Transepithelial phototherapeutic keratectomy for treatment-resistant recurrent corneal erosion syndrome.

BACKGROUND: To evaluate the efficacy and safety of trans-epithelial phototherapeutic keratectomy (TE-PTK) as a treatment for recurrent corneal erosion syndrome (RCES) in patients with symptoms refractory to conventional treatments. METHODS: All patients who received TE-PTK treatment for RCES had failed 3 or more conventional treatments and were reviewed, and if met criteria, approved by healthcare workers of the British Columbia public health authority (Medical Services Plan (MSP). A retrospective chart review and telephone survey were conducted at the Pacific Laser Eye Centre (PLEC). Exclusion criteria were ocular co-morbidities potentially affecting treatment efficacy. RESULTS: This study included 593 eyes of 555 patients (46.2% male; 50.9 ± 14.2 years old) who underwent TE-PTK. The leading identified causes of RCES were trauma (45.7%) and anterior basement membrane dystrophy (44.2%). The most common pre-PTK interventions were ocular lubricants (90.9%), hypertonic solutions (77.9%), and bandage contact lenses (50.9%). Thirty-six eyes had undergone surgical interventions such as stromal puncture, epithelial debridement, or diamond burr polishing. Post-PTK, 78% of patients did not require any subsequent therapies and 20% required ongoing drops. Six patients (1.1%) reported no symptom improvement and required repeat TE-PTK for ongoing RCES symptoms after initial TE-PTK. All 6 eyes were successfully retreated with TE-PTK (average time to retreatment was 11.3 ± 14.9 months). There was no significant difference in best corrected visual acuity pre- vs. post-operatively. The mean post-operative follow-up was 60.5 months (range: 5-127 months). CONCLUSION: TE-PTK has a good efficacy and safety profile for treatment-resistant RCES. The third-party public health-reviewed nature of this study, the low recurrence rate of RCES, and the low PTK retreatment rate suggest that TE-PTK might be considered for wider use in the management of RCES.

Limbal stem cell deficiency secondary to systemic paclitaxel (Taxol) for breast cancer: a case report.

BACKGROUND: Paclitaxel (PTX) is an antineoplastic drug widely used in treatments for ovarian, breast, and small-cell lung cancer. Although ocular effects associated with PTX have been previously described, very few studies have specifically reported systemic PTX as a contributing factor for limbal stem cell deficiency (LSCD), which is characterized by the loss of stem cell and barrier function of the limbus leading to progressive pain and reduction in visual acuity. Described here is a unique case where a patient was diagnosed with LSCD secondary to PTX use for the treatment of breast cancer, at doses of PTX far lower than what is reported in current literature. CASE PRESENTATION: A 73-year-old woman with a previous diagnosis of breast cancer with liver metastasis presented with a complaint of increasing pain in the left eye more than the right, along with decreasing visual acuity in both eyes following 3 months of PTX therapy for recurrent liver metastases. Upon examination, best-corrected visual acuity was 20/100 in the right eye and counting fingers on the left. Peripheral neovascularization, stromal scarring, and features of limbal stem cell deficiency (LSCD) were noted on the right cornea. A central neurotrophic ulcer with thinning to 50% and 360 degrees of conjunctivalization were noted on the left. After the discontinuation PTX with doxorubicin as the substitute, there was no further progression of her LSCD, and stabilization of her ocular surface was achieved. CONCLUSION: Although chemotherapy induced LSCD is a relatively rare adverse event, it is essential for clinicians starting new chemotherapy agents to consider the potential ocular toxicities that may result in their use. Ophthalmology review is recommended for patients after starting PTX therapy to assess for signs of LSCD, particularly in patients where drug toxicity can be aggravated due to impaired hepatic function.

Characteristics of an Acanthamoeba keratitis outbreak in British Columbia between 2003 and 2007.

