Entropy of corneal nerve fibers distribution observed by laser scanning confocal microscopy: A noninvasive quantitative method to characterize the corneal innervation in Sjogren's syndrome patients.

Sjogren's syndrome (SS) is a progressive autoimmune condition mainly affecting the salivary and lacrimal glands with an incidence of primary SS between 1/100 and 1/1,000. SS implies an alteration in the epithelium and subepithelium innervation, with consequent reduction of corneal sensitivity. It is necessary to have noninvasive quantitative methods to characterize the status of the corneal nerve fibers of the patients in order to choose and follow the best therapy. Entropy (information dimension) of the nerve corneal fibers distribution observed by confocal microscopy was evaluated in patients with primary SS (n = 30, 6 males, 24 females, 21-81 years), diagnosed by biopsy of salivary gland and blood tests and in sex- age-matched healthy subjects (n = 12). Corneal nerve fiber density, Langerhans cell count, and cell density in the nerve plexus images were also evaluated. In selected patients salivary gland atrophy degree was also evaluated. Nerve corneal distribution observed by confocal microscopy is fractal. Entropy of the corneal nerve distribution statistically distinguishes between SS patients and healthy subjects: patients present a lower value of information dimension of the corneal nerve fibers distribution than healthy individuals (P < 0.001). Percentage of grouped cases classified by entropy according to the subjects (selected patients vs. healthy) showed a 100% sensitivity and 96% specificity, P < 0.0001 with a low value of coefficient of variation among the individuals (6-7 times lower than the other morphometric indexes). Entropy correlated with the severity of the disease (salivary gland atrophy degree, P < 0.01). Evaluation of entropy of the corneal nerve distribution observed by a laser confocal microscopy appears to quantitatively and noninvasively characterize an aspect of the SS patients in relation to the recognition of an impairment of their ocular surface, giving us for the first time a method to objectively and precisely characterize the corneal innervation status in the SS patients.

Bilateral dexamethasone intravitreal implant in a young patient with Vogt-Koyanagi-Harada disease and refractory uveitis.

Vogt-Koyanagi-Harada disease (VKHD) is a multisystemic disorder characterized by granulomatous panuveitis with exudative retinal detachments, often associated with neurologic and cutaneous manifestations. Therapy relies mainly on the use of corticosteroids, administrated as oral or intravenous high-dose pulses, and immunosuppressants. However, since macular edema and retinal detachment can often be refractory to systemic therapies, intravitreal triamcinolone acetate has been used successfully. Herein, we report the first case of refractory bilateral panuveitis in a young patient with VKHD successfully treated with dexamethasone intravitreal implant.

Pulsed Light Accelerated Crosslinking versus Continuous Light Accelerated Crosslinking: One-Year Results.

Purpose. To compare functional results in two cohorts of patients undergoing epithelium-off pulsed (pl-ACXL) and continuous light accelerated corneal collagen crosslinking (cl-ACXL) with dextran-free riboflavin solution and high-fluence ultraviolet A irradiation. Design. It is a prospective, comparative, and interventional clinical study. Methods. 20 patients affected by progressive keratoconus were enrolled in the study. 10 eyes of 10 patients underwent an epithelium-off pl-ACXL by the KXL UV-A source (Avedro Inc., Waltham, MS, USA) with 8 minutes (1 sec. on/1 sec. off) of UV-A exposure at 30 mW/cm(2) and energy dose of 7.2 J/cm(2); 10 eyes of 10 patients underwent an epithelium-off cl-ACXL at 30 mW/cm(2) for 4 minutes. Riboflavin 0.1% dextran-free solution was used for a 10-minutes corneal soaking. Patients underwent clinical examination of uncorrected distance visual acuity and corrected distance visual acuity (UDVA and CDVA), corneal topography and aberrometry (CSO EyeTop, Florence, Italy), corneal OCT optical pachymetry (Cirrus OCT, Zeiss Meditec, Jena, Germany), endothelial cells count (I-Conan Non Co Robot), and in vivo scanning laser confocal microscopy (Heidelberg, Germany) at 1, 3, 6, and 12 months of follow-up. Results. Functional results one year after cl-ACXL and pl-ACXL demonstrated keratoconus stability in both groups. Functional outcomes were found to be better in epithelium-off pulsed light accelerated treatment together with showing a deeper stromal penetration. No endothelial damage was recorded during the follow-up in both groups. Conclusions. The study confirmed that oxygen represents the main driver of collagen crosslinking reaction. Pulsed light treatment optimized intraoperative oxygen availability improving postoperative functional outcomes compared with continuous light treatment.