Daniel Röck

Influence of Axial Length on Thickness Measurements Using Spectral-Domain Optical Coherence Tomography

PURPOSE The purpose of this study was to assess the influence of axial length on spectral-domain optical coherence tomography (SD-OCT) thickness measurements in patients with subretinal visual implants. METHODS Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implants were analyzed retrospectively. These patients participated in the monocentric part of a multicenter trial. The axial length was measured in three short (<22.5 mm), three medium (22.51-25.50 mm), and two long (>25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of a subretinal implant microchip (70 μm) was measured on 15 images per eye with SD-OCT, using the software calipers. RESULTS The mean axial length was 20.8 ± 0.8 mm in short eyes, 23.3 ± 0.4 mm in medium eyes, and 26.3 ± 0.5 mm in long eyes. We found in short eyes, in medium eyes, and in long eyes a mean value of microchip thickness measurements from SD-OCT of 82.9 ± 1.4 μm, 70.5 ± 1.3 μm, and 64.2 ± 1.3 μm, respectively. The thickness measurements decreased in SD-OCT measurements with longer axial lengths significantly (P < 0.0001). CONCLUSIONS Axial length influences SD-OCT thickness measurements. Our findings demonstrate accuracy of the scaling in SD-OCT thickness measurements in emmetropic medium eyes. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. There is a need for larger sample-size studies to confirm our results. (ClinicalTrials.gov number, NCT01024803.).

Evaluation of Factors Limiting Corneal Donation

BACKGROUND This study aimed to investigate factors limiting corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS We retrospectively studied all hospital deaths from January 2012 to December 2015, considering each deceased patient as a potential corneal donor. During this period an ophthalmic resident managed corneal donor procurement on a full-time basis. Various factors limiting corneal donation were examined. RESULTS Among the 3412 deaths, 2937 (86.1%) displayed nonfulfillment of corneal donation. Consent for corneal donation was obtained in 475 cases (13.9%). The mean annual corneal donation rate was 13.9 donors per 100 deaths (range: 11.2-17.8). The leading causes of nonfulfillment of corneal donations were refusal to donate (49.8%, 1698 cases) and medical contraindications (23.6%, 805 cases). After next-of-kin interview of 2173 potential donors (109 potential donors were excluded because of logistical problems), willingness to participate in corneal donation was present in 475 cases (21.9%), whereas in 1698 cases (78.1%) corneal donation was refused. CONCLUSIONS Our study showed refusal to donate is the most important factor limiting corneal donation. It seems that increasing the knowledge of people about corneal donation through public education and media are necessary to address the corneal shortage.

Reduktion der postoperativen Endophthalmitisrate durch intrakamerale Cerfuroximgabe: Ergebnisse aus 5 Jahren Erfahrungen an der Universitäts-Augenklinik Tübingen

BACKGROUND Cataract surgery is the most commonly performed surgical procedure in developed countries. The annual number of cataract surgeries in Germany is about 600,000. Acute postoperative endophthalmitis is a very severe and the most dreaded complication of cataract surgery. Various operative and non-operative measures have been suggested to prevent this serious complication. The European Society of Cataract & Refractive Surgeons (ESCRS) study of intracameral cefuroxime was the first prospective, randomised and partially placebo-controlled clinical trial showing the efficacy of antibiotic prophylaxis to prevent endophthalmitis in 2007. The aim of this retrospective study is to investigate a possible reduction of intracameral cefuroxime to prevent postoperative endophthalmitis at the University Eye Hospital Tübingen. PATIENTS AND METHODS During the period from January 2002 to August 2013, 2 time periods were determined based on the adoption of intracameral cefuroxime injections after cataract surgery. From January 2002 to May 2009 patients received at the end of cataract surgery a subconjunctival administration of 50 mg of mezlocillin and postoperative antibiotic eye drops (gentamicin) without intracameral injection. From June 2009 to August 2013, patients received an intracameral injection of cefuroxime while antibiotic drops (moxifloxacin) were used too. The rates of postoperative infectious endophthalmitis during these 2 periods were calculated. RESULTS 31 cases of endophthalmitis occurred in 31,386 cataract surgeries. The overall cumulative incidence was 0.99 per 1000 patients. The incidence in the first period without intracameral cefuroxime injection was 1.38 (95 % confidence interval [CI]: 1.03-1.72) per 1000 patients and in the second period 0.44 (95 % CI: 0.34-0.54) per 1000 patients (p < 0.001). CONCLUSION Intracameral injection of cefuroxime reduces the rate of postoperative infectious endophthalmitis in cataract surgery significantly.

