Stadiengerechte Therapie der kongenitalen Aniridie

A Cross-sectional Analysis of 556 Eyes Entering the Homburg Aniridia Centre

PURPOSE

Congenital aniridia is a severe malformation of almost all eye segments. In addition, endocrinological, metabolic, and central nervous systems diseases may be present. In order to develop better treatment options for this rare disease, an aniridia center must be established. The purpose of this work is to summarize ophthalmic findings of aniridia subjects examined at the Department of Ophthalmology, Saarland University Medical Center in Homburg.

METHODS

Our retrospective single-center study included patients who underwent a comprehensive ophthalmic examination through the head of the KiOLoN ("Kinderophthalmologie", Orthoptics, Low Vision and Neuroophthalmology) Unit of the department between June 2003 and January 2022. Data at the first examination time point have been included.

RESULTS

Of 286 subjects, 556 eyes of (20.1 ± 20.1 years; 45.5% males) were included. There was nystagmus in 518 (93.7%) eyes, and strabismus in 327 (58.8%) eyes. There were 436 (78.4%) eyes with age-appropriate axial length, 104 (18.7%) eyes with microphthalmos, and 13 (2.3%) eyes with buphthalmos. There was iris malformation with atypical coloboma in 34 eyes (6.1%), more than 6 clock hours of iris remnants in 61 eyes (10.9%), less than 6 clock hours of iris remnants in 96 eyes (17.2%), and complete aniridia in 320 (57.5%) eyes. The patients were graded according to the following aniridia-associated keratopathy (AAK) stages: Stage 0 (96 eyes [17.2%], no keratopathy), Stage 1 (178 eyes [32.0%]), Stage 2 (107 eyes [19.2%]), Stage 3 (67 eyes [12.0%]), Stage 4 (62 eyes [11.1%]), Stage 5 (45 eyes [8.0%]). There was secondary glaucoma in 307 (55.5%), macular hypoplasia in 395 (71.4%), and congenital optic nerve head pathology in 223 (40.3%) eyes. The iris malformation type was significantly positively correlated with AAK stage, lens properties, presence of glaucoma, congenital macular, and optic nerve head properties (p < 0.001 for all), while complete aniridia showed the most complications.

CONCLUSIONS

At the Homburg Aniridia Center, the most common ophthalmic signs in congenital aniridia were AAK, iris malformation, cataract, and macular hypoplasia. The iris malformation type may indicate future expression of AAK, cataract, and glaucoma development and it is correlated with a congenital optic nerve head and macular pathology. Our registry will support further detailed longitudinal analysis of ophthalmic and systemic diseases of aniridia subjects during long-term follow-up.

The Effect of Glaucoma Treatment on Aniridia-Associated Keratopathy (AAK) - A Report from the Homburg Register for Congenital Aniridia

BACKGROUND

Congenital aniridia is a severe malformation of almost all eye segments. Aniridia-associated keratopathy (AAK) and secondary glaucoma, which occur in more than 50% of affected individuals, are typically progressive and pose a high risk of blindness for patients with congenital aniridia. Our aim was to investigate the effect of glaucoma treatment on AAK in patients of the Homburg Aniridia Center.

METHODS

Our retrospective monocentric study included patients who underwent a comprehensive ophthalmological examination at the Homburg Aniridia Center between June 2003 and January 2022.

RESULTS

There were 556 eyes of 286 subjects (20.1 ± 20.1 years; 45.5% males) included. In 307 (55.2%) eyes of 163 subjects (27.5 ± 16.3 years; 43.1% males), glaucoma was present at the time of examination. The mean intraocular pressure in the glaucoma group was 19.0 mmHg (± 8.0), while in the non-glaucoma group, it was 14.1 mmHg (± 3.6) (p < 0.001). In the glaucoma group, 68 patients used antiglaucomatous topical monotherapy, 51 patients used 2 agents, 41 patients used 3 agents, 7 patients used quadruple therapy, and 140 did not use topical therapy (e.g., after pressure-lowering surgery, pain-free end-stage glaucoma, or incompliance). Patients were classified according to the following stages of AAK: Stage 0 (96 eyes [17.2%], no keratopathy), Stage 1 (178 eyes [32.0%]), Stage 2 (107 eyes [19.2%]), Stage 3 (67 eyes [12.0%]), Stage 4 (62 eyes [11.1%]), Stage 5 (45 eyes [8.0%]). The mean stage of AAK was 1.4 (1.2 - 1.5) in the group without eye drops, 1.9 (1.5 - 2.2) in the group with monotherapy, 1.8 (1.5 - 2.1) in the group with 2 drugs, 1.9 (1.5 - 2.2) in the group with 3 drugs, 3.4 (2.3 - 4.6) in the group with 4 drugs, and 3.3 (3.1 - 3.6) after antiglaucomatous surgery. The stage of AAK was significantly positively correlated with the number of pressure-lowering eye drops (p < 0.05) and prior pressure-lowering surgery (p < 0.05). Prostaglandin analogues were not correlated with a higher AAK stage compared to the other drug groups.

