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ObjectiveTo investigate the role of bandage contact lenses (BCL) and topical steroids as risk factors for the development of microbial keratitis after epithelium-off corneal collagen cross-linking (CXL).Methods and AnalysisPatients undergoing CXL between February 2011 and July 2017 were included. Patients were divided into two groups: those who were treated postoperatively with a BCL, topical antimicrobial and steroids (group 1) and those who received only a topical antimicrobial until healing of the epithelial defect before introduction of topical steroids (group 2).Results1273 eyes of 964 patients were included. Group 1 comprised 316 eyes and group 2 comprised 957 eyes. There were no significant differences in the presence of persisting corneal haze or scarring between the two groups (p=0.57). Microbial keratitis occurred in nine eyes (0.71% of eyes) of eight (0.83%) patients (one case was bilateral) out of 1273 eyes. Staphylococcus aureus was cultured from corneal scrapes in seven out of nine (77.8%) cases and from contiguous sites in the two cases. All cases occurred in group 1 (incidence=2.85%) and none in group 2 (pConclusionThe use of BCL and topical steroids prior to healing of the epithelium is a significant risk factor for microbial keratitis. S. aureus is the most common micro-organism and is likely to originate from an endogenous site. Not using a BCL and delaying the introduction of topical steroids until epithelial healing significantly reduce the risk of developing microbial keratitis without increasing the risk of persistent corneal haze.

The study objective is to evaluate a scoring system to assess the quality of anesthesia used in ophthalmic surgery.This is an observational prospective study.The setting is at an operating theater.Patients are all patients undergoing ophthalmic surgery, October 2012.Quality of ophthalmic anesthesia was measured using an interval scale by the operating surgeon. Parameters were graded depending on the type and route of anesthetic: central eye position, anesthesia, akinesia of the eye and or body, soft tissue or orbital hemorrhage, and absence of vitreous bulge.The measurements are quality score and proportion of optimal and suboptimal cases of anesthesia and number of surgical complications.Data were collected on 349 consecutive cases including cataract (55%), retinal (14%), corneal transplant (6%), and strabismus surgery (6%). Sub-Tenon was the most commonly performed (31%) followed by peribulbar (PB) (26%), general anesthesia (GA) (20%), topical (17%), and retrobulbar (RB) (6%) anesthesia. There were 11 surgical complications: posterior capsule rupture (7), dislocated lens (2), and orbital hemorrhage (2). Sub-Tenon had lower quality scores than PB (P = .006), RB (P = .028), and GA (P.001); and PB and RB had lower scores than GA (P.01). There was a significant association between suboptimal anesthesia and surgical complications (P.001), odds ratio = 3.94 (95% confidence interval, 1.03-15.12; P = .046).The quality of ophthalmic anesthesia is an important component of the surgical procedure and should be considered in any risk stratification. Suboptimal anesthesia is associated with an increased rate of surgical complications.

To evaluate graft size on outcome following Descemet stripping automated endothelial keratoplasty (DSAEK) METHODS: Consecutive patients who had undergone a DSAEK for Fuchs endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK) with at least 1 year of follow-up. Patients were divided into three groups according to the size of the donor trephine:9, 9 and 9.5 mm. Main outcomes were postoperative best corrected visual acuity (BCVA) and graft failure. Grafts were prepared using an automated microkeratome. For larger grafts (≥9 mm), a manual dissection of the residual peripheral ring of anterior lamella was performed before trephination. Donor age, endothelial cell density (ECD) and postmortem times; recipient details including risk factors, comorbidity, surgical complications and postoperative BCVA and graft survival were analysed.Of 174 patients, 131 were included: 84 (64%) with FED and 47 (36%) with PBK. Mean preoperative and postoperative BCVA were 1.01±0.76 and 0.2±0.2 logMAR, respectively, at 12 months with 80.5% achieving 20/40 or better. Postoperative BCVA was significantly associated with ECD (p=0.005), PBK or FED (p=0.004), risk factors (p=0.007) and comorbidity (p=0.016). Eleven patients (8.40%) experienced endothelial graft failure; 17.86% for9 mm, 7.69% for 9 mm and 3.84% for 9.5 mm trephine sized grafts. Graft failure was significantly associated with ECD (p=0.039) and graft trephine size (p=0.04).Larger grafts occupy a smaller chord length in the eye than the trephine size and are expected to provide 10%-20% more endothelial cells. Increased graft size and donor ECD is significantly associated with a reduced graft failure rate.

ObjectivePrediction errors are increased among patients presenting for cataract surgery post laser vision correction (LVC) as biometric relationships are altered. We investigated the prediction errors of five formulae among these patients.Methods and analysisThe intended refractive error was calculated as a sphero-cylinder and as a spherical equivalent for analysis. For determining the difference between the intended and postoperative refractive error, data were transformed into components of Long's formalism, before changing into sphero-cylinder notation. These differences in refractive errors were compared between the five formulae and to that of a control group using a Kruskal-Wallis test. An F-test was used to compare the variances of the difference distributions.Results22 eyes post LVC and 19 control eyes were included for analysis. Comparing both groups, there were significant differences in the postoperative refractive error (p=0.038). The differences between the intended and postoperative refractive error were greater in post LVC eyes than control eyes (p=0.012), irrespective of the calculation method for the intended refractive error (pConclusionBiometry calculations were less precise for patients who had LVC than patients without LVC. No particular biometry formula appears to be superior among patients post LVC.

