Economic evaluation of deep anterior lamellar keratoplasty versus penetrating keratoplasty in The Netherlands

Impacts of keratoconus on quality of life: a qualitative study

BACKGROUND/AIMS

To identify the domains of quality of life (QoL) in people with keratoconus.

METHODS

Semi structured in-depth in person and telephone interviews were conducted with participants diagnosed with keratoconus and recruited from the Sydney Eye Hospital, Sydney, Australia. Thematic analysis of interview content was conducted using inductive and deductive processes. Data was collected until thematic saturation was obtained.

RESULTS

33 patients with keratoconus with median age 37 (range 18 to 65) years and majority male (n = 25; 75.8%) were interviewed and a total of 2551 quotes coded. Thematic analysis resulted in 7 broad themes, Driving (199 references), Career (259 references), Symptoms (647 references), Enjoyment (149 references), Relationships (250 references), Financial (104 references) and Healthcare (881 references). Most references described a negative relationship between keratoconus and these 7 domains. The diverse QoL issues expressed included frustration with treatment effectiveness, fear of disease progression, inconvenience with contact lenses, forced career changes and job loss, cost of contact lenses, and feelings of isolation and discrimination. Themes and subthemes described a complex and varied relationship between keratoconus and QoL.

CONCLUSION

Severe quality of life impairment was experienced by keratoconus patients despite treatment. Keratoconus diminishes various aspects of individual's QoL. Therapies able to improve QoL are still needed for keratoconus.

Trial-based cost-effectiveness analysis of Descemet membrane endothelial keratoplasty (DMEK) versus ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK)

PURPOSE

To evaluate the cost-effectiveness of Descemet Membrane Endothelial Keratoplasy (DMEK) versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK).

METHODS

A cost-effectiveness analysis using data from a multicenter randomized clinical trial was performed. The time horizon was 12 months postoperatively. Patients with Fuchs' endothelial dystrophy were randomized to DMEK (n = 29) or UT-DSAEK (n = 24). Relevant resources from healthcare and societal perspectives were included in the cost analysis. Quality-Adjusted Life Years (QALYs) were determined using the Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D-5L questionnaires. The main outcome was the incremental cost-effectiveness ratio (ICER; incremental societal costs per QALY).

RESULTS

Societal costs averaged €8851 (US$11 406) for DMEK and €8320 (US$10 722) for UT-DSAEK. Higher costs in the DMEK group were mainly caused by higher rebubbling and regraft rates (21% and 7%, vs. 4% and 0% in the UT-DSAEK group). HUI3 QALYs were 0.70 (DMEK) and 0.79 (UT-DSAEK). EQ-5D-5L QALYs were 0.83 (DMEK) and 0.86 (UT-DSAEK). The ICER indicated DMEK was dominated by UT-DSAEK in both analyses. The cost-effectiveness probability for DMEK ranged from 21% to 5% (HUI3 QALYs) and 27%-14% (EQ-5D-5L QALYs), assuming the maximum acceptable ICER ranged from €2500 to €80.000 (US$3222-US$103 093) per QALY.

CONCLUSION

The base case cost-effectiveness analysis favoured UT-DSAEK over DMEK, as costs of DMEK were higher while QALYs were lower. Further studies are required to assess long-term rebubbling and regraft rates and graft survival.

Ex Vivo Evaluation of a Pressure-Sensitive Device to Aid Big Bubble Intrastromal Dissection in Deep Anterior Lamellar Keratoplasty

Purpose

To develop and perform ex vivo testing for a device designed for semiquantitative determination of intracorneal dissection depth during big bubble (BB) deep anterior lamellar keratoplasty.

Methods

A prototype device connected to a syringe and cannula was designed to determine depth of intrastromal placement based on air rebound pressure emitted by a software controlled generator. Ex vivo testing of the device was conducted on human corneas mounted on an artificial anterior chamber in three experiments: (1) cannula purposely introduced at different depths measured with anterior segment optical coherence tomography, (2) cannula introduced as per the BB technique, and (3) simulation of the BB technique guided by the device.

