The pivotal role of Bifida Ferment Lysate on reinforcing the skin barrier function and maintaining homeostasis of skin defenses in vitro.

BACKGROUND: The semiactive or inactive probiotics or their extracts used in dermatology have interesting properties to ameliorate signs of irritated skin and enhance the skin barrier. Bifidobacterium, as the most common probiotics, which has been found to be effective in reducing acne and improving the skin barrier function of atopic dermatitis. Bifida Ferment Lysate (BFL) can be obtained from Bifidobacterium by fermentation and extraction. PURPOSE: In this study, we investigated the effect of a topically used BFL on the skin using in vitro evaluation methods. RESULTS: The results showed that upregulation of skin physical barrier gene (FLG, LOR, IVL, TGM1, and AQP3) and antimicrobial peptide gene (CAMP and hBD-2) in HaCaT cells by BFL might be responsible for skin barrier resistance. In addition, BFL had strong antioxidant properties representing a dose-dependent increasing of the scavenging capacity of DPPH, ABTS, hydroxyl, and superoxide radicals. BFL treatment also fundamentally inhibited the intracellular ROS and MDA production and improved the activities of antioxidant enzymes (CAT and GSH-Px) in H2 O2 -stimulated HaCaT cells. As a good immunomodulatory factor, BFL efficiently decreased the secretion of IL-8 and TNF-α cytokines, and COX-2 mRNA expression in LPS-induced THP-1 macrophages. CONCLUSION: BFL can strengthen the skin barrier function and stimulate skin barrier resistance, to reinforce the skin against oxidative stress and inflammatory stimuli.

Repeated Intraperitoneal Administration of Low-Concentration Methylcellulose Leads to Systemic Histologic Lesions Without Loss of Preclinical Phenotype.

Methylcellulose (MC; 0.5% concentration) is commonly used when evaluating investigational agents for efficacy in preclinical models of disease. When administered by the oral (PO) route, MC is considered a Food and Drug Administration "generally recognized as safe" compound. Yet, there is limited data pertaining to the tolerability and impact on model fidelity of repeated intraperitoneal administration of 0.5% MC. Chronic administration of high-concentration MC (2%-2.5%) has been used to induce anemia, splenomegaly, and lesions in multiple organ systems in several preclinical species. Histopathological findings from a diagnostic pathologic analysis of a single mouse from our laboratory with experimentally induced chronic seizures that had received repeated intraperitoneal administration of antiseizure drugs delivered in MC revealed similar widespread lesions. This study thus tested the hypothesis that chronic administration of intraperitoneal, but not PO, MC incites histologic lesions without effects on preclinical phenotype. Male CF-1 mice (n = 2-14/group) were randomized to receive either 6 weeks of twice weekly 0.5% MC or saline (intraperitoneal or PO) following induction of chronic seizures. Histology of a subset of mice revealed lesions in kidney, liver, mediastinal lymph nodes, mesentery, aorta, and choroid plexus only in intraperitoneal MC-treated mice (n = 7/7). Kindled mice that received MC PO (n = 5) or saline (intraperitoneal n = 6, PO n = 3) had no lesions. There were no effects of intraperitoneal MC treatment on body weight, appearance, seizure stability, or behavior. Nonetheless, our findings suggest that repeated intraperitoneal, but not PO, MC elicits systemic organ damage without impacting the model phenotype, which may confound interpretation of investigational drug-induced histologic lesions. SIGNIFICANCE STATEMENT: Methylcellulose (0.5% concentration) is commonly used when evaluating investigational agents for efficacy in preclinical models of disease. Herein, we demonstrate that repeated administration of 0.5% methylcellulose by the intraperitoneal, but not oral, route results in systemic inflammation and presence of foam-laden macrophages but does not impact the behavioral phenotype of a rodent model of neurological disease.

Effect on tomato plant and fruit of the application of biopolymer-oregano essential oil coatings.