CONCLUSIONS

At the Homburg Aniridia Center, patients using topical antiglaucomatous quadruple therapy or who had previously undergone antiglaucomatous surgery had by far the highest AAK stage. The different drug groups had no influence on the AAK stage.

[Modern corneal diagnostics as the key for the correct classification of the disease and optimal treatment decisions]

Corneal diseases include a wide spectrum of different manifestations (inflammatory/noninflammatory) that need to be accurately classified for precise diagnosis and targeted treatment. In addition to the anamnesis and slit lamp biomicroscopy, further device-based examinations can be performed to narrow down the diagnosis. Nowadays, modern corneal imaging provides a variety of technologies, such as topography, tomography, in vivo confocal microscopy and analysis of biomechanics, which are able to reliably classify different pathologies. Knowledge of the available examination modalities helps to guide differential diagnostic considerations, facilitating the indication for stage-appropriate microsurgical intervention.

[Optical rehabilitation and pediatric ophthalmological care following keratoplasty for childhood corneal opacities]

BACKGROUND

The younger the children are at the time of corneal transplantation, the worse the survival prognosis of the graft.

PREOPERATIVE CONSIDERATIONS

Preoperative considerations are significant in terms of accurate parental education, ensuring adherence to treatment and choosing the appropriate surgical time frame (amblyopia versus graft failure, compliance of the patient). Parental education must include the reduced visual prognosis in young children, exceptions being later acquired corneal pathologies such as inflammatory corneal scars (herpes) and keratoconus.

POSTOPERATIVE CARE

A distinction must be made between morphological care after transplantation and refractive correction as well as treatment of amblyopia. The younger the children, the less favorable the prognosis for the transplant and the more often multiple examinations with anesthesia are necessary in order to detect complications, such as infiltrates or suture loosening at an early stage. Especially unilateral congenital pathologies often do not lead to a sufficient improvement of amblyopia (refractory amblyopia, poor compliance).

CONCLUSION

The prognosis after keratoplasty in childhood is already partly decided by the careful evaluation of indications (no surgery of a sclerocornea) and the detailed and realistic clarification for the parents (cooperation with long-term ocular and systemic treatment even if the child has poor compliance, frequent check-ups, reduced chances of amblyopia treatment). The younger the child is at the time of transplantation, the more frequent are graft failure and the development of complications. Later manifesting diseases in older children (herpetic corneal scars, keratoconus) have a better prognosis.

Outcomes of Human Leukocyte Antigen-Matched Allogeneic Cultivated Limbal Epithelial Transplantation in Aniridia-Associated Keratopathy-A Single-Center Retrospective Analysis

PURPOSE

To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivated limbal epithelial stem cell grafts in the treatment of aniridia-associated keratopathy (AAK).

METHODS

Six eyes of 6 patients with severe AAK received an allogeneic stem cell graft between January 2010 and March 2017. Anatomical and functional results were assessed at 6 months, 1 year, 2 years, and the final follow-up visit available. Safety analysis was performed by considering all perioperative and postoperative adverse events and additional surgeries required during the follow-up period.

RESULTS

The mean follow-up was 53.6 months (range 24-104 months). In most patients (80%), there was an early improvement of the keratopathy postoperatively, which slowly regressed during longer follow-up. At the final follow-up, 4 of the eyes were graded as failure and 1 eye was graded as partial success. Grading the sixth eye was not possible because of an adverse event. None of the patients maintained a total anatomical success in the long-term. Only 1 patient maintained a modest improvement in best-corrected visual acuity from hand motion to counting fingers. Four serious adverse events were recorded in 2 patients.

CONCLUSIONS

Severe AAK remains a challenging condition to manage. Transplantation of allogenic ex vivo cultivated limbal stem cells may provide a temporary improvement in ocular surface stability, but anatomical and functional results are poor in the long-term. The eyes are prone to adverse events, and any surgical treatment should take this into consideration.

An attempt to optimize the outcome of penetrating keratoplasty in congenital aniridia-associated keratopathy (AAK)

Purpose

To propose an optimized microsurgical and medical approach to reduce the risk of complications after penetrating keratoplasty (PKP) in patients with aniridia-associated keratopathy (AAK).

Methods

Retrospective observational case series of 25 PKP performed in 16 patients with AAK. Preoperative indications were endothelial decompensation and vascularized scars (68%) or graft failure (32%) due to limbal stem cell deficiency. The optimized approach included a combination of a small corneal graft size (around 7.0 mm), interrupted 10–0nylon sutures, simultaneous AMT as a patch, large bandage contact lens, temporary lateral tarsorrhaphy, postoperative autologous serum eye drops, and systemic immunosuppression. Main outcome measures included: visual acuity, transplant survival, and complications encountered during follow-up of 107 weeks on average.