Results

A positive pressure differential and successful BB were observed only when the cannula was positioned within 150 microns from the endothelial plane. In all successful BB cases (21/40), a repeatable increase in tissue rebound pressure was detected, which was not recorded in unsuccessful cases. The device was able to signal to the surgeon correct placement of the cannula (successful BB) in 16 of 17 cases and incorrect placement of the cannula (unsuccessful BB) in 8 of 8 cases (94.1% sensitivity, 100% specificity).

Conclusions

In our ex vivo model, this novel medical device could reliably signal cannula positioning in the deep stroma for effective pneumatic dissection and possibly aid technical execution of BB deep anterior lamellar keratoplasty.

Translational Relevance

A medical device that standardizes big bubble deep anterior lamellar keratoplasty could increase the overall success rate of the surgical procedure and aid popularization of deep anterior lamellar keratoplasty.

Long-Term Outcomes of Bowman Layer Inlay Transplantation for the Treatment of Progressive Keratoconus

PURPOSE

To report long-term clinical outcomes and estimated success rates after Bowman layer (BL) inlay transplantation in eyes treated for progressive keratoconus (KC).

METHODS

Thirty-five eyes (29 patients) with progressive KC underwent BL inlay transplantation. Best-corrected spectacle and contact lens visual acuity, Scheimpflug-based corneal tomography [simulated and maximum keratometry (Kmax)], central corneal thickness, thinnest point thickness, complications, and success rate were evaluated up to 8 years postoperatively for the total group and 2 subgroups [group 1: preoperative Kmax > 69 diopter (D) (n = 26); group 2: preoperative Kmax < 69D (n = 9)].

RESULTS

Mean logarithm of the minimum angle of resolution best contact lens-corrected visual acuity for the total group and the 2 subgroups did not change from preoperative up to the last available follow-up (all P > 0.05), whereas best spectacle-corrected visual acuity improved for group 1 ( P = 0.03). Group 1 showed an average Kmax reduction of 7D in the first month ( P < 0.001) with no further changes up to 8 years postoperatively ( P > 0.05), whereas no significant changes were observed in group 2 (all P > 0.05). Postoperative KC progression occurred in 4 eyes (n = 3 group 1, n = 1 group 2) and 1 eye (group 2) underwent retransplantation for unsatisfactory visual performance. Kaplan-Meier analysis showed an estimated success rate of 85% at the 5 to 8 years follow-up in group 1 and of 75% at the 5 to 7 years follow-up for group 2.

CONCLUSIONS

BL inlay transplantation stabilized KC in most eyes along with preservation of contact lens tolerance up to 8 years postoperatively and may be a successful treatment option, in particular for eyes with progressive advanced KC (Kmax > 69D).

Assessment of patient-reported outcome measures used in corneal transplantation: a systematic review

The aim of this study was to review all the articles that have implemented patient-reported outcome measures (PROMs) to evaluate the quality of life (QoL) in corneal transplantation and discuss quality assessments of the PROMs. An extensive literature review was undertaken to identify all the studies that used PROMs to assess the QoL in corneal transplantation. Non-original or review articles, articles on other subject area and articles on cost-effectiveness/utility without PROM data/results were excluded. Each PROM was assessed against the following criteria: content development (item identification and item selection), psychometric properties, validity, reliability, and responsiveness. 425 articles were identified of which 35 articles were included in the final review. PROMs in corneal transplantation were used to (a) evaluate the QoL after surgery, (b) compare the QoL scores between different surgical techniques and (c) determine the relationship between QoL and objective measures such as visual acuity, visual field and stereoacuity. A total of 17 PROMs were used to assess QoL in corneal transplantation. Whilst this search did not produce any PROMs that were specifically designed to assess corneal transplantation, most studies were found to have employed the National Eye Institute Visual Function Questionnaire 25 (NEI VFQ 25). The Visual Function Index 14 (VF 14) performed better in the present quality assessment criteria compared to other PROMs, however, the NEI VFQ 25 and the VF 14 PROMs were not specifically developed for corneal transplantation and therefore the QoL assessment made using these PROMs may be incomplete. As improvements in various forms of lamellar transplantation surgery techniques such as UT-DSAEK and FT-DSAEK have resulted in better visual outcomes, improved graft survival and reduced complications, a corneal transplantation specific PROM will be useful in clinical settings to compare the outcomes of different surgical techniques from the patient perspective.

