft survival was similar in eyes with and without prior hydrops.

Corneal surgery in keratoconus: which type, which technique, which outcomes?

Keratoconus is a disease characterized by progressive thinning, bulging, and distortion of the cornea. Advanced cases usually present with loss of vision due to high irregular astigmatism. A majority of these cases require surgical intervention. This review provides an update on the current treatment modalities of corneal surgery available for the management of advanced corneal ectasias.

The impact of donor age and endothelial cell density on graft survival following penetrating keratoplasty

PURPOSE

To determine if donor age and preoperative endothelial cell density (ECD) affect corneal endothelial failure following penetrating keratoplasty (PK).

METHODS

Preoperative and postoperative data for PKs performed in the UK between April 1999 and March 2012 were analysed. Donor age was split into three groups (0-60, 61-75 and >75 years) and donor ECD was split into three groups (≤2400, 2401-2600 and >2600 cells/mm²). Cox proportional hazards regression was used to determine whether the selected subgroups of donor age and donor ECD have an impact on endothelial failure and a systematic analysis of the interaction between donor ECD and donor age was conducted. The analysis was stratified for primary corneal diagnosis (Fuchs endothelial dystrophy (FED), pseudophakic bullous keratopathy (PBK) and other) and corrected for potentially confounding factors (human leukocyte antigen matching, donor trephine diameter, deep vascularisation, the occurrence of reversible rejection episodes and receipt of systemic antiviral medication, long-term steroids or other immunosuppressive agents).

RESULTS

A total of 9415 patients, from the National Health Service Blood and Transplant UK Transplant Registry, who received their first PK for visual reasons were included in this study. The overall 5-year graft survival rate due to endothelial failure was 89%. Survival rates in recipients with FED, PBK and 'all other indications' were 95%, 83% and 89%, respectively. Our analysis shows that donor ECD did not affect outcome following corneal graft within the preselected categories, irrespective of diagnosis and after allowing for any potential confounding factors. Furthermore, HRs for each level of donor ECD, relative to >2600 cells/mm², for each combination of age group and indication, were not statistically significant.

CONCLUSIONS

We were unable to detect a significant effect of donor age, up to 90 years, and preoperative donor ECD, above the lower limit of 2200 cells/mm², on endothelial failure at 5 years following PK.

Femtosecond Laser-Assisted Intrastromal Relaxing Incisions After Penetrating Keratoplasty: Effect of Incision Depth

PURPOSE

To correlate the efficacy of femtosecond laser-assisted intrastromal relaxing incisions after penetrating keratoplasty with the posterior depth of corneal incisions.

METHODS

Twenty eyes of 20 patients were treated for regular postoperative penetrating keratoplasty astigmatism. Sutures had been removed and refraction had stabilized. Ultrasound pachymetry was used to calculate incisional depth. Femtosecond laser-assisted paired arcuate incisions were made inside the graft stroma, leaving 90 µm of intact anterior cornea including epithelium. The intact posterior corneal margin was 10% of the measured corneal thickness for 10 patients (10% group) and 125 µm for the remaining 10 patients (125-µm group). Follow-up visits consisted of biomicroscopy, intraocular pressure measurement, fundus examination, and topographic evaluation using anterior segment optical coherence tomography at 1 and 3 months. Postoperative corneal thickness and the depth of incisions were measured with optical coherence tomography.

RESULTS

Corrected distance visual acuity improved from 0.5 to 0.3 logMAR (Snellen: 20/63 to 20/40, P < .05) in the 10% group and remained constant in the 125-µm group. The refractive cylinder decreased by 34% in the 10% group (range: 0% to 60%), but did not change in the 125-µm group. The topographic anterior cylinder decreased in both groups by 48% (range: 0% to 67%) and 13% (range: 0% to 38%), respectively. The smaller the posterior intact corneal margin, the higher the surgically induced astigmatism (P < .05).

CONCLUSIONS

Efficacy of femtosecond laser-assisted intrastromal relaxing incisions is correlated with the posterior depth of the incisions. The deeper incisions were more effective.