OBJECTIVE: Quantify and describe Acanthamoeba keratitis (AK) cases in British Columbia (BC). DESIGN: A comparison of annual incidence rates confirms the presence of an outbreak. A case series describes characteristics of the outbreak. PARTICIPANTS: All laboratory-confirmed AK cases (persons) in BC (1988-2011; n = 68) were included in the incidence rate comparison. Of the 42 cases (persons) between 2003 and 2007, 32 were selected to interview (laboratory confirmed, 2005-2007), and the 23 who completed interviews form the case series. METHODS: A comparison of standardized annual incidence rates in historic to outbreak periods is performed by z-score test. A telephone interview and descriptive analysis detailing demographics, risk factors, and contact lens (CL) wearing habits was completed for 23 cases. MAIN OUTCOME MEASURES: We measure number of laboratory confirmed cases in BC. In addition, risk factors and potential exposures of these cases are reported. RESULTS: The annual incidence of AK increased significantly from 0.029 to 0.200 per 100 000 population between historic years (1988-2002) and outbreak years (2003-2007; P = 0.022). The annual incidence of AK has since returned to near historic levels (0.056/100 000 population). The case series identified multiple risk factors, including the use of a specific recalled solution (60.9%), daily soft CL wear (95.7%), all-in-one solutions (95.7%), showering while wearing CL (65.2%), and generally poor CL hygiene. CONCLUSIONS: A significant increase in annual AK incidence occurred between 2003 and 2007 in BC. After 2007, the incidence of AK returned to near historic levels. The recalled solution was associated with many cases; however, other risk factors were also identified, including being unaware of the recall and poor CL hygiene practices, highlighting the need for improved education about the severity of AK and consequences of improper CL hygiene. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Smoke Gets in the Eye: A systematic review of case reports of ocular complications of crack cocaine use.

ISSUES: Use of crack cocaine and associated medical complications persists globally. Some reports in medical literature describe a sight-threatening condition commonly referred to as 'crack eye' or 'crack eye syndrome'. The purpose of this review is to describe what is known about crack eye from case reports in peer-reviewed literature. APPROACH: A structured search was completed in MEDLINE, TOXLINE, EMBASE, PsychInfo, Scopus and Biomed Central, to collect case reports and case series on corneal complications attributed to crack cocaine smoking. KEY FINDINGS: Of 111 articles screened, 11 contained case reports or series. Thirty individual cases of 'crack eye' were reported. The majority (63%) of cases had bilateral involvement; 83% of all cases with microbial culture results had corneal infections. Aggressive treatment caused an improvement in 95% of all cases and 23% of all cases were lost to follow up. Of those who received treatment for corneal complications associated with crack cocaine, 22% remained with significant visual impairment (hand motions only) in the affected eye. IMPLICATIONS: Clinicians should consider crack cocaine involvement in patients presenting with corneal disease without known predisposing factors, and elicit comprehensive drug histories to prevent a reduction in visual acuity. CONCLUSION: Corneal complications of crack cocaine smoking are caused by a number of synergistic factors, including direct toxicity of crack cocaine vapours to surface cells, impairment of neurogenic support to corneal epithelial integrity, desiccation of the eye surface due to diminished blinking reflex, low level chemical burns and mechanical denudement of surface cells through eye rubbing.

Local anaesthesia as a standard of care for penetrating keratoplasty?

BACKGROUND/OBJECTIVES: To determine preferences in the use of local anaesthesia (LA) versus general anaesthesia (GA) for penetrating keratoplasty (PK), and to examine the safety of LA for PK. SUBJECTS/METHODS: A retrospective analysis of PKs performed at an ophthalmology department in Canada from 01/01/2008 to 01/01/2020 was conducted to investigate rate of major complications. A questionnaire was also sent out to cornea specialists in the United Kingdom (UK) and Canada to determine trends in anaesthesia use for PK. Data on anaesthesia use in keratoplasty data was also obtained from the National Health Service Blood and Tissue (NHSBT) register. RESULTS: The retrospective study found that 2143 PKs were performed under LA by 4 surgeons. The following complications were revealed: 1 acute anxiety attack with tachycardia, 3 extraocular myotoxicity cases requiring squint surgery, 1 expulsive suprachoroidal haemorrhage and 1 retrobulbar haemorrhage. The survey revealed 92% of cornea specialists in Canada preferred LA to GA. In the UK, 4.5% of specialists preferred LA, with most preferring GA due to suprachoroidal haemorrhage risk. NHSBT data revealed that 86.6% of 6181 PKs performed in UK between 01/04/2015 and 31/03/2020 were done under GA. CONCLUSIONS: LA is preferred for PK in Canada, in contrast to the UK where GA is preferred. Our retrospective study suggests a low incidence of LA-related complications. We suggest that LA should be considered for most cornea transplant techniques, including optical penetrating keratoplasty. Rising worldwide keratoplasty numbers, ageing populations and risks of pandemics (e.g. COVID-19) give more reason for reduced reliance on GA.

Intraocular lens power calculations after myopic laser refractive surgery: a comparison of methods in 173 eyes.

