Cost effectiveness of the type II Boston keratoprosthesis

Acute and Chronic Ophthalmic Involvement in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis - A Comprehensive Review and Guide to Therapy. II. Ophthalmic Disease

Our purpose is to comprehensively review the state of the art with regard to Stevens- Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with particular attention to improving the management of associated ocular surface complications. SJS and TEN are two ends of a spectrum of immune-mediated disease, characterized in the acute phase by a febrile illness followed by skin and mucous membrane necrosis and detachment. Part I of this review focused on the systemic aspects of SJS/TEN and was published in the January 2016 issue of this journal. The purpose of Part II is to summarize the ocular manifestations and their management through all phases of SJS/TEN, from acute to chronic. We hope this effort will assist ophthalmologists in their management of SJS/TEN, so that patients with this complex and debilitating disease receive the best possible care and experience the most optimal outcomes in their vision and quality of life.

Long-term visual acuity, retention and complications observed with the type-I and type-II Boston keratoprostheses in an Irish population

AIM

To evaluate the outcomes of the type-I and type-II Boston keratoprostheses in a single Irish centre.

METHODS

A retrospective chart review of keratoprosthesis implantations carried out in our institution from November 2002 to March 2014 was performed. All procedures were performed by a single surgeon (WP).

RESULTS

Thirty-four keratoprosthesis implantations were carried out in 31 patients with a mean follow-up of 42±31 months (range 2-110 months). Seventeen patients were female (54.8%) and 14 were male (45.2%). The majority of keratoprostheses implanted were type-I (31/34, 91.2%), and three were type-II (3/34, 8.8%). Twenty-nine patients (85.3%) had an improvement in distance best-corrected visual acuity (BCVA) from baseline. Fifty per cent (17/34) of patients had a best-ever BCVA of at least 6/12. Eighteen patients (64.3%) retained a BCVA of at least 6/60 at 1 year. Over the course of follow-up, six keratoprostheses were explanted from six eyes of five patients, one of which was a type-II keratoprosthesis. Twenty-six patients (76.5%) developed postoperative complications. Complications included retroprosthetic membrane (18 patients, 52.9%), an exacerbation or new diagnosis of glaucoma (6 patients, 17.6%), endophthalmitis (5 patients, 14.7%) and retinal detachment (2 patients, 5.9%).

CONCLUSIONS

These data demonstrate excellent visual acuity and retention outcomes in a cohort with a long follow-up period in a single centre. Complications remain a considerable source of morbidity. These outcomes provide further evidence for the long-term stability of type-I and type-II Boston keratoprostheses in the management of patients in whom a traditional graft is likely to fail.

Prosthetic replacement of the ocular surface ecosystem as treatment for ocular surface disease in patients with a history of Stevens-Johnson syndrome/toxic epidermal necrolysis

PURPOSE

To report the visual outcomes of prosthetic replacement of the ocular surface ecosystem (PROSE) treatment in patients with ocular surface disease related to Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN).

DESIGN

Retrospective cohort study.

SUBJECTS

We included 86 patients (167 eyes) with history of SJS/TEN who underwent PROSE treatment from January 1, 2006, to January 1, 2011.

METHODS

Etiology, previous interventions, change in visual acuity, change in visual function, and duration of follow-up are reported. Paired t test and Friedman test with Dunn's post hoc test for multiple comparisons were used for statistical analysis.

MAIN OUTCOME MEASURES

Visual acuity at last follow-up and visual function based on the National Eye Institute 25-item Visual Functioning Questionnaire (NEI VFQ-25) at 6 months.

RESULTS

We treated 35 males and 51 females with a history of SJS/TENS; median age was 36 years. The most common reported etiologies for SJS/TENS were antibiotics (n = 25), ibuprofen (n = 15), and lamotrigine (n = 11). The median visual acuity at the initial visit was 20/60 (range, 20/400-20/25; 0.48 logarithm of the minimum angle of resolution [logMAR]), and the visual acuity at completion of customization was 20/25 (range, 20/200-20/20; 0.096 logMAR; P < 0.001), with no decline in median acuity at the end of follow-up. Median duration of follow-up was 16 months. There was a significant improvement in the visual function of the patients based on the NEI VFQ-25 questionnaire (mean of 48 points at baseline vs. mean of 72 points at 6 months; P < 0.001). In addition, there was also an improvement in the self-reported general health of the patients (mean of 57 points at baseline vs. mean of 65 points at 6 months; P < 0.01).

CONCLUSIONS

In a large cohort of patients with chronic ocular surface disease related to SJS/TEN, PROSE treatment offers sustained and significant large improvement in visual function and acuity.

Cost-effectiveness of osteo-odonto keratoprosthesis in Singapore

PURPOSE

To determine the long-term cost-effectiveness of osteo-odonto keratoprosthesis (OOKP) relative to no treatment among patients with end-stage corneal and ocular surface diseases in Singapore.

DESIGN

Cost-effectiveness analysis based on data from a retrospective cohort study.

METHODS

From a health system perspective, we calculated the incremental cost-effectiveness ratio of OOKP treatment relative to no treatment over a 30-year horizon, based on data from a cohort of 23 patients who underwent OOKP surgery between 2004 and 2009 at Singapore National Eye Centre. Preoperative and postoperative vision-related quality-of-life values were estimated from patients' visual outcomes and were used to calculate the gain in quality-adjusted life years (QALYs) resulting from OOKP treatment. Unsubsidized costs for surgery, consultations, examinations, medications, follow-up visits, and treatments for complications were retrieved from patients' bills to estimate the total costs associated with OOKP treatment. Sensitivity analyses were conducted to test the robustness of the model.

RESULTS

Over a 30-year period, OOKP treatment, compared with no treatment, improved QALYs by 3.991 among patients with end-stage corneal and ocular surface diseases at an additional cost of S$67 840 (US$55 150), resulting in an incremental cost-effectiveness ratio of S$17 000/QALY (US$13 820/QALY).

CONCLUSIONS

Based on commonly cited cost-effectiveness benchmarks, the OOKP is a cost-effective treatment for patients with end-stage corneal and ocular surface diseases.

Corneal transplantation

Corneal transplantation or keratoplasty has developed rapidly in the past 10 years. Penetrating keratoplasty, a procedure consisting of full-thickness replacement of the cornea, has been the dominant procedure for more than half a century, and successfully caters to most causes of corneal blindness. The adoption by specialist surgeons of newer forms of lamellar transplantation surgery, which selectively replace only diseased layers of the cornea, has been a fundamental change in recent years. Deep anterior lamellar keratoplasty is replacing penetrating keratoplasty for disorders affecting the corneal stromal layers, while eliminating the risk of endothelial rejection. Endothelial keratoplasty, which selectively replaces the corneal endothelium in patients with endothelial disease, has resulted in more rapid and predictable visual outcomes. Other emerging therapies are ocular surface reconstruction and artificial cornea (keratoprosthesis) surgery, which have become more widely available because of rapid advances in these techniques. Collectively, these advances have resulted in improved outcomes, and have expanded the number of cases of corneal blindness, which can now be treated successfully. Femtosecond-laser-assisted surgery, bioengineered corneas, and medical treatment for endothelial disease are also likely to play a part in the future.