Express implant in Urrets-Zavalia syndrome after descemet's stripping automated endothelial keratoplasty

CASE REPORT

The first case is described on a patient with Urrets-Zavalía syndrome after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) in whom an ExPRESS implant was used.

DISCUSSION

The ExPRESS implant is a useful tool for complex cases of post-surgical glaucoma where patients need to avoid post-operative inflammation and risks (corneal transplant patients). It is also very useful in cases with a high risk of fibrosis due to previous interventions.

Treatment options for advanced keratoconus: A review

Traditionally, the mainstay of treatment for advanced keratoconus (KC) has been either penetrating or deep anterior lamellar keratoplasty (PK or DALK, respectively). The success of both operations, however, has been somewhat tempered by potential difficulties and complications, both intraoperatively and postoperatively. These include suture and wound-healing problems, progression of disease in the recipient rim, allograft reaction, and persistent irregular astigmatism. Taken together, these have been the inspiration for an ongoing search for less troublesome therapeutic alternatives. These include ultraviolet crosslinking and intracorneal ring segments, both of which were originally constrained in their indication exclusively to eyes with mild to moderate disease. More recently, Bowman layer transplantation has been introduced for reversing corneal ectasia in eyes with advanced KC, re-enabling comfortable contact lens wear and permitting PK and DALK to be postponed or avoided entirely. We offer a summary of the current and emerging treatment options for advanced KC, aiming to provide the corneal specialist useful information in selecting the optimal therapy for individual patients.

Corneal blindness and xenotransplantation

Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

Long-term comparison of full-bed deep anterior lamellar keratoplasty and penetrating keratoplasty in treating keratoconus

OBJECTIVE

To compare postoperative outcomes of full-bed deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in treating keratoconus.

METHODS

Seventy-five eyes of 64 patients who received full-bed DALK and 52 eyes of 51 patients who received PK between June 2000 and August 2010 were included in this retrospective study. Full-bed DALK was performed using Yao's hooking-detaching technique. PK was performed using a standard technique. Intraoperative and postoperative complications, visual acuity, rejection, graft survival, endothelial cell density, corneal sensation recovery, and re-innervation were compared between the two groups.

RESULTS

A best correct visual acuity of 0.5 or better was achieved in 90.7% of eyes after full-bed DALK and in 92.3% of eyes after PK (P=0.75). By the fifth postoperative year, graft endothelial cell loss reached 34.6% in the PK group vs. 13.9% in the full-bed DALK group (P<0.001). There were no statistical differences in corneal sensitivity recovery or corneal re-innervation between the groups (P>0.05). Intraoperative microperforation occurred in seven out of 75 (9.3%) eyes with a temporally postoperative double anterior chamber in two eyes in the full-bed DALK group. Postoperative complications in the PK vs. the full-bed DALK groups respectively were: rejection (7.7% vs. 0%, P=0.015), high intraocular pressure (IOP) (46.2% vs. 1.3%, P<0.001), secondary glaucoma (9.6% vs. 0%, P=0.006), complicated cataract (19.2% vs. 0%, P<0.001), and wound dehiscence (9.6% vs. 0%, P=0.006).

CONCLUSIONS

Both full-bed DALK and PK can offer long-term satisfactory visual outcomes for keratoconus. Graft rejection, secondary glaucoma, complicated cataracts, and constant endothelial cell loss were observed in eyes only after PK.

Keratoconus: current perspectives

Keratoconus is characterized by progressive corneal protrusion and thinning, leading to irregular astigmatism and impairment in visual function. The etiology and pathogenesis of the condition are not fully understood. However, significant strides have been made in early clinical detection of the disease, as well as towards providing optimal optical and surgical correction for improving the quality of vision in affected patients. The past two decades, in particular, have seen exciting new developments promising to alter the natural history of keratoconus in a favorable way for the first time. This comprehensive review focuses on analyzing the role of advanced imaging techniques in the diagnosis and treatment of keratoconus and evaluating the evidence supporting or refuting the efficacy of therapeutic advances for keratoconus, such as newer contact lens designs, collagen crosslinking, deep anterior lamellar keratoplasty, intracorneal ring segments, photorefractive keratectomy, and phakic intraocular lenses.

