Activation and detoxification of dinitropyrenes by cytosol and microsomes from Aroclor-pretreated rats in the Ames and umu assays

PURPOSE: To evaluate the efficacy of topical mitomycin C in treating conjunctival and corneal epithelial dysplasia and neoplasia. METHODS: Seven eyes of seven patients with conjunctival and corneal epithelial dysplasia and neoplasia were treated with one drop of topical mitomycin C 0.04% four times a day for 7 days in alternate weeks. The patients' charts were reviewed retrospectively. Patients with either multiple recurrences or extensive ocular surface involvement were treated. In all eyes, the diagnosis of epithelial dysplasia or neoplasia was confirmed by histopathology before the onset of therapy. Patients were examined at least every 14 days during treatment and examined at intervals after completion of treatment. RESULTS: With topical mitomycin C, six eyes of seven patients had complete clinical regression of their conjunctival and corneal epithelial dysplasia and neoplasia. One eye of one patient had partial clinical regression of conjunctival and corneal epithelial dysplasia. Follow-up after completion of topical mitomycin C therapy and excision of residual disease ranged from 2 to 16 months (mean, 9 months; SD, 4.3 months) and was without clinical sign of recurrence. Topical mitomycin C therapy was associated with transitory ocular discomfort, conjunctival injection, tearing, photophobia, and punctate epithelial keratopathy. CONCLUSION: In this small series of eyes, topical mitomycin C was effective as a treatment for conjunctival and corneal epithelial dysplasia and neoplasia.     

Communicating more effectively with the confused or demented patient

AIMS/BACKGROUND: Ocular cicatricial pemphigoid (OCP) can present with severe conjunctival inflammation that requires systemic immunosuppression to avoid serious ocular morbidity. This study aimed to assess the clinical response to cyclophosphamide and short term, high dose prednisolone in this group of patients. METHODS: A prospective, unmasked study assessed patients presenting with either 'severe' ocular inflammation (n = 4) or 'marked' or 'severe' ocular inflammation that had failed to respond to other systemic immunosuppression (n = 6). Nineteen inflamed eyes of 10 consecutive patients were enrolled. RESULTS: The ocular inflammation resolved in 15 eyes in a mean time of 2.4 months. Two eyes perforated despite treatment and one patient was unable to tolerate the medication. Progressive cicatrisation occurred in 21%. CONCLUSION: Cyclophosphamide and short term, high dose prednisolone are effective in severe inflammation caused by OCP but may not completely prevent cicatrisation.     

Single intraoperative application versus postoperative mitomycin C eye drops in pterygium surgery

PURPOSE: To determine the minimum effective dosage, most effective route of administration and long-term effects of mitomycin C for prevention of recurrence after pterygium surgery. METHODS: In a prospective, masked study, 227 patients undergoing surgery for primary pterygia were assigned randomly to five groups: group 1 received a single intraoperative application of 0.2 mg/ml mitomycin C for 3 minutes; group 2 received a single intraoperative application of 0.4 mg/ml mitomycin C for 3 minutes; group 3 received mitomycin C eye drops 0.2 mg/ml three times daily for 7 days; group 4 received mitomycin C eye drops 0.4 mg/ml three times daily for 14 days; group 5 acted as a control (surgery alone). RESULTS: After a mean follow-up time of 28 months, recurrence rates of 6.66%, 4.08%, 4.26%, 4.44%, and 29.27%, respectively, were observed. Statistical analysis showed significant differences between groups receiving mitomycin C and the control (P < or = 0.001). There was no statistical difference among treated groups (P > or = 0.0681). No complications of therapy were observed. CONCLUSION: These results support the efficacy and relative safety of a single, low-concentration, intraoperative application of mitomycin C in pterygium surgery together with the use of a conjunctival flap, avoiding excessive cauterization of the sclera and leaving bare sclera.     