Cost-effectiveness of Descemet stripping automated endothelial keratoplasty versus penetrating keratoplasty in patients with endothelial dysfunction in India

Purpose:

The aim of this study was to compare the cost-effectiveness and perform cost-utility analysis of Descemet stripping automated endothelial keratoplasty (DSAEK) vs. penetrating keratoplasty (PK) in Indian population.

Methods:

This was an institutional, ambispective, observational study. Patients who underwent PK or DSAEK for endothelial dysfunction were included and followed up for 2 years; those with other ocular comorbidities were excluded. The analysis was performed from the patient’s perspective receiving subsidized treatment at a tertiary care hospital. Detailed history, ophthalmic examination, total expenditure by patient, and clinical outcomes were recorded. The main outcome measures were best spectacle-corrected visual acuity (BSCVA), graft survival (Kaplan–Meier survival estimates), incremental cost-effectiveness ratio (ICER), and incremental cost-utility ratio (ICUR). Utility values were based on quality-adjusted life years (QALYs) associated with visual acuity outcomes. Statistical analysis was performed using SPSS software package, version 12.1; a value of P < 0.05 was considered statistically significant.

Results:

A total of 120 patients (PK: 60, DSAEK: 60) were included. At 2 years, for a similar logMAR BSCVA, [PK (0.32 ± 0.02), DSAEK (0.25 ± 0.02); P = 0.078], the overall cost for PK (13511.1 ± 803.3 INR) was significantly more than DSAEK (11092.9 ± 492.1 INR) (difference = 1952.6 INR; P = 0.01). ICER of DSAEK relative to PK was –39,052 INR for improvement in 1 logMAR unit BSCVA. ICUR of DSAEK relative to PK was –1,95,260 INR for improvement in 1 QALY.

Conclusion:

DSAEK was more cost-effective than PK in patients with endothelial dysfunction at 2 years.

Cost-effectiveness analysis of preloaded versus non-preloaded Descemet membrane endothelial keratoplasty for the treatment of Fuchs endothelial corneal dystrophy in an academic centre

AIMS

To determine the cost-effectiveness of preloaded Descemet membrane endothelial keratoplasty (pDMEK) versus non-preloaded DMEK (n-pDMEK) for the treatment of Fuchs endothelial corneal dystrophy (FECD).

METHODS

From a societal and healthcare perspective, this retrospective cost-effectiveness analysis analysed a cohort of 58 patients with FECD receiving pDMEK (n=38) or n-pDMEK (n=30) from 2016 to 2018 in the Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, USA. Exclusion criteria were previous ocular surgeries (other than uncomplicated cataract surgery), including other keratoplasty procedures, ocular pathological conditions as glaucoma, amblyopia, laser treatments, or any retinal or corneal disease. The main outcome parameters were the incremental cost-utility ratio (ICUR) and net monetary benefit (NMB).

RESULTS

pDMEK was less costly compared with n-pDMEK (healthcare: $13 886 vs $15 329; societal: $20 805 vs $22 262), with a slighter greater utility (QALY 0.6682 vs QALY 0.6640) over a time horizon of 15 years. pDMEK offered a slightly higher clinical effectiveness (+0.0042 QALY/patient) at a lower cost (healthcare: -$1444 per patient; societal: -$1457 per patient) in improving visual acuity in this cohort of patients with FECD. pDMEK achieved a favourable ICUR and NMB compared with n-pDMEK. Based on sensitivity analyses performed, the economic model was robust.

CONCLUSIONS

From the societal and healthcare perspective, pDMEK was less costly and generated comparable utility values relative to n-pDMEK. Therefore, pDMEK appears to be cost-effective and cost saving with respect to n-pDMEK. Further long-term follow-up data are needed to confirm these findings.

Effect of Corneal Transplantation on Patient-Reported Outcomes and Potential Predictors: A Systematic Review

PURPOSE

To investigate the effect and potential predictors of corneal transplantation on patient-reported outcomes such as quality of life, visual functioning, and mental health by systematically reviewing the literature.

METHODS

Studies with 1 preoperative and at least 1 postoperative measurement were searched for in relevant literature databases. Methodological quality was assessed using the Quality Assessment Tool for Quantitative Studies, and effect sizes were calculated.