Penetrating keratoplasty for keratoconus: visual and graft survival outcomes

OBJECTIVES

To evaluate the complications, and visual and graft survival outcomes in eyes that had undergone penetrating keratoplasty (PKP) for keratoconus.

METHODOLOGY

This restrospective study includes 311 patients with keratoconus who had undergone PKP between January 1, 2001, and December 31, 2002, at King Khaled Eye Specialist Hospital. All patients were followed up postoperatively (maximum follow-up, 65.77 months).

RESULTS

The mean age of patients with keratoconus at transplantation was 23.72 years. A preoperative best spectacle-corrected visual acuity (BSCVA) OF 20/40 or better was achieved in 13 eyes (4.2%). At a mean follow-up of 27 months, 212 eyes (68.2%) achieved a BSCVA of 20/40 or better. Postoperative visual acuity was significantly associated with preoperative visual acuity (P < 0.00). Only 6 eyes (1.9%) experienced graft failure, with a mean follow-up of 23.62 months. The graft rejection rate (6.8%) was a significant risk factor for failure (P = 0.00). Age, gender, corneal graft diameter, and intraoperative vitreous loss had no statistically significant effects on the PKP outcome (P> 0.05). Kaplan-Meier analysis revealed that the probabilities of graft survival were 99.8% at 1 year and 97.6% at 5 years after transplantation.

CONCLUSION

Performing PKP in eyes with keratoconus is associated with good visual results and an excellent graft outcome.

Long-term outcomes of penetrating keratoplasty for keratoconus with resolved corneal hydrops

PURPOSE

To address the controversial issue of whether the occurrence of corneal hydrops adversely affects the fate of subsequent penetrating keratoplasty (PK), this study compared the long-term outcomes of PK in keratoconic eyes with resolved corneal hydrops with those without prior corneal hydrops.

METHODS

This was a retrospective chart review of 102 eyes of 102 patients with keratoconus who underwent PK. The primary outcome measure was endothelial rejection-free allograft survival and the secondary outcomes were vision, postoperative complications, and histopathologic findings of corneal buttons obtained during PK.

RESULTS

The mean follow-up after PK was 5.5 ± 3.3 years. The Kaplan-Meier endothelial rejection-free allograft survival at 1 and 5 years post-PK were 93.7% ± 4% and 82.6% ± 7%, respectively, in 32 eyes with hydrops and 100% and 98% ± 2%, respectively, in 70 eyes without hydrops (P = 0.04). Multivariate analysis showed that the risk of endothelial rejection episodes was greater in eyes with longer duration of corneal hydrops (P = 0.019) and coexistent ocular allergy (P = 0.012). All rejection episodes were reversed medically and only 1 allograft failed because of postoperative endophthalmitis. More than 90% of eyes achieved a visual acuity of better than 20/40. Common postoperative complications were cataract and graft infiltrate. Histopathology in cases of resolved hydrops after intracameral gas showed unique compression artifacts like folding and burial of the broken ends of Descemet membrane in the stroma.

CONCLUSIONS

Although endothelial rejection episodes are more common in eyes with resolved corneal hydrops, long-term allograft survival and visual results after PK in eyes with keratoconus are excellent, irrespective of prior corneal hydrops.

Scalability and severity of keratoconus in children

PURPOSE

To assess the severity of keratoconus at diagnosis and its scalability over a period of 2 years in children compared to adults.

DESIGN

A retrospective monocentric study was conducted in the National Reference Center for Keratoconus, Bordeaux (France), between October 1997 and November 2010.

METHODS

In total, 216 patients were studied, comprising 49 patients (22.7%) aged ≤ 15 and 167 patients (77.3%) aged ≥ 27 years at diagnosis, who were seen within 2 years of diagnosis. Severity at diagnosis was assessed using Krumeich's classification, and the scalability criteria of the US Food and Drug Administration (2010) were used. Student t tests and χ(2) tests were performed to compare the 2 groups.

