Effects of the COVID-19 pandemic on neovascular age-related macular degeneration and response to delayed Anti-VEGF treatment.

OBJECTIVES: To investigate the effects of the COVID-19 pandemic on the treatment course of neovascular age-related macular degeneration (nAMD) patients who received anti-VEGF injection therapy with real-life data. METHODS: This retrospective study consisted of 116 eyes of 106 patients. Ophthalmic examination, assessment of best-corrected visual acuity (BCVA), optical coherence tomography (OCT) findings and data of last two visits before restrictions (V-2 and V-1) and the first visit (V0) after the release of national lockdown and subsequent visits (V1 and Vlast) were recorded. The lockdown period was determined by the time interval between March 11 and June 1, 2020. MAIN RESULTS: The injection interval before V-1 was significantly longer than the interval after V0 (2.56±0.9 vs. 2.14±0.8 months, P=0.02). While the median central macular thickness (CMT) was significantly increased at V0 compared to V-1 [274(132-711) vs. 238(136-628), P<0.001], the median CMT was significantly lower at V1 compared to V0 [256 (136-591) vs. 274(132-711), P=0.003]. The median BCVA was 0.67(0.1-1.1) logMAR at V-1 and significantly worsened to 0.78 (0.1-1.2) logMAR at V0 (P=0.003). Although the median BCVA improved to 0.69 logMAR (0.1-1.2) at Vlast, the difference did not reach statistical significance compared to V0 (P=0.08). CONCLUSION: Treatment delay due to the COVID-19 pandemic cause progression of nAMD and visual impairment. To plan more frequent anti-VEGF treatments and visits may be an appropriate approach until the disease stabilizes. However, it should be kept in mind that despite the improvement in OCT findings, the desired success in VA could not be achieved in the short term.

Treatment of aqueous bisphenol A using nano-sized zero-valent iron in the presence of hydrogen peroxide and persulfate oxidants.

Bisphenol A (BPA) is an industrial pollutant considered as one of the major endocrine-disrupting chemicals found in natural waters. In the present study, the use of a commercial, air-stable, zero-valent iron (ZVI) powder, consisting of Fe0 surface stabilized nanoparticles was examined for the treatment of 20 mg/L, aqueous BPA solutions. The influence of pH (3, 5, 7), addition of hydrogen peroxide (HP) and persulfate (PS) oxidants (0.0, 1.25 and 2.5 mM) as well as temperature (25 and 50 °C) was studied for BPA treatment with 1 g/L ZVI. ZVI coupled with HP or PS provided an effective treatment system, which was based on rapid ZVI-mediated decomposition of the above-mentioned oxidants, resulting in complete BPA as well as significant total organic carbon (TOC) (88%) removals, in particular when PS was employed as the oxidant. Increasing the PS concentration and reaction temperature dramatically enhanced PS decomposition and BPA removal rates, whereas HP was not very effective in TOC removals and at elevated temperatures. According to the bioassays conducted with Vibrio fischeri and Pseudokirchneriella subcapitata, the acute toxicity of aqueous BPA fluctuated at first but decreased appreciably at the end of ZVI/PS treatment.

Degradation and toxicity assessment of the nonionic surfactant Triton™ X-45 by the peroxymonosulfate/UV-C process.