Ultrastructural changes in rabbit ciliary body after extraocular mitomycin C

PURPOSE: To study the ultrastructural changes in ciliary body epithelium of the rabbit eye after subconjunctival injections of mitomycin C. METHODS: One eye of six New Zealand white rabbits was given a subconjunctival injection at the 12-o'clock position with 0.005, 0.02, 0.08, 0.1, 0.12, or 0.16 mg mitomycin C. The fellow eye was given a subconjunctival injection of balanced salt solution. Two weeks after treatment, the eyes were enucleated, and the ciliary body was exposed and submerged in fresh 4% paraformaldehyde/2% glutaraldehyde in 0.1 M phosphate buffer, pH 7.4, at 4 degrees C. Electron microscopy of the ciliary body was performed at two sites: the injection site (12-o'clock position) and 180 degrees away (6-o'clock position). RESULTS: At dosages of 0.1 mg and higher, ciliary body epithelial cells beneath the injection site were thinned. There were vacuoles and expansion of intracellular and intercellular spaces. Plasma membrane infoldings were disrupted, and the apical membrane was thinned. Mitochondria and nuclei were normal. Ciliary body epithelium at 6-o'clock position showed only mild architectural distortion of the plasma membrane infoldings. Eyes that received lower doses of mitomycin C (0.005 mg, 0.02 mg, and 0.08 mg) and balanced salt solution showed normal ciliary body epithelium at the injection site and 180 degrees away. CONCLUSIONS: Subconjunctival injection of mitomycin C in the rabbit produces dose-dependent localized ultrastructural changes of the ciliary body epithelium.     

A randomized clinical trial of the nonsteroidal eyedrop diclofenac after strabismus surgery

OBJECTIVE: This study aimed to compare the anti-inflammatory and analgesic effects of topical diclofenac sodium 0.1% (Voltaren) with prednisolone sodium phosphate 1% ophthalmic solution after strabismus surgery. DESIGN: A prospective, double-masked, randomized, two-center clinical trial. PARTICIPANTS: Eighty eyes of 52 patients undergoing strabismus surgery were examined. INTERVENTION: For 1 week after surgery, the eye that was operated on received one drop of either diclofenac or prednisolone four times a day. MAIN OUTCOME MEASURES: The diclofenac- and prednisolone-treated eyes were compared on postoperative days 3 and 7 with respect to signs of inflammation (e.g., erythema, edema, discharge), patient comfort, and conjunctival incisional healing. RESULTS: On postoperative day 7, in eyes that received prednisolone, the conjunctival defects were larger (P = 0.004) and more frequent (P = 0.02). For all subjects, despite adequate statistical power, there was no statistically significant difference in inflammatory scores between eyes that received diclofenac or prednisolone. In cases of bilateral surgery, however, there was less postoperative erythema and edema in the diclofenac-treated eyes. CONCLUSIONS: In the first week after strabismus surgery, topical diclofenac proved at least as effective as prednisolone in controlling inflammation and discomfort with less delay in incisional wound healing. Topical diclofenac, a nonsteroidal anti-inflammatory agent, may be considered for use after strabismus surgery in place of corticosteroids.     

The acute pain service: effective or expensive care?

AIM: The authors investigated the safety and intraocular pressure (IOP) lowering effectiveness of trabeculectomy augmented with mitomycin C application beneath the scleral flap, and assessed the influence of preoperative risk factors on the surgical outcome. METHODS: A retrospective study of 72 consecutive high risk eyes undergoing trabeculectomy with adjunctive mitomycin C (0.2 mg/ml) applied under the scleral flap for 5 minutes was performed. Each eye was ascribed a score based on the number of preoperative risk factors, and categorised into one of three risk factor groups. Success was described as unqualified where IOP was < or = 21 mm Hg without medication and qualified where antiglaucomatous therapy was required to maintain it at such a level. A life table analysis of IOP control was calculated. RESULTS: The mean IOP (SD) fell from a preoperative level of 28.4 (6.9) to a level of 16.63 (8.06) mm Hg at the last follow up (paired Student's t test: p < 0.0001). Fifty two eyes (72%) were classed as unqualified successes. The survival rates did not differ significantly between different risk factor groups (log rank test: chi 2 = 0.967, p > 0.1). The incidence of postoperative complications compared favourably with reports of mitomycin C application between Tenon's capsule and the undissected scleral bed. CONCLUSION: The results illustrate that mitomycin C applied beneath the scleral flap during trabeculectomy in high risk eyes is associated with a success rate comparable to other modes of application. The incidence of potentially serious complications such as conjunctival wound leak and prolonged hypotony was lower than previously published data reporting sub-Tenon's administration of mitomycin C. The number and nature of preoperative risk factors do not appear to influence the surgical outcome. A possible mechanism of action is proposed.     