BACKGROUND: Oregano essential oil (EO) was incorporated into film-forming dispersions (FFDs) based on biopolymers (chitosan and/or methylcellulose) at two different concentrations. The effect of the application of the FFDs was evaluated on tomato plants (cultivar Micro-Tom) at three different stages of development, and on pre-harvest and postharvest applications on tomato fruit. RESULTS: The application of the FFDs at '3 Leaves' stage caused phytotoxic problems, which were lethal when the EO was applied without biopolymers. Even though plant growth and development were delayed, the total biomass and the crop yield were not affected by biopolymer-EO treatments. When the FFDs were applied in the 'Fruit' stage the pre-harvest application of FFDs had no negative effects. All FFDs containing EO significantly reduced the respiration rate of tomato fruit and diminished weight loss during storage. Moreover, biopolymer-EO FFDs led to a decrease in the fungal decay of tomato fruit inoculated with Rhizopus stolonifer spores, as compared with non-treated tomato fruit and those coated with FFDs without EO. CONCLUSION: The application of biopolymer-oregano essential oil coatings has been proven to be an effective treatment to control R. stolonifer in tomato fruit. © 2016 Society of Chemical Industry.

Formulation and in vivo evaluation of probiotics-encapsulated pellets with hydroxypropyl methylcellulose acetate succinate (HPMCAS).

The aim of this study was to formulate probiotics-encapsulated pellets with hydroxypropyl methylcellulose acetate succinate (HPMCAS) using a dry powder coating technique to improve the storage stability, acid resistance, and intestinal adherence of viable bacteria (Lactobacillus acidophilus and Bifidobacteria animalis ssp. Lactis). Dry coated pellet (DCP) loaded with probiotics was optimized with respect to the quantity of the HPMCAS, an enteric coating polymer (108 mg), and the kinds and amounts of plasticizer (triethyl citrate, 15.7 mg; acetylated monoglyceride, 6.8 mg), by evaluating the survival rate of the bacteria during preparation process and in an acidic medium. Dry coating process allows the whole survivals of living bacteria during preparation process. The DCP formulation exhibited markedly higher acid tolerability and storage stability compared to uncoated viable bacteria. In an in vivo mucosal adherence study in rats, a profound colonization of viable bacteria in the small and large intestine was observed in rats receiving DCP system (p<0.05) compared to rats receiving uncoated probiotics. Moreover, we found that the repeated DCP administration noticeably inhibited intestinal penetration of endotoxin, a potent inflammatory stimulant, from intestinal mucus. The novel DCP system may be an alternative approach for improving bacterial viability in the preparation process and in an acidic medium, and to promote mucosal colonization of probiotic bacteria in the human gut.

Results of a Multicenter, Randomized, Double-Masked, Placebo-Controlled Clinical Study of the Efficacy and Safety of Visomitin Eye Drops in Patients with Dry Eye Syndrome.

INTRODUCTION: This article presents the results of an international, multicenter, randomized, double-masked, placebo-controlled clinical study of Visomitin (Mitotech LLC, Moscow, Russian Federation) eye drops in patients with dry eye syndrome (DES). Visomitin is the first registered (in Russia) drug with a mitochondria-targeted antioxidant (SkQ1) as the active ingredient. METHODS: In this multicenter (10 sites) study of 240 subjects with DES, study drug (Visomitin or placebo) was self-administered three times daily (TID) for 6 weeks, followed by a 6-week follow-up period. Seven in-office study visits occurred every 2 weeks during both the treatment and follow-up periods. Efficacy measures included Schirmer's test, tear break-up time, fluorescein staining, meniscus height, and visual acuity. Safety measures included adverse events, slit lamp biomicroscopy, tonometry, blood pressure, and heart rate. Tolerability was also evaluated. RESULTS: This clinical study showed the effectiveness of Visomitin eye drops in the treatment of signs and symptoms of DES compared with placebo. The study showed that a 6-week course of TID topical instillation of Visomitin significantly improved the functional state of the cornea; Visomitin increased tear film stability and reduced corneal damage. Significant reduction of dry eye symptoms (such as dryness, burning, grittiness, and blurred vision) was also observed. CONCLUSION: Based on the results of this study, Visomitin is effective and safe for use in eye patients with DES for protection from corneal damage. FUNDING: Mitotech LLC.