The degradation and mineralization of the nonionic surfactant octylphenol ethoxylate (OPEO), commercially known as Triton™ X-45, by the peroxymonosulfate (PMS)/UV-C process were investigated. Three different toxicity tests (Daphnia magna, Vibrio fischeri and Pseudokirchneriella subcapitata) as well as the Yeast Estrogen Screen (YES) bioassay were undertaken to evaluate the potential toxic and estrogenic effects of OPEO and its oxidation products. OPEO removal was very fast and complete after 7 min via PMS/UV-C treatment under the investigated reaction conditions (OPEO = 20 mg L(-1) (47 µM); TOC = 12 mg L(-1); PMS = 2.5 mM; initial reaction pH = 6.5; applied UV-C dose = 21 Wh L(-1)). TOC removal also proceeded rapidly; a gradual decrease was observed resulting in an overall TOC removal of 84%. The toxic responses of PMS/UV-C treated OPEO solutions varied according to the test organism used in the bioassay. Daphnia magna was found to be most sensitive to aqueous OPEO, whereas Pseudokirchneriella subcapitata appeared to be the least sensitive one. Daphnia magna and Vibrio fischeri tests revealed that the inhibitory effect of OPEO decreased significantly during the course of treatment. On the other hand, PMS/UV-C oxidation products exhibited a high toxic effect towards Pseudokirchneriella subcapitata (around 60%). YES test results underlined the need for improving the PMS/UV-C treatment performance to remove the estrogenic activity of OPEO and its oxidation products.

The importance of structural and gel fractions in determining shear sensitivity of sludge.

Shear sensitivity measurements with variation of ingredients in a synthetic sludge can be related to biosolids' structural properties and particulate amount. The shear sensitivity is primarily controlled by the gel fraction, with alginate and the associated cations increasing the gel-like behavior. However the effect of particulate fraction on shear sensitivity should also be taken into account. Shear sensitivity is thus a complex parameter including two types of response: the resistance to dispersed mass concentration into centrate, and the maintenance of desired strength while the solids concentration increases in the shear field.

Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results.

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (U.S.) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.

Physical characteristics of a waste activated sludge: conditioning responses and correlations with a synthetic surrogate.

The efficient and economic management of waste activated sludge (WAS) requires a proper understanding of the sludge's material properties. Though there has been much study of WAS, an adequate linkage between its physical and chemical properties has been elusive. In particular, the conditioning and dewatering of WAS are expensive operations, and the addition of polymer to WAS leads to even more complex material behavior that is difficult to optimize. This paper reports on an extensive characterization of WAS, both with and without polymer conditioning. We combined the classical "jar test" approach with less conventional rheometric and electrokinetic measurements. In addition to the use of sampled WAS, a synthetic surrogate sludge was formulated, attempting to duplicate properties of WAS and allow more extensive characterization of a reproducible surrogate to WAS. Results with both the synthetic surrogate and WAS indicated that the traditional, electrokinetic, and rheological properties were related. However, the dose optima by rheometry were somewhat higher in both cases.

Refractive outcome of single running suture adjustment in penetrating keratoplasty.

PURPOSE: To evaluate the effectiveness of single running suture adjustment in reducing postoperative astigmatism and improving visual acuity in patients who have undergone penetrating keratoplasty. METHODS: Eighteen eyes of 18 patients who underwent penetrating keratoplasty at the Department of Ophthalmology, Baskent University between May 1997 and December 2000 and who had an astigmatism over 2 diopters (D) at the fourth postoperative week were included. All eyes underwent suture adjustment at the fourth week and eight eyes with residual astigmatism above 3 D underwent a second adjustment at the eighth week. Final astigmatism and visual acuity findings were evaluated 28 weeks postoperatively. RESULTS: The mean postoperative keratometric and refractive astigmatism were 5.76 +/- 0.88 D (range=4.50-7.76) and 5.22 +/- 0.78 D (range=4.0-7.0) at the fourth week, which were decreased to 2.82 +/- 0.99 D (range=1.25-4.62, p=0.0001) and 2.61 +/- 1.01 D (range= 1.0-4.5, p=0.0001) after suture adjustment, respectively. In eight eyes at the eighth week, a second suture adjustment reduced the average keratometric and refractive astigmatism from 3.86 +/- 0.65 D (range=2.75-4.62) and 3.81 +/- 0.44 D (range=3.25-4.50) to 2.33 +/- 0.91 D (range=0.87-3.50, p=0.012) and 2.06 +/- 0.68 D (range=1.0-2.75, p=0.011), respectively. At the 28th week, the average keratometric and refractive astigmatism levels for the entire cohort, which were 2.39 +/- 1.06 D (range=1.0-3.50) and 2.25 +/- 0.96 D (range=1.0-3.25), respectively, showed a statistically significant decrease when compared with the levels before the first suture adjustment (p=0.0001 for both data). The mean best-corrected visual acuity was 20/25 on the Snellen chart at the 28th week. CONCLUSIONS: Postoperative adjustment of single running suture is a safe and effective way of reducing postkeratoplasty astigmatism.