Myocardial turnover of endogenous opioids and calcitonin-gene-related peptide in the human heart and the effects of spinal cord stimulation on pacing-induced angina pectoris

OBJECTIVE: The authors determine if the intraoperative placement of paclitaxel powder in the subconjunctival space improves the outcome of glaucoma filtration surgery in rabbits. METHODS: A posterior lip sclerectomy was performed in the right eye of 24 New Zealand white rabbits. Before the conjunctiva was fully sutured, 8 mg of mannitol powder alone, or 8 mg of mannitol powder containing either 10 micrograms or 250 micrograms of paclitaxel, was placed in the subconjunctival space of six eyes each in masked fashion. An additional six animals were treated with episcleral application of a sponge soaked in a solution of 0.5 mg/ml of mitomycin C (MMC) for 5 minutes before the sclerectomy was performed. Intraocular pressure and bleb size were measured until the operation had failed or until the 7 weeks of observation had concluded. RESULTS: Both paclitaxel powder and MMC solution improved the outcome of filtration surgery in this model as measured by magnitude of intraocular pressure (IOP) lowering and duration of surgical success. No toxic effect of either drug was observed, although endophthalmitis was observed in eight animals followed for more than 3 weeks. CONCLUSION: The introduction of paclitaxel into the subconjunctival space at the conclusion of filtration surgery has an effect comparable to intraoperative MMC.     

Decrease of capsular opacification with adjunctive mitomycin C in combined glaucoma and cataract surgery

OBJECTIVE: The authors investigated the incidence of capsular opacification requiring YAG capsulotomy after primary trabeculectomy combined with phacoemulsification and implantation of all polymethylmethacrylate intraocular lenses. DESIGN: A prospective randomized study. PARTICIPANTS: One hundred seventy-four eyes of 174 nonselected patients with primary open-angle glaucoma (POAG) were randomized to either no adjunctive mitomycin C (MMC) control group of 93 eyes of 93 patients) or adjunctive subconjunctival MMC (MMC group of 81 eyes of 81 patients) during the primary glaucoma triple procedure (PGTP). INTERVENTION: Primary glaucoma triple procedure with and without MMC and YAG laser capsulotomy for posterior capsular opacification (PCO) was performed. MAIN OUTCOME MEASURES: The incidences of YAG capsulotomy for PCO were compared between the control and MMC groups and also between the control group and the MMC subgroups (1 minute, 3 minutes, and 5 minutes of MMC application) using Kaplan-Meier analysis with Mantel-Cox log-rank test. Cox proportional hazard regression analysis also was performed to identify significant factors affecting capsular opacification. RESULTS: The control and MMC groups were similar in preoperative characteristics. However, the probability of PCO requiring YAG capsulotomy was significantly lower in the MMC group than in the control group (P = 0.004). Among the MMC subgroups, MMC application for 3 minutes was most effective and significant when compared with that of the control group (P = 0.002). Although not as significant as the intraoperative use of MMC (P = 0.002), old age (P = 0.026) and presence of diabetes mellitus (P = 0.035) were also identified as significant beneficial factors for decreasing the incidence of YAG capsulotomy for PCO in Cox proportional hazard regression analysis. CONCLUSION: Intraoperative subconjunctival MMC application during combined glaucoma and cataract surgery has a beneficial effect of inhibiting PCO after combined surgery in patients with POAG. Thus, after intraoperative subconjunctival application of MMC at the concentration of 0.5 mg/ml for 3 minutes, the aqueous MMC level must have been great enough to inhibit the lens epithelial cell proliferation to result in a long-term decrease in PCO.     