The purpose was to investigate the survival of Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with an Ahmed glaucoma valve (AGV). The study had a retrospective case-series of patients with an AGV in the anterior chamber undergoing a DSAEK. Included in the analysis were graft size, number of previous operations, post-operative glaucoma medications, post-operative intraocular pressure (IOP) control, graft size and donor factors (age, endothelial cell density, and post-mortem time). A generalised linear model with binary logistic regression was used to test for an effect on graft survival at 1 year and 1.5 years. Fourteen eyes from 13 patients were included. The survival rate of the first DSAEK at 6, 12, 18, 24 and 30-months was 85%, 71%, 50%, 36% and 30%, respectively. The mean duration to graft failure was 12.9 ± 6.2 months. Five of the seven failed first grafts went on to have a repeat DSAEK. The mean follow-up in this subgroup was 30.7 ± 18.4 months. The survival rate of second DSAEK at 6, 12, 18 and 24 months was 100% (5/5), 100% (5/5), 75% (3/4) and 67% (2/3). Only one second DSAEK failed in the duration of the study and went on to receive a third DSAEK which failed at 18-months. The mean IOP within the first year was significantly lower for grafts that survived at 1 and 1.5 years (17.4 mmHg, 16.9 mmHg) than for grafts that failed (19.4 mmHg, 19.4 mmHg) (p = 0.04, p = 0.009). DSAEK is a viable alternative to PK to restore visual function in eyes with an AGV sited in the anterior chamber. IOP is an important risk factor for graft failure.

We present a technique to achieve ultrathin Descemet-stripping automated endothelial keratoplasty (DSAEK). Using a simple method of controlling artificial anterior chamber pressure and drying the corneal surface, it was possible to thin the donor cornea at a rate of 11 μm a minute. When the donor cornea was between 500 μm and 510 μm, a single pass was made using a 350 μm microkeratome head followed by a peripheral dissection. The resulting mean graft thickness was 83.2 μm ± 14.9 (SD) (range 50 to 98 μm) with a mean peripheral graft edge thickness of 106.8 ± 10.9 μm (range 90 to 120 μm). There were no surgical complications, and all grafts remained attached. This is a reliable method for preparing ultrathin donor corneal lenticules for DSAEK in the operating room or eye bank without using multiple microkeratome heads or risking double passes.

To determine whether the keratometric and refractive surgical effects of paired intrastromal corneal ring segments (ICRS) depend on their alignment relative to steep and flat topographic meridians.St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom.Comparative case series.Keratoconic patients who had two 0.3 mm Intacs ICRS inserted were retrospectively grouped depending on alignment of segments within 30 degrees either side of the steep (meridional group) or the flat (perpendicular group) topographic meridians, respectively, with the rest in the oblique group. Principal outcome measures were changes in visual acuity, refractive surgical effect, and keratometric surgical effect 4 months postoperatively.Forty eyes of 40 patients were included. There was a significant reduction in keratometric power (flattening) (P.01) but not in refractive error in all 3 groups. The reduction in keratometric astigmatism was significantly greater in the perpendicular group (-2.67 diopters [D]) than in the meridional group (-0.65 D) (P=.03), with the oblique group (-0.9 D) in between (P=.12). The principal reduction was flattening orthogonal to the incision site, with relative steepening in the axis of ICRS alignment. In all groups, variations in the refractive surgical effect and keratometric surgical effect were very high.Placement of two 0.3 mm ICRS had a variable effect with limited predictability. There was predominant flattening of the cornea orthogonal to the axis of ICRS alignment. Irrespective of the location of preoperative steep and flat keratometric meridians, the maximum reduction in astigmatism occurred when the incision and the segments were placed along the flat topographic meridian.No author has a financial or proprietary interest in any material or method mentioned.

Purpose To determine the surgically induced refractive and keratometric effects of intrastromal corneal ring segments (ICRS). Setting St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom. Design Case series. Methods Keratoconic patients had implantation of 2 vertically aligned 0.3 mm Intacs ICRS with the incision site at 90 degrees. Principal outcome measures were changes in visual acuity and refractive and keratometric effects (analyzed using methods of Kaye and Harris) 4 months postoperatively. Subgroup analysis was based on the Krumeich classification. Results Twenty-nine eyes (29 patients) were included. There was a significant difference between the mean preoperative (−5.16 +1.93 × 162.05) and postoperative (−2.64 +1.07 × 137.25) refractive errors ( P =.01), with a mean refractive surgical effect of +1.35 +1.48 × 88.71 (SD +2.76 +4.78 × 149.62), and between the mean preoperative (51.32/2.28 @ 122.33) and postoperative (48.23/2.36 @ 92.10) keratometric powers ( P =.001), with a mean keratometric surgical effect of −3.87/2.54 @ 61.77 (SD 1.37/4.20 @ 136). The irregularity index in the 3.0 mm zone decreased from 11.56 diopters (D) to 8.78 D. Refractive and keratometric surgical effects showed little difference within stages I through III and were greater in stage IV. Conclusions Placement of two 0.3 mm ICRS caused overall flattening of the cornea (2.00 D to 3.00 D), with more flattening orthogonal to the incision site at 90 degrees. Variability of this effect, principally in the steep and flat meridians, limited the predictability of ICRS. Corneal behavior may differ with other incision sites. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

PURPOSE To compare the refractive and visual outcomes of combined penetrating keratoplasty and cataract surgery (triple procedure) with those of sequential surgery (penetrating keratoplasty followed by secondary cataract extraction and posterior chamber intraocular lens implantation). METHODS Forty-six consecutive patients undergoing triple procedure or sequential surgery performed by two surgeons were reviewed retrospectively. The triple procedure group consisted of 23 patients and the sequential surgery group also consisted of 23 patients. Refractive and visual outcomes were collected and analyzed with at least 1 year of follow-up for both groups. Both the difference from target and the variability of the refractive outcome were analyzed. RESULTS Best spectacle corrected visual acuity of 6/12 or better was achieved in 16 eyes (69.8%) in the triple procedure group and in 19 eyes (82.6%) in the sequential surgery group. For both the triple and sequential groups, there was no difference between the mean postoperative refractive outcome (-2.73/+1.05 x 109 SD = 4.30/1.42/4.43) and (-1.33/+0.79 x 175 SD = 2.39/1.16/2.33) compared with the mean target refraction (-0.77, SD = 1.16 and -0.43, SD = 0.99), (p = 0.39 and 0.48), respectively. In addition, there was no significant difference in the variability of the refractive outcome between the two groups (p > 0.99). CONCLUSIONS Sequential surgery appears to offer no significant advantages over the triple procedure in terms of refractive predictability or variability. There was a slight trend toward more patients achieving 6/12 or better vision in the sequential group.