Tear function tests and conjunctival impression cytology before and after hormone replacement therapy in postmenopausal women.

PURPOSE: To investigate the effect of hormone replacement therapy (HRT) on postmenopausal tear function and the conjunctival epithelium. METHODS: Schirmer I-Jones test, tear film break-up time (BUT), and impression cytology findings were analyzed in 34 eyes of 17 women who were at least two years postmenopausal and not taking HRT: This series of tests was repeated after three months on HRT. RESULTS: The patients' average age was 53.82 +/- 3.6 years, and the mean time postmenopause was 35.29 +/- 11.59 months. There was no significant difference in the Schirmer I-Jones test results before and after three months of HRT (p > 0.05). However, the BUT (p < 0.05) and impression cytology (p < 0.05) findings were significantly affected by HRT. CONCLUSIONS: HRT may alleviate postmenopausal dry eye symptoms by increasing goblet cell density.

Pro- and anti-inflammatory forms of interleukin-1 in the tear fluid and conjunctiva of patients with dry-eye disease.

PURPOSE: To compare the expression of the pro- and anti-inflammatory forms of interleukin (IL)-1 in the tear fluid and conjunctival epithelium of normal eyes and those with dry-eye disease. METHODS: The concentrations of IL-1 alpha, IL-1 beta (precursor and mature forms), and IL-1 receptor antagonist (IL-1Ra) were measured by ELISA in tear fluid samples obtained from normal individuals and patients with dry eye who had rosacea-associated meibomian gland disease (MGD) or Sjögren's syndrome (SS) aqueous tear deficiency (ATD). These cytokines were also measured in normal tear fluid before and after nasal stimulation to induce reflex tearing. The relative expression of these cytokines was evaluated in conjunctival impression cytology specimens and conjunctival biopsy tissue obtained from normal subjects and SS ATD-affected patients using immunofluorescent staining. Matrix metalloproteinase (MMP)-9 concentration and activity in the tear fluid were evaluated with gelatin zymography and with an MMP-9 activity assay kit, respectively. RESULTS: Compared with normal subjects, the concentration of IL-1 alpha and mature IL-1 beta in the tear fluid was increased, and the concentration of precursor IL-1 beta was decreased in patients with MGD (P < 0.05, P = 0.02, and P < 0.01, respectively) and SS ATD (P < 0.001, P = 0.02, and P < 0.001, respectively). There was no significant change in the concentration of IL-1 alpha, precursor IL-1 beta, and IL-1Ra in reflex tear fluid, indicating that the lacrimal glands may secrete these cytokines. The activity of MMP-9, a physiological activator of IL-1 beta, was significantly elevated in the tear fluid of both dry-eye groups compared with normal subjects. A strong positive correlation was observed between the intensity of corneal fluorescein staining and the tear fluid IL-1 alpha concentration (r(2) = 0.17, P < 0.02) and the mature-to-precursor IL-1 beta ratio (r(2) = 0.46, P < 0.001). Positive immunofluorescent staining for IL-1 alpha, mature IL-1 beta, and IL-1Ra was observed in a significantly greater percentage of conjunctival cytology specimens from eyes with SS ATD than in those from normal eyes (P < 0.01 for IL-1 alpha, P < 0.009 for mature IL-1 beta, and P < 0.05 for IL-1Ra). CONCLUSIONS: Dry-eye disease is accompanied by an increase in the proinflammatory forms of IL-1 (IL-1 alpha and mature IL-1 beta) and a decrease in the biologically inactive precursor IL-1 beta in tear fluid. Increased protease activity on the ocular surface may be one mechanism by which precursor IL-1 beta is cleaved to the mature, biologically active form. The conjunctival epithelium appears to be one source of the increased concentration of IL-1 in the tear fluid of patients with dry-eye disease. These results suggest that IL-1 may play a key role in the pathogenesis of keratoconjunctivitis sicca.