Effect of local administration of mitomycin C on intraocular pressure

BACKGROUND: Animal studies suggest that the decrease of intraocular pressure after application of mitomycin C is particularly mediated by toxic effects on the substance of ciliary body. Moreover it has been shown that the concentration of mitomycin C after topical application in the aqueous humour is as high when performing fistulating surgery. In this prospective study we wanted to investigate whether the topical application of mitomycin C would result in a significant decrease of intraocular pressure. PATIENTS AND METHODS: Forty-one eyes of 41 patients underwent pterygium surgery using a bare sclera technique. Afterwards phototherapeutic keratectomy with the excimer laser (193 nm) was performed in the area of the excision. In hospital mitomycin C eye drops (0.02%) were given twice daily for four days. The intraocular pressure of treated and untreated eyes was measured with applanation tonometry at least three times per day preoperatively, postoperatively at the fourteenth day and after 6 month. RESULTS: Mean intraocular pressure of the treated eyes was preoperatively 15.73 +/- 2.35 mm Hg, 14 days postoperatively 15.92 +/- 2.79 mm Hg and at the last examination 15.86 +/- 2.39 mm Hg. For untreated eyes the mean intraocular pressure was preoperatively 15.70 +/- 2.04 mm Hg, after 14 days 15.76 +/- 2.96 mm Hg and at the last examination 15.89 +/- 2.67 mm Hg. Consequently there was no statistically significant change of intraocular pressure in the eyes treated with mitomycin C. Furthermore there were no significant differences of intraocular pressure between treated and untreated eyes at any time of postoperative check-up. CONCLUSION: The short-term local application of mitomycin C did not result in a detectable change of intraocular pressure and is therefore probably an alternative to intraoperative application during filtration surgery.     

Recurrent bleb infections

AIM: To report the patient characteristics, causative organisms, and clinical outcomes in patients with recurrent bleb related ocular infections. METHODS: The medical records of all patients diagnosed with bleb related ocular infection at the New York Eye and Ear Infirmary over a 10 year period were reviewed. Recurrent bleb infection was defined as at least two episodes of bleb purulence with or without associated intraocular inflammation separated by a quiescent period of at least 3 months. RESULTS: Recurrent bleb infections developed in 12 eyes of 12 patients (10 men, two women) a mean of 16.3 (SD 17.9) months (range 3-51 months) after the initial infection. Two patients developed a third episode 3 and 20 months, respectively, after the second infection, yielding a total of 14 recurrent infection episodes. Recurrent infection developed after trabeculectomy in 11 eyes (adjunctive 5-fluorouracil, nine eyes; mitomycin C, one eye; no antifibrosis agent, one eye) and following cataract extraction with inadvertent bleb formation in one eye. Four (36.4%) of the filtered eyes had undergone trabeculectomy at the inferior limbus. The mean follow up time from filtering surgery to the first bleb related infection was 28 months for the nine patients treated with 5-fluorouracil and 14 months for the single patient treated with mitomycin C. 11 (78.6%) cases had a documented bleb leak in the 4 week period before or at the time of recurrent infection. Topical, prophylactic antibiotics had been used in 7/14 (50%) cases. The same organism was cultured from the initial and recurrent infections in 2/14 (14.3%) cases. CONCLUSION: Eyes that have been successfully treated for bleb related infection remain at risk for recurrent infection. No apparent correlation exists between organisms responsible for the initial and recurrent infections. The increased rate of recurrent bleb related infection in patients receiving adjunctive 5-fluorouracil compared to mitomycin C may have been related to the longer follow up of the 5-fluorouracil eyes.     

Long-term effects of postoperative subconjunctival injections of mitomycin-C in the rabbit eye

AIM: Single or multiple subconjunctival injections of mitomycin-C (MMC) may offer one way of establishing the total dosage of MMC more accurately. The method also allows re-applications later postoperatively. In this experimental, randomized prospective study we compared the effects of a single intraoperative application of MMC at the filtering site and a single postoperative subconjunctival injection of the drug. METHODS: The left eyes of 32 pigmented rabbits were divided into two groups. In the first group we applied MMC intraoperatively (IO) with a 4 x 1 mm surgical sponge soaked in a MMC solution (0.5 mg/ml). In the second group we injected 0.4 ml of the same solution subconjunctivally (SC) immediately after (conjunctival) suture. Post-operative evaluation was carried out every day during the first week, then every three days until day 58. Survival analyses were done for intraocular pressure (IOP) and bleb failure. Log-rank tests were used to compare survival differences between the groups. RESULTS: The IO group showed longer survival parameters than the SC group (p < 0.05), both in the control of IOP and as regards blebs. The histological persistence of fistulas was similar. The IO group, however, had a higher incidence of undesirable side effects. CONCLUSIONS: Our findings suggest IO application of MMC is more effective in reducing fibroblast ingrowth. However, subconjunctival application offers certain advantages such as the possibility of repeating the treatment postoperatively and, therefore, using a smaller initial dose.     