Purpose: To study the effect of surface properties of materials on cellular behaviour and the formation of posterior capsular opacification (PCO). Methods: Polymethylmethacrylate, silicone and a hydrophobic acrylic were plasma treated and used in tissue culture. The changes in surface properties were quantified by dynamic contact angle measurements. Bovine lens epithelial cells (BLECs) were seeded onto these materials and cultured for 1 month. Serial photographs were taken. The cells were then fixed and stained to facilitate counting. Results: Plasma treatment significantly increased the hydrophilicity of surfaces. BLECs grew on all surfaces but significantly more cells adhered to the treated than the untreated surfaces. On the untreated surfaces the BLECs had a fibroblastic morphology whereas on the treated surfaces the cells maintained their epithelial morphology. Conclusions: Posterior capsular opacification is a form of wound healing and the behaviour of lens epithelial cells is central to its progression. Emphasis has been on the elimination of residual lens epithelial cells to combat PCO. This study demonstrated that the phenotype of BLECs was influenced by the surface properties of the intraocular lens materials. Gas plasma treatment of the materials increased their hydrophilicity and allowed the adhered BLECs to maintain their normal epithelial morphology. We believe that controlled growth of lens epithelial cells may reduce the incidence of PCO.

To test the agreement of intraocular pressure (IOP) measurements made with Luneau SA applanators and Goldmann applanator. A single-blind crossover trial. IOPs were measured in both eyes of subjects with both applanators. Type of applanator was alternated to eliminate systematic bias. Multiple observers were used. Observers were blind to the scale while performing measurements but not to the type of applanator used. The appearance of the meniscus was assessed semiquantitatively. All measurements were combined and presented in a Bland–Altman plot. A total of 140 eyes of 79 subjects were tested by seven observers. The range of measurements was 6–45 mmHg (mean 17.8 mmHg) for the Goldmann applanator. On average, the Luneau SA applanator (range of measurements 4–36 mmHg) gave a measurement of 2.35 mmHg less than the Goldmann standard. The standard deviation of these differences was 2.13 mmHg, giving an upper 95% confidence limit of 6.53 mmHg and a lower 95% confidence limit of −1.83 mmHg. The measurements agreed in only 24 out of 140 instances. In 28 eyes, the disposable tonometer end point was difficult to assess owing to excessively thick rings. Linear extrapolation suggests an increase in difference with increasing IOP. The inter-head inaccuracy, tendency to underestimate IOP, and lack of systematic inaccuracy make a corrective algorithm impossible to formulate. The range of variation between the Luneau SA disposable applanator and the Goldmann standard is sufficiently large to influence clinical management decisions. We speculate that one explanation is the interaction of the tonometer with the tear film, making end point determination difficult. Further research is being undertaken.

Chronic papillary conjunctivitis has been described following adenoviral conjunctivitis. It is unknown however, how long adenovirus is able to persist in the tear film and conjunctiva. To determine if adenovirus persists in the ocular surface following adenoviral conjunctivitis, 304 patients with a history of adenovirus conjunctivitis from whom an adenovirus had been isolated 10 years previously were sent a questionnaire regarding persistent or recurrent symptoms and were invited to attend. Patients were examined and samples of tears and conjunctival cells were collected from both eyes using tear film washes, filter paper, and swabs, the latter for virus isolation. Extracted DNA from the ocular samples was amplified using primers for herpes simplex virus (thymidine kinase) and adenovirus (hexon) genes. Adenovirus amplicons were sequenced and compared to original serotype. Thirty patients attended, 19 of whom had persistent papillary conjunctivitis. Evidence of adenovirus DNA was detected in 17 of 30 patients, 15 of whom also had evidence of a chronic papillary conjunctivitis. Adenovirus DNA was significantly associated with papillary conjunctivitis (P = 0.03). Adenovirus amplicons were successfully sequenced from six patients. Four patients harbored type 3 adenovirus, the same serotype with which they were infected originally 10 years previously. Two patients were infected originally with adenovirus serotype 3 but the current serotype was type 4. Infection of the ocular surface with adenovirus may predispose to the development of a persistent or recurrent conjunctivitis, the presence of which, appears to be associated with evidence of long term persistence of adenovirus DNA.

Members of the thrombospondin (TSP) family of proteins have been implicated in wound healing. The cells of the corneal stroma (keratocytes) are capable of synthesising TSP-1 in a wound repair phenotype, but do not appear to produce the protein in the normal human adult cornea. We employed reverse-transcriptase polymerase chain reaction (RT-PCR) to determine whether human corneal stromal cells can express TSPs other than TSP-1. Cultured keratocytes contained messenger RNA (mRNA) for TSP-2 and TSP-3 (in addition to TSP-1), but not for TSP-4 or cartilage oligomeric matrix protein (COMP; TSP-5). Keratocytes in the normal cornea contained mRNA for TSP-1 but not for other TSPs. The distribution of keratocyte TSP-2 and TSP-3 immunoreactivity had some similarities to that of TSP-1 and, like TSP-1, neither protein could be detected in the cells of the normal corneal stroma. The observations suggest that keratocytes in wound repair phenotype produce TSP-2 and TSP-3 in addition to TSP-1. TSPs may play a pivotal role in corneal stromal repair and, since TSP-1 and TSP-2 have anti-angiogenic properties, may also have a function in regulating the avascularity of the central cornea.