RESULTS

Keratoconus in children was significantly more severe at diagnosis, with 27.8% being stage 4 vs 7.8% of adults (P < .0001). In addition, ophthalmoscopic signs were more frequent in children (42.9% vs 29.5%, P = .05), while mean values of maximum, average, and minimum keratometry as well as simulated keratometric astigmatism were higher (P < .0001, P = .0002, P = .0005, and P = .001, respectively). After diagnosis, keratoconus did not evolve more frequently in children. However, in the case of progression, keratoconus evolved faster in children, with significant differences in the spherical equivalent and maximum and minimum keratometry (P = .03, P = .02, P = .04, respectively).

CONCLUSION

At diagnosis, keratoconus is often more advanced in children than in adults, with faster disease progression. Early detection and close monitoring are therefore crucial in young patients.

Efficacy and safety of long-term corticosteroid eye drops after penetrating keratoplasty: a prospective, randomized, clinical trial

PURPOSE

Endothelial rejection remains a major cause of graft failure after penetrating keratoplasty (PKP). Topical corticosteroids are the gold standard for preventing rejection; however, protocols for corticosteroid treatment have been diverse. The aim of the present study was to examine the efficacy and safety of long-term use of corticosteroid eye drops after PKP in a randomized, clinical trial.

DESIGN

Randomized, nonblinded, clinical trial.

PARTICIPANTS

We enrolled 42 patients (21 males and 21 females) with a mean age of 65.3 years who underwent PKP and maintained graft clarity for >1 year with topical steroid eye drops.

INTERVENTION

Patients were randomly assigned to 1 of 2 groups: Administration of 0.1% fluorometholone 3 times a day (steroid group) or discontinuation of steroid eye drops (no steroid group). All patients were followed for 12 months.

MAIN OUTCOME MEASURES

Proportion of eyes without endothelial rejection and the proportion of eyes with clear grafts and the incidence of local or systemic side effects.

RESULTS

Of the initial 42 patients, 4 in the steroid group and 6 in the no steroid group did not complete the trial. Of the patients who completed the trial, 1 patient in the steroid group and 6 in the no steroid group developed endothelial rejection at an average of 5.2±4.5 (mean ± standard deviation) months after study enrollment. The difference in the incidence of rejection between groups was found to be significant by both chi-square (P = 0.027) and Kaplan-Meier analyses (log-rank test, P = 0.032). No difference was observed between the 2 groups in visual acuity, intraocular pressure, epithelial damage, tear-film break-up time, cataract progression, infection, or incidence of systemic side effects.

CONCLUSIONS

Prolonged use of 0.1% fluorometholone was beneficial for the prevention of rejection after PKP. Because no adverse consequences were noted, we recommend continuing use of the low-dose corticosteroids, even in non-high-risk cases.

The role of atopy in corneal graft survival in keratoconus

PURPOSE

To compare the prevalence of endothelial rejection episodes and the probability of graft survival after initial and repeat penetrating keratoplasty (PK) in patients with keratoconus with and without atopy.

METHODS

A retrospective review was conducted of all patients receiving PK for keratoconus at the University of Texas Southwestern Medical Center at Dallas from 1988 to 2009. Inclusion criteria involved those with both an International Classification of Diseases-9 code for keratoconus and a Current Procedural Terminology code for PK based on a computer database search. Patients younger than 18 years were excluded. These records were then reviewed for a history of atopic disorders. The main outcome measures included the prevalence of endothelial rejection episodes and the probability of graft survival. The probability of corneal graft survival in patients with and without a history of atopy was compared using the Kaplan-Meier method.

RESULTS

There were 168 grafts in 122 patients. There were 66 (39.2%) and 102 (60.8%) grafts with and without a history of atopy, respectively. Bilateral first grafts were required in 32 patients, 14 and 18 patients with and without a history of atopy, respectively. The atopic and nonatopic groups had no significant differences with respect to age, preexisting ocular conditions, concomitant surgical procedures, and length of follow-up. Men received first grafts significantly more frequently than women in the nonatopic group (P = 0.029); however, there was no sex difference in repeat grafts. There were no significant differences in the prevalence of endothelial rejection episodes after the first (P = 0.716), second (P > 0.999), and third or further grafts (P > 0.999). Graft survival between the atopic and nonatopic groups did not differ significantly in the first (P = 0.881), second (P = 0.752), or third or further graft (P = 0.157). Among first grafts in the atopic group, no statistically significant difference in survival existed among patients analyzed with different manifestations of atopy (P = 0.061). One episode of allograft endothelial rejection created a statistically significant difference in ultimate graft survival probability in both the atopic (P = 0.003) and nonatopic (P = 0.002) groups.