Conjunctival wound closure by saline injection in sutureless, scleral tunnel incision phacoemulsification

PURPOSE: To compare two methods of conjunctival closure in phacoemulsification. SETTING: Frimley Park Hospital NHS Trust, Surrey, England. METHODS: This prospective, randomized study comprised 40 patients (40 eyes) who had phacoemulsification via superior axis scleral tunnels and implantation of a poly(methyl methacrylate) intraocular lens with a 5.5 mm optic diameter. In 24 eyes, the conjunctival wound was closed manually with a Moorfields forceps (Group A). In 16, 0.5 ml of balanced salt solution was injected subconjunctivally to reappose the conjunctival wound (Group B). Conjunctival reapposition was assessed by measuring the maximum radial distance of bare sclera preoperatively and during outpatient clinic visits at 1, 7, and 28 days postoperatively. RESULTS: Follow-up was obtained on 38 eyes. One day after surgery, total wound closure was achieved in 15 of 16 eyes in Group B; however, closure was still incomplete in 13 of 22 Group A eyes. At 7 days postoperatively, the size of the conjunctival wound remained significantly smaller in Group B eyes (P < .01). CONCLUSION: The saline injection produced a faster rate of conjunctival wound closure than standard manual reapposition.     

Trabeculectomy with adjunctive mitomycin C in pediatric glaucoma

PURPOSE: To determine the safety and efficacy of trabeculectomy with adjunctive mitomycin C in patients 17 years of age or younger, and to identify risk factors for failure of this surgical technique. METHODS: Retrospective review of consecutive cases of pediatric glaucoma that underwent mitomycin C augmented trabeculectomy between January 1991 and December 1995. Forty-nine patients (60 eyes) with a mean age of 7.6 years (range, 6 weeks to 17.6 years) were identified and followed up until repeat glaucoma surgery, or after a minimum of 6 months. Success was defined as intraocular pressure control of 22 mm Hg or less with or without topical glaucoma control medication, no evidence of glaucoma progression, no further glaucoma surgery necessary, and no visually devastating complication. RESULTS: Cumulative probabilities of success +/- SD for 49 eyes (one eye per patient) were 67% +/- 13% at 12 months and 59% +/- 15% at 24 months. Multivariate regression analysis yielded the following characteristics as significantly increased risk for failure: age of less than 1 year at time of surgery (risk ratio, 5.6; confidence interval, 2.1 to 14.7; P = .0005), and aphakia (risk ratio, 2.7; confidence interval, 1.1 to 6.9; P = .0364). Shallow anterior chamber (17 [28%] of 60 eyes) and serous choroidal detachment (13 [22%] of 60 eyes) were the most common complications. Four (11%) of 38 eyes with obtainable Snellen acuity were noted to have a decrease in best-corrected visual acuity of more than 2 Snellen lines or loss of light perception. In 5 (8%) of 60 eyes bleb-related endophthalmitis was noted. CONCLUSIONS: Trabeculectomy with adjunctive mitomycin C is generally effective for the treatment of pediatric glaucoma, especially in phakic children over 1 year of age. However, late-onset bleb-related endophthalmitis is a substantial risk in this patient population.     

Iterative selection from a Salmonella typhimurium cosmid library can lead to the isolation of an atypically small plasmid

OBJECTIVE: To determine whether ocular cicatricial pemphigoid (OCP) may represent a distinct immunopathologic disease when it is pure ocular cicatricial pemphigoid (POCP) (e.g., only confined to the conjunctiva) or when it is associated with skin or extraocular mucous membrane lesions or both (OCP+). DESIGN: Prospective, immunologic, and immunopathologic study with special emphasis on direct immunoelectron microscopy. PARTICIPANTS: Six patients with POCP and seven patients with OCP+. INTERVENTION: After informed consent was obtained, a conjunctival biopsy was performed in all patients. Skin and extraocular mucosa biopsy specimens were harvested in selected cases only. MAIN OUTCOME MEASURES: Results of direct immunofluorescence and direct immunoelectron microscopy without freezing on conjunctival and skin biopsy specimens, indirect immunofluorescence, and Western immunoblotting analysis were analyzed. RESULTS: Results of direct immunoelectron microscopic examination of the conjunctiva showed the presence of immune deposits in the upper lamina lucida of the basement membrane zone in the six patients with POCP, whereas the immune reactants were located in the lower part of the lamina lucida and in the lamina densa of the basement membrane zone (conjunctiva, buccal mucosa, and skin) in the seven patients with OCP+. Direct immunofluorescence was positive in the biopsy specimens of three patients with POCP (50%) and the seven patients with OCP+ (100%). Results of indirect immunofluorescence study showed circulating autoantibody levels only in two patients with OCP+, and results of Western immunoblot analysis were negative. CONCLUSIONS: Results of direct immunoelectron microscopic examination of the conjunctiva support the hypothesis that POCP may be a disease entity distinct from mucocutaneous cicatricial pemphigoid.     