Dentifrice fluoride and abrasivity interplay on artificial caries lesions.

Incipient caries lesions on smooth surfaces may be subjected to toothbrushing, potentially leading to remineralization and/or abrasive wear. The interplay of dentifrice abrasivity and fluoride on this process is largely unknown and was investigated on three artificially created lesions with different mineral content/distribution. 120 bovine enamel specimens were randomly allocated to 12 groups (n = 10), resulting from the association of (1) lesion type [methylcellulose acid gel (MeC); carboxymethylcellulose solution (CMC); hydroxyethylcellulose gel (HEC)], (2) slurry abrasive level [low (REA 4/ RDA 69); high (REA 7/RDA 208)], and (3) fluoride concentration [0/275 ppm (14.5 mM) F as NaF]. After lesion creation, specimens were brushed in an automated brushing machine with the test slurries (50 strokes 2×/day). Specimens were kept in artificial saliva in between brushings and overnight. Enamel surface loss (SL) was determined by optical profilometry after lesion creation, 1, 3 and 5 days. Two enamel sections (from baseline and post-brushing areas) were obtained and analyzed microradiographically. Data were analyzed by analysis of variance and Tukey's tests (α = 5%). Brushing with high-abrasive slurry caused more SL than brushing with low-abrasive slurry. For MeC and CMC lesions, fluoride had a protective effect on SL from day 3 on. Furthermore, for MeC and CMC, there was a significant mineral gain in the remaining lesions except when brushed with high-abrasive slurries and 0 ppm F. For HEC, a significant mineral gain took place when low-abrasive slurry was used with fluoride. The tested lesions responded differently to the toothbrushing procedures. Both slurry fluoride content and abrasivity directly impacted SL and mineral gain of enamel caries lesions.

Two episodes of anaphylaxis following exposure to hydroxypropyl methylcellulose during cataract surgery.

UNLABELLED: We report a case of immediate severe anaphylaxis to hydroxypropyl methylcellulose (HPMC) on 2 separate occasions during cataract surgery in a 71-year-old patient. Skin prick tests were positive for HPMC, a constituent of Ocucoat and Xylocaine gel, which were administered intraocularly during surgery. Skin prick tests were also positive for methylcellulose. Based on symptoms and clinical signs of anaphylaxis following 2 separate cataract operations together with positive prick tests to HPMC, HPMC is the most plausible cause of the reactions. The patient has since had uneventful surgery for a detached retina avoiding HPMC. This case stresses the importance of considering all medication given to patients as possible causes of an anaphylactic reaction. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

[In vitro evaluation of corneal damages after instillation of eye drops using rat debrided corneal epithelium: changes of corneal damage due to benzalkonium chloride by addition of thickening agents].

Benzalkonium chloride (BAC) is known to cause corneal epithelial damage. In this study we investigated the effect of a BAC solution containing a thickening agent, which enhanced residence time in the eyes, on corneal wound healing using in vivo rat model debrided corneal epithelium. 0.5% or 1.0% methylcellulose (MC), carboxymethylcellulose (CMC) and hydroxypropyl-methylcellulose (HPMC) were used as the thickening agent. The levels of corneal wound healing of rat eyes injected with saline were alone approximately 45.0% at 12 h and 93.6% at 24 h after corneal epithelial abrasion, and healing was almost complete at 36 h. The healing rate in the rat eye treated just with MC, CMC and HPMC was higher than that in those injected with saline. In contrast to the treatment result using only this thickening agent, the healing rate in the eye treated with BAC was lower than that in those injected with saline: the corneal wounds in the BAC-treated eye showed approximately 20% healing at 12 h after abrasion. The injection of 0.02% BAC solution containing MC, CMC and HPMC more significantly delayed the healing than did the injection of 0.02% BAC alone. The results show that the in vivo evaluation method for corneal damage using rat debrided corneal epithelium reflects a toxic change depending upon residence time. These findings provide valuable safety and efficacy information for use in the design of eye drops.