PURPOSE: To evaluate and compare published methods of intraocular lens (IOL) power calculation after myopic laser refractive surgery in a large, multi-surgeon study. DESIGN: Retrospective case series. PARTICIPANTS: A total of 173 eyes of 117 patients who had uneventful LASIK (89) or photorefractive keratectomy (84) for myopia and subsequent cataract surgery. METHODS: Data were collected from primary sources in patient charts. The Clinical History Method (vertex corrected to the corneal plane), the Aramberri Double-K, the Latkany Flat-K, the Feiz and Mannis, the R-Factor, the Corneal Bypass, the Masket (2006), the Haigis-L, and the Shammas.cd postrefractive adjustment methods were evaluated in conjunction with third- and fourth-generation optical vergence formulas, as appropriate. Intraocular lens power required for emmetropia was back-calculated using stable post-cataract surgery manifest refraction and implanted IOL power, and then formula accuracy was compared. MAIN OUTCOME MEASURES: Prediction error arithmetic mean ± standard deviation (SD), range (minimum and maximum), and percent within 0 to -1.0 diopters (D), ±0.5 D, ±1.0 D, and ±2.0 D relative to target refraction. RESULTS: The top 5 corneal power adjustment techniques and formula combinations in terms of mean prediction errors, standard deviations, and minimizing hyperopic "refractive surprises" were the Masket with the Hoffer Q formula, the Shammas.cd with the Shammas-PL formula, the Haigis-L, the Clinical History Method with the Hoffer Q, and the Latkany Flat-K with the SRK/T with mean arithmetic prediction errors and standard deviations of -0.18±0.87 D, -0.10±1.02 D, -0.26±1.13 D, -0.27±1.04 D, and -0.37±0.91 D, respectively. CONCLUSIONS: By using these methods, 70% to 85% of eyes could achieve visual outcomes within 1.0 D of target refraction. The Shammas and the Haigis-L methods have the advantage of not requiring potentially inaccurate historical information.

Giant cell arteritis presenting with bilateral loss of vision and jaw pain: reminder of a potentially devastating condition.

A case of giant cell arteritis was diagnosed in a woman who presented with bilateral loss of vision that did not improve with intravenous corticosteroid therapy. Preceding her vision loss, the patient had other symptoms consistent with this diagnosis, notably significant jaw pain and arthralgias. The diverse symptoms of giant cell arteritis are discussed, along with the features that can be used to distinguish jaw pain associated with this condition from the pain of temporomandibular joint pathology. An increased awareness of giant cell arteritis should lead to earlier diagnosis and treatment and avoidance of the devastating consequences of this condition.

New treatment algorithm for keratoconus and cataract: small-aperture IOL insertion with sequential topography-guided photorefractive keratectomy and simultaneous accelerated corneal crosslinking.

PURPOSE: To describe a new treatment algorithm aimed at optimizing refractive outcomes for patients with keratoconus and cataract. SETTING: Private practice in Sydney, Australia. DESIGN: Retrospective case series. METHODS: This procedural approach involves cataract extraction with small-aperture intraocular lens (IOL) insertion, IC-8 IOL (AcuFocus, Inc.), followed by topography-guided photorefractive keratectomy (T-PRK) with simultaneous corneal crosslinking (CXL). Cataract surgery was performed with an initial 2.4 mm clear corneal incision enlarged to 3.5 mm to accommodate IC-8 IOL insertion. Once eyes demonstrated stable corneal tomography and refraction, T-PRK was performed using Schwind excimer laser (500 Hz) with the Vancouver custom topographical neutralization technique, aiming to achieve low myopia. CXL was performed immediately after T-PRK using Optolink hypotonic riboflavin with LIGHTLink-CXL (Lightmed) with 5.4 J total energy delivered at an 18 mw/cm2 irradiance. RESULTS: Outcomes of 4 eyes are reported with all achieving rigid gas-permeable (RGP) contact lens independence, improved corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA), and regularization of corneal curvature with cone reduction. The mean CDVA improved from 0.43 preoperatively to 0.07 postoperatively (P = .00), and the mean UDVA improved from 0.81 preoperatively to 0.29 postoperatively (P = .04). Postoperative UNVA ranged from N.8 to N.12. CONCLUSIONS: This treatment algorithm demonstrates unique combination of existing corneal and cataract surgical procedures to achieve satisfactory refractive outcomes and RGP contact lens independence in patients with keratoconus and cataract.

Topography-Guided Photorefractive Keratectomy for Postkeratoplasty Astigmatism: Long-Term Outcomes.

