Deep sclerectomy and trabeculectomy augmented with Mitomycin C: 2-year post-operative outcomes.

PURPOSE: Two-year post-operative outcomes of both deep sclerectomy (DS) and trabeculectomy surgery (Trab) augmented with Mitomycin C (MMC) at a single tertiary eye centre. METHODS: Retrospective review of DS + MMC and trabeculectomy + MMC at a single centre between February 2015 and March 2018. Patients with a minimum of 12-month follow-up were included. Post-operative follow-up: day 1, week 1, months 1/3/6/12/18/24. Primary outcomes: changes in intraocular pressure (IOP) and changes in LogMAR visual acuity (BCVA) pre- and post-procedure. SECONDARY OUTCOMES: changes in number of eye drops, number of follow-up clinic visits, post-operative complications and further surgical interventions. Complete success: IOP ≤ 21 mmHg off all IOP-lowering medications. Qualified success: IOP ≤ 21 mmHg on medication. Failure: IOP > 21 mmHg at 24 months or ≤ 5 mmHg on 2 consecutive follow-up visits after 3 months +/- additional incisional glaucoma surgery +/- loss of light perception. Statistical analysis performed using Microsoft Excel + SPSS. RESULTS: 90 eyes: DS + MMC = 46 eyes, Trab + MMC = 44 eyes. DS + MMC v Trab + MMC: mean pre-op IOP = 19.57 mmHg v 18.89 mmHg, significantly reduced at all post-operative time-points for both groups (p < 0.001). Mean IOP reduction from baseline = 33.94% v 38.39%; > 30% IOP reduction = 54.35% v 68.18%. IOP ≤ 16 mmHg = 82.61% (38/46) v 95.46% (42/44), IOP ≤ 12 mmHg = 52.17% (24/46) v 72.72% (32/44). Complete success = 67.39% v 61.36%, qualified success = 26.09% v 29.55%, failure = 6.52% v 9.09%. Post-op BCVA: no statistically significant differences between two groups (p = 0.09). Mean pre-op drops v post-op drops = 2.98 v 0.38 (DS + MMC; p < 0.001); 2.68 v 0.39 (Trab + MMC; p < 0.001). Further surgical intervention = 13% v 29.55%. Mean number of post-op clinic visits DS + MMC v Trab + MMC = 10.09 v 13.02 (p = 0.005). CONCLUSION: Both procedures achieve sustained intraocular pressure and drop reduction at 2 years post-op. DS + MMC has lower complication rates requiring less intervention and significantly fewer clinic visits, which may be an important factor for deciding surgical management of glaucoma patients in the era of Covid-19 to reduce patient/clinician exposure to the virus.

Outcome of Descemet stripping automated endothelial keratoplasty in eyes with an Ahmed glaucoma valve.

PURPOSE: The purpose was to investigate the survival of Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with an Ahmed glaucoma valve (AGV). METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Swept-Source Anterior Segment Optical Coherence Tomography Imaging and Quantification of Bleb Parameters in Glaucoma Filtration Surgery.

This paper describes a technique for using swept-source anterior segment optical coherence tomography (AS-OCT) to visualize internal bleb microstructure and objectively quantify dimensions of the scleral flap and trabeculo-Descemet window (TDW) in non-penetrating glaucoma filtration surgery (GFS). This was a cross-sectional study of 107 filtering blebs of 67 patients who had undergone deep sclerectomy surgery at least 12 months prior. The mean post-operative follow-up duration was 6.5 years +/- 4.1 [standard deviation (SD)]. The maximal bleb height was significantly greater in the complete success (CS) blebs compared to the qualified success (QS) and failed (F) blebs (1.48 vs. 1.17 vs. 1.10 mm in CS vs. QS vs. F, one-way ANOVA, p < 0.0001). In a subcohort of deep sclerectomy blebs augmented by intraoperative Mitomycin-C, the trabeculo-Descemet window was significantly longer in the complete success compared to the qualified success group (613.7 vs. 378.1 vs. 450.8 µm in CS vs. QS vs. F, p = 0.004). The scleral flap length, thickness, and width were otherwise similar across the three outcome groups. The quantification of surgical parameters that influence aqueous outflow in non-penetrating GFS can help surgeons better understand the influence of these structures on aqueous outflow and improve surgical outcomes.

Sequential versus combined penetrating keratoplasty and cataract surgery.

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.

Intraobserver reproducibility and interobserver agreement of demarcation line depth measurements following corneal cross linking.

PURPOSE: The aim of this study was to evaluate the intraobserver reproducibility of demarcation line depth measurement in keratoconic patients after epithelium-off corneal collagen cross linking and assess the interobserver variability/agreement among examiners of various experience levels. METHODS: 56 eyes of 56 patients undergoing corneal collagen cross linking for progressive keratoconus were enrolled. After 4 weeks, all patients underwent an anterior segment optical coherence tomography (AS-OCT; CASIA SS-1000; Tomey, Nagoya, Japan) in the cross-linked eye by four masked examiners (two medical students (S1 and S2) and two corneal fellows (F1 and F2)) in order to identify and measure the demarcation line depth in experienced and non-experienced users. The intraclass correlation coefficient and the coefficient of variation were calculated. Agreement between raters was evaluated using Bland-Altman plots, intraclass correlation coefficient and weighted-kappa statistics comparing raters in pairs. RESULTS: The average demarcation line depth of all measurements was 254.34 ± 72.3 µm, varying from 84 to 459 µm. The intraclass correlation coefficient evaluating the reproducibility of measurements for F1 was 0.9379 (95% confidence interval (CI) =0.9035-0.9619), for the second (F2), it was 0.9837 (95% confidence interval = 0.9743-0.9901), while intraclass correlation coefficient between medical students was calculated 0.844. The overall intraclass correlation coefficient among all four observers was 0.8706 (95% confidence interval = 0.8061-0.9185). The coefficient of variation for repeated measurements was 5.981 µm (95% confidence interval = 3.966-7.471) and 3.312 µm (95% confidence interval = 2.468-3.981) for F1 and F2 raters, respectively. The percentage of demarcation line detection was 90.32%. CONCLUSION: The reproducibility of demarcation line measures although very good (intraclass correlation coefficient > 0.9), yielded a difference between the two experienced raters. Furthermore, the novice raters did not reach an excellent level of agreement with the expert ones showing greater variability in their recordings.

Corneal biomechanics and biomechanically corrected intraocular pressure in primary open-angle glaucoma, ocular hypertension and controls.

AIMS: To compare the biomechanically corrected intraocular pressure (IOP) estimate (bIOP) provided by the Corvis-ST with Goldmann applanation tonometry (GAT-IOP) in patients with high-tension and normal-tension primary open-angle glaucoma (POAG; HTG and NTG), ocular hypertension (OHT) and controls. Moreover, we compared dynamic corneal response parameters (