Pseudokeratoconus caused by rosacea.

PURPOSE: A case of inferior corneal thinning and high astigmatism with features of keratoconus in a patient with long-standing ocular rosacea is described. METHODS: Axial curvature mapping was performed with the Tomey TMS-1 videokeratoscopy instrument and corneal thickness mapping was performed with the Orbscan Corneal Topography System (CTS). Tear clearance was assessed by measuring the concentration of fluorescein in the tear fluid with a fluorometer. RESULTS: There were inferior corneal thinning and opacification in both eyes. Tear fluorescein clearance was markedly delayed in the right eye. There was asymmetric inferior corneal steepening in both eyes with I-S values of 1 in the right eye and 5.9 in the left eye. There were 5.9 diopters of astigmatism at 85 degrees in the right eye and 7.3 diopters of astigmatism at 73 degrees in the left eye. Corneal pachymetry mapping with the Orbscan CTS showed a normal central corneal thickness and maximal thinning in the inferotemporal periphery of the right cornea and inferonasal periphery of the left cornea. CONCLUSION: Chronic ocular rosacea can produce inferior corneal thinning and high astigmatism with some features of keratoconus. The inferior pattern of thinning in rosacea may be related to chronic exposure of the inferior cornea to inflammatory and matrix-degrading factors in the inferior tear meniscus.

Treatment of recalcitrant recurrent corneal erosions with inhibitors of matrix metalloproteinase-9, doxycycline and corticosteroids.

PURPOSE: To review the efficacy of inhibitors of matrix metalloproteinase-9, corticosteroids, and doxycycline for treatment of recalcitrant recurrent corneal erosion. METHODS: Retrospective, clinic-based, interventional case series. The medical records of seven consecutive patients who were treated between January 1995 to January 2000 for recurrent corneal erosion who had not responded to conventional therapy were reviewed. Treatment of seven eyes of seven patients consisted of oral doxycycline (50 mg, two times a day) for 2 months along with a topical corticosteroid (either methylprednisolone 1%, prednisolone acetate 1%, or fluoromethalone 0.1%) three times a day, for 2 to 3 weeks. The effects of doxycycline and methylprednisolone on metalloproteinase-9 activity in human corneal epithelial cultures were evaluated by gelatin zymography and a commercial metalloproteinase-9 activity assay kit. RESULT: Fingernail injury in three of the seven eyes was the most common form of corneal injury. There was no evidence of epithelial basement membrane or corneal stromal dystrophy in any of the patients, although epithelial microcysts were observed in the involved area in three patients. One eye had intact elevated corneal epithelium that showed abnormal diffuse staining with fluorescein dye, and six eyes had a corneal epithelial defect at the time of presentation. In all seven eyes, pain resolved and epithelial defects healed within 2 to 10 days after initiation of therapy. No recurrence was observed during an average follow-up period of 21.9 months (range, 1.5 to 60 months). Methylprednisolone and doxycycline each produced a statistically significant decrease in amount and activity of metalloproteinase-9 in conditioned media of human corneal epithelial cultures. CONCLUSIONS: Therapy with a combination of medications that inhibit metalloproteinase-9 produced rapid resolution and prevented further recurrence of cases of recurrent corneal erosions that were unresponsive to conventional therapies.

Effects of laser in situ keratomileusis on tear production, clearance, and the ocular surface.

