Daniel M. Gore

United Kingdom survey of antibiotic prophylaxis practice after publication of the ESCRS Endophthalmitis Study

&NA; The European Society of Cataract & Refractive Surgeons Endophthalmitis Study published preliminary results in 2006 showing a near 5‐fold decrease in the rates of postoperative endophthalmitis with the use of intracameral cefuroxime. The study findings have generated considerable controversy, and 1 year later its recommendations had been heeded by only 6% of American Society of Cataract and Refractive Surgery (ASCRS) members. This poll sought to gauge the uptake among surgeons in the United Kingdom and survey their response to its findings. Fifty‐five percent of respondents were using intracameral cefuroxime; 48% had switched after publication of the ESCRS study. Of those remaining, 68% reported their main concern was the risk for dilution errors in the absence of a commercially preformulated preparation, with 67% stating they would switch if such a product became available. Sixty‐eight percent considered the lack of a subconjunctival cefuroxime treatment arm within the study a major methodology flaw. Sixty‐seven percent said they do not consider penicillin allergy a contraindication to intracameral cefuroxime use, with the remaining 33% opting for alternative antibiotic prophylaxis. The majority of United Kingdom and Ireland Society of Cataract and Refractive Surgeons members have switched to intracameral cefuroxime, despite the absence of previously preferred practice in the study design. The major barrier to its further use appears to be the lack of a commercially available preformulated preparation.

Cataract surgery outcome in eyes with keratoconus

Background To review the refractive outcome of cataract surgery in eyes with keratoconus. Methods We retrospectively reviewed the medical records of 64 consecutive patients (92 eyes) who underwent cataract surgery with implantation of a spherical intraocular lens (IOL). We recorded the method of refractive correction and the effect of the keratometry (K) on the biometry prediction error (BPE). Results 35 eyes had mild keratoconus (mean K<48 dioptres (D)), 40 had moderate keratoconus (mean K 48 D to 55 D) and 17 had severe keratoconus (mean K>55 D). Actual K values were used in all eyes with mild or moderate keratoconus with a target refraction of approximately −1.0 D in mild keratoconus and −1.5 D in moderate keratoconus that resulted in a mean BPE of 0.0 D and +0.3 D, respectively. The actual K values were used in eight of the 17 eyes with severe keratoconus with a mean target refraction of −5.4 D, which resulted in a mean BPE of +6.8 D. In the remaining nine eyes, a standard K value of 43.25 D was used with a mean target refraction of −1.8 D, which resulted in a mean BPE of +0.6 D. Conclusions Using the actual K values with a target of low myopia is a suitable option for spherical IOL selection for eyes with a mean K of ≤55 D. When there is severe keratoconus, the use of actual K values can result in a large hyperopic error and the use of standard K value in these eyes should be considered.

Peripheral Hypertrophic Subepithelial Corneal Degeneration: Nomenclature, Phenotypes, and Long-Term Outcomes

PURPOSE To describe the long-term outcomes of peripheral hypertrophic subepithelial corneal degeneration. DESIGN Retrospective case series. PARTICIPANTS Twenty-two patients under the care of the External Disease Service, Moorfields Eye Hospital. METHODS All patients matching clinical diagnostic criteria were included. Symptomatic patients were managed either conservatively or were offered superficial keratectomy in progressive cases where symptom control was inadequate. All excised tissue was examined histologically. MAIN OUTCOME MEASURES Clinical phenotype, symptoms, recurrence rate after surgery, and histopathologic results. RESULTS Twenty-two white patients (20 women and 2 men; age range, 27-88 years; median age, 42 years) had peripheral, usually bilateral (20/22 [91%]), elevated circumferential peripheral subepithelial corneal opacities and adjacent abnormal limbal vasculature, with or without pseudopterygia in 9 patients (41%), among whom 7 (32%) patients had bilateral disease. Apart from the abnormal vasculature, there were no signs of chronic ocular surface inflammation. Symptoms were ocular surface discomfort in 10 patients (45%), reduced vision in 4 patients (18%), and both of these in 5 patients (23%). Three patients (14%) were asymptomatic. There was no treatment in 6 patients (27%), topical lubricants in 8 patients (36%), spectacles in 1 patient (5%), and superficial keratectomy in 7 patients (32%; 5 bilateral), which was repeated for incomplete primary excision in 1 eye of 2 patients (9%) and for a bilateral recurrence in 1 patient (5%). Median follow-up after excision was 5 years (range, 1-11 years). Histopathologic changes were similar to those observed in pterygia (vascular component) and Salzmanns nodular degeneration (corneal component). CONCLUSIONS Peripheral hypertrophic subepithelial corneal degeneration is an uncommon, usually bilateral, idiopathic disorder, occurring mostly in white women with a distinct phenotype. The condition was first described in 2003. Further cases among some patients have been described in more recent case series of Salzmanns nodular degeneration and diffuse keratoconjunctival proliferation, as well as in the previously described familial pterygoid corneal degeneration. Surgical excision was required in 30% of patients in this series, with infrequent short-term recurrences. The cause is uncertain. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