CONCLUSIONS

Among patients with keratoconus receiving PK, there is no statistically significant difference in the prevalence of endothelial graft rejection episodes or probability of graft survival between patients with and without a clinical history of atopy.

Artisan iris-supported phakic IOL implantation in patients with keratoconus: a review of 16 eyes

PURPOSE

To evaluate the clinical outcomes of Artisan phakic intraocular lens (PIOL; Ophtec BV) implantation in patients with stable keratoconus.

METHODS

In a prospective, nonrandomized case series, 14 Artisan PIOLs and 2 toric Artisan PIOLs were implanted in 13 patients (16 eyes) with stable keratoconus who had contact lens intolerance. Pre- and postoperative data were collected.

RESULTS

Mean follow-up was 14.2 ± 7.8 months. Preoperative uncorrected distance visual acuity (UDVA) was counting fingers in all patients. Mean final logMAR (Snellen equivalent) UDVA and corrected distance visual acuity (CDVA) were 0.15(20/28) ± 0.13 and 0.11(20/26) ± 0.10, respectively. The improvements in UDVA and CDVA were statistically significant (P<.0001 and P<.002, respectively). All patients achieved a final UDVA of 20/40 or better, and 84.6% had a final CDVA of 20/32 or better. No postoperative complications occurred except for two cases of sterile uveitis.

CONCLUSIONS

Implantation of the Artisan PIOL is effective in improving visual acuity in patients with stable keratoconus. Long-term safety remains to be established as no postoperative endothelial cell counts were performed.

Collagen copolymer toric posterior chamber phakic intraocular lens in eyes with keratoconus

PURPOSE

To assess the safety, efficacy, stability, and predictability of collagen copolymer toric phakic intraocular lens (pIOL) implantation to correct myopia and astigmatism in eyes with keratoconus.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

METHODS

This prospective study comprised keratoconic eyes that had implantation of a toric Intraocular Collamer Lens. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and postoperative complications were evaluated 1, 3, 6, and 12 months postoperatively.

RESULTS

Preoperatively, the mean spherical equivalent in the 30 eyes (21 patients) was -5.38 diopters (D) +/- 3.26 (SD) (range -13.50 to -0.63 D) and the mean cylinder, -3.48 +/- 1.24 D (range -1.75 to -6.00 D). At 12 months, 86.7% of the eyes were within +/-0.50 D of the attempted refraction and all eyes were within +/-1.00 D. For the astigmatic components J0 and J45, 83.3% of eyes and 86.7% of eyes, respectively, were within +/-0.50 D. The mean Snellen UDVA was 0.81 +/- 0.20 and the mean CDVA, 0.83 +/- 0.18; CDVA was 20/40 or better in 29 eyes 96.7% of eyes and 20/25 or better in 22 eyes (73.3%). No eyes lost more than 2 lines of CDVA; 29 eyes (96.7%) maintained or gained 1 or more lines. The efficacy index was 1.07 and the safety index, 1.16. There were no complications or adverse events.

CONCLUSIONS

The results confirm that toric ICL implantation is a predictable, effective procedure to correct ametropia in eyes with keratoconus. Predictability and stability were achieved early and remained fairly stable up to 12 months.

Extended long-term results of penetrating keratoplasty for keratoconus

PURPOSE

To investigate the extended long-term results of penetrating keratoplasty (PK) for keratoconus.

METHODS

The subjects were all patients with clinical keratoconus who underwent initial PK at University of Tokyo from 1971 to 1990 and whose medical records were available. Data were retrieved from the medical records. Kaplan-Meier survival analysis was performed to estimate the cumulative probability of immune reaction-free grafts and graft survival.