PURPOSE: To evaluate components of the integrated ocular surface/lacrimal gland unit in a series of patients before and after undergoing bilateral laser in situ keratomileusis (LASIK). DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Forty-eight eyes of 14 men and 34 women (age range, 26-54; mean, 39.2 years) who underwent bilateral LASIK for myopia or myopic astigmatism. METHODS: LASIK was performed using a VISX Star Excimer Laser (Santa Clara, CA). Patients completed a questionnaire containing 11 questions that evaluated the character and severity of ocular irritation symptoms. Snellen visual acuity, tear fluorescein clearance, corneal fluorescein staining, aqueous tear production by the Schirmer 1 test, and corneal and conjunctival sensitivity were measured in each eye. Corneal surface regularity (SRI) was evaluated with the Tomey TMS-1 (Tomey, Cambridge, MA) topography instrument. Each randomly chosen eye was evaluated 1 to 2 days (T0) before LASIK and 7 days (T1), 1 (T2), 2 (T3), 6 (T4), 12 (T5), and 16 (T6) months postoperatively. A Wilcoxon test, two-tailed paired t test, Friedman test, or analysis of variance were used for statistical comparisons. MAIN OUTCOME MEASURES: Components of the integrated ocular surface/lacrimal gland unit. RESULTS: Both corneal and conjunctival sensitivity were noted to be significantly decreased from preoperative levels at 1week, 1 month, 12 months, and 16 months postoperatively (P < 0.0002 at each time point). Symptom severity scores were significantly increased at 1 week, 12 months, and 16 months postoperatively (P < 0.007 at all time points). The mean Schirmer 1 test scores were 24 +/- 14 mm preoperatively, and they decreased to 18 +/- 14 mm by 1 month postoperatively (P < 0.001). Tear fluorescein clearance showed a linear increase postoperatively and was significantly greater than baseline (P < 0.001) at each time point. There was a significant increase in punctate corneal fluorescein staining at 1 week postoperatively (P < 0.0001), but staining returned to baseline by 12 months. There was a statistically significant increase in SRI 1 week postoperatively (P < 0.007) with return to baseline levels by 6 months. CONCLUSIONS: Sensory denervation of the ocular surface after bilateral LASIK disrupts ocular surface tear dynamics and causes irritation symptoms. Patients undergoing LASIK should be informed of these risks.

Management of hypotony maculopathy and a large filtering bleb after trabeculectomy with mitomycin C: success with argon laser therapy.

We report a patient with postkeratoplasty glaucoma that developed a large, filtering bleb following trabeculectomy with intraoperative antimetabolite treatment. The hypotony and the bleb were managed using argon laser photocoagulation. A 26-year-old female patient underwent penetrating keratoplasty in the left eye for keratoconus. Postoperatively, her elevated intraocular pressure could not be controlled medically, and the patient underwent a trabeculectomy with intraoperative antimetabolite application. Two months later, hypotony maculopathy, optic disc edema, and choroidal folds developed, and her vision dropped. Steroid treatment and soft contact lenses did not help. Photocoagulation was applied twice to the surface of the bleb and the surrounding area. After the photocoagulation therapy, the patient's vision improved, intraocular pressure increased, and the optic disc edema and macular folds had resolved. Argon laser photocoagulation applied to a large filtering bleb associated with hypotony maculopathy is a useful treatment for bleb remodeling and elevating intraocular pressure.

Impression cytology of the conjunctival epithelium in patients with chronic renal failure.

AIMS: To assess ocular surface changes in patients with chronic renal failure (CRF), to compare the results with the degree of corneo-conjunctival calcium deposits, and to determine whether precipitation of calcium salts predisposes ocular surface modifications. METHODS: Impression cytology from 50 CRF patients on regular haemodialysis and 22 age and sex matched control subjects were studied. Specimens were obtained from the temporal bulbar conjunctiva using cellulose acetate filter paper. The samples were fixed in 95% ethanol, stained with the periodic acid Schiff (PAS) stain, and evaluated by light microscopy and were graded by a masked observer. Corneo-conjunctival calcification was graded by the Porter and Crombie classification. RESULTS: In the study group, three patients (6%) disclosed grade 0, 14 patients (28%) grade 1, and 33 patients (66%) grade 2-3 cytological changes. There was a statistically significant difference between the patient and the control groups (p= 0.0007), but no correlation could be found between the impression cytology grades and the calcium deposit grades (p=0.62). CONCLUSION: The ocular surfaces of CRF patients differ significantly from those of normal individuals, and it can be detected using impression cytology. These data suggest that the severity of conjunctival changes are not related to the presence or extent of calcium deposition.