Results

A complete modified keratoplasty scheme was used in 10 of 25 PKP (group 1), while at least one of the modifications was missing in the other 15 PKP (group 2). After 8 weeks of follow-up, the epithelium was closed in 23 eyes. Visual acuity improved in 19 eyes at 6 months of follow-up, and remained stable in six eyes. None of the eyes showed a decrease in visual acuity. At the last post-operative follow-up, this visual improvement persisted in 14 eyes and graft survival rate after 156 weeks (3 years) was 69% in group 1 versus 44% in group 2 (p = 0.39, log-rank test). Secondary corneal neovascularization (8%), scarring (4%), ulcer (4%), or graft rejection (8%) happened mostly in the second group which was missing at least one of the suggested modifications.

Conclusions

PKP in congenital aniridia must be considered as a high-risk keratoplasty. An optimized therapeutic approach seems to be promising in order to reduce the postoperative complication rate in these most difficult eyes.

Congenital aniridia - A comprehensive review of clinical features and therapeutic approaches

Congenital aniridia is a rare genetic eye disorder with total or partial absence of the iris from birth. In most cases the genetic origin of aniridia is a mutation in the PAX6 gene, leading to involvement of most eye structures. Hypoplasia of the fovea is usually present and is associated with reduced visual acuity and nystagmus. Aniridia-associated keratopathy, glaucoma, and cataract are serious and progressive complications that can further reduce visual function. Treatment of the ocular complications of aniridia is challenging and has a high risk of side effects. New approaches such as stem cell therapy may, however, offer better prognoses. We describe the various ocular manifestations of aniridia, with a special focus on conditions that commonly require treatment. We also review the growing literature reporting systemic manifestations of the disease.

The application of human amniotic membrane in the surgical management of limbal stem cell deficiency

The application of human amniotic membrane (AM) has a wide spectrum of indications in the treatment of ocular surface disorders. Transplantation of AM has been incorporated routinely as a component of ocular surface reconstruction in a variety of ocular pathologies. The application of human AM can be combined with nearly all types of limbal transplantation in treating limbal stem cell deficiency (LSCD). AM provides support and possible protection to the transplanted limbal tissues and limbal stem cells owing to its mechanical and biological properties, and these properties are thought to enhance the success rate of LSC transplantation. This paper reviews the current literature on the applications of AM in the surgical management of LSCD and summarizes the outcome of different surgical approaches. The current literature contains mostly low-level evidences in supporting the role of AM. The efficacy of AM in LSC transplantation needs to be confirmed by randomized controlled clinical trials.

Clinical anatomy of the anterior chamber angle in congenital aniridia and consequences for trabeculotomy/cyclophotocoagulation

Intraocular pressure lowering surgery in congenital aniridia glaucoma (CAG) can be complicated by dysgenesis of the limbal region, anterior chamber angle, iris, and lens. The anterior segments of 23 eyes (17 patients) with congenital aniridia were investigated under general anesthesia using ultrasound biomicroscopy (UBM). The structures of the anterior segment were examined: distance of ciliary body processes from the anterior chamber angle and positioning of Schlemm's canal. A surgical plan was created on the basis of these data. Schlemm's canal was detected in 21 of the 23 examined eyes. The mean distance from the anterior chamber angle was 1.3 ± 0.4 mm (range: 0.5-to 2.1 mm). The mean distance between the anterior chamber angle and the ciliary body was 561 ± 301 µm (range: 270-1,300 µm). The mean prominence of the ciliary body towards the lens was 799 ± 352 µm (range: 210-1,660 µm). This resulted in a precise UBM-based trabeculotomy. In addition, the ciliary body was detected and coagulated ab externo with a diode laser probe (810 nm) using diaphanoscopy and UBM. An initial UBM examination of the anterior segment is essential in eyes with CAG scheduled for trabeculotomy or cyclophotocoagulation. Clin. Anat. 31:64-67, 2018. © 2017 Wiley Periodicals, Inc.

Congenital Aniridia and the Ocular Surface

Aniridia is a congenital pan-ocular disorder caused by haplo-insufficiency of Pax6, a crucial gene for proper development of the eye. Aniridia affects a range of eye structures, including the cornea, iris, anterior chamber angle, lens, and fovea. The ocular surface, in particular, can be severely affected by a progressive pathology termed aniridia-associated keratopathy (AAK), markedly contributing to impaired vision. The purpose of this review is to provide an update of the current knowledge of the genetic, clinical, micro-morphological, and molecular aspects of AAK. We draw upon material presented in the literature and from our own observations in large aniridia cohorts. We summarize signs and symptoms of AAK, describe current options for management, and discuss the latest research findings that may lead to better diagnosis and new treatment or prevention strategies for this debilitating ocular surface condition.