Clinical validation of point-source corneal topography in keratoplasty.

PURPOSE: To validate the clinical performance of point-source corneal topography (PCT) in postpenetrating keratoplasty (PKP) eyes and to compare it with conventional Placido-based topography. METHODS: Corneal elevation maps of the anterior corneal surface were obtained from 20 post-PKP corneas using PCT (VU topographer, prototype; VU University Medical Center, Amsterdam, The Netherlands) and Placido-based topography (Keratron, Optikon 2000, Rome, Italy). Corneal surface parameters are calculated in terms of radius and asphericity. Corneal aberrations were characterized using standard Zernike convention. An artificial surface with quadrafoil feature (SUMIPRO, Almelo, The Netherlands) was measured and used as a reference to assess instrument performance compared with the gold standard. RESULTS: The differences (mean ± std of PCT - Placido) found between the two types of topographers in measurements of post-PKP eyes are 0.02 ± 0.21 mm (p=0.64) for radius of curvature, 0.14 ± 0.49 (p=0.23) for asphericity, -0.19 ± 1.67 µm (p=0.61) for corneal astigmatism, -0.25 ± 1.34 µm (p=0.41) for corneal coma, 0.23 ± 0.82 µm (p=0.23) for corneal trefoil, and 0.15 ± 0.28 µm (p=0.02) for corneal quadrafoil. The PCT measured the artificial surface more accurate (rms error 0.16 µm; 0.12 eq. Dpt.) than the Placido-based topographer (rms error 1.50 µm; 1.15 eq. Dpt.). CONCLUSIONS: PCT is more accurate than Placido-based topography in measuring quadrafoil aberration.

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

PURPOSE: To evaluate the cost effectiveness of deep anterior lamellar keratoplasty (DALK) versus penetrating keratoplasty (PK) in The Netherlands. DESIGN: Cost-effectiveness analysis alongside a randomized, multicenter clinical trial. METHODS: Fifty-three patients with corneal stromal pathologic features not affecting the endothelium were included with 28 patients in the DALK group and 25 in the PK group. Quality of life was measured before surgery and 3, 6, and 12 months after surgery. The main outcome measures were incremental cost-effectiveness ratios per clinically improved patient on the 25-item National Eye Institute Visual Functioning Questionnaire and per patient with endothelial cell loss of maximally 20% within the first year. RESULTS: Mean total bootstrapped costs per patient were €7607 (US$10,498) in the DALK group and €6552 (US$9042) in the PK group. The incremental cost-effectiveness ratios were €9977 (US$13,768) per clinically improved patient on the 25-item National Eye Institute Visual Functioning Questionnaire and €6900 (US$9522) per patient with cell loss of maximally 20%. In patients without perforation of the Descemet membrane, the incremental cost-effectiveness ratio was €5250 (US$7245) per patient. CONCLUSIONS: This study shows that DALK is more costly and more effective as compared with PK. Results on the 25-item National Eye Institute Visual Functioning Questionnaire were in favor of DALK, and endothelial cell loss in DALK patients remained stable after 6 months, whereas cell loss in PK patients continued. Furthermore, DALK procedures performed without perforation of the Descemet membrane were more effective. However, because it is unknown what society is willing to pay for an additional improved patient, cost effectiveness of DALK within a limited follow-up period of 12 months is unclear. Cost effectiveness of DALK may improve over time because of lower graft failure.

Endothelial cell loss and visual outcome of deep anterior lamellar keratoplasty versus penetrating keratoplasty: a randomized multicenter clinical trial.

OBJECTIVE: To compare endothelial cell (EC) loss, visual and refractive outcomes, and complications after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK). DESIGN: Randomized, multicenter clinical trial. PARTICIPANTS: Fifty-six eyes of 56 patients with a corneal stromal pathology not affecting the endothelium were randomized to DALK or PK. METHODS: The DALK procedure was performed according to Anwar's big-bubble technique. Patients underwent an ophthalmic examination preoperatively and 3, 6, and 12 months postoperatively. MAIN OUTCOME MEASURES: Endothelial cell loss, refractive and topographic astigmatism, spherical equivalent, uncorrected visual acuity, and best spectacle-corrected visual acuity (BSCVA) were measured, and complications were recorded. RESULTS: Endothelial cell loss was significantly higher after PK compared with DALK procedures performed without perforation of Descemet's membrane (12 months: 27.7% ± 11.1% vs. 12.9% ± 17.6%). The BSCVA was significantly better in the PK group at 3 and 6 months after surgery but was not significantly different 12 months after surgery (0.39 ± 0.3 logarithm of the minimum angle of resolution [logMAR] in DALK and 0.31 ± 0.3 logMAR in PK). At 12 months postoperatively, refractive and topographic astigmatism in the DALK and PK groups were -3.37 ± 2.3 diopters (D) and -3.76 ± 2.1 D (P = 0.53), and 3.57 ± 2.3 D and 4.16 ± 2.0 D (P = 0.34), respectively. (Micro)perforation of the Descemet's membrane occurred in 32% (9/28) of the DALK eyes, and 18% (5/28) of the patients required conversion to PK. Endothelial cell loss was not significantly different between DALK and PK when cases with perforation of Descemet's membrane were included in the (intention-to-treat) analysis (12 months: 19.1 ± 21.6 vs. 27.7 ± 11.1 P = 0.112). Rejection episodes were reported in 1 patient in the DALK group (epithelial rejection) and 3 patients in the PK group (all endothelial rejections). No graft failure occurred. CONCLUSIONS: One year after DALK performed without perforation of Descemet's membrane, EC loss is significantly lower, whereas the BSCVA is comparable to that in the PK group. In addition, no endothelial rejection occurred in the DALK group. However, Descemet's membrane perforation remains a major complication in DALK and warrants improvements to standardize the big-bubble technique.