PURPOSE: To evaluate the long-term efficacy and safety of topography-guided photorefractive keratectomy (TG-PRK) for postkeratoplasty refractive error correction. METHODS: A retrospective interventional case series of 54 eyes of 50 patients who underwent previous corneal transplants. Unaided distance visual acuity (UDVA) and best corrected visual acuity (CDVA), manifest refraction, mean central keratometric value, mean keratometric astigmatism, and postoperative complications were reviewed. RESULTS: Final follow-up was at mean 31 (±17) months. Sixteen point seven percent of eyes underwent more than 1 surface ablation. Mean UDVA improved from 0.96 ± 0.06 logarithm of the minimum angle of resolution (LogMAR) preoperatively to 0.46 ± 0.05 LogMAR of resolution at the final follow-up (Bonferroni, P < 0.0001). Mean UDVA improved by 4.4 Snellen lines. Improvement in CDVA was not significant, although a significant improvement was noted when eyes with preoperative CDVA <20/40 were analyzed separately (t test, P = 0.005). Mean astigmatism improved from -4.4 ± 0.26 D preoperatively to -2.4 ± 0.26 D at the final follow-up (Bonferroni, P < 0.0001), whereas mean SEQ improved from -2.5 ± 0.39 D preoperatively to -1.1 ± 0.25 D (Bonferroni, P = 0.02). In total, 9% at the preoperative visit and 55% at the final visit had less than 2 D of astigmatism, respectively. Keratometric astigmatism decreased from 5.24 ± 0.36 D preoperatively to 2.98 ± 0.34 D at the final follow-up (t test, P < 0.0001). No eyes developed clinically significant haze, 14.8% developed regression, and 13% had a reduction of 2 or more CDVA lines. CONCLUSIONS: Postkeratoplasty topography-guided photorefractive keratectomy has good long-term efficacy and safety, resulting in significant UDVA, refractive, and keratometric improvement. Regression can occur after the first year of treatment, emphasizing the importance of long-term follow-up.

Immediate and short term visual recovery after SmartSurfACE photorefractive keratectomy.

PURPOSE: To investigate immediate and short-term visual recovery in a large cohort of 2093 myopic eyes (with or without astigmatism) treated with SmartSurfACE procedure, a combination of Transepithelial Photo Refractive Keratectomy (PRK) and Smart Pulse Technology (SPT, SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). METHODS: In this retrospective case series, post-operative outcomes were evaluated immediately after the surgery (Day 0), at day 1 and 3 months postoperatively, after myopic SmartSurfACE treatment with mean pre-operative spherical equivalent -4.65±2.53D and range from -16.13D to -0.13D. In all cases, pre and postoperative standard examinations were performed. The analysis evaluated preoperative Corrected and Uncorrected Distance Visual Acuity (CDVA and UDVA, respectively), and postoperative UDVA, monocularly and binocularly, immediately after the surgery, at day 1 and 3 month follow up. RESULTS: Sixty-two percent eyes achieved monocular UDVA 20/40 or better immediately after the surgery, while 82% patients achieved binocular UDVA 20/32 or better immediately after the surgery. At 3-month postoperatively, monocular UDVA 20/25 or better was achieved in 94% eyes. Treated eyes achieved immediately after the surgery or by the next day mean UDVA 20/41±8. UDVA improved significantly from Day 1 to 3-months follow up (p<0.0001 for both OS and OD) to mean UDVA 20/21±5 (equal to preoperative CDVA 20/21±8). CONCLUSION: Immediate and short-term visual recovery after SmartSurfACE PRK in our large cohort was rapid, providing functional binocular UDVA immediately after the surgery.

Oral Miltefosine as Adjunctive Treatment for Recalcitrant Acanthamoeba Keratitis.

PURPOSE: Acanthamoeba keratitis is a rare, vision-threatening disease. Commercially available antiamoebics are poorly cysticidal and highly toxic, and therapeutic keratoplasties can be complicated by recurrence or graft failure. We aimed to discuss the use of oral miltefosine for treatment of recalcitrant Acanthamoeba keratitis. METHODS: A 44-year-old contact lens wearer presented with a 2-week history of red painful eye and decreasing vision. After poorly responding to topical corticosteroid on the presumptive diagnosis of anterior uveitis, she developed radial keratoneuritis. Corneal scraping was positive for Acanthamoeba. No clinical response to treatment was observed with topical chlorhexidine 0.02%, polyhexamethylene biguanide 0.02%, and oral voriconazole. She then underwent 2 therapeutic keratoplasties with prompt recurrence of the disease in the keratoplasty graft. RESULTS: Oral miltefosine was added to the treatment. She underwent a third penetrating keratoplasty 8 months later. The excised button was negative for amoeba. She continued miltefosine for 3 more months. No recurrence was observed after 30 months. CONCLUSIONS: This case shows resolution of recalcitrant Acanthamoeba keratitis with oral miltefosine in an immunocompetent patient. Further clinical evidence would be needed to possibly incorporate this medication in the antiamoebic armamentarium.

