Mechanical pump dacryoreservoirs.

BACKGROUND: The two most important characteristics of the natural tear are its chemophysical properties and the continuity of its delivery. The chemical characteristics of tears are very difficult to reproduce since they contain more than 200 different components. In severe dry eyes - due to their relative short residence - manual application of artificial tears from small bottles to the eye has to be performed every 5-10 min, while at night no lubrication at all is provided. Previously, for continuous lubrication of the ocular surface, dacryoreservoirs attached to spectacles or placed in pockets of the patient's clothes were used, but were often complicated by infection. A new option is the implantable pump dacryoreservoir. MATERIAL AND METHODS: In 21 patients with a Schirmer test without anaesthesia of <2mm in 5 min, a Medtronic 60-ml reservoir was implanted into a pocket under the subcutaneous tissues of the anterior abdominal wall and connected to a silicone catheter that ascended subcutaneously along the chest, neck and temple to the upper conjunctival fornix. The results of this procedure and complications associated with the implantation of reservoirs in general - as evaluated on the basis of a Medline search - are presented. RESULTS: Postoperatively all patients reported a dramatic improvement of dry eye symptoms. Slit-lamp microscopy revealed a substantially prolonged break-up time and a reduction of signs of ocular surface disease such as superficial punctuate keratopathy and conjunctival hyperaemia. A penetrating keratoplasty was successfully performed in 2 eyes with an implanted dacryoreservoir and remained clear throughout the follow-up of up to 3.5 years. No infections of the catheter reservoir were observed. Prominent parts of the catheter induced skin ulceration, but no infection, in 2 patients which was managed successfully by removal of the catheter, systemic antibiotics and subsequent re-implantation of a new catheter. A literature review showed that infection is not a frequent problem with implantable and external reservoirs. CONCLUSION: At present, this is the only safe and effective method able to maintain a continuous lubrication of the ocular surface with artificial tears, and the only one that allows corneal, conjunctival or limbal transplantations in severe dry eyes.

Minor salivary gland transplantation.

INTRODUCTION: Minor oral salivary glands exist in large numbers in the labial, buccal and palatal mucosa, and account for approximately half of the baseline secretion of saliva. They can be transplanted together with the overlying mucosa as a complex graft to the posterior lamella of the eyelids to increase ocular surface lubrication and reduce discomfort in dry eyes. MATERIAL AND METHODS: The surgical methods and the results of this technique in 17 patients are described. All patients had been retractive to medical treatment. The recipient bed over the lower or upper lid retractors and a donor tissue of lower labial mucosa with its submucosal minor salivary glands of approximately 2.5 x 2 cm were prepared by means of a surgical knife or Ellman Surgitron high-frequency/low-temperature radiosurgical device. The graft was cut in two strips of approximately 2.5 x 1 cm size and sutured to the recipient site with interrupted or running sutures. The labial wound was left open for second intention healing. RESULTS: All grafts remained viable and vascularised within 1 week. Vascularisation of the graft was associated with an improvement of symptoms and increased ocular surface lubrication. Complications included temporary labial hypaesthesia, partial necrosis of the graft (n = 1), herpes simplex virus keratitis (n = 1) and epiphora (n = 1). Viable glandular tissue was found in specimens taken 18 and 36 months postoperatively. Other reported complications include lid malpositioning such as ptosis and entropium. CONCLUSION: Transplantation of minor salivary glands is a promising new treatment option for severe dry eyes. The procedure is simple with minimal surgical risks. These grafts remain viable in over 90% and seem to be capable of sustaining a basal secretion for up to 36 months. Since experience with this technique is still very limited, prospective controlled studies have to be performed to establish the long-term survival of the glands and to characterise the salivary tear film and its impact on the ocular surface.

REM sleep: tear secretion and dreams.

Although a number of hypotheses exist to explain the reasons for the rapid eye movement (REM) phase of sleep, the physical movements themselves have not been explained or interpreted in the literature. The author theorizes that REM during sleep serves not only to increase the lacrimal secretion and to humidify and lubricate the ocular surface, but also to redistribute the secretion on the ocular surface and to inform the conjunctiva-associated lymphoid tissue (CALT) system. He hypothesizes that when eyes move in REM periods to humidify the ocular surface, they indirectly release phenomena of the visual activity, producing dreams.

Histopathologic limbus evolution after alkaline burns.

PURPOSE: To study the histopathologic evolution of the corneal limbus after alkaline burns according to the clinical severity and therapy used. METHODS: A prospective study of 15 eyes from 12 patients (9 men and 3 women) with moderate and severe alkaline burns was performed. All patients were divided into 2 groups in accordance with the clinical ocular severity and the therapy that was used: medical therapy, amniotic membrane transplantation (AMT), autologous limbal transplantation (ALT), and ALT combined with AMT (ALT + AMT). Biopsies were obtained from affected limbal areas immediately after the ocular burn and 9 months later. RESULTS: Limbal regeneration was limited to small areas in patients with moderate burns treated with medical therapy; in contrast, the limbal structure showed significant stromal and epithelial regeneration in patients with moderate burns treated with AMT. There was an important stromal regeneration with an incomplete reepithelialization in patients with severe burns treated with AMT. Patients treated with ALT showed a good reepithelialization with a defective stromal regeneration. Epithelial and stromal regeneration was notable in patients with severe burns treated with ALT + AMT. CONCLUSIONS: In patients with moderate alkaline burns, AMT improved both limbal stromal and epithelial regeneration more effectively than medical therapy. In patients with severe burns, the best reepithelialization and stromal regeneration were obtained with ALT + AMT.

Ramon Castroviejo centenary: a life dedicated to corneal transplantation.

Ramon Castroviejo is widely recognized as one of the 10 most influential people in ophthalmology of the 20th century. Castroviejo was instrumental in the advancement of keratoplastic surgery, and his contributions as a researcher, surgeon, and teacher have benefited many.

Choosing the location of corneal incision based on preexisting astigmatism in phacoemulsification.

PURPOSE: To investigate the best location of clear-cornea incision in phacoemulsification, depending on preexisting corneal astigmatism. DESIGN: Randomized clinical trial and noncomparative interventional case series. METHODS: A total of 574 patients in five stages were assigned to the following incisions: superior or temporal (n = 89), superior (n = 141), superior or superior plus relaxing (n = 102), nasal or temporal (n = 156), and incisions based on applying conclusions of preceding and current studies (n = 86). Visual acuity, refraction, biomicroscopy, keratometry, and videokeratography (Fourier analysis) were performed before and after phacoemulsification and intraocular lens implantation (3.5-mm incision). main outcome measures: Corneal refractive and surface regularity index change between preoperative and 6-month postoperative examination. Visual acuity at 6 months. RESULTS: In patients without corneal astigmatism, corneal changes induced were greater in superior than temporal incision. After a superior incision (preoperative steep axis at 90 degrees), a shift of the axis 90 degrees away was less likely with at least 1.5 diopters of astigmatism. A perpendicular relaxing limbal incision decreased corneal changes. Nasal incision induced greater corneal change than temporal incision (preoperative steep axis at 180 degrees). A shift of this axis 90 degrees away was more likely with astigmatism < 0.75 diopters in temporal incision and < 1.25 diopters in nasal incision. CONCLUSIONS: Superior incision is recommended with at least 1.5 diopters of astigmatism and steep axis at 90 degrees. Temporal incision is recommended with astigmatism < 1.5 diopters and steep axis at 90 degrees, negligible astigmatism, or astigmatism < 0.75 diopters and steep axis at 180 degrees. Nasal incision is recommended with at least 0.75 diopters of astigmatism and steep axis at 180 degrees.