Tobias Hager

Confocal microscopy in acanthamoeba keratitis as an early relapse-marker

Acanthameoba keratitis is a serious ophthalmological condition with a potentially vision‐threatening prognosis. Early diagnosis and recognition of relapse, and the detection of persistent Acanthamoeba cysts, are essential for informing the prognosis and managing the condition. We suggest the use of in vivo confocal microscopy not only to identify the early signs of relapse after keratoplasty in patients with Acanthamoeba keratitis, but also as an additional follow‐up tool after antimicrobial crosslinking. This study shows that in vivo confocal microscopy is, in experienced hands, a quick and reliable diagnostic tool. Clin. Anat. 31:60–63, 2018.

Clinical Phenotypes of Fuchs Endothelial Corneal Dystrophy (FECD), Disease Progression, Differential Diagnosis, and Medical Therapy

The hallmark of Fuchs endothelial corneal dystrophy (FECD) is corneal “guttae”. However, some eyes with cornea guttata will never progress to FECD! Thus, we should talk about FECD not before endothelial decompensation = “swelling” = “increased central corneal thickness” does occur. Early-onset FECD with well-defined genetic cause must be differentiated from late-onset FECD. Differential diagnosis to other endothelial dystrophies is typically an easy task. FECD must be differentiated from pseudoexfoliation (PEX) keratopathy with respect to incidence of secondary glaucoma, therapeutic necessities, and prognosis of corneal transplantation. Concerning microsurgery, FECD is a friend, while PEX keratopathy is a challenge. Thus, differentiation to PEX keratopathy is not just an academic problem! Progression of FECD cannot be defined via endothelial cell counts, because numbers are notoriously measured wrong. Neither manual nor automated endothelial cell count will give valid results in case of unevenly distributed guttae. Progression should be defined via best-corrected visual acuity (worse morning vs afternoon), glare, corneal thickness profile (tomography), and cell morphology. For many decades, symptomatic medical therapy consisted of unpreserved hyperosmolar (5 %) sodium chloride solution. Preclinical causative approaches include lithium, N-acetylcysteine, and the ROCK inhibitor.

Ocular side effects of biological agents in oncology: what should the clinician be aware of?

During the last 20 years, biologicals have become increasingly relevant in oncologic therapy. Depending on the medication used, there are different profiles of ocular side effects. Although these can be present in up to 70% of patients, they are generally underreported in the literature. Therefore, the pathophysiological details of their development are often poorly understood. Herein we attempt to identify groups of biologicals to which a specific side effect profile can be assigned. We also tried to capture all relevant side effects and therefore conducted several database investigation including Medline, Cochrane library, and the drugs section of the US Food and Drug Administration (FDA), using the following search strings: “name of biological agent (both generic and commercial names)” AND “eye” OR “ocular”. If we found a side effect that has been associated with a drug, we researched Medline using the following search string: “name of biological agent” (both generic and commercial names) AND “term for the specific side effect”. Due to the wealth of material we report only the drugs that are approved by the FDA.

Penetrating Keratoplasty for Keratoconus – Excimer Versus Femtosecond Laser Trephination

Background: In case of keratoconus, rigid gas-permeable contact lenses as the correction method of first choice allow for a good visual acuity for quite some time. In a severe stage of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no more tolerated. In case of existing contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis. Methods: In case of advanced keratoconus – especially after corneal hydrops due to rupture of Descemet’s membrane – penetrating keratoplasty (PKP) still is the surgical method of first choice. Noncontact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in case of “keratoconus recurrences” due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size („as large as possible – as small as necessary“). Limbal centration will be preferred intraoperatively due to optical displacement of the pupil. During the last 10 years femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach. Results: Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces “vertical tilt” and “horizontal torsion” of the graft in the recipient bed, thus resulting in significantly less “all-sutures-out” keratometric astigmatism (2.8 vs. 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. Refractive outcomes of femtosecond laser keratoplasty, however, resemble that of the motor trephine. Conclusions: In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination with intraoperative pitfalls and high postoperative astigmatism.

Excimer versus Femtosecond Laser Assisted Penetrating Keratoplasty in Keratoconus and Fuchs Dystrophy: Intraoperative Pitfalls

Purpose. To assess the intraoperative results comparing two non-mechanical laser assisted penetrating keratoplasty approaches in keratoconus and Fuchs dystrophy. Patients and Methods. 68 patients (age 18 to 87 years) with keratoconus or Fuchs dystrophy were randomly distributed to 4 groups. 35 eyes with keratoconus and 33 eyes with Fuchs dystrophy were treated with either excimer laser ([Exc] groups I and II) or femtosecond laser-assisted ([FLAK] groups III and IV) penetrating keratoplasty. Main intraoperative outcome measures included intraoperative decentration, need for additional interrupted sutures, alignment of orientation markers, and intraocular positive pressure (vis a tergo). Results. Intraoperative recipient decentration occurred in 4 eyes of groups III/IV but in none of groups I/II. Additional interrupted sutures were not necessary in groups I/II but in 5 eyes of groups III/IV. Orientation markers were all aligned in groups I/II but were partly misaligned in 8 eyes of groups III/IV. Intraocular positive pressure grade was recognized in 12 eyes of groups I/II and in 19 eyes of groups III/IV. In particular, in group III, severe vis a tergo occurred in 8 eyes. Conclusions. Intraoperative decentration, misalignment of the donor in the recipient bed, and need for additional interrupted sutures as well as high percentage of severe intraocular positive pressure were predominantly present in the femtosecond laser in keratoconus eyes.