Descemet membrane endothelial keratoplasty in cases with existing scleral-sutured and iris-sutured intraocular lenses

BackgroundTo report two cases of Descemet Membrane Endothelial Keratoplasty (DMEK) in patients with existing scleral-fixated and iris-fixated intraocular lenses (sf-IOL and if-IOL, respectively).Case presentationDMEK procedures were performed on a 49-year-old woman with a pre-existing sf-IOL (case 1) and a 69-year-old woman with a pre-existing if-IOL (case 2) in order to treat secondary corneal edema due to pseudophakic bullous keratopathy. Visual acuity, refractive error, intraocular pressure, slit lamp examination, pachymetry measurements and endothelial cell density (ECD) were considered and repeated during follow-ups.Both cases had no intraoperative complications. At postoperative day 1 graft centration and complete attachment were noted. The IOL positions were unchanged in comparison to their preoperative positions. In case 1, visual acuity improved from 1/15 at 1 meter preoperative to 20/200 within one week and to 20/63 within 12 weeks of follow up. In case 2, visual acuity improved from counting fingers at 1 meter preoperative to 20/200 within one week and to 20/100 within 12 weeks of follow-up. In case 2 a partial graft dislocation was observed at postoperative day twenty. Complete graft re-apposition was achieved by rebubbling procedure performed with intracameral air injection.ConclusionsDMEK surgery in the treatment of pseudophakic bullous keratopathy in the presence of sf-IOL and if-IOL can successfully be performed. These eyes are at increased risk of IOL dislocation into the vitreous cavity during DMEK surgery.

Rates of and Experiences with Corneal Donation at the University Hospital Tübingen From 2002 To 2015

BACKGROUND This study aimed to report the rates and experiences of corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS Data from all cornea donors from January 2002 to December 2015 were analyzed. The rates of corneal donation were examined. From 2002 to 2008, an ophthalmic resident handled the corneal donor procurement in addition to his ward work. From 2009 to 2015, an ophthalmic resident handled the corneal donor procurement on a full-time basis. RESULTS Among the 10 260 deaths, consent for corneal donation was obtained in 892 cases. The mean annual corneal donation rate was 8.7 donors per 100 deaths (range: 2.0-17.8). The mean corneal donation rate in the first period without a full-time ophthalmic resident in the eye bank team was 4.0 donors per 100 deaths (95 % confidence interval [CI]: 1.0-6.9) and in the second period 12.3 donors per 100 deaths (95 % CI: 3.2-21.5) (P<0.0001). Comparing the periods before and after the modification of the eye bank team, the corneal donation rate was increased by more than 3 times. CONCLUSIONS Our study showed the influence of the eye banking team on the corneal donation rate. Modification of the eye bank team, by recruiting a full-time resident at a University Hospital with 1500 beds, increased the corneal donation rate by more than 3 times. It appears necessary to strengthen this team with sufficient staff levels to improve donor rates.

Effect of Organ Scandal on Corneal Donation Rate and Organ Donors at a German University Hospital

BACKGROUND The purpose of this study was to assess the effect of an organ transplantation scandal on the rate of corneal donations and organ donors at the University Hospital Tübingen. MATERIAL AND METHODS Data from all hospital deaths from January 2012 to December 2013 were analyzed retrospectively. Each deceased patient was considered as a potential corneal donor. The corneal donor procurement was handled by an ophthalmic resident on a full-time basis with standard used unchanged set of procedures. Each patient who died due to cerebral complications was considered as a potential organ donor. During the two-year period, a German transplantation scandal occurred at the end of 2012 and received worldwide attention. The rates of corneal donation and organ donation in 2012 and 2013 were examined and evaluated. RESULTS Among the 1685 deceased patients, approval for corneal donation was received in 220 cases (13.1%): 124 cases (15.0%) in 2012 and 96 cases (11.2%) in 2013. This corresponds to a decline of 23%. The leading causes of nonfulfillment of corneal donations were refusal to donation: 401 cases (48.4%) in 2012 and 445 cases (52.0%) in 2013; and medical contraindications: 201 cases (24.2%) in 2012 and 212 cases (24.8%) in 2013. During the two-year period, consent for organ donation was obtained in 25 cases (1.5%): 15 cases (1.8%) in 2012 and 10 cases (1.2%) in 2013. The number of realized organ donors was 20 cases (1.2%): 12 cases (1.4%) in 2012 and 8 cases (0.9%) in 2013. This corresponds to a decline of 33%. CONCLUSIONS After a transplantation scandal, the number of realized corneal donors and realized organ donors decreased significantly. It seems that increasing professional performance is very important to gaining trust inside and outside the hospital and improving corneal and organ donation rate.