Characterization and optimization of orodispersible mosapride film formulations.

Orodispersible film (ODF) technology offers new possibilities for drug delivery by providing the advantages of oral delivery coupled with the enhanced onset of action and convenience to special patient categories such as pediatrics and geriatrics. In this study, mosapride (MOS) was formulated in an ODF preparation that can be used for treatment of patients who suffer from gastrointestinal disorders, especially difficulty in swallowing due to gastroesophageal reflux disease. Poloxamer 188 was used to solubilize MOS to allow its incorporation into the film matrix. The films were prepared by solvent-casting method using different polymer ratios of maltodextrin and hydroxypropyl methylcellulose and plasticizer levels of glycerol and propylene glycol. A D-optimal design was utilized to study the effect of polymer ratio, plasticizer type, and level on film mechanical properties, disintegration time, and dissolution rate. Statistical analysis of the experimental design showed that the increase of maltodextrin fraction and plasticizer level conferred optimum attributes to the prepared films in terms of film elasticity, film disintegration time, and MOS release rate. The ODF formulations were further tested for moisture sorption capacity, with formulations containing a higher ratio of maltodextrin and percent plasticizer showing more moisture uptake. The optimum film composition was also tested in vivo for film palatability and disintegration time. An optimized mosapride orodispersible film formulation was achieved that could be of benefit to patients suffering from gastrointestinal disorders.

Osmotic nephrosis due to the use of anti-adhesive membrane intraperitoneally.

BACKGROUND: A common strategy for the prevention of intra-abdominal adhesions post-operatively has been the application of adhesion barriers into the peritoneal cavity. Side effects of these barriers are infection, abscesses and inadequate wound healing. There is no information about such a side effect of these materials on renal function. The aim of this study was to evaluate the effect of two different, commercially available polysaccharide-based anti-adhesive materials on renal function. METHODS: In 24 adult Wistar rats, an abdominal midline incision was performed, and an anti-adhesion membrane was placed in the peritoneal cavity so as to cover its whole surface. Four rats were used as the control group. In 12 rats, a membrane of macromolecular polysaccharides, weighing 40 mg/cm2, was placed intra-abdominally and in 8 rats, a hyaluronic acid-hydroacidmethylcellulose membrane weighing 0.4 mg/cm2 was placed. At 24 or 70 h, the rats were sacrificed, and we evaluated changes in serum creatinine, urea, uric acid, K and Na, and histologic examination of the kidney was performed. RESULTS: The use of the thicker macromolecular membrane was associated with a rise in serum creatinine and urea levels, vacuolization of all the tubular epithelial cells and mild interstitial infiltration. Rats in which the hyaluronic acid-hydroacidmethylcellulose membrane was used did not show any creatinine elevation, and they presented milder histologic lesions. CONCLUSION: Polysaccharide and cellulose anti-adhesive membrane cause renal damage with tubular cell vacuolization. The severity of kidney damage is relative to the quantity of the membrane material used.

Submucosal injection of 0.4% hydroxypropyl methylcellulose facilitates endoscopic mucosal resection of early gastrointestinal tumors.