RESULTS

Of 1445 unique publications, 14 studies, including 15 study designs, were described in 16 publications. Four randomized controlled trials, 1 controlled clinical trial, 1 cohort study, and 1 before-after study (BA) were of good quality; 6 BAs were of moderate quality; and 2 BAs were of weak quality. Patients generally improved 12 months after transplantation on health-related quality of life (effect size between 0.08 and -3.06), vision-related quality of life (-0.67 and -6.65), visual functioning (-0.55 and -0.63), and subjective visual symptoms (-0.31 and -0.86). Patient satisfaction was high (-0.95). Patients improved on depression (-0.31) but remained stable on anxiety (-0.05) 4 months after transplantation. Predictors of positive outcomes were lower preoperative visual acuity and visual functioning, better postoperative visual factors, younger age, and male sex.

CONCLUSIONS

Corneal transplantation showed overall beneficial effects on patient-reported outcomes. Knowledge of these effects and predictors might result in better treatment, more patient-centered care, and more realistic expectations on the part of patients and ophthalmologists. Future studies should focus on not only health- and vision-related quality of life but also mental health and labor participation using longitudinal study designs.

Vision-Related Quality of Life after Corneal Transplantation

PURPOSE

To determine the vision-related quality of life (VR-QoL) and its dimensions in corneal transplant recipients.

METHODS

This cross-sectional study was carried out on 100 patients who underwent penetrating keratoplasty. Data collection tools included a demographic questionnaire, satisfaction questionnaire, and Persian version of the 39-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ 39).

RESULTS

The composite score of VR-QoL in corneal transplant recipients was 54.39 ± 9.22 (32.9-71.01). The highest mean score among subscales was related to color vision (74.75 ± 27.63) and the lowest related to dependency (31.06 ± 31.02). The results showed that there is a reverse correlation between VR-QoL with both age (r = -0.364; P < 0.001) and the numbers of years after the transplantation (r = -0.362; P < 0.001). However, there was a correlation between satisfaction and VR-QoL (r = 0.679; P < 0.001). Furthermore, the results showed that there is a significant difference in VR-QoL between men and women (P < 0.001) and also a significant difference in VR-QoL between unilateral and bilateral graft recipients (P < 0.001).

CONCLUSIONS

The corneal transplant has the highest impact on color vision and the lowest on dependency. Moreover, the results of this study provide a comprehensive picture for the state of vision and overall health status of patients for health-care providers to enhance the patient care.

Trial-based cost-effectiveness analysis of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) versus DSAEK

PURPOSE

To evaluate the cost-effectiveness of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) versus standard DSAEK.

METHODS

A cost-effectiveness analysis using data from a multicentre randomized clinical trial was performed. The time horizon was 12 months postoperatively. Sixty-four eyes of 64 patients with Fuchs' endothelial dystrophy were included and randomized to UT-DSAEK (n = 33) or DSAEK (n = 31). Relevant resources from healthcare and societal perspectives were included in the cost analysis. Quality-adjusted life years (QALYs) were determined using the Health Utilities Index Mark 3 questionnaire. The main outcome was the incremental cost-effectiveness ratio (ICER; incremental societal costs per QALY).

RESULTS

Societal costs were €9431 (US$11 586) for UT-DSAEK and €9110 (US$11 192) for DSAEK. Quality-adjusted life years (QALYs) were 0.74 in both groups. The ICER indicated inferiority of UT-DSAEK. The cost-effectiveness probability ranged from 37% to 42%, assuming the maximum acceptable ICER ranged from €2500-€80 000 (US$3071-US$98 280) per QALY. Additional analyses were performed omitting one UT-DSAEK patient who required a regraft [ICER €9057 (US$11 127) per QALY, cost-effectiveness probability: 44-62%] and correcting QALYs for an imbalance in baseline utilities [ICER €23 827 (US$29 271) per QALY, cost-effectiveness probability: 36-59%]. Furthermore, the ICER was €2101 (US$2581) per patient with clinical improvement in best spectacle-corrected visual acuity (≥0.2 logMAR) and €3274 (US$4022) per patient with clinical improvement in National Eye Institute Visual Functioning Questionnaire-25 composite score (≥10 points).

CONCLUSION

The base case analysis favoured DSAEK, since costs of UT-DSAEK were higher while QALYs were comparable. However, additional analyses revealed no preference for UT-DSAEK or DSAEK. Further cost-effectiveness studies are required to reduce uncertainty.