Factors influencing the contamination rate of human organ-cultured corneas

To assess the influence of donor, environment and storage factors on the contamination rate of organ‐cultured corneas, to consider the microbiological species causing corneal contamination and to investigate the corresponding sensitivities.

Trends in corneal transplantation at the University Eye Hospital in Tübingen, Germany over the last 12 years: 2004 – 2015

Purpose This study aimed to investigate the trends in the surgical methods and leading indications for corneal transplantations carried out over the last 12 years. Methods The data from the corneal graft waiting list and from all keratoplasties carried out between 2004 and 2015 at the University Eye Hospital in Tübingen were retrospectively analyzed. Results A total of 1,185 keratoplasties were performed between 2004 and 2015 at this hospital. The most common surgical indications for corneal transplantation were Fuchs’ endothelial corneal dystrophy (35.2%) and keratoconus (18.9%) with keratoconus being the leading cause during early years (from 2004 to 2009) and Fuch’s dystrophy being the leading cause from 2010 to 2015. Overall, the total count of performed keratoplasties increased, from 385 corneal transplantations during the first 6-year period to 800 corneal transplantations during the second 6-year period (P = 0.008, using Mann-Whitney test). The Descemet’s membrane endothelial keratoplasty has become the favored surgical method for endothelial disorders with the number of Descemet’s membrane endothelial keratoplasties increasing significantly from 2008 to 2015. This increasing trend was statistically significant (P < 0.001 using multivariate adaptive regression splines (MARS). A decreasing trend was also noted for the rate of penetrating keratoplasty since 2008 (P < 0.001 using MARS). Conclusions This research showed major changes in the preferred corneal transplantation techniques and leading indications for keratoplasty over the last 12 years. More importantly, it seems that the rapid development and implementation of endothelial keratoplasty, especially the Descemet’s membrane endothelial keratoplasty, has had a profound effect on and begun a new era in corneal transplantation.

Surgical management of a conjunctival nevus with amniotic membrane transplantation

Purpose Nevi of the conjunctiva are usually benign pigmented tumorous lesions located in the bulbar conjunctiva. In most conjunctival nevus cases, the patient wants the lesion to be removed for cosmetic reasons, but excisional biopsies are best for lesions suspicious for malignancy. This case report illustrates the intraoperative surgical management, histological findings, and the course of healing in a conjunctival nevus patient. Case report A 26-year-old man was referred to our eye hospital with a large bulbar conjunctival nevus of the right eye. Upon examination, there was a large pigmented lesion with numerous small cysts present on the superior bulbar conjunctiva. The conjunctival tumor was resected, and an amniotic membrane transplantation was performed for the bulbar conjunctival reconstruction. The histopathological diagnosis suggested a conjunctival nevus. After the resection, a reduction in the inflammation and healing of the conjunctival lesion could be seen. The epithelialization of the bulbar conjunctiva over the amniotic membrane was complete 4 weeks after the resection. At the 6-month follow-up, there was no sign of recurrence or any postoperative complications. Conclusion A surgical excision combined with reconstruction via amniotic membrane transplantation is effective and economical for the treatment of large conjunctival lesions.

Management of a neurotrophic deep corneal ulcer with amniotic membrane transplantation in a patient with functional monocular vision: A case report

Rationale: Amniotic membrane transplantation (AMT) has been performed therapeutically in humans for over 100 years. In recent 2 decades AMTs have been used increasingly and successfully to treat various types of ophthalmic indications. Patient concerns: An 83-year-old man was referred to our eye hospital with a refractory neurotrophic deep corneal ulcer of the left eye. Diagnoses: The best-corrected visual acuity of the left eye was 0.5 (0.3 logMAR) and of the right eye was 0.05 (1.3 logMAR), which was caused by a central retinal vein occlusion 5 years previously. In cases of binocular vision, a large amniotic membrane patch can cover the whole cornea, including the optical axis. However, in cases with functional monocular vision, as in the case reported here, the AMT has to be performed without the involvement of the optical axis to ensure vision for the patient. Otherwise the patient would have a massively restricted view like looking through waxed paper for at least 2–4 weeks until the overlay dissolved. Interventions: For this case, an AMT using a modified sandwich technique was applied without involvement of the optic axis to ensure vision for the patient. This case report illustrates this eyes course of healing over time. Outcomes: A reduction in the inflammation and healing of the corneal ulcer could be seen. In addition, the corneal vascularization decreased. Six months after the AMT, a slit-lamp examination revealed stable findings. The best-corrected visual acuity of the left eye had increased to 0.8 (0.1 logMAR). Lessons: To the best of our knowledge, a case report on the management of a neurotrophic deep corneal ulcer with AMT in a patient with functional monocular vision has never been undertaken before.