Epidemiology of bacterial corneal ulcers at tertiary centres in Vancouver, B.C.

OBJECTIVE: To report the epidemiology of culture-positive bacterial corneal ulcers in Vancouver, B.C., Canada. DESIGN: Retrospective, observational case series. METHODS: Predetermined search terms were entered into the hospitals' electronic microbiology databases to create a cohort of patients who had undergone corneal scrapings for ulcers from April 2006 to March 2011. All specimens were plated on culture media. Cultured species were identified, and antimicrobial sensitivities were obtained. Clinical charts were then reviewed to identify associated risk factors. RESULTS: In total 281 corneal scrapings were included, with a positive culture recovery rate of 75%. Bacterial keratitis accounted for 84.8% of culture-positive ulcers, followed by fungi (10%) and finally Acanthamoeba (5.2%); 73% of ulcers were monomicrobial in origin and 28% polymicrobial. We found an increase in Gram-negative micro-organisms over time. General sensitivity to antibiotics did not change over time. A major risk factor for Gram-positive involvement was ocular surface disease, whereas contact lens wear was a major risk factor for Gram-negative involvement. CONCLUSIONS: Bacterial keratitis was found to be the major cause of infectious keratitis in Vancouver, B.C. The majority of bacterial ulcers were caused by Gram-positive bacteria. However, we found an increase in Gram-negative involvement over time. Contact lens wear was identified as the major risk factor for development of Gram-negative ulcers. Pre-existing ocular disease was associated with Gram-positive infection. Susceptibility of Gram-negative bacteria to common broad-spectrum antibiotics was high, but susceptibility of Gram-positive bacteria to these antibiotics was lower and more variable.

Focal limbal stem cell deficiency associated with soft contact lens wear.

OBJECTIVE: The aim of this study is to summarize the clinical characteristics of patients with contact lens-associated focal limbal stem cell deficiency (FLSCD) from a tertiary corneal referral centre. DESIGN: Retrospective, observational case series in a tertiary care centre. METHODS: Patients with contact lens-associated FLCSD were identified in our database. Clinical data were retrieved by chart review. A questionnaire asking for contact lens brand, type, cleaning solution, and duration of contact lens wear was sent to the patients with telephone follow-up. Clinical features and recovery time were identified. RESULTS: Twenty-seven eyes of 17 patients were identified with superior corneal whorl-like patches of opaque epithelium, sometimes accompanied by neovascularization. Of the patients, 17/17 used soft contact lenses, with a mean wearing duration of 11.4 hours per day. Patients had been wearing lenses for an average of 18.1 years. Silicone hydrogel lenses were noted in 12/17 cases. LSCD was superior in all 27 eyes, and all of them improved with contact lens wear cessation, preservative-free topical steroids, and preservative-free artificial tears. Visual acuity improved from 20/28 to 20/22 (p < 0.001). CONCLUSIONS: Contact lens-associated FLSCD typically presents in the superior cornea with whorl-like epithelial opacities advancing from the limbus. Conservative medical treatment is available and shows a high success rate after a slow recovery.

Postoperative Corneal Asphericity in Low, Moderate, and High Myopic Eyes After Transepithelial PRK Using a New Pulse Allocation.