Predictive Factors for Successful Type 1 Big Bubble during Deep Anterior Lamellar Keratoplasty

Objective

Big bubble (BB)-deep anterior lamellar keratoplasty (DALK) has become the reference transplantation technique for corneal stromal disorders. Type 1 BB is the desired aspect but it is not constant. We aimed to determine the predictive factors of type 1 BB success.

Methods

Observational cohort study including 77 consecutive eyes of 77 patients undergoing DALK by one surgeon at a single reference center without any selection. Clinical and spectral domain optical coherence tomography data were collected pre- and postoperatively.

Results

Stromal scars were found in 91.8% of cases and were located in the anterior (90.9%), mid (67.5%), and posterior (36.4%) stroma. Type 1 BB (49.3% of cases) was significantly associated with the absence of scars in the posterior stroma, stage 1-3 keratoconus, and deep trephination. Among eyes with posterior scars, type 1 BB was associated with higher minimal corneal thickness, maximum-minimum corneal thickness < 220 μm, and diagnosis other than keratoconus. Eyes with type 1 BB featured significantly thinner residual stromal bed (22 ± 8 µm versus 61 ± 28 µm), thinner corneas at 12, 24, and 36 months, and better visual acuity at 12 months compared with eyes with no type 1 BB. Conversely, no significant differences between both groups were observed for graft survival, visual acuity at 24 and 36 months, and endothelial cell density at 12 and 36 months.

Conclusion

OCT assessment before DALK is useful for choosing trephination depth that should be as deep as possible and for looking for posterior scars. The BB technique may not be the most appropriate method in keratoconus with posterior scars. Follow-up data do not support the need for conversion to penetrating keratoplasty when type 1 BB cannot be obtained nor does it support the need for performing a penetrating keratoplasty as a first-choice procedure in eyes with posterior stromal scars.

Pathogenesis of Keratoconus: The intriguing therapeutic potential of Prolactin-inducible protein

Keratoconus (KC) is the most common ectatic corneal disease, with clinical findings that include discomfort, visual disturbance and possible blindness if left untreated. KC affects approximately 1:400 to 1:2000 people worldwide, including both males and females. The aetiology and onset of KC remains a puzzle and as a result, the ability to treat or reverse the disease is hampered. Sex hormones are known to play a role in the maintenance of the structure and integrity of the human cornea. Hormone levels have been reported to alter corneal thickness, curvature, and sensitivity during different times of menstrual cycle. Surprisingly, the role of sex hormones in corneal diseases and KC has been largely neglected. Prolactin-induced protein, known to be regulated by sex hormones, is a new KC biomarker that has been recently proposed. Studies herein discuss the role of sex hormones as a control mechanism for KC onset and progression and evidence supporting the view that prolactin-induced protein is an important hormonally regulated biomarker in KC is discussed.

Etiology of Global Corneal Blindness and Current Practices of Corneal Transplantation: A Focused Review

PURPOSE

The purpose of this focused review was to explore the etiologies of corneal blindness worldwide and compare them with the indications and type of keratoplasties (eg, full-thickness penetrating keratoplasty, anterior lamellar keratoplasty, or endothelial keratoplasty) performed.

METHODS

A literature search of the articles published in the top 10 journals (based on the Altmetrics score) relevant to corneal transplantation within the past 20 years was performed to determine how the focus within corneal transplantation has changed over time. These data were compared with the prevalence and etiology of corneal blindness in each respective region worldwide.

RESULTS

The leading etiologies of corneal blindness worldwide are primarily due to anterior corneal pathology with a normal endothelium, and the prevalence is highest in developing countries. In addition, the number and type of corneal transplantations performed globally indicate that current practices are disproportionately skewed in favor of endothelial keratoplasty, which is targeted for the pathology prevalent in developed countries. Despite the large number of individuals who would benefit from anterior lamellar keratoplasty, this technique seems to be infrequently performed.

CONCLUSIONS

Most corneal blindness worldwide is secondary to anterior corneal pathology because of infections and trauma. However, this does not align with the current trends and practices in the field of corneal transplantation. We discuss potential solutions to address the current leading causes of global corneal blindness, including increasing the number of anterior lamellar keratoplasties performed, using long-term preserved corneas by trained surgeons, and improving eye bank handling and distribution of procured tissues.