A Comparison of Different Corneal Iontophoresis Protocols for Promoting Transepithelial Riboflavin Penetration

PURPOSE To measure corneal riboflavin penetration using different transepithelial iontophoresis protocols. METHODS Freshly enucleated rabbit eyes were divided into nine treatment groups of 4 eyes. One group, in which 0.1% wt/vol riboflavin was applied for 30 minutes without iontophoresis after corneal epithelial debridement, acted as a control. The remaining groups were treated with an intact epithelium using different riboflavin formulations and varying iontophoresis current, soak, and rinse times. After riboflavin application, eyes were snap frozen in liquid nitrogen. Corneal cross sections 35 μm thick were then imaged immediately by two-photon fluorescence microscopy, using image processing software to quantify stromal riboflavin concentration at different corneal depths. RESULTS In the epithelium-on iontophoresis treatment groups, greater stromal riboflavin penetration was achieved with higher-concentration riboflavin solutions, greater iontophoresis dosage, and longer solution contact times. A protocol utilizing 0.25% wt/vol riboflavin with benzalkonium chloride (BAC) 0.01% and two cycles of applied current and subsequent soaking (1 mA 5 minutes, soak 5 minutes; 0.5 mA 5 minutes, soak 5 minutes) achieved similar stromal riboflavin penetration to epithelium-off controls. The best-performing non-BAC-containing protocol produced stromal riboflavin penetration approximately 60% that of epithelium-off controls. Riboflavin solutions containing saline resulted in minimal stromal penetration. Riboflavin loading within the epithelium was equivalent to or higher than that in the subjacent stroma, despite rinsing the ocular surface with balanced salt solution. CONCLUSIONS Modified iontophoresis protocols can significantly improve transepithelial riboflavin penetration in experimental corneal collagen cross-linking.

Acanthamoeba Sclerokeratitis: Epidemiology, Clinical Features, and Treatment Outcomes

PURPOSE To describe the epidemiology, clinical features, and treatment outcomes of Acanthamoeba sclerokeratitis (ASK). DESIGN Retrospective case series. PARTICIPANTS All cases of both Acanthamoeba keratitis (AK) and ASK identified between January 1, 2000, and January 8, 2011, at Moorfields Eye Hospital. METHODS Acanthamoeba keratitis was defined as the presence of AK with concurrent ipsilateral scleral inflammation. Topical steroids and oral nonsteroidal anti-inflammatory drugs (NSAIDs) were used as the first line of treatment. In unresponsive cases, oral NSAIDs were replaced by oral prednisolone with cyclosporine, azathioprine, or mycophenolate as steroid-sparing agents. Cyclosporine was combined with azathioprine or mycophenolate in cases unresponsive to only 1 of these drugs alone. MAIN OUTCOME MEASURES Epidemiology, clinical phenotype, response to therapy, resolution of inflammation, visual outcome, corneal transplantation, and enucleation rate. RESULTS From a series of 178 patients with AK, 36 eyes of 33 patients (18.5%) developed ASK. A total of 25 of 33 patients (76%) with ASK were tertiary referrals. The incidence of the disease in greater London was 0.13 per million, and the incidence in this population of patients with AK was 33 of 178 (18.5%). Mild scleritis/limbitis responsive to topical steroids and oral NSAIDs was present in 11 of 36 eyes (31%), and moderate/severe scleritis, requiring systemic immunosuppressive therapy, was present in 25 eyes (69%). Before the initiation of ASK treatment, 2 of 36 eyes (6%) had corrected distance visual acuity (CDVA) ≥ 20/40. The length of ASK treatment was 15.3 ± 20.7 months. The follow-up after discontinuation of scleritis treatment was 27.2 ± 31.8 months. An improvement in visual acuity was recorded in 23 of 36 eyes (64%). At the final visit, 13 of 36 eyes (36%) had CDVA ≥ 20/40. Control of scleral inflammation and pain was achieved in all but 2 eyes (2 enucleations). Cataract developed in 10 of 36 eyes (28%), and 14 of 36 eyes (39%) developed a persistent epithelial defect. Keratoplasty was performed in 21 of 36 eyes (58%), 9 therapeutic/tectonic and 12 for visual rehabilitation. Six eyes had more than 1 keratoplasty. The mild scleritis group had better outcomes in terms of visual improvement and need for keratoplasty. CONCLUSIONS Acanthamoeba sclerokeratitis is associated with poor clinical outcomes. Management of ASK with anti-inflammatory/immunosuppressive treatment is usually effective in reducing both scleral inflammation and symptoms and possibly reduces the number of enucleations.

Outcomes of pseudophakic retinal detachment

Purpose:  To provide data on the outcome of pseudophakic retinal detachment (PRD).