PURPOSE: To evaluate the postoperative asphericity in low, moderate, and high myopic eyes after combined transepithelial photorefractive keratectomy and SmartSurfACE treatment (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). METHODS: In this retrospective case series, the outcomes of myopic SmartSurfACE were evaluated at 3 months postoperatively in 106 eyes and divided into low (less than -4.125 diopters [D]), moderate (-4.125 to -6.25 D), and high (more than -6.25 D) myopia groups. In all cases, standard examinations and preoperative and postoperative corneal topography (SCHWIND Sirius) were performed. The analysis comprised evaluating the change in asphericity versus planned correction, comparing expected and achieved postoperative asphericity for all eyes, and comparison of the three groups in terms of the preoperative and postoperatively expected and achieved asphericity. RESULTS At 3 months postoperatively, the low myopia group (n = 33) improved average negative asphericity (Q = -0.04 ± 0.17 preoperative vs -0.19 ± 0.20 postoperative, P < .05). The moderate myopia group (n = 35) maintained or slightly improved average negative asphericity (Q = -0.07 ± 0.14 preoperative vs -0.05 ± 0.24 postoperative, P = .35). For the high myopia group (n = 38), the eyes became more oblate compared to the preoperative status (Q = -0.09 ± 0.15 preoperative vs 0.62 ± 0.70 postoperative, P < .05). In terms of asphericity, the difference between the three groups was not statistically significant preoperatively (P > .10), but showed significant differences postoperatively (P < .007). The cohort's average preoperative corrected distance visual acuity was 0.01 ± 0.04 logMAR (range: 0.0 to 0.18 logMAR) and uncorrected distance visual acuity was 0.03 ± 0.08 logMAR (range: -0.12 to 0.40 logMAR) 3 months postoperatively. CONCLUSIONS: SmartSurfACE maintained or slightly improved preoperative corneal asphericity for low to moderate myopic corrections (up to -6.00 D). This may provide advantages in the quality of vision and the onset of presbyopic symptoms after laser refractive surgery in myopic patients. [J Refract Surg. 2017;33(12):820-826.].

Paediatric infectious keratitis at tertiary referral centres in Vancouver, Canada.

OBJECTIVE: To report the clinical and microbiological profiles of paediatric patients with infectious keratitis in Vancouver, Canada. DESIGN: In this observational case series, the microbiology results and medical records of 17 eyes with microbial keratitis in 16 children aged 17 years or younger were retrospectively reviewed. These patients had undergone corneal scraping between May 2006 and April 2011 at BC Children's Hospital or Vancouver General Hospital Eye Care Centre in Vancouver, British Columbia, Canada. Demographic information, clinical features, predisposing factors, results of microbiology studies, antibiotic susceptibilities, treatment course and outcomes were analysed. RESULTS: The mean age of patients was 11±5.7 years (range 1-17 years) and the male:female ratio was 1.4:1. Major predisposing factors were contact lens wear (6/17; 35%), and pre-existing ocular surface conditions including blepharitis (3/17; 18%) and Stevens-Johnson syndrome (3/17; 18%). Four patients had a previous corneal ulcer. The most commonly isolated microorganisms were Staphylococcus epidermidis and Acanthamoeba. Acanthamoeba was isolated in 67% of contact lens-related corneal ulcers, while the remaining 33% of contact lens-related corneal ulcers were associated with infection with Pseudomonas aeruginosa. Final visual acuity was better than 20/60 in 9 out of 16 patients (56%). Three patients subsequently required surgical management with either penetrating keratoplasty or deep anterior lamellar keratoplasty for treatment of corneal scarring. CONCLUSIONS: Contact lens wear and pre-existing ocular surface conditions are significant risk factors for the development of infectious keratitis in our paediatric population. Knowledge of regional patterns of infection and susceptibility are essential in ensuring prompt treatment of this potentially sight-threatening condition.

Use of polymyxin as an endotoxin blocker in the prevention of diffuse lamellar keratitis in an animal model.

PURPOSE: To determine whether bacterial endotoxin, lipopolysaccharide (LPS), could induce diffuse lamellar keratitis (DLK) in an animal model and whether DLK could be prevented by endotoxin blockers such as polymyxin. METHODS: Laser in situ keratomileusis (LASIK) flaps were created in rabbit eyes. The stromal bed was treated with 20 microg of Burkholderia cepacia LPS or balanced salt solution (BSS). Development of DLK, histological degree of inflammation, and presence of LPS detected by anti-LPS antibody were evaluated after 48 hours. In a second experiment, all eyes received LPS and were randomly assigned to receive either polymyxin in the form of two drops of Polytrim (Allergan, Irvine, Calif) on the stromal bed or two drops of BSS. RESULTS: In the animal model study, LPS was significantly associated with the development of DLK (P<.05, n=30). Infiltration with polymorphonuclear cells and presence of DLK were found in LPS treated eyes but not in controls. In the second experiment, 4 (27%) of 15 eyes that received polymyxin in addition to LPS developed DLK compared to 18 (95%) of 19 eyes that received only LPS (P<.05, n=34). There was a trend towards higher flap displacement in polymyxin treated eyes but this was not significant (P=.07). CONCLUSIONS: Diffuse lamellar keratitis in a rabbit model can be caused by bacterial endotoxin (LPS). Endotoxin blockers, such as polymyxin, are effective in decreasing the incidence of endotoxin-induced DLK in a rabbit model.