BACKGROUND AND AIMS: Submucosal injection of a viscoelastic solution prolongs submucosal lift, thus, facilitating endoscopic mucosal resection. Our objective was to assess the safety and clinical effectiveness of 0.4% hydroxypropyl methylcellulose (HPMC) as a submucosal injectant for endoscopic mucosal resection. PATIENTS AND METHODS: A prospective, open-label, multicenter, phase 2 study was conducted at 2 academic institutions in Brazil. Eligible participants included patients with early gastrointestinal tumors larger than 10 mm. Outcomes evaluated included complete resection rates, volume of HPMC injected, duration of the submucosal cushion as assessed visually, histology of the resected leisons, and complication rates. RESULTS: Over a 12-month period, 36 eligible patients with superficial neoplastic lesions (stomach 14, colon 11, rectum 5, esophagus 3, duodenum 3) were prospectively enrolled in the study. The mean size of the resected specimen was 20.4 mm (10 to 60 mm). The mean volume of 0.4% HPMC injected was 10.7 mL (range 4 to 35 mL). The mean duration of the submucosal fluid cushion was 27 minutes (range 9 to 70 min). Complete resection was successfully completed in 89%. Five patients (14%) developed immediate bleeding requiring endoclip and APC application. Esophageal perforation occurred in 1 patient requiring surgical intervention. There were no local or systemic adverse events related to HPMC use over the follow-up period (mean 2.2 mo). CONCLUSION: HPMC solution (0.4%) provides an effective submucosal fluid cushion and is safe for endoscopic resection of early gastrointestinal neoplastic lesions.

Comparison of cross-sectional hardness and transverse microradiography of artificial carious enamel lesions induced by different demineralising solutions and gels.

The aims of this study were: (1) to correlate surface (SH) and cross-sectional hardness (CSH) with microradiographic parameters of artificial enamel lesions; (2) to compare lesions prepared by different protocols. Fifty bovine enamel specimens were allocated by stratified randomisation according to their initial SH values to five groups and lesions produced by different methods: MC gel (methylcellulose gel/lactic acid, pH 4.6, 14 days); PA gel (polyacrylic acid/lactic acid/hydroxyapatite, pH 4.8, 16 h); MHDP (undersaturated lactate buffer/methyl diphosphonate, pH 5.0, 6 days); buffer (undersaturated acetate buffer/fluoride, pH 5.0, 16 h), and pH cycling (7 days). SH of the lesions (SH(1)) was measured. The specimens were longitudinally sectioned and transverse microradiography (TMR) and CSH measured at 10- to 220-microm depth from the surface. Overall, there was a medium correlation but non-linear and variable relationship between mineral content and radicalCSH. radicalSH(1) was weakly to moderately correlated with surface layer properties, weakly correlated with lesion depth but uncorrelated with integrated mineral loss. MHDP lesions showed the highest subsurface mineral loss, followed by pH cycling, buffer, PA gel and MC gel lesions. The conclusions were: (1) CSH, as an alternative to TMR, does not estimate mineral content very accurately, but gives information about mechanical properties of lesions; (2) SH should not be used to analyse lesions; (3) artificial caries lesions produced by the protocols differ, especially considering the method of analysis.

Hydroxypropylmethylcellulose significantly lowers blood cholesterol in mildly hypercholesterolemic human subjects.

OBJECTIVE: To determine the cholesterol-lowering efficacy of hydroxypropylmethylcellulose (HPMC) in mildly hypercholesterolemic humans. SUBJECTS: Trial one: entry mean (range) total serum cholesterol values of eight female and four male subjects were 6.48 (5.57-7.51) mmol l(-1) (250 (215-290) mg dl(-1)) and 6.60 (5.57-7.64) mmol l(-1) (255 (215-295) mg dl(-1)), respectively. Trial two: corresponding values for 20 women and 20 men were 5.96 (5.43-6.48) mmol l(-1) 230 (210-250) mg dl(-1)) and 6.05 (5.46-6.63) mmol l(-1) 233 (211-256) mg dl(-1)), respectively. RESULTS: Trial one: HPMC decreased (P< or =0.05) total and LDL-cholesterol 9.3 and 15.3% (medium), 16.9 and 23.5% (high) and 13.8 and 19.4% (ultra-high), respectively, over placebo. Trial two: total and LDL-cholesterol decreased (P< or =0.05) throughout the 8 weeks, with mean (weeks 4-8) reductions of 7 and 8% at 5 g day(-1), and 12 and 15% at 15 g day(-1), respectively, over placebo. Adverse effects were minimal. Trial one: medium, high and ultra-high viscosity HPMC at 15 g day(-1) for 1 week each;1-week wash-out between treatments. Trial two: ultra-high viscosity HPMC at 5 or 15 g day(-1) for 8 weeks. CONCLUSIONS: HPMC soluble fiber, especially high-viscosity grades, significantly lowers cholesterol at well-tolerated doses, showing promise as a treatment of hypercholesterolemia.

