A Case Report of Successful Cataract Surgery in Theil-Behnke Corneal Dystrophy: A Visual Rehabilitation for the Patient Open Access

Thiel-Behnke corneal dystrophy is a genetic disorder impacting both the corneal stroma and epithelium, leading to progressive vision problems. Corneal dystrophies are inherited disorders where abnormal material builds up in the cornea, affecting its transparency and refractive ability [1]. Typically beginning in early adulthood, symptoms may include recurring corneal erosions, pain, and sensitivity to light. The condition is autosomal dominant and is diagnosed through clinical corneal dystrophies by location: epithelial and subepithelial, TGFB1-related dystrophies, stromal, and endothelial. Due to its rarity, Thiel-Behnke corneal dystrophy is often mistaken for other dystrophies or keratitis. The condition is associated with mutations in the TGFB1 gene located on chromosome 5q31 [2‒7]. Early identification and proper management are critical to halt progression and preserve sight.

Here, we present case of a woman with corneal dystrophy affecting both eyes, matching the features of Thiel-Behnke dystrophy. The patient was initially treated conservatively for her dystrophy. This case report is unique as she later underwent surgical treatment for her cataract in the left eye even with the dystrophy and she had good visual outcomes.

A woman in her early 50s without any notable medical history reported increasing blurring of vision in her left eye over the last 3 months, along with a history of recurrent corneal erosions in childhood. There was no history of ocular trauma, contact lens use, or any family history of eye disease.

Her best-corrected visual acuity in right eye (OD) was 6/60–6/36 (−8.00/−5.00 × 180) and left eye (OS) was 2/60, PR accurate – not improving. Near vision in OD was N12 and OS was not improving. A detailed slit-lamp examination revealed characteristic honeycomb-shaped corneal opacities in both eyes (BE), with the OS more severely affected (Figs. 1-3). Additional findings included nebular corneal opacities and a Hudson-Stahli, a brown line in the lower region of cornea. The OD axial length measured 25.90 mm, and the OS was 27.33 mm. Keratometry readings of OD was K1(flat) 46.00@179 and K2(steep) 50.57@94 and OS was K1(flat) 43.50@170 and K2(steep) 46.00@ 90.

Anterior segment optical coherence tomography confirmed the diagnosis by showing a typical sawtooth pattern in Bowman’s layer (Fig. 4). The patient was assessed for cataract grading, which was determined to be grade 2 nuclear sclerosis with a 5 mm dilation in BE. Fundus examination was normal.

Treatment involved lubricating eye drops and hypertonic saline to ease symptoms and reduce corneal swelling. The patient was instructed to avoid rubbing of eye and was counselled about the chronic nature of her condition. The patient was counselled for her left eye cataract surgery under guarded visual prognosis.

Investigations were sent and the patient was counselled for small incision cataract surgery under local anaesthesia with polymethyl methacrylate lens. A scan was done with SRK II formula and polymethyl methacrylate 21.00 mm was decided for the patient. Intra-operatively, procedure time was a little longer than usual as the dystrophy was in the centre of the cornea and it obscured the vision of the surgeon. Viscoat (sodium chondroitin sulfate/sodium hyaluronate) was used. Bandage contact lens was not used by the surgeon. Her post-operative day 1 vision was 1/60 (no centre) and after 6 weeks post-operatively her final best-corrected visual acuity was 6/36p – NI.

The patient was extremely satisfied with her final visual outcome in OS inspite of the corneal dystrophy that still existed. Regular follow-up visits were recommended every 6 months to keep a check on the progression of the corneal findings. The possibility of surgical options like phototherapeutic keratectomy (PTK) was also discussed in case of further progression to her corneal dystrophy. Later on, her children were also screened for the same and her son was diagnosed with Thiel-Behnke dystrophy in both eyes, which again proved the inheritance condition of the dystrophy.

The characteristic honeycomb-shaped opacities seen on slit-lamp examination are key to diagnosis but often require high clinical suspicion. AS-OCT is a helpful diagnostic tool. Genetic counselling is important to inform patients of the hereditary nature of the disease [7]. Treatment focuses on symptom management and preventing corneal erosion recurrence, with lubricating drops and hypertonic saline typically used first.

In such a scenario, the surgeon should go ahead with the cataract surgery if the grading is operable with guarded visual prognosis mentioned in consent. Even if not a full 6/6 vision, the little difference in visual outcome will also matter for the patient and her relatives is what is proven in this case.

Surgical interventions for corneal dystrophy such as PTK may be considered if conservative treatment fails, though it carries risks such as an irregular corneal surface and hyperopic shift. While penetrating keratoplasty has shown excellent results, it is associated with risks like graft rejection and astigmatism. Thiel-Behnke corneal dystrophy generally has a better prognosis compared to other dystrophies. Newer surgical techniques like femtosecond laser-assisted anterior lamellar keratoplasty can treat larger areas than PTK and have shown promising results. The use of wavefront-guided PRK is described to reduce the hyperopic shift induced by PTK and might enhance the effect of PTK. Research is ongoing in the field of gene therapy to prevent the recurrence of corneal dystrophies. The primary take-away lesson from this case report is that even when corneal dystrophy is diagnosed in a patient cataract surgery should be considered if the grade is significant to help them ease their daily living. The CARE Checklist has been completed by the authors for this case report, attached as online supplementary material (for all online suppl. material, see https://doi.org/10.1159/000544846).

Authors sincerely thank Ms. Madhura Deshkmukh, faculty of Central Research Centre, for helping and guiding them in this publication.

Ethical approval is not required for this study in accordance with local or national guidelines. Written informed consent was obtained from the patient and relative for publication of the details of their medical case.

The authors have no conflicts of interest to declare.

This study was not supported by any sponsor or funder.

Radhika Paranjpe, Varsha Manade, and Preethi Abraham: contributions to the conception or design of the work, the acquisition, analysis, or interpretation of data for the work, and drafting the work or reviewing it critically for important intellectual content. Khushboo Goyal and Surbhi Chodvadiya: contributions to the conception or design of the work or the acquisition, analysis, or interpretation of data for the work.

The data that support the findings of this study are not publicly available due to privacy reasons but are available from the corresponding author upon reasonable request.