Diffuse lamellar keratitis complicating laser in situ keratomileusis: post-marketing surveillance of an emerging disease in British Columbia, Canada, 2000-2002.

PURPOSE: To describe a surveillance system and summarize data between January 2000 and December 2002 regarding diffuse lamellar keratitis (DLK), a complication of laser in situ keratomileusis (LASIK) surgery. SETTING: Community-based clinics in British Columbia, Canada, in which LASIK surgery is performed. METHODS: Monthly, all clinics in which LASIK is performed reported the number of LASIK procedures and nonnominal cases of DLK (by grade and onset date) to the British Columbia Centre for Disease Control. Diffuse lamellar keratitis outbreaks were investigated, and prevention and control measures were recommended. RESULTS: From 2000 to 2002, approximately 72,000 LASIK procedures were performed, with a mean DLK incidence rate of 0.67% (95% confidence interval, 0.61-0.73). The overall proportion of DLK cases attributed to outbreaks was 64%, decreasing from 72% in 2000 to 40% in 2003. CONCLUSIONS: An effective DLK surveillance program was implemented at all laser refractive clinics in British Columbia. Reported DLK incidence was 0.67 cases per 100 procedures, with 64% occurring in outbreaks.

The corneal ulcer one-touch study: a simplified microbiological specimen collection method.

PURPOSE: To determine if a new, single-sample device (ESwab; Copan Diagnostics, Inc) can simplify the traditional multi-sample approach to specimen collection in infectious keratitis. DESIGN: Prospective, diagnostic test evaluation. METHODS: In this institutional study, patients with suspected infectious keratitis meeting traditional criteria for diagnostic corneal specimen collection and culture were randomized to the order of first specimen collection method: ESwab or a sample directly plated for growth on chocolate agar. This was followed by standard samples for blood agar, Gram stain, Sabouraud agar, thioglycolate broth, and brain heart infusion broth in all cases. The specimens collected using the 2 approaches were analyzed separately by the laboratory in a masked fashion. The main outcome measure was positive growth on cultured media. RESULTS: Eighty-one eyes from 80 consecutive patients were sampled. Culture positivity rate for the multi-sample method and ESwab was 70% and 69%, respectively, with a 75% agreement rate. ESwab sensitivity was 84% (95% confidence interval [CI]: 72%-93%), with a specificity of 67% (95% CI: 45%-84%). Positive and negative predictive values of the ESwab were 86% (95% CI: 74%-94%) and 64% (95% CI: 43%-82%), respectively. There was no difference in positive culture reports with respect to the order of specimen collection technique used. CONCLUSIONS: The single-sample ESwab method is a more accessible and less cumbersome approach to corneal culturing for ophthalmologists, particularly those in the community setting who do not have access to the full set of traditional culture materials. Culture results using this single-sample approach were comparable to the multi-sample method.

Outcome of corneal transplantation: can a prioritisation system predict outcome?

BACKGROUND: In 1995 a prioritisation system for patients waiting for corneal transplantation surgery was adopted in British Columbia. In 1997 a routine outcome assessment programme was adopted. The authors sought to determine the outcomes of corneal transplant surgery in the province of British Columbia and to evaluate if they were associated with waiting list prioritisation. METHODS: Since May 1997 all patients who receive a corneal transplant are enrolled in the Eye Bank of British Columbia (EBBC) outcome assessment programme. Each patient fills out a visual function assessment (VFA) questionnaire before and 12 months after surgery. Data on visual acuity, pain, demographics, and other ocular complications are collected from both patients and surgeons before and after operation. RESULTS: 269 patients were enrolled in the programme between May 1997 and April 1998. 12 month follow up showed that visual acuity improved in 69.9% of patients, while it remained the same in 20.8%, and got worse in 5.9%. Overall, at follow up 16.6% of patients had intermittent pain and 5.0% had constant pain. 78.6% of patients who experienced intermittent or constant pain before surgery reported no pain at follow up. Visual function improved in 72.4% of patients, remained the same in 4.1%, and worsened in 23.5%. 88% of patients improved in at least one of the three outcome categories. Patients who had the greatest improvement had been assigned the highest priority for surgery. The 11% of patients who did not improve in any of the three categories (visual acuity, pain, or visual function) were more likely to have a preoperative visual acuity better than 20/60, most likely to have old trauma or Fuchs' dystrophy as their primary diagnosis, and to have had fewer points in the EBBC priority scoring system. CONCLUSION: The finding that patients who had a high preoperative priority score were more likely to have a good outcome suggests that the priority system was accurately identifying patients at greatest need for surgery. These findings also suggest that outcome from corneal transplant surgery is best measured as a combination of clinical indices and patient derived indices. A routine outcome assessment programme and prioritisation system can assist surgeons and eye banks in better case selection and in anticipating both objective and subjective improvement following surgery.