Head-to-head comparison of oral contrast agents for cross-sectional enterography: small bowel distention, timing, and side effects.

OBJECTIVE: To determine small bowel distention, scanning time, and side effects of commercially available oral contrast agents used in cross-sectional enterography. METHODS: Ten healthy volunteers ingested 2000 mL of water, methylcellulose, polyethylene glycol (PEG), or 1350 mL of low-concentration barium (LCB) followed by 500 mL water on different days. Magnetic resonance imaging occurred every 10 minutes from 30 to 90 minutes after ingestion. Small bowel distention was compared between time points and agents. Volunteers ranked side effects, drinking difficulty, and preference. RESULTS: By quantitative assessment, PEG and LCB distended small bowel loops better than water and methylcellulose (P < 0.0001). Time to optimal distention of the terminal ileum was from 51 to 72 minutes. Water and methylcellulose had the fewest side effects. Water was the most preferred contrast and PEG the least. CONCLUSIONS: Polyethylene glycol and LCB distend small bowel better than water and methylcellulose. Polyethylene glycol was the most difficult to drink and least preferred agent.

Efficacy, tolerability and comfort of a 0.3% hypromellose gel ophthalmic lubricant in the treatment of patients with moderate to severe dry eye syndrome.

OBJECTIVE: To evaluate efficacy, safety and comfort of a 0.3% hypromellose (HM) eye gel (GenTeal Lubricant Eye Gel), with a sodium perborate preservative system and carbomer gelling agent, in patients with dry eye. RESEARCH DESIGN AND METHODS: Patients with moderate-to-severe dry eye syndrome were enrolled in this open label study and assessed at three visits; a screening consultation (baseline) and two follow-up visits on day 14 (+/- 4 days) and day 28 (+/- 4 days). All screening, evaluation and follow-up visits were carried out at the Tauber Eye Center (formerly the Hunkeler Eye Center), Kansas City. Patients were treated with the product over a 4-week period. They were instructed to use the product at least two times daily, more if necessary, with one drop instilled into the conjunctive sac of both eyes. MAIN OUTCOME MEASURES: Efficacy was measured by ocular symptoms (burning, stinging, foreign body sensation, dryness, pain/soreness and photophobia), ocular signs (eyelid erythema, bulbar conjunctival injection and corneal superficial punctate keratitis score), tear breakup time and global assessment of ocular comfort. Tolerability measures were change from baseline in best corrected Snellen visual acuity and monitoring of adverse events. RESULTS: Thirty-seven patients completed this study. The mean sum symptom score at each visit was significantly lower compared with baseline with approximately 30% reduction in the sum symptom score at 2 weeks and approximately 33% at 4 weeks after treatment initiation (p < 0.001). Mean individual symptom scores for dryness, stinging and foreign body sensation decreased by approximately 40% at the end of the study (p < 0.02). Tear breakup time increased from baseline by 53% and 59% at 2 and 4 weeks, respectively (p < 0.001). The proportion of patients reporting a global evaluation of slightly better or much better was approximately 74% at 2 weeks and 78% at 4 weeks after treatment initiation. The product was well tolerated, with one related adverse event reported. CONCLUSIONS: In a small, open-label study, this 0.3% HM eye gel showed statistically significant effects in relieving ocular symptoms and provides a well-tolerated formula that effectively reduced symptoms and improved ocular comfort in patients with dry eye syndrome.