Systematic review comparing penetrating keratoplasty and deep anterior lamellar keratoplasty for management of keratoconus

AIM

Perception of reduced incidence of graft rejection after deep anterior lamellar keratoplasty (DALK) has attracted many surgeons towards this technique in keratoconus. This review aims to compare the visual, refractive and graft outcomes after penetrating keratoplasty (PK) and DALK for keratoconus.

METHODS

Electronic searches of PubMed, MEDLINE, EMBASE, Latin American and Caribbean Health Sciences Literature database (LILACS), metaRegister of Controlled Trials (mRCT), ClinicalTrial.gov and the WHO International Clinical Trials Registry Platform (ICTRP) were performed. We included randomized control trials (RCTs) and comparative studies to assess primary and secondary outcomes after PK and DALK in eyes with keratoconus. Primary outcome was best-corrected visual acuity (BCVA) LogMAR at ≥6 months. Secondary outcomes included number of patients with BCVA≥0 LogMAR, uncorrected visual acuity (UCVA) LogMAR, spherical equivalent (SE), refractive and keratometric astigmatism, endothelial cell density (ECD) cell/mm², graft rejection and graft survival.

RESULTS

Eighteen studies (including 2 RCTs) compared DALK (965 eyes) and PK (2402 eyes) for keratoconus. There was strong evidence through RCTs suggesting better LogMAR BCVA at ≥6 months and better LogMAR UCVA with PK; reduced refractive astigmatism and rejection with DALK and no difference in SE and keratometric astigmatism. Moreover, there was weak evidence to suggest better BCVA≥0 LogMAR after PK and no difference in ECD between the two techniques.

CONCLUSIONS

Despite the popularity of DALK amongst corneal surgeons for keratoconus, there is a paucity of high quality RCTs. The existing limited evidence confirms reduced rejection and refractive astigmatism with DALK but better visual outcomes with PK. Internationally agreed data sets and follow-up protocol are warranted.

Deep anterior lamellar keratoplasty versus penetrating keratoplasty for treating keratoconus

BACKGROUND

Keratoconus is an ectatic (weakening) disease of the cornea, which is the clear surface at the front of the eye. Approximately 10% to 15% of patients diagnosed with keratoconus require corneal transplantation. This may be full-thickness (penetrating) or partial-thickness (lamellar).

OBJECTIVES

To compare visual outcomes after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty for keratoconus, and to compare additional outcomes relating to factors which may contribute to poor visual outcomes (e.g. astigmatism, graft rejection and failure).

SEARCH METHODS

We searched a number of electronic databases including CENTRAL, PubMed and EMBASE without using any date or language restrictions. We last searched the electronic databases on 31 October 2013. We also handsearched the proceedings of several international ophthalmic conferences.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing the outcomes of DALK and penetrating keratoplasty in the treatment of keratoconus.

DATA COLLECTION AND ANALYSIS

Two authors assessed trial quality and extracted data independently. For dichotomous data (graft failure, rejection, achievement of functional vision) results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). For continuous data (postoperative best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), keratometric astigmatism and spherical equivalent) results were expressed as mean differences (MDs) and 95% CIs.