Immediate and short term visual recovery after SmartSurfACE photorefractive keratectomy / Recuperación visual inmediata y a corto plazo tras queratectomía fotorrefractiva SmartSurf ACE

PURPOSE: To investigate immediate and short-term visual recovery in a large cohort of 2093 myopic eyes (with or without astigmatism) treated with SmartSurfACE procedure, a combination of Transepithelial Photo Refractive Keratectomy (PRK) and Smart Pulse Technology (SPT, SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). METHODS: In this retrospective case series, post-operative outcomes were evaluated immediately after the surgery (Day 0), at day 1 and 3 months postoperatively, after myopic SmartSurfACE treatment with mean pre-operative spherical equivalent -4.65 ± 2.53 D and range from -16.13D to- 0.13D. In all cases, pre and postoperative standard examinations were performed. The analysis evaluated preoperative Corrected and Uncorrected Distance Visual Acuity (CDVA and UDVA, respectively), and postoperative UDVA, monocularly and binocularly, immediately after the surgery, at day 1 and 3 month follow up. RESULTS: Sixty-two percent eyes achieved monocular UDVA 20/40 or better immediately after the surgery, while 82% patients achieved binocular UDVA 20/32 or better immediately after the surgery. At 3-month postoperatively, monocular UDVA 20/25 or better was achieved in 94% eyes. Treated eyes achieved immediately after the surgery or by the next day mean UDVA 20/41 ± 8. UDVA improved significantly from Day 1 to 3-months follow up (p < 0.0001 for both OS and OD) to mean UDVA 20/21 ± 5 (equal to preoperative CDVA 20/21 ± 8). CONCLUSION: Immediate and short-term visual recovery after SmartSurfACE PRK in our large cohort was rapid, providing functional binocular UDVA immediately after the surgery

OBJETIVO: Investigar la recuperación visual inmediata y a corto plazo en una amplia cohorte de 2.093 ojos miópicos (con o sin astigmatismo) tratados con el procedimiento SmartSurfACE, una combinación de Queratectomía Fotorrefractiva Transepitelial (PRK) y SPT (Smart Pulse Technology, SCHWIND eye-tech-solutions GmbH, Kleinostheim, Alemania). MÉTODOS: En esta serie de casos retrospectivos, se evaluaron los resultados post-operatorios inmediatamente tras la cirugía (Día 0), al día siguiente a la misma, y a los tres meses de la intervención, tras el tratamiento de la miopía con SmartSurfACE, con un equivalente esférico preoperatorio medio -4,65 ± 2,53D y rango desde -16,13D a -0,13D. En todos los casos se realizaron exámenes estándar preoperatorios y postoperatorios. El análisis evaluó preoperatoriamente la agudeza visual de lejos corregida y no corregida (CDVA y UDVA), y postoperatoriamente UDVA, monocular y binocular, inmediatamente tras la cirugía, al día siguiente, y a los tres meses de seguimiento. RESULTADOS: El 62% de los ojos logró UDVA monocular 20/40 o un valor mejor inmediatamente tras la cirugía, y el 82% de los pacientes logró UDVA binocular 20/32 o un mejor valor inmediatamente tras la cirugía. A los tres meses de la intervención, se logró UDVA monocular 20/25 o un valor mejor en el 94% de los ojos. Los ojos tratados lograron inmediatamente tras la cirugía o al día siguiente UDVA 20/41 ± 8. UDVA mejoró significativamente entre el día siguiente y los tres meses de seguimiento (p < 0,0001 para ambos ojos) a un valor medio de 20/21 ± 5 (igual a CDVA preoperatoria de 20/21 ± 8). CONCLUSIÓN: La recuperación visual inmediata y a corto plazo tras PRK con SmartSurfACE en nuestra amplia cohorte fue rápida, logrando una UDVA binocular funcional inmediatamente tras la cirugía