Palliative intubation of esophageal prosthesis in two patients with lung cancer

PURPOSE: Severe eye burns often result in extensive necrosis of the conjunctiva and episcleral tissue. Video fluorescein angiography was performed to reveal the perfusion of the anterior eye segment after severe eye burns. METHODS: A scanning laser ophthalmoscope was used for anterior segment fluorescein angiography in 12 patients (14 eyes) with severe burns grade III-IV and in 7 healthy volunteers. RESULTS: Necrotic tissues occurred as non perfused areas and remained dark throughout the whole angiogram. In general, the borders from healthy to necrotic conjunctival tissue were sharply demarcated. Thus, the extent of scleral and limbal ischemia could be determined exactly. Injured vessels showed hyperfluorescence with late leakage. Damage of the subconjunctival tissue appeared as a deep weak fluorescence in the early angiography and exhibited patchy leakage in the late angiogram. CONCLUSIONS: Anterior segment angiography provides a basis for deciding the extent of surgical debridement of necrotic tissue in the acute phase of the burn. The determination of the extent of limbal and scleral ischemia may give useful information for early plastic-reconstructive procedures.     

Comparative intraocular penetration of topical and injected cefuroxime

AIMS: The choice of a prophylactic antibiotic for cataract surgery is dependent on its antibacterial activity and tissue penetration. The influence of the route and timing of administration of cefuroxime on its intraocular concentrations was examined. METHODS: 120 patients were recruited before cataract surgery into a prospective trial to compare the anterior chamber concentration of cefuroxime at a fixed time after administration by three routes. In a further 110 patients, the interval before sampling was varied in order to permit an examination of the kinetics of penetration. In another 10 patients, cefuroxime was given topically at the completion of surgery to assess the effect of a corneal wound on aqueous penetration. Cefuroxime concentrations were measured by high performance liquid chromatography on 0.2 ml samples of aqueous aspirated from the anterior chamber. Mean aqueous concentrations of cefuroxime for each group were compared using Student's t test. RESULTS: After 25 mg cefuroxime, mean aqueous concentrations increased in the order forniceal (< 0.1 microgram/ml) < topical (0.18 microgram/ml) < subconjunctival (2.31 microgram/ml) when sampled 12-24 minutes after administration. Aqueous concentrations of cefuroxime reached a peak between 80 and 110 minutes after both forniceal and peribulbar injection but were still rising at this time after subconjunctival injection. Topical application of 12.5 mg cefuroxime to eyes with a 10 mm corneal wound resulted in a mean aqueous concentration of 9.34 micrograms/ml. CONCLUSION: In the intact eye, only sub-conjunctival injection resulted in clinically significant aqueous concentrations of cefuroxime (> 1 microgram/ml) between 12 and 24 minutes after administration. For all routes, maximal aqueous concentrations were delayed by at least 80 minutes from administration. In the presence of a corneal wound, high aqueous levels of cefuroxime were rapidly attained after topical application.     

In vitro activity of SCH 27899 (Ziracin) against Legionella species

PURPOSE: To report the efficacy of topical mitomycin C in preventing local recurrences after incomplete surgical excision of conjunctival squamous cell neoplasia. METHODS: Four patients presented with unilateral conjunctival tumors. Excisional biopsy results revealed conjunctival intraepithelial neoplasia with an intact basement membrane. Neoplastic cells were present in at least one of the surgical borders of the excised conjunctiva in all four cases. Patients were treated with topical mitomycin C 0.02% three times daily for 2 weeks to prevent recurrences. RESULTS: All four patients were free of clinically detectable tumors after a mean follow-up period of 20 months (range, 16-23 months). Side effects included mild discomfort, redness, photophobia, and punctate epithelial keratopathy that subsided on discontinuation of the medication. CONCLUSION: Postoperative topical mitomycin C application may be a useful adjunct to prevent recurrences in patients with incompletely excised conjunctival squamous cell neoplasia.     

