Stage-Related Therapy of Corneal Dystrophies
ABSTRACT Corneal dystrophies typically result in a gradual bilateral loss of vision in a primary 'white eye' - often in conjunction with epithelial defects in later stages. Treatment of corneal dystrophies needs to be stage-related. To ensure a stage-related therapeutic approach, an adequate classification based on clinical, histopathological and genetic knowledge is indispensable. In principle, topical medications, contact lenses and various microsurgical approaches are applicable. In case of predominantly superficial dystrophies of the epithelium, basal membrane and/or Bowman's layer (map-dot-fingerprint, Meesmann, Lisch, Reis-Bücklers, Thiel-Behnke), recurrent epithelial defects may complicate the clinical picture. If conservative therapy with gels/ointments, application of therapeutic contact lenses and/or conventional corneal abrasion are not successful, phototherapeutic keratectomy (PTK) using a 193-nm excimer laser is the method of choice today. PTK can be repeated several times, thus post poning corneal transplantation (lamellar or even penetrating) for a long time. Three major goals may be achieved by PTK depending on the diagnosis: (1) to remove superficial opacities; (2) to regularize the surface and treat irregular astigmatism, and (3) to improve the adherence of the epithelium. In dystrophies with depositions predominantly in the stroma (e.g. granular, lattice, macular, recurrence on the graft), PTK may be a reasonable alternative to anterior lamellar or penetrating keratoplasty (PKP) depending on the exact localization of the lesions. Besides exact determination of the depth of depositions using a slit lamp, a preoperative topography analysis is indispensable. The therapy of endothelial dystrophies depends on diagnosis and age: Fuchs endothelial corneal dystrophy will need corneal transplantation (e.g. when visual acuity drops below 0.4). In contrast, transplantation will only be very rarely necessary in posterior polymorphous corneal dystrophy, but the intraocular pressure has to be checked frequently. Especially in elderly patients with reduced compliance, posterior lamellar keratoplasty - preferably in the form of Descemet stripping automated endothelial keratoplasty - may be performed instead of PKP. In case of congenital hereditary endothelial dystrophy, the best time point of PKP has to be determined with regard to amblyopia (surgery too late) and inadequate follow-up (surgery too early) together with parents and pediatric ophthalmologists on an individual basis. In conclusion, for stage-related therapy of corneal dystrophies, besides contact lenses, PTK and PKP, various techniques of lamellar keratoplasties represent an indispensable enrichment of our corneal microsurgical spectrum today.
- SourceAvailable from: Hermann A M Mucke[Show abstract] [Hide abstract]
ABSTRACT: We have used a focused and comprehensive ophthalmology patent database to characterize the international patenting landscape dedicated to the pharmacological treatment of cataract, corneal opacities and dystrophies, and complicated refractive errors. A total of 201 disclosures related to cataract or corneal clouding (published between 1982 and 2011), and 99 documents (published between 1991 and 2011) related to refractive or geometry errors were identified. Current applications for the treatment or prevention of primary cataract have ceased to address diabetic cataract specifically through the inhibition of glycation-specific mechanisms. The most innovative approaches for pharmacotherapy of the lens focus on phase separation inhibitors, modulators of the TGF-β pathway, and matrix metalloproteinase inhibition. Patenting for the prevention of secondary cataracts as a delayed complication of intraocular lens insertion follows similar routes. For keratoconus, progressive myopia and Avellino corneal dystrophy, the focus remains on efficiently stabilizing the corrected shape of the cornea in the course of orthokeratology treatments. We expect future patenting in the fields of our investigation to concentrate more heavily on molecular medicine, in close lockstep with biotechnology and genetic testing.Pharmaceutical patent analyst 05/2012; 1(2):165-75. DOI:10.4155/ppa.12.23
- [Show abstract] [Hide abstract]
ABSTRACT: PURPOSE:: To report the perioperative complications and clinical outcomes after deep anterior lamellar keratoplasty (DALK) using the big bubble technique in eyes with stromal corneal dystrophies. PATIENTS AND METHODS:: Seventy-four eyes of 65 patients who underwent DALK for stromal corneal dystrophies were evaluated in this retrospective interventional case series study. Main outcome measures were intraoperative and postoperative complications, postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, spherical equivalent refraction, and topographic astigmatism. RESULTS:: There were 44 eyes with macular corneal dystrophy, 18 eyes with lattice dystrophy, and 12 eyes with granular dystrophy. DALK was completed in 69 cases (94.6%). Descemet membrane microperforations occurred in 6 eyes (8.7%). The mean follow-up period was 43.5 ± 23.9 months, ranging from 12 to 96 months. Postoperative best spectacle-corrected visual acuity of 0.5 or better was present in 52 of 69 eyes (75.4%). There were 3 episodes of stromal graft rejection, which responded to topical therapy. Lattice dystrophy recurred in 6 eyes (35.3%). CONCLUSION:: DALK using the big bubble technique is an effective procedure in the treatment of patients with corneal stromal dystrophies. Recurrence of lattice dystrophy was relatively high.Cornea 07/2012; 32(3). DOI:10.1097/ICO.0b013e31825718ca · 2.36 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Concomitant with new innovations in the field of refractive surgery, therapeutic excimer laser applications like phototherapeutic keratectomy (PTK) and topography-guided customised ablation treatment are gaining high importance and undergoing rapid evolution. Nowadays, PTK is an effective treatment modality for superficial corneal pathologies. Primary indications are decreased epithelial adherence, superficial opacifications and an irregular corneal surface. For the right indication and successful treatment of corneal pathologies with PTK, a knowledge of the size, depth and nature of the pathology, as well as the refractive status of both eyes is important. Next to slit-lamp examination, objective measuring systems like the topography, confocal microscopy and the anterior segment OCT facilitate presurgical planning. Regarding the treatment procedure the surgeon can choose between a variety of methods. PTK can be combined with manual epithelial debridement or done by only using the excimer laser. In the case of an irregular corneal surface, depending on the pathology, masking fluids or topography-guided custom ablation protocols can increase the visual outcome. To avoid recurrence of the underlying pathology (e.g., corneal dystrophy, haze), the topical application of 0.02 % mitomycin C for 20-60 seconds has proved to be a safe and effective procedure. If the surgeon considers all the patient-related factors carefully and manages to combine the available treatment options correctly, PTK embodies an effective and minimally invasive alternative to lamellar or penetrating keratoplasty.Klinische Monatsblätter für Augenheilkunde 06/2013; 230(6):595-603. DOI:10.1055/s-0032-1328507 · 0.67 Impact Factor