Collagen corneal shields were developed as a corneal bandage lens and are currently indicated for ocular surface protection following surgery and in traumatic and nontraumatic corneal conditions. Collagen shields are manufactured from porcine or bovine collagen and three different collagen shields are currently available with dissolution times of 12, 24, and 72 hours. The theoretical, experimental, and clinical evidence supports a role for collagen corneal shields as a drug delivery device and in the promotion of epithelial and stromal healing. Presoaking the collagen shield in a pharmacological agent with adjunctive topical treatment represents the most efficacious method of utilizing collagen shields for drug delivery. In microbial keratitis collagen shields can enhance drug delivery, promote epithelial and stromal healing, neutralize collagenases, and reduce corneal inflammation. This review will examine the evidence that supports the role of collagen shields in drug delivery and corneal wound healing. Despite a large volume of experimental (animal) work, studies on human subjects, particularly randomized controlled trials, are lacking. The authors are advocating the reassessment of the application and benefits of corneal collagen shields to clinical practice.

Introduction: The Van Herick method is a quick and easy way to estimate anterior chamber depth, which allows grading of patients according to the likelihood of having primary acute closed-angle glaucoma. However, as the test is highly subjective, measurements and thus grading may vary between observers. Aim: The aim of this study was to investigate the degree of variation of Van Herick scores among observers and to investigate agreement between temporal and nasal scores. Materials and Methods: A total of 15 observers measured the temporal and nasal Van Herick scores from 18 patients, grouped into cohorts at outpatient glaucoma and corneal clinic. Analysis of data involved assigning a patient to a Van Herick grade based on the median score and then determining the mean standard deviation and percentage consistency for each grade. Results: We found that Grades 1 and 4 had a high mean percentage consistency (80% and 84.6%, respectively) and a low mean standard deviation (0.45 and 0.26, respectively). Grades 2 and 3 had low mean percentage consistencies (57.5 and 5, respectively) and high mean standard deviations (0.71 and 0.89, respectively). The temporal and nasal scores showed good agreement (κ = 0.61P < 0.001). Conclusion: The Van Herick score has a good interobserver reliability for Grades 1 and 4; however, Grades 2 and 3 require further tests such as gonioscopy or ocular coherence tomography. Temporal and nasal scores demonstrated good agreement; therefore, if the nasal score cannot be measured due to nasal bridge size, the temporal can be used as an approximation.

Purpose The detection and diagnosis of glaucoma is challenging for health professionals. In the UK, approximately 45% of patients are discharged from secondary care after one visit. Automated imaging technologies are easy to perform and could potentially be used by trained technicians as triage tests for glaucoma diagnosis. The GATE study aims to compare the diagnostic performance of three technologies, Heidelberg Retina Tomograph (HRT-III), Scanning laser polarimetry (GDx-ECC) and Optical Coherence Tomography (Spectralis), as triage tests in secondary care for glaucoma diagnosis.

A recent paper by Kobayashi and co-workers1 on temporary amniotic membrane patching for acute chemical burns highlights the difficulty in the consistent classification of this type of injury. Roper-Hall’s classification of acute chemical injuries to the eye is based on the original classification of Ballen2,3 and there is little difference between them. However, in neither classification is the grade based on the most severe sign. This immediately leads to the problem of trying to classify an eye having, for example, corneal signs of one grade and conjunctival signs of another. There is also difficulty in grading the conjunctival and limbal injuries. Dua et al 4 recognised the problem of assessing limbal stem cell damage and proposed a quasi-analogue scale in order to incorporate intergrade variations. They suggested using limbal fluorescein staining as a marker of limbal stem cell damage. However, their grading scheme is complex and departs significantly from that of Roper-Hall. Although fluorescein staining is a useful sign, it does not necessarily imply limbal stem cell damage or failure and has not been shown to be a better index of limbal damage than perilimbal ischaemia. Importantly, it is also becoming apparent, that both the fornices and mucocutaneous junction of the conjunctiva are important for conjunctival regeneration.5–7 In fact, Roper Hall stressed the importance of involvement of contiguous areas of the conjunctiva, which may lead to symblepharon formation.4 Although there are limitations with Roper-Hall’s classification, it is simple and remains popular. Rather than replace Roper-Hall’s and Ballen’s classification,2,3 we suggest a modification, which addresses some of the issues raised and makes the classification more robust. One of the questions that needs to be answered is whether to base the grade of injury upon the most severe sign or on a combination of …

To determine whether the risk of graft failure in patients with glaucoma is dependent on the indication for penetrating keratoplasty (PK).Retrospective cohort study.All patients on the United Kingdom Transplant Registry undergoing their first PK over a 7-year period with at least 1 year of follow-up were included. Data were collected on indication for PK, presence and management of glaucoma, graft diameter, recipient risk factors, and graft survival. Kaplan-Meier survival curves, a Cox regression model, and χ(2) and t tests were used in group comparisons.A total of 6255 transplants in eyes without glaucoma and 1994 in eyes with glaucoma were analyzed. Three-year transplant survival was 86% and 72% respectively (P.0001), and 73% in eyes with medically managed glaucoma compared to 63% in surgically managed glaucoma (P = .07). Glaucoma patients undergoing PK for pseudophakic bullous keratopathy or Fuchs dystrophy had significantly increased relative risks of graft failure (1.5 and 1.9 with topical and 2.0 and 3.1 with oral antiglaucoma medication respectively, compared to those without glaucoma). There was no equivalent significant difference for those with keratoconus, previous noncataract ocular surgery, trauma, or noninfectious ulcerative keratitis. Endothelial decompensation accounted for a significantly greater proportion of graft failure in recipients with glaucoma (topical [9%] and oral medication [13%]) than in those without glaucoma (3%) (P.001).The presence of glaucoma carries an increased risk of graft failure, in particular from endothelial decompensation. This risk is, however, also dependent on the indication for PK, with transplants undertaken for primary corneal endothelial disease carrying a higher risk.