Scleral melting in a patient with carotid artery obstruction.

PURPOSE: To report a case of severe scleral melting in a patient with carotid artery obstruction. METHODS: This is an observational case report. We reviewed the patient's chart and the available literature on ocular melting and ocular ischemia. RESULTS: A 71-year-old man with a history of carotid vascular disease and a blind left eye due to a previous vascular accident developed scleral melting of the right eye. Despite frequent lubricants, systemic immunosuppressives, and repeated conjunctiva transplants, the thinning progressed and his visual acuity deteriorated. Intensive screening for possible underlying diseases revealed no infectious or collagen vascular disease. Magnetic resonance angiography, however, showed a subtotal obstruction of the right internal carotid artery. Further investigations revealed coronary artery obstruction. Carotid surgery combined with coronary artery bypass grafting was performed, and a stable ocular situation was achieved. CONCLUSIONS: Although a causal factor cannot always be determined, corneoscleral melting should be regarded as a manifestation of underlying systemic or ocular disorders. In the absence of more common causes of corneoscleral melting, a thorough workup is warranted and might reveal life-threatening disorders.

Donor-to-host transmitted Candida endophthalmitis after penetrating keratoplasty.

OBJECTIVE: To report the first case of Candida albicans endophthalmitis following penetrating keratoplasty after warm preservation. DESIGN: Observational case report. METHODS: We reviewed the patient's chart and the available literature on fungal endophthalmitis after keratoplasty. RESULTS: After keratoplasty, a 45-year-old man developed an endophthalmitis on the first postoperative day. The same day, results of the culture of the transportation medium were available and revealed Candida albicans. Despite therapy with topical and subtenon amphotericin B, there was no clinical improvement, and a regraft was performed 4 days after the initial corneal transplant. A best corrected visual acuity of 20/32 was achieved. CONCLUSION: The majority of reported cases of postkeratoplasty candidal endophthalmitis are associated with cold storage preservation and a poor prognosis of the affected eye. We describe a case of postkeratoplasty candidal endophthalmitis after organ-cultured preservation, with a final visual acuity above expectations. In our opinion, early diagnosis based on routine culturing of the transportation medium and early removal of the infected corneal graft when local antifungal therapy failed are important factors contributing to the good clinical outcome.

Prognostic value of Hutchinson's sign in acute herpes zoster ophthalmicus.

PURPOSE: To determine the prognostic value of nasociliary skin lesions (Hutchinson's sign) for ocular inflammation and corneal sensory denervation in acute herpes zoster ophthalmicus. METHODS: A longitudinal observational study with a 2-month follow-up was performed involving 83 non-immunocompromised adults with acute herpes zoster ophthalmicus, with a skin rash duration of less than 7 days, referred by their general practitioner. All skin lesions at the tip, the side and the root of the nose, representing the dermatomes of the external nasal and infratrochlear branches of the nasociliary nerve, were documented by taking photographs and marking anatomical drawings. Ocular inflammatory signs were observed by slit-lamp biomicroscopy, and corneal sensitivity was measured with the Cochet-Bonnet esthesiometer at 2-month follow-up. RESULTS: Hutchinson's sign was a powerful predictor of ocular inflammation and corneal denervation in herpes zoster ophthalmicus [relative risks: 3.35 (CI 95%: 1.82-6.15) and 4.02 (CI 95%:1.55-10.42), respectively]. The manifestation of herpes zoster skin lesions at the dermatomes of both nasociliary branches was invariably associated with the development of ocular inflammation. CONCLUSION: Clinicians should be alert for early skin lesions within the complete nasociliary dermatome, because they are a reliable prognostic sign of sight-threatening ocular complications in acute herpes zoster ophthalmicus.