Constitutively low expression of collagen XIII alpha 1 may help explain the vulnerability of the inferior rectus muscle to thyroid-associated ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO) has a predilection for inferior rectus muscle that has never been explained. We conducted immunohistochemical staining for the soluble cleaved form of collagen XIII alpha 1 (COL13A1) and found constitutively low expression of COL13A1 in normal human inferior rectus muscles and moderate expression of COL13A1 in normal human medial rectus muscles. COL13A1 is known to be essential to development and maintenance of neuromuscular junctions and there is some evidence to suggest it may help support normal immune function. The combination of constitutively low expression of COL13A1, high physiological and metabolic demands, and consequentially relatively high exposure to stressors via the blood stream may help explain the particular vulnerability of inferior rectus to TAO compared to other extraocular muscles.

Overexpression of collagen XIII in extraocular fat affected by active thyroid-associated ophthalmopathy: A crucial piece of the puzzle?

Thyroid-associated ophthalmopathy (TAO) causes irreversible increase in extraocular fat volume that contributes to the risk of exophthalmos and compressive optic neuropathy. Collagen XIII is implicated in uncontrolled cell growth in some tumours, but we are not aware of any studies of collagen XIII in TAO-affected solid tissue to date. We conducted immunohistochemical staining for collagen XIII alpha 1 (COL13A1), present in both the transmembrane and cleaved forms of collagen XIII, in consecutive prospectively collected human extraocular tissue specimens from patients with TAO and controls. We identified overexpression of collagen XIII in active TAO-affected fat. We discuss how species and cell-type specific responses of collagen XIII to stressors may help explain the different phenotypes of TAO.

Evaluation of a short-term topical interferon α-2b treatment for histologically proven melanoma and primary acquired melanosis with atypia.

OBJECTIVE: To evaluate the efficiency of series of 6-week treatments with brief intervals (6-week = 1 cycle) of topical Interferon α-2b (IFNα-2b) treatment in primary acquired melanosis (PAM) with atypia and melanoma of the conjunctiva. PATIENTS AND METHODS: Five patients with biopsy-proven PAM with atypia and seven patients with melanoma of the conjunctiva, treated with topical IFNα-2b (1 million units/ml, 5 times daily), were included in the study. All patients had colour photographs and the tumour area was measured manually for each patient before and after treatment. RESULTS: The median age of 12 patients at initiation of treatment was 61.5 years (range 39-75 years). The mean therapy duration was 2.4 cycles (range 1-6 cycle). Compared to pretreatment lesion dimension, the mean decrease in tumour size were after the first cycle 66% (range 18-98%; p = 0.004; n = 10 patients), after the second cycle 55% (range 10-100%; p = 0.016; n = 7 patients), and after the third cycle 74% (range 23-100%; n = 3 patients). In one patient 6 cycles of topical IFNα-2b were needed. The decrease in size was 22% after the 4(th) cycle, 34% after the 5(th) cycle, and 98% after the 6(th) cycle. CONCLUSION: Our clinical experience demonstrates promising results of topical IFNα-2b treatment for PAM with atypia and melanoma of the conjunctiva without any local or systemic side effects. However, future multicenter prospective studies are recommended to confirm the efficiency and safety of topical IFNα-2b treatment.

Dermis fat grafts as primary and secondary orbital implants.

INTRODUCTION: This study was performed to evaluate the outcome after autologous dermis-fat graft [DFG] orbital implants in a large sample. MATERIALS AND METHODS: A retrospective chart review of all primary and secondary DFGs in a 16-year period was done. Aesthetic and functional results, patients' satisfaction and postoperative complications were evaluated. RESULTS: In total 468 DFGs were performed in the study period (315 primary [I°] and 153 secondary [II°] DGFs). In the analysis, 173 DFG I° and 66 DFG II° were included as sufficient follow-up was available. Median follow-up after DFG I° was 21.5 months and 14 months after DFG II°. After DFG I°, in 76% of patients motility of the graft was possible in all directions; 81% had good fitting of the prosthesis and 83% were highly satisfied with the results. Mean width of palpebral apertures was 0.2 mm smaller and Hertel exophthalmometry revealed a mean enophthalmus of 1.6 mm on the operated side compared to the fellow-eye. After DFG II°, motility was possible in all directions in 34% of patients. Fitting of the prosthesis was good/reasonable in 49%/41% and patients were highly satisfied in 57%. On average, on the operated side palpebral apertures were 0.6 mm smaller and Hertel measurements showed an enophthalmus of 2.6 mm. Major complications were uncommon. Complete necrosis of the implant was more often observed after II° (6.1%) than after I° DFG (3.5%). DISCUSSION: In this large sample, DFG proved to be an effective and safe method for the reconstruction of anophthalmic sockets.