The use of cyclosporin is well established within the ophthalmology community, especially against sight threatening intraocular inflammation. It is well known however, that immunosuppression in general is a risk factor for the development of malignancy and numerous studies point to the risk imposed by cyclosporin. This article analyses and reviews all relevant studies with regard to the development of malignancy associated with the use of cyclosporin and extrapolates this into the ophthalmic setting. This is to enable clinicians to assess the risks in individual patients and to present a monitoring regime which can be used in patients undergoing cyclosporin treatment. The review is solely concerned with the risk of the development of malignancy following cyclosporin immunosuppression and not with any other adverse effect.

PURPOSE. To study factors involved in the development of refractive error in premature infants with or without retinopathy of prematurity (ROP). METHODS. Premature infants in the national ROP screening program were recruited and examined longitudinally between 32 and 52 weeks’ postmenstrual age. Axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) were measured on the A-scan biometer. Corneal curvature was recorded with video-ophthalmophakometry and refractive state was determined with routine cycloplegic retinoscopy. Multilevel modeling techniques were used to study relationships between all the variables and stage of ROP throughout the study period, as well as individual growth rates. RESULTS. One hundred thirty-six infants were included. AL and ACD showed linear patterns of growth, whereas LT changed little over the study. Corneal curvature showed quadratic growth patterns in infants unaffected by ROP, but showed linear growth if ROP developed. Corneal curvature correlated well with refractive state. Most infants were myopic at the start of the study, became emmetropic around term, and were hypermetropic toward the end of the study. However, the eyes that were treated for ROP showed little change in refractive error; with significantly less hypermetropia by the end of the study. CONCLUSIONS. Eyes of premature infants have shorter axial lengths, shallower anterior chambers, and more highly curved corneas than eyes of full-term infants. These differences become more significant as the severity of ROP increases. Premature eyes develop less of the expected hypermetropia in fullterm eyes, mainly due to differences in ACD and corneal curvature. These differences are most significant in eyes that receive laser treatment for ROP. (Invest Ophthalmol Vis Sci. 2008;49:5199 –5207) DOI:10.1167/iovs.06-0114

Background: The ability to perform biometry accurately on a dilated pupil can greatly facilitate the efficiency of a cataract service as it can be done on the day of surgery. The purpose of this study was to assess the repeatability of axial length (AL) calculations in undilated pupils and measure the difference in predicted and actual refractive outcomes in dilated pupils compared with undilated pupils. Methods: First, intraobserver repeatability was assessed by taking two consecutive recordings of AL using applanation A-scan ultrasonography in undilated pupils in 21 eyes. The mean AL for each eye was compared with a measurement made following pupil dilatation. Second, we audited the mean spherical equivalent refractive errors following routine cataract surgery in 38 patients with undilated pupils and 36 patients with dilated pupils. Results: The mean difference in intraobserver measurements was −0.05 mm (standard deviation [SD] 0.15) with pupils undilated. Following pupil dilatation, the mean dilated AL differed from the mean undilated AL reading by only 0.03 mm (P > 0.05). The mean differences between planned and actual refractive error were 0.71D (SD 0.54) and 0.55D (SD 0.41) in dilated and undilated patients, respectively. This was not statistically significant (P > 0.05). The range of differences between target and actual refraction was −1.45D to 2.70D for undilated patients and −1.88D to 1.18D in dilated patients. Conclusion: Although there was a greater spread of postoperative refractive errors in the dilated group, there were no statistically or clinically significant differences in postoperative refractive errors between the two categories of patients. Our study shows that applanation biometry may be safely performed for the purpose of cataract surgery after pupil dilatation.

Cataract surgery is the most common surgical operation carried out by ophthalmologists. Patients undergoing cataract surgery have been found to have a low level of understanding of the operation, and this is increasingly being linked with increasing patient dissatisfaction.1 Pager’s recent article2 showed that a simple inexpensive videotape showing patients what to expect from cataract surgery increases their understanding and satisfaction with the surgery, as well as reduces patient anxiety. We carried out a cross-sectional study to look at whether a multimedia visual computer …

Aim: To determine the elimination kinetics of intracameral vancomycin administered as a bolus injection at the end of phacoemulsification cataract surgery. Methods: Vancomycin 1 mg/0.1 ml saline solution was administered to 19 patients by intracameral bolus injection at the end of routine cataract surgery. The aqueous concentration of vancomycin was determined in nine patients 1 minute after administration and in 10 patients 18–24 hours postoperatively. Aqueous samples were obtained by inserting a Rycroft cannula into the anterior chamber via the side port incision. Fluorescence polarisation immunoassay was used to calculate the aqueous vancomycin concentration. Results: The median (interquartile range) vancomycin concentration was 5458 (4756–6389) mg/l at 1 minute and 40.6 (25.9–47.1) mg/l 18 to 24 hours (median 19 hours) postoperatively. The vancomycin concentration exceeded the minimum inhibitory concentration (MIC) of endophthalmitis-causing gram-positive bacteria by a factor of 4 for up to 26 hours postoperatively. No adverse event or reaction was noted. Conclusion: Following bolus intracameral injection at the end of cataract surgery the concentration of vancomycin in the anterior chamber vastly exceeds its MIC for at least 24 hours but is predicted to fall below the MIC after 33 hours.