The effects of experimental tear film removal on corneal surface regularity and barrier function.

PURPOSE: To evaluate corneal surface regularity and asymmetry, corneal thickness, barrier function, and contrast sensitivity after experimental removal of the precorneal tear layer. DESIGN: Prospective, clinic-based, nonrandomized (self-controlled) comparative trial. PARTICIPANTS: Six eyes of six healthy volunteers (three males, three females; age range, 29-40 years). METHODS: A precorneal tear lesion was created by pressing a sterile Biopore (Millipore, Bedford, MA) Teflon membrane against the central cornea. Corneal topography with both the Topographic Modeling System (TMS-1; Computed Anatomy, Tomey Technology, Cambridge, MA) and the Orbscan (Orbscan Inc., Salt Lake City, UT) were performed before the lesion was created and 30 seconds, 1 hour, and 4 hours after the lesion was created. Surface regularity and surface asymmetry indices were evaluated by the TMS-1 topography system. Maximum and minimum keratometric readings, corneal fluorescein staining, contrast sensitivity, and corneal thickness were evaluated before and after the tear lesion. Cytologic membranes were stained for MUC4 mucin using an indirect immunofluorescent staining technique. Confocal microscopy was performed to evaluate the integrity of the corneal epithelium in two eyes. Analysis of variance with polynomial contrasts was used to examine time trends of the outcome variables. MAIN OUTCOME MEASURES: The change in corneal surface regularity and asymmetry indices, corneal thickness, permeability to fluorescein dye, and contrast sensitivity before and after the lesion was made were compared. RESULTS: The corneal epithelium in the area of the lesion showed intense fluorescein staining 30 seconds postlesion but appeared normal by 4 hours. Confluent, homogeneous staining for MUC4 mucin was observed on the membranes used to create the lesion in all cases. The surface regularity index measured with the TMS-1 increased after the lesion was created and decreased toward normal by 4 hours (P = 0.017). Corneal thickness measured by the Orbscan instrument significantly increased in the central (P = 0.001), superior (P = 0.006), inferotemporal (P < 0.001) and superotemporal (P = 0.001) cornea immediately following the lesion and returned to normal by 4 hours. The lesion caused a decrease in visual acuity at 6.30%, 4% and 2.5% contrast sensitivities 1 hour postlesion and these measurements returned to prelesion values by 4 hours (P = 0.085, P = 0.005, P = 0.043). CONCLUSIONS: The precorneal tear layer serves as a permeability barrier and is essential for maintaining a smooth quality optical surface.

Effect of wind instrument playing on intraocular pressure.

PURPOSE: To evaluate the effect of wind instrument playing on intraocular pressure. METHODS: In a prospective, nonrandomized clinical trial, 24 eyes of 24 wind instrument players with no history of any ocular or systemic disease were evaluated. The musicians were members of Bilkent Academic Symphony Orchestra of Bilkent University in Ankara. A complete eye examination, including best-corrected visual acuity, slit-lamp examination, and fundus examination, was performed. The intraocular pressure was measured before and after a 90-minute rehearsal of a piece by Wagner. All intraocular pressure measurements were carried out by the same researcher using Goldmann applanation tonometry. The difference in intraocular pressure measurements before and after the 90-minute wind instrument-playing performance was analyzed. RESULTS: The mean intraocular pressure was 13.79 +/- 1.93 mm Hg before and 15.12 +/- 2.44 mm Hg after the performance. Wind instrument playing significantly increased the mean intraocular pressure by 9.6% (P = 0.0149). CONCLUSION: These results indicate that wind instrument playing may significantly increase intraocular pressure in healthy patients. The significance of this finding for patients with suspected normal-tension or high-tension glaucoma needs further evaluation.