New model of conjunctival scarring in the mouse eye

AIMS: To establish a simple model of conjunctival wound healing in the mouse eye. METHODS: 4 week old BABL/c mouse eyes were studied over a 14 day period. Surgical procedure under general anaesthesia involved a blunt dissection of the conjunctiva performed by injection of 25 microliters of PBS via a 27 gauge needle into one eye, while the contralateral eye was used as control. Mice were assessed clinically and sacrificed at 1, 2, 3, 7, and 14 days after surgery. Enucleated eyes were prepared for histological analysis. Development of scar tissue was studied with haematoxylin and eosin, oxidation aldehyde fuchsin, and van Gieson stains, with assessment of cellularity, extracellular matrix formation, and wound characterisation. RESULTS: Histological analysis revealed a marked and characteristic healing response initiated by a predominantly granulocytic inflammatory reaction at day 1 with peak fibroblast activity 3 days after surgery. Oxytalan fibres and newly laid collagen fibres were detected early in the subconjunctival wound area and up to 7 days after surgery. Remodelling and complete organisation of scar tissue was evident by day 14. CONCLUSION: A single subconjunctival injection in the mouse eye results in a marked and consistent healing response. This represents a simple, inexpensive, and reliable animal model of conjunctival scarring. The mouse is a biologically well characterised animal model and allows the use of a wide variety of molecular tools. There are potentially significant clinical applications, in particular in investigating the effects of modulating agents such as antimetabolites, growth factors, and their antagonists on conjunctival scarring.     

Phacoemulsification and lens implantation in patients treated with aspirin or warfarin

PURPOSE: To determine the incidence and nature of hemorrhagic complications in patients having phacoemulsification and foldable intraocular lens (IOL) implantation while taking aspirin or warfarin. SETTING: The Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles, California, USA. METHODS: This retrospective study reviewed the charts from the practice of 1 ophthalmic surgeon. The type of medication, dosage, indication for anticoagulant therapy, type of incision, type of anesthesia, and intraoperative and postoperative hemorrhagic complications were recorded. RESULTS: Sixty-two patients (82 eyes) taking aspirin and 25 patients (31 eyes) taking warfarin were identified. Seven eyes in the aspirin group (8.5%) and 3 in the warfarin group (9.7%) experienced subconjunctival hemorrhages. Eight of the 10 subconjunctival hemorrhages occurred in eyes with scleral incisions. The remaining 2 occurred in eyes with corneal incisions. No eye developed lid ecchymosis, retrobulbar hemorrhage, hyphema, or suprachoroidal hemorrhage. CONCLUSIONS: Phacoemulsification with foldable IOL implantation was performed safely in patients taking aspirin or warfarin. Subconjunctival hemorrhage was the most common hemorrhagic complication.     

Extraction site healing in rats. A radiologic densitometric study

PURPOSE: To establish the effects of single intraoperative exposures to either 5-fluorouracil (5-FU) or two different concentrations of mitomycin C (MMC) on filtration surgery in the rabbit. METHODS: A prospective, randomized, masked-observer, placebo-controlled study was performed to compare the effects on filtration surgery in rabbits of a single 5-minute intraoperative exposure to 5-FU (50 mg/ml), MMC (0.2 mg/ml), or MMC (0.4 mg/ml) with control eyes treated with distilled water. RESULTS: Intraocular pressures (IOPs) remained lower for longer and bleb survival was increased (P < 0.05) with all three treatments compared with control eyes. The effect of 5-FU was more transient than MMC. Bleb survival was prolonged in the following order: MMC 0.4 > MMC 0.2 > 5-FU 50 mg/ml. At 30 days, blebs were present in 100% of eyes treated with MMC 0.4 mg/ml, 60% of eyes treated with MMC 0.2 mg/ml, and 0% of eyes treated with 5-FU 50 mg/ml or distilled water. The blebs in the eyes treated with MMC were thinner, and significant complications (endophthalmitis, transient corneal opacification and neovascularization, and a presumed bleb leak) only occurred in the eyes treated with MMC 0.4 mg/ml. CONCLUSIONS: The authors' results suggest that 5-FU and MMC at these concentrations, delivered as a single intraoperative dose, prolong the survival of filtration surgery for different lengths of time in the rabbit, which is a model that normally exhibits aggressive healing and rapid failure of filtration surgery. The implications of these potentially titratable effects for filtration surgery in different categories of patients are discussed.