PURPOSE To characterize the corneal topographic features in a family with nanophthalmos. METHODS Two observational case reports and a review of the literature. Corneal shape was analyzed using a topographic modeling system (TMS) and an Orbscan topographic system, with further analysis based on Fourier series and Zernicke polynomials. A control group was used for comparison. RESULTS Two female family members with nanophthalmos belonging to the same generation showed significant irregular corneal astigmatism and corneal steepening. CONCLUSION Topographic corneal steepening and irregular astigmatism seems to be associated in 1 family with inherited nanophthalmos. Higher degrees of irregular astigmatism, which were not evident without a topographic analysis, may account, in part, for the unexplained visual reduction.

To study the effect of surface properties of materials on cellular behaviour and the formation of posterior capsular opacification (PCO).Polymethylmethacrylate, silicone and a hydrophobic acrylic were plasma treated and used in tissue culture. The changes in surface properties were quantified by dynamic contact angle measurements. Bovine lens epithelial cells (BLECs) were seeded onto these materials and cultured for 1 month. Serial photographs were taken. The cells were then fixed and stained to facilitate counting.Plasma treatment significantly increased the hydrophilicity of surfaces. BLECs grew on all surfaces but significantly more cells adhered to the treated than the untreated surfaces. On the untreated surfaces the BLECs had a fibroblastic morphology whereas on the treated surfaces the cells maintained their epithelial morphology.Posterior capsular opacification is a form of wound healing and the behaviour of lens epithelial cells is central to its progression. Emphasis has been on the elimination of residual lens epithelial cells to combat PCO. This study demonstrated that the phenotype of BLECs was influenced by the surface properties of the intraocular lens materials. Gas plasma treatment of the materials increased their hydrophilicity and allowed the adhered BLECs to maintain their normal epithelial morphology. We believe that controlled growth of lens epithelial cells may reduce the incidence of PCO.

Disposable tonometers are increasingly being adopted partly because of concerns over the transmission of variant Creutzfeldt-Jakob disease and partly for convenience. Recently, we have found one such tonometer (Tonojet by Luneau Ophthalmologie, France) underestimated the intraocular pressure (IOP). We hypothesized that this underestimation was caused by a difference in the surface property of the tonometers. A tensiometer was used to measure the suction force resulting from interfacial tension between a solution of lignocaine and fluorescein and the tonometers. The results showed that the suction force was significantly greater for the Goldmann compared to the Tonojet. The magnitude of this force was too small to account for the difference in IOP measurements. The Tonojet was less hydrophilic than the Goldmann, and the contact angle of the fluid was therefore greater. For a given tear film, less hydrophilic tonometers will tend to have thicker mires, and this may lead to underestimation of the IOP. When such disposable tonometers are used, it is recommended care should be taken to reject readings from thick mires.

PURPOSE To report a case of localized bullous keratopathy and total corneal decompensation secondary to iridocorneal touch in iridoschisis. DESIGN Single interventional case report with pathologic correlation. METHODS An 80-year-old man with bilateral iridoschisis presented with loss of vision in the left eye (OS). Examination of the OS showed shallow anterior chamber (AC), cortical cataract, and free-floating iris fibers causing iridocorneal touch, leading to localized bullous keratopathy and total corneal decompensation. Ultrasound biomicroscopy (UBM) confirmed the area of iridocorneal contact. RESULTS Penetrating keratoplasty combined with cataract extraction and posterior chamber lens implantation was performed in the OS. Histopathology of the corneal button showed features of corneal edema and endothelial cell loss with evidence of iridocorneal contact. CONCLUSIONS Iridoschisis is an uncommon cause of bullous keratopathy and corneal decompensation. Patients with iridoschisis may need specular microscopy to determine the status of the corneal endothelium.

Stromal vascularization is a frequent occurrence in herpes simplex keratitis (HSK) and carries a poor prognosis for penetrating keratoplasty. The pathogenesis may involve disruption of the normal equilibrium between angiogenic and anti-angiogenic factors in and around the cornea. Thrombospondin (TSP) 1 and 2 are multifunctional matricellular glycoproteins with potent anti-angiogenic properties and are expressed by human keratocytes in a stromal wound repair model. We hypothesize that the synthesis of these anti-angiogenic proteins by keratocytes is inhibited by HSV1 and that such a mechanism may contribute to stromal vascularization in HSK.Nonconfluent monolayers of human keratocytes were infected with HSV1 at a multiplicity of infection of 5 virus particles/keratocyte. Expression of TSP1 and TSP2 was determined by immunohistochemistry and SDS-polyacrylamide gel electrophoresis at 0, 2, 4, 6, 8, 24, 48, and 72 h after infection (ai). Expression of glyceraldehyde 3 phosphate dehydrogenase (GAPDH) served as a control. Expression of immediate early and late viral proteins was also determined. Protein expression was quantified by densitometric analysis of the immunoblot bands.Human keratocytes supported the growth of HSV1 at all times ai. TSP1 and TSP2 were downregulated as early as 4 h ai to a 50% reduction by 8 h (p0.002), and were absent from 24 h ai (p0.001). There was no change in the level of expression of GAPDH throughout the duration of the experiment. Immediate early viral proteins (HSV1:ICP27) could be detected from 6 h ai reaching maximum intensity 24 h ai and late proteins (HSV:1gD) were expressed from 24 h.The synthesis of TSP1 and TSP2 is selectively downregulated by HSV1 infection in human keratocytes. Addition of these proteins or their angio-active peptides in early stage HSK therapy may be an important adjuvant in controlling HSV1 induced corneal vascularization.