Complications of extracapsular cataract surgery in chronic renal failure patients.

PURPOSE: In chronic renal failure (CRF) patients the risk of per- and post-operative complications in cataract surgery is high. The most frequent complications observed in these patients and the prevalence of cataract were studied. METHODS: Eighty-two CRF patients who had undergone ophthalmic examination between December 1996 and April 1998 at Baskent University, Department of Ophthalmology, were retrospectively analysed. Of 82 patients, 18 eyes of 14 CRF patients between 37 and 79 years of age underwent cataract extraction. Planned extracapsular cataract extraction was performed in all patients and all but one had posterior chamber intraocular lens implantation. In the post-operative period, scrapings of the corneal infiltrates were cultured and smears were examined, and the conjunctiva was swabbed and cultured also. RESULTS: Per-operative hypotony and scleral collapse occurred in 1 patient, and another had haemorrhage in the anterior chamber. Post-operatively, suture infiltration was observed in 10 eyes. These lesions disappeared after topical steroid and antibiotic treatment. CONCLUSIONS: Patients with CRF require special surgical considerations since they face both general surgical problems and others that arise due to their disease.

Slime production by coagulase-negative staphylococci isolated in chronic blepharitis.

BACKGROUND: The purpose of the study was to determine the impact of slime-producing strains of coagulase-negative staphylococci (CNS) on non-ulcerative blepharitis. Formerly considered harmless organisms, CNS are now recognised as opportunistic pathogens. Although these microorganisms are a component of normal conjunctival flora, they often produce the typical signs and symptoms of chronic staphylococcal blepharoconjunctivitis. Certain strains produce a polysaccharide extracellular material called "slime". Slime production is considered to be associated with the virulence of the organism. METHODS: Swabs were taken from the lids of 38 eyes of 19 patients with chronic non-ulcerative blepharitis and cultured for CNS. A group of 42 normal control eyes were similarly sampled. The strains of CNS isolated from 26 eyes (68.4%) of the patients with blepharitis and 25 eyes (59.5%) of the normal subjects were studied for slime layer production. RESULTS: No significant difference was found between normal subjects and patients in the incidence of slime producing CNS strains from the conjunctiva. The antibiotic sensitivity profiles of the slime-producing strains were no different from the slime-negative isolates in the blepharitis (p=0.85) and normal group (p=0.25). CONCLUSIONS: Our data suggest that slime production by CNS does not play a significant role in the pathogenesis of staphylococcal blepharitis.

Is tear calcium an indicator of ocular calcification in patients with chronic renal failure?

BACKGROUND: In patients with chronic renal failure (CRF) on regular dialysis treatment, limboconjunctival degeneration and calcifications are common. The mechanisms of ectopic conjunctival and corneal calcification remain largely speculative. The aim of the present work was to study tear calcium levels in patients with chronic renal failure, which could alter calcium excretion patterns, and to examine whether the calcium level in tear fluid is of more diagnostic importance than static calcium levels in blood. METHODS: Tear calcium levels were measured in 25 patients with chronic renal failure, compared with 14 normal subjects. Conjunctival and corneal calcium deposits were graded by the Porter and Crombie classification. RESULTS: While 11 of the 25 patients had no clinically apparent calcium deposits, six had Grade 1 or 2, and eight had Grade 3 and over limboconjunctival calcification. Mean tear calcium levels were 1.436 +/- 0.165 mg/dl in the patients and 1.307 +/- 0.155 mg/dl in the normal group. The difference was not significant (P = 0.572). No correlation was found between the grade of the calcium deposits and tear calcium levels. CONCLUSIONS: Tear calcium level has no diagnostic importance for the development of ocular calcification in chronic renal failure.