RESULTS

One hundred twenty-five eyes in 125 patients met the entry criteria. The average age at the time of PK was 25.0 +/- 8.9 years. With an average follow-up period of 15.3 +/- 9.7 years, 12 eyes (9.6%) experienced rejection and 5 eyes (4.0%) experienced graft failure. Average best-corrected visual acuity in logarithm of the minimum angle of resolution at preoperation, 10, 20, and 25 years after surgery was 1.54 +/- 0.68, 0.06 +/- 0.22, 0.03 +/- 0.17, and 0.14 +/- 0.42, respectively. The cumulative probability of graft survival at 10, 20, and 25 years after PK was 98.8%, 97.0%, and 93.2%, respectively.

CONCLUSIONS

Recovery of visual acuity was good after PK for keratoconus in an extended follow-up. The graft survival rate, however, gradually decreased 20 years after PK.

Longterm follow-up of penetrating keratoplasty for keratoconus

PURPOSE

This study aims to describe the current visual and refractive status of patients who underwent penetrating keratoplasty (PK) for keratoconus > 20 years ago and to report on the current status of their grafts.

METHODS

A total of 138 eyes in 103 patients were grafted for keratoconus between August 1968 and December 1985. Patients who had not undergone retransplantation were invited to attend a clinical examination. Forty-eight patients (with 61 grafts) accepted the invitation and were examined.

RESULTS

The average length of time since PK was 26.9 years (standard deviation [SD] 4.2 years, range 20.8-38.0 years, n = 61). The average graft age at examination was 82.1 years (SD 19.9 years, range 41-115 years). A total of 80% (49 of 61 grafts) of the examined eyes had a clear graft and 46% (28 of 61 eyes) had best spectacle-corrected visual acuity (BSCVA) > or = 0.5. The mean endothelial cell density per mm(2) was 894 (SD 4.6, range 470-1775). The mean central corneal thickness of the clear grafts was 0.565 mm (SD 0.048 mm).

CONCLUSIONS

Penetrating keratoplasty for keratoconus has a good longterm prognosis; half of the eyes examined in this study had BSCVA > or = 0.5 at > 20 years after surgery.

Fixed dilated pupil (urrets-zavalia syndrome) after deep anterior lamellar keratoplasty

PURPOSE

To report 4 cases that developed fixed dilated pupil after deep anterior lamellar keratoplasty (DALK) for treating keratoconus and granular corneal dystrophy.

METHODS

Four patients underwent DALK (either Melles's manual dissection or Anwar's big-bubble technique) with diagnosis of keratoconus (2 cases) and granular corneal dystrophy (2 cases). In Melles's technique, the anterior chamber was fully filled with air at the beginning of procedure. When corneal dissection was complete, air was replaced with balanced salt solution. In Anwar's technique, a large bubble was formed between Descemet's membrane and the deepest stroma. Viscoelastic was not used within the anterior chamber in either technique. For microperforation, air was left in the anterior chamber for a couple of days. Two patients developed severe fibrinous anterior uveitis that was controlled with intense topical and systemic steroid. Other two patients developed high intraocular pressure that was controlled with antiglaucoma medications.

RESULTS

After 1-2 weeks, all 4 DALK patients developed fixed dilated pupil and posterior synechiae; 2 patients developed a faint anterior subcapsular opacity. Of 286 patients who underwent DALK, 6 patients had microperforation (2%) and 4 patients developed fixed dilated pupil (1.4%). Best-corrected visual acuity (BCVA) decreased in all patients; most of them complained about visual symptoms like glare and halo at night.

CONCLUSIONS

Fixed dilated pupil (Urrets-Zavalia syndrome) is an uncommon but rather serious complication of corneal transplantation. Iris ischemia is the most common proposing mechanism. Decreased BCVA and visual symptoms at night (glare and halo) are late sequelae.A fixed dilated pupil with iris atrophy (Urrets-Zavalia syndrome) is an uncommon postoperative complication that was originally described after penetrating keratoplasty for keratoconus. In these cases, the iris is fixed and dilated and adheres to anterior lens capsule. Prepupillary iris atrophy is usually seen and may be accompanied by a severe fibrinous reaction and anterior subcapsular lens opacity.