Permanent visual loss in eyes with keratoconus

Editor, K eratoconus is normally considered to be a benign condition. In early disease visual rehabilitation can be achieved with glasses or contact lenses. However, over time, scarring or contact lens intolerance can develop, and an estimated 21% of patients eventually require keratoplasty Lass et al. (1990). Because the risk of permanent visual loss is unknown, we have attempted to estimate the prevalence of blindness associated with keratoconus. We searched the electronic healthcare records of Moorfields Eye Hospital for the period January 2005–September 2011 using keywords keratoconus and blind. The total of search results with keratoconus was recorded, and the medical records of patients who satisfied both criteria were reviewed. The inclusion criterion was blindness in an eye with preexisting keratoconus. Blindness was defined according to the World Health Organization criterion of a corrected distance visual acuity (CDVA) of <3/60. Additional data recorded were demographics, ocular and medical comorbidity, surgical intervention and history of trauma. For statistical analysis, Snellen acuity was converted to LogMAR equivalents. LogMAR equivalents for count fingers (CF), hand movements (HM), light perception (LP) and no light perception (NLP) were 1.85, 2.30, 2.70 and 3.00, respectively SchulzeBonsel et al. (2006). Patients with an unrelated cause for their blindness (e.g. retinitis pigmentosa) were excluded. A total of 6399 patients with keratoconus attended during the study period. The records of 77 patients were reviewed, of which 58 were excluded because the acuity was ≥3/60 (n = 36) or because there was an unassociated blinding condition (n = 22). The remaining 23 eyes of 19 patients (median follow-up, 8.1 years; range, 0.2–37.7 years) had a median final CDVA of 1/60 (range, 1/60 to NLP) with 11 eyes NLP (Table 1). Corneal transplantation had been performed in 9 (47.4%) eyes of the 19 patients (median number of grafts, 1; range, 1–7). During the study period, 394 (6.2%) of the 6399 patients received a transplant. Ocular trauma was the most common cause for severe visual loss (seven eyes, two following assault and five following accidental injury), all of which were NLP. Atopic keratoconjunctivitis (six patients) was the commonest associated risk factor. Four eyes were blind following the complications of intraocular surgery (one endophthalmitis, one pseudophakic retinal detachment, two irreversible allograft failure). Ten eyes (six patients) were functionally blind due to advanced keratoconus, including four patients with Down syndrome or other learning difficulties, who could not tolerate visual correction and in whom keratoplasty was declined. During the study period,

Refractive outcomes in anterior chamber intraocular lenses

To the Editor,The 2008 United Kingdom Royal College of Oph-thalmologists’ (RCOphth) Cataract Surgery Guide-lines included, for the first time, a biometricbenchmark of achieving a final spherical equivalent(SE) within ±1 dioptre (D) of the target in 85 % ofcases [1]. This was based on a prospective analysis of4,806 eyes with in-the-bag lens implantation, with83.4 and 53.6 % within ±1 and ±0.5 D of predictedSE, respectively [2].We retrospectively applied this benchmark to anauditofrefractiveoutcomesforanteriorchamberlenses(ACIOL). Data were available in 52 eyes implantedwith 122UV lenses (Bausch & Lomb Inc., New York,NY,USA),a polymethylmethacrylate open-loop angle-supported design available in two lengths: 12.5 mm(S122UV) and 13.75 mm (L122UV). The manufac-turer’s A-constant of 115.8 was used in all cases.Subjective refractions were performed in 41 (79 %) of52 eyes, with the remainder by auto-refraction. Finalrefraction following suture removal revealed 71.2 %within ±1Dand40.4%within±0.5 D of target SE.Mean difference between target and achieved SE was0.37 D (range -1.77 to 2.54, SD 0.89); no differenceswere observed between refraction methods (p = 0.31,t test) or the two lens lengths (p = 0.44, t test), norwhether the lens was implanted as a primary orsecondary procedure (p = 0.41, t test). Weak correla-tion between increasing anterior chamber depth andgreater hypermetropic error was demonstrated (Pear-son’s correlation, r = 0.23). Raw data were submittedto the Users Group for Laser Interference Biometry(ULIB) website, providing an optimized A-constant of115.1 for use with the SRK/T formula (http://www.augenklinik.uni-wuerzburg.de/ulib/c1.htm).Comparative published outcomes predominantlyinvolve extracapsular extractions, although none pro-vide SE outcomes in the same RCOphth format:98 % ± 3D[3], 86 % ± 2D[4] and mean SE -0.73[5]. The largest series of 83 ACIOLs between 1991and 2005 (method of surgery not stated), reported amean refractive outcome of -0.8 D ± 1.67 [6].While RCOphth guidelines are not explicitly lim-ited to in-the-bag implantation, with the routine use ofoptical biometry, modern lens calculation formulaeand A-constant optimization there is no reason whyrefractive benchmarks should not be applied toanterior chamber implantation. While the inherentlimitations of this small retrospective audit areacknowledged, our data suggest that refractive out-comes with ACIOLs can be judged by the samebiometric standards.