MAIN RESULTS

We identified two completed studies, with a total of 111 participants (n = 30 and n = 81), both conducted in Iran, that met our inclusion criteria. Participants had moderate to severe keratoconus pre-operatively and were randomly allocated to receive either DALK or penetrating keratoplasty. Only one eye of each participant was treated as part of the trials. The smaller study had 12 month follow-up data for all participants. For the larger study, four DALK surgeries had to be abandoned due to technical failure and visual and refractive outcomes were not measured in these participants. Follow-up length for the remaining 77 participants ranged from 6.8 to 36.4 months, with all 77 followed for at least three months post-suture removal. Details of the randomisation procedure were unavailable for the smaller study and so sensitivity analyses were conducted to determine if the results from this study had affected the overall results of the review.Neither of the included studies reported a difference between groups on any of the measures of post-graft visual achievement, keratometric astigmatism or spherical equivalent. A single case of graft failure in a penetrating keratoplasty was reported. No postoperative graft failures were reported in the DALK group of either study.Instances of graft rejection were reported in both groups, in both studies. The majority of these cases were successfully treated with steroids. The data, which related to all cases in each study - given that the four cases that did not go ahead as planned had already technically failed without presence of rejection - showed that rejection was less likely to occur in DALK (odds ratio (OR): 0.33, 95% confidence interval (CI) 0.14 to 0.81, GRADE rating: moderate).Results of the sensitivity analysis indicated that inclusion of the Razmju 2011 study did not bias the results with regards to rejection episodes. While sensitivity analysis showed altered results with regards to failure rates, the data available from the Javadi 2010 study alone had a very wide 95% CI, suggesting an imprecise estimate. Therefore, even after removal of the Razmju 2011 data, it is still difficult to draw conclusions regarding superiority of one technique over another with regards to graft failure.DALK was unable to be completed as planned in four cases and in a further three cases, complications during dissection required further intervention. Other adverse events, of varying severity, were reported in both intervention groups with similar frequency. For both types of surgery, these included postoperative astigmatism, steroid induced ocular hypertension and persistent epithelial defects. In recipients of DALK, one participant had interface neovascularisation (a proliferation of blood vessels where the host and donor cornea come together) and one had wrinkling of Descemet's membrane, the basement membrane separating the corneal stroma from the corneal endothelium. In the penetrating keratoplasty groups, one participant required graft resuturing and one had an atonic pupil, a condition in which the pupil dilates and is non-reactive.Overall, the quality of the evidence was rated as very low to moderate, with methodological limitations, incomplete data analysis and imprecision of findings, as well as high risk of bias in several areas for both studies.

AUTHORS' CONCLUSIONS

We found no evidence to support a difference in outcomes with regards to BCVA at three months post-graft or at any of the other time points analysed (GRADE rating: very low). We also found no evidence of a difference in outcomes with regards to graft survival, final UCVA or keratometric outcomes. We found some evidence that rejection is more likely to occur following penetrating keratoplasty than DALK (GRADE rating: moderate). The small number of studies included in the review and methodological issues relating to the two, mean that the overall quality of the evidence in this review is low. There is currently insufficient evidence to determine which technique may offer better overall outcomes - final visual acuity and time to attain this, keratometric stabilisation, risk of rejection or failure, or both, and risk of other adverse events - for patients with keratoconus. Large randomised trials comparing the outcomes of penetrating keratoplasty and DALK in the treatment of keratoconus are needed.

Economic evaluation of endothelial keratoplasty techniques and penetrating keratoplasty in the Netherlands

PURPOSE

To evaluate cost-effectiveness of penetrating keratoplasty (PK), femtosecond laser-assisted Descemet stripping endothelial keratoplasty (FS-DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK).

DESIGN

Cost-effectiveness analysis based on data from a randomized multicenter clinical trial and a noncomparative prospective study.

METHODS

Data of 118 patients with corneal endothelial dysfunction were analyzed in the economic evaluation. Forty patients were included in the PK group, 36 in the FS-DSEK group, and 42 in the DSAEK group. The primary incremental cost-effectiveness ratio (ICER) was the incremental costs per clinically improved patient, defined as a patient with a combined effectiveness of both a clinically improved BSCVA (defined as an improvement of at least 2 lines) and a clinically acceptable refractive astigmatism (defined as less than or equal to 3.0 diopters). Analysis was based on a 1-year follow-up period after transplantation.

RESULTS

The percentage of treated patients who met the combined effectiveness measures was 52% for DSAEK, 44% for PK, and 43% for FS-DSEK. Mean total costs per patient were €6674 (US$7942), €12 443 (US$14 807), and €7072 (US$8416) in the PK group, FS-DSEK group, and DSAEK group, respectively. FS-DSEK was less effective and more costly compared to both DSAEK and PK. DSAEK was more costly but also more effective compared to PK, resulting in incremental costs of €4975 (US$5920) per additional clinically improved patient.

CONCLUSIONS

The results of this study show that FS-DSEK was not cost-effective compared to PK and DSAEK. DSAEK, on the other hand, was more costly but also more effective compared to PK. Including societal costs, a longer follow-up period and preparation of the lamellar transplant buttons in a national cornea bank could improve the cost-effectiveness of DSAEK.