Purpose: To describe bilateral corneal endothelial abnormalities associated with thalidomide toxicity. Methods: Observational case report. Results: A 30-year-old man, born with bilateral hypoplastic upper limb defects (phocomelia) caused by thalidomide toxicity, presented with bilateral symmetrical comeal endothelial changes resembling guttata without corneal edema. Pachymetry, specular microscopy, and confocal microscopy were performed. Biomicroscopy findings over a 10-year follow-up showed no changes. Conclusions: Nonprogressive bilateral corneal endothelial changes resembling cornea guttata should possibly be included in the ocular manifestations ofthalidomide toxicity. We postulate that thalidomide may have affected the migration and development of the mesenchymal neural crest cells, which are the developmental precursors of the corneal endothelium and stroma.

To determine whether human keratocytes synthesize thrombospondins 2 and 3 (TSP-2, TSP-3) in a collagen matrix and the effect of addition of antibodies to TSP-2 and TSP-3 on keratocyte-populated collagen matrix contraction.Keratocyte-populated collagen matrices were evaluated for TSP-2 and TSP-3 mRNA. Sections of matrices were stained by immunohistochemistry for TSP-2 and TSP-3. Keratocyte populated collagen matrices were treated with antibodies specific for TSP-2 and TSP-3 and these preparations were evaluated for contraction and keratocyte morphology.Keratocyte derived fibroblasts in collagen matrices contained TSP-2 and TSP-3 mRNA, and the cells were immunoreactive for both proteins. Compared to controls, an antibody specific to the N-terminal domain of TSP-2 significantly inhibited matrix contraction for up to 10 days at a concentration of 20 microg/ml antibody. At 2 microg/ml TSP-2 antibody concentration significant inhibition occurred up to 3 days. Removal of the antibody from the media reversed the inhibitory effect. Cultured keratocytes in TSP-2 treated collagen matrices appeared more rounded than keratocytes in control matrices. An antibody specific to TSP-3 had no effect on matrix contraction or keratocyte morphology.Keratocyte derived fibroblasts synthesize TSP-2 and TSP-3 when seeded in collagen matrices. Antibody specific to TSP-2 reversibly inhibits matrix contraction. TSP-2 may play a key role in keratocyte/collagen matrix interactions, as may occur during corneal stromal repair.

This investigation studied the factors involved in the development of refractive error (RE) in premature infants unaffected by retinopathy of prematurity (ROP).Premature infants enrolled in the national ROP screening program were recruited and examined at 32, 36, 40, 44, and 52 weeks' postmenstrual age. At each examination, axial length (AXL), anterior chamber depth (ACD), and lens thickness (LT) were measured on the A-scan biometer. Corneal curvature (CC) was recorded with a video-ophthalmophakometer, and refractive state was determined with routine cycloplegic refraction. Multilevel modeling techniques were used to determine the relationships between all the variables throughout the study period, as well as individual growth rates.Sixty-eight premature infants were included. AXL and ACD showed linear patterns of growth, whereas LT changed little over the study period. CC showed a quadratic growth pattern, and unlike the previous variables, correlated well with refractive state. Premature infants were myopes at the start of the study, with refraction becoming emmetropic as they neared full term and then hypermetropic toward the end of the study.Most of the components of refractive status showed linear patterns of growth during this early phase of ocular development. CC displayed a more complex pattern of growth, which correlated well with refractive state. Compared with full-term infants examined around term, this group has shorter AXLs, shallower anterior chambers, and more highly curved corneas. In addition, less of the expected hypermetropia developed in the premature group, which seems mainly due to the differences in ACD and corneal curvature.

Objectives (1) Test the feasibility and the safety of guided transnasal trephination in creating a nasolacrimal fistula. (2) Develop an appropriate lacrimal maintainer and test its value in modulating healing at the fistula site. Design Prospective, noncomparative interventional case series. Participants Five cadavers and 19 patients. Method A transcanalicular lacrimal probe penetrated the lacrimal fossa to guide the passage of a flexible trephine up the nose, which created the nasolacrimal communication. A special wide-caliber lacrimal maintainer was inserted along lacrimal tubes within the created passage. Outcome measures For cadaveric study, direct inspection after dissection of the facial flap was performed. For the clinical trial, subjective improvement in watery eye, dye testing, lacrimal probing, lacrimal irrigation, and endoscopic nasal examination. Results The technique resulted in the creation of a regular fistula of reproducible diameter into which a standard-shaped wide caliber maintainer could be inserted. Three months after removal of the maintainer and 6 months after surgery, a patent ostium was achieved in 17 of 18 (94%) patients who had a completed procedure. Relief of symptoms was achieved in 83%. Conclusions Guided endoscopic dacryocystorhinostomy provides a simple and safe option for the treatment of nasolacrimal duct obstruction. The lacrimal maintainer is a useful device to achieve a large patent nasolacrimal communication.

Corneal clarity is maintained by its endothelium, which functions abnormally in the endothelial dystrophies, leading to corneal opacification. This group of conditions includes Fuchs' endothelial dystrophy of the cornea (FECD), one of the commonest indications for corneal transplantation performed in developed countries, posterior polymorphous dystrophy (PPCD) and the congenital hereditary endothelial dystrophies (CHED). A genome-wide search of a three-generation family with early-onset FECD demonstrated significant linkage with D1S2830 (Z(max) = 3.72, theta = 0.0). Refinement of the critical region defined a 6-7 cM interval of chromosome 1p34.3-p32 within which lies the COL8A2 gene. This encodes the 703 amino acid alpha2 chain of type VIII collagen, a short-chain collagen which is a component of endothelial basement membranes and which represented a strong candidate gene. Analysis of its coding sequence defined a missense mutation (gln455lys) within the triple helical domain of the protein in this family. Mutation analysis in patients with FECD and PPCD demonstrated further missense substitutions in familial and sporadic cases of FECD as well as in a single family with PPCD. This is the first description of the molecular basis of any of the corneal endothelial dystrophies or of mutations in type VIII collagen in association with human disease. This suggests that the underlying pathogenesis of FECD and PPCD may be related to disturbance of the role of type VIII collagen in influencing the terminal differentiation of the neural crest derived corneal endothelial cell.