[Treatment of pediatric cataracts. Part 2: IOL implantation, postoperative complications, aphakia management and postoperative development].

There is a lot of uncertainty concerning intraocular lens (IOL) implantation for pediatric cataracts. The appropriate age which ocular abnormalities are contraindications and according to which formula IOL should be calculated are controversial. In addition to the imperative of identifying postoperative complications, such as secondary cataract formation and secondary glaucoma in a sufficiently timely manner, a modern management of aphakia with refractive compensation and occlusion is necessary. Some easy rules can help prevent pitfalls.ZusammenfassungBezüglich der Intraokularlinsen (IOL)-Implantation bestehen bei der kindlichen Katarakt viele Unsicherheiten. Umstritten sind das geeignete Alter, welche okulären Veränderungen Kontraindikationen darstellen und nach welchen Formeln die IOL berechnet werden sollte. Neben der Notwendigkeit, postoperative Komplikationen wie Nachstarentwicklung und Sekundärglaukom rechtzeitig zu erkennen, ist in der Nachbetreuung ein modernes Aphakiemanagement mit Refraktionsausgleich und Okklusion notwendig. Einige einfache Regeln können hier helfen, Versäumnissen vorzubeugen.AbstractThere is a lot of uncertainty concerning intraocular lens (IOL) implantation for pediatric cataracts. The appropriate age which ocular abnormalities are contraindications and according to which formula IOL should be calculated are controversial. In addition to the imperative of identifying postoperative complications, such as secondary cataract formation and secondary glaucoma in a sufficiently timely manner, a modern management of aphakia with refractive compensation and occlusion is necessary. Some easy rules can help prevent pitfalls.

Behandlung der kindlichen Katarakte

There is a lot of uncertainty concerning intraocular lens (IOL) implantation for pediatric cataracts. The appropriate age which ocular abnormalities are contraindications and according to which formula IOL should be calculated are controversial. In addition to the imperative of identifying postoperative complications, such as secondary cataract formation and secondary glaucoma in a sufficiently timely manner, a modern management of aphakia with refractive compensation and occlusion is necessary. Some easy rules can help prevent pitfalls.ZusammenfassungBezüglich der Intraokularlinsen (IOL)-Implantation bestehen bei der kindlichen Katarakt viele Unsicherheiten. Umstritten sind das geeignete Alter, welche okulären Veränderungen Kontraindikationen darstellen und nach welchen Formeln die IOL berechnet werden sollte. Neben der Notwendigkeit, postoperative Komplikationen wie Nachstarentwicklung und Sekundärglaukom rechtzeitig zu erkennen, ist in der Nachbetreuung ein modernes Aphakiemanagement mit Refraktionsausgleich und Okklusion notwendig. Einige einfache Regeln können hier helfen, Versäumnissen vorzubeugen.AbstractThere is a lot of uncertainty concerning intraocular lens (IOL) implantation for pediatric cataracts. The appropriate age which ocular abnormalities are contraindications and according to which formula IOL should be calculated are controversial. In addition to the imperative of identifying postoperative complications, such as secondary cataract formation and secondary glaucoma in a sufficiently timely manner, a modern management of aphakia with refractive compensation and occlusion is necessary. Some easy rules can help prevent pitfalls.

Multiphoton tomography of the human eye

Multiphoton tomography (MPT) is a novel label-free clinical imaging method for non-invasive tissue imaging with high spatial (300 nm) and temporal (100 ps) resolutions. In vivo optical histology can be realized due to the nonlinear excitation of endogenous fluorophores and second-harmonic generation (SHG) of collagen. Furthermore, optical metabolic imaging (OMI) is performed by two-photon autofluorescence lifetime imaging (FLIM). So far, applications of the multiphoton tomographs DermaInspect and MPTflex were limited to dermatology. Novel applications include intraoperative brain tumor imaging as well as cornea imaging. In this work we describe two-photon imaging of ex vivo human corneas unsuitable for transplantation. Furthermore, the cross-linking (CXL) process of corneal collagen based on UVA exposure and 0.1 % riboflavin was studied. The pharmacokinetics of the photosensitizer could be detected with high spatial resolution. Interestingly, an increase in the stromal autofluorescence intensity and modifications of the autofluorescence lifetimes were observed in the human corneal samples within a few days following CXL.

Intraocular juvenile xanthogranuloma of the iris in an adult patient

Purpose Juvenile xanthogranuloma (JXG) is a rare histiocytic skin disease primarily of young children, which may also affect ocular structures and in particular the iris. Observations This is a case report of a fifty-year-old patient without skin lesions showing a progressive decrease of visual acuity, iris vascularization and a yellowish iris tumor in the iridocorneal angle of his right eye. Treatment with topical and systemic prednisolone led to full recovery of visual acuity, tumor regression and restitutio ad integrum. Conclusions and importance Although the juvenile xanthogranuloma is a very rare skin disease of young children, it may also affect the eye and in particular the iris in adult patients. There exists no standard treatment, the first-line therapy in most cases, however, is topical and systemic prednisolone application.

[Treatment of cataracts in childhood I: clinical picture und surgical approach].

Despite progress in microsurgical treatment, pediatric cataracts still imply potential risks for pathological unilateral or bilateral visual and binocular development. Surgical approaches have changed fundamentally over the last 30 years which are directly associated with modifications in the postoperative care. Due to these parallel developments a continuous dynamic process arises between anterior segment surgeons and pediatric ophthalmologists so that only small case series exist which try to combine both subspecialties because until now it was not possible to gather enough experience with a single linear approach. The first article of this two part series will explain the variability of the disease and surgical approaches and the second part will try to convey a linear approach for the postoperative care.