Change in intraocular pressure within 1 week of phacoemulsification and intraocular lens implantation using Adatocel.

PURPOSE: To examine the change in intraocular pressure (IOP) within 1 week of phacoemulsification and foldable posterior chamber intraocular lens (PC IOL) implantation using Adatocel (hydroxypropyl methylcellulose 2% [HPMC]). SETTING: Department of Ophthalmology, University of Sciences, Faculty of Medicine, Pécs, Hungary. METHODS: In this prospective study, the IOP in 118 eyes of 118 patients (57 men, 61 women, mean age 68 years +/- 7.8 [SD]) with no history of glaucoma was assessed by Goldmann applanation tonometry 2 to 3, 6 to 8, and 22 to 24 hours and 1 week after uneventful phacoemulsification and PC IOL implantation. The effect of the removal of Adatocel ("partial removal" from the anterior chamber [AC] only versus "complete removal" from behind of the IOL as well), the lens type (Medicontur 601 HP versus Bausch & Lomb Hydroview), and the type of anesthesia (topical versus parabulbar) were compared. Statistical analysis was performed using the Student t test, and P< or =.05 was considered statistically significant. RESULTS: The mean preoperative IOP was 13.83 +/- 2.5 mmHg. There were no significant differences at any time in postoperative IOP measurements between the 2 IOL types and the 2 modes of anesthesia. At 2 to 3 hours, 6 to 8 hours, and 22 to 24 hours, the IOP was significantly higher in the 30 eyes in which the Adatocel was partially removed (from the AC only) than in the 88 eyes in which it was completely removed (from behind the PC IOL as well) (P< or =.05, P< or =.01, and P< or =.001, respectively). CONCLUSION: Severe postoperative IOP spikes in nonglaucomatous patients after uneventful phacoemulsification cataract surgery are rare. The type of implanted PC IOL and the mode of anesthesia had no significant effect on postoperative IOP. Total removal of the ophthalmic viscosurgical device, even when using HPMCs such as Adatocel, is necessary to prevent postoperative IOP spikes.

Ocular surface changes with applanation contact lens and coupling fluid use after argon laser photocoagulation in noninsulin-dependent diabetes mellitus.

PURPOSE: To describe the effect of coupling solutions used during laser photocoagulation on the ocular surface of patients with noninsulin-dependent diabetes mellitus (NIDDM). DESIGN: A prospective case-controlled study. METHODS: Ninety-two eyes of 46 NIDDM patients with clinically significant macular edema, poor metabolic control of diabetes, and peripheral neuropathy and 100 eyes of 50 normal control subjects were studied. The patients' eyes were assigned to argon green focal/grid laser photocoagulation using an applanation contact lens and one of the coupling fluids; 2% methocel, Thilo-Tears Gel, 1.4% sodium hyaluronate, or 0.9% simple saline. The control subjects received time-matched three-mirror contact lens fundus examinations. All subjects underwent corneal sensitivity measurements, Schirmer test, tear film breakup time, and corneal fluorescein staining before as well as 3 and 8 days after the laser procedures and contact lens examinations. Patients with corneal problems persisting after 8 days were followed longer. RESULTS: Diabetic eyes assigned to 2% methocel and 1.4% sodium hyaluronate had significantly lower mean corneal sensitivities and break-up time values as well as significantly higher mean fluorescein staining scores at all examination points after laser photocoagulation. All diabetic eyes with aqueous deficiency assigned to 2% methocel and 1.4% sodium hyaluronate developed delayed corneal epithelial healing. CONCLUSION: The use of viscous coupling solutions during applanation contact lens-aided laser procedures may be detrimental for the corneal epithelium in poorly controlled NIDDM patients with peripheral neuropathy and coexisting aqueous deficiency.