Peribulbar anaesthesia is a form of regional anaesthesia which has been used with increasing popularity in cataract surgery. Recently indications for its use have been extended to include surgery for vitreo-retinal disease and strabismus. This study shows that in nine of 11 patients in whom the oculocardiac reflex was stimulated by traction on an extra-ocular muscle, peribulbar anaesthesia failed to abolish the reflex. In each of these patients, the reflex manifested as a bradycardia. In one subject, the bradycardia was profound, showing no QRS complex for five seconds. We recommend that cardiac rhythm be monitored throughout procedures performed under peribulbar anaesthesia, and that a vagolytic agent be available for immediate use.

Topically applied steroids are effective in the treatment of eczema, but when applied regularly to facial lesions can cause sight-threatening glaucoma.

During combined cataract extraction and intraocular lens insertion in eyes undergoing removal of silicone oil, we noted that oil became adherent to the implant. This adhesion persisted post-operatively. Although patients seemed not to be symptomatic as a result of this effect, the oil interferes with the fundal examination. Since heparin-coated intraocular lenses are more hydrophilic than unmodified lenses, oil should spread less well on these lenses and therefore be less adherent. This study was conducted to test this hypothesis. Heparin-surface-modified and unmodified polymethylmethacrylate (PMMA) lenses were immersed in 1000 centistoke neat silicone oil and in an emulsion of silicone oil taken from a patient. The lenses were washed with saline solution in an attempt to remove adherent oil. The lenses were photographed for examination and qualitative comparison. It was found that both neat and emulsified silicone oil was strongly adherent to both surface-modified and unmodified lenses, and could not easily be washed off. The heparin-coated lenses showed a tendency for adherence of emulsified oil. It is concluded that heparin coating of intraocular lenses does not prevent, though may reduce, oil adherence. We recommend that care be taken to avoid contact between oil and implant during combined oil removal and cataract extraction.

Summary points Early attempts at refractive surgery used partial thickness corneal incisions to alter the curvature of the cornea, with the most popular technique being radial keratotomy. In 1990 the Prospective Evaluation of Radial Keratotomy study found that outcomes were unpredictable and unstable, and this led to the use of ablative laser refractive surgery instead.1 We review evidence for the efficacy of laser refractive surgery mainly from randomised controlled trials and discuss suitability, contraindications, and potential complications of the procedure to help generalists in answering patients’ queries. #### Sources and selection criteria We searched PubMed for articles in English on laser refractive surgery. We also consulted guidelines issued by the Royal College of Ophthalmologists, the American Academy of Ophthalmologists, and the National Institute for Health and Clinical Excellence. We identified systematic reviews and randomised controlled trials as well as informative and relevant level C research. Search terms were “laser assisted in situ keratomileusis”, “laser epithelial keratomileusis”, “photoreactive keratotomy”, “myopia”, “hyperopia”, “astigmatism”, and “laser surgery”. Refractive error was recently reviewed in the BMJ .2 Refraction (measured in dioptres) is the process by which light is focused on the retina. The optical components of the eye are the lens, the length of the eyeball, and the cornea. The cornea provides three quarters of the overall refractive power of the eye. If the eyeball is too long …

A modification of the trabeculectomy technique was designed in an attempt to increase the outflow of aqueous into the subconjunctival space in the early post-operative period. This ‘high flow’ method was compared with a control group of eyes undergoing a standard trabeculectomy. Fifty-three eyes of 44 patients were recruited to this study. Follow-up was for a minimum of 12 months (mean 20 months). The high flow method resulted in lower intraocular pressures (IOP) on days 1 and 2 and shallower anterior chambers without increased incidence of con-junctival wound leak, suggesting that high outflow was indeed achieved. However, long-term control of IOP was not better than that achieved by the conventional technique. IOP control (IOP

PURPOSE To determine the reproducibility and the normal reference range of pulsatile ocular blood flow (POBF) values in healthy subjects using the Ocular Blood Flow Tonograph (OBF Laboratories, UK Ltd., Wiltshire, England). METHOD Pulsatile ocular blood flow was measured in one eye of each of 83 patients. Coefficient of reliability was determined by calculation of intraclass correlation coefficient via one-way analysis of variance. Mean difference between measurements was calculated for bias and first exposure effects. Pulsatile ocular blood flow from 163 healthy individuals were analyzed to determine the distribution, mean, standard deviation (SD), range, and the 5th and 95th percentile values. The influence of age, blood pressure, pulse rate, and intraocular pressure on pulsatile ocular blood flow was determined by regression analysis. RESULTS Reliability coefficient for pulsatile ocular blood flow values ranging from 290 microliters/min to 2,196 microliters/min was 0.92. Variation in bias and first exposure effect were not significant. Pulsatile ocular blood flow values were normally distributed. Mean values were 669.90 +/- 233.0 microliters/min in men and 841.90 +/- 254.6 microliters/min in women. Fifth and ninety-fifth percentile values were 364.75 microliters/min and 1,266.10 microliters/min in men and 397.18 microliters/min and 1,346.10 microliters/min in women. Pulsatile ocular blood flow was significantly influenced by pulse rate. CONCLUSION This study confirms the reliability of the Ocular Blood Flow Tonograph in repeated measurements of POBF within individuals over short time intervals. The high interindividual variation in POBF may invalidate comparison of POBF between individuals, and the wide range of normal values may limit the value of using a low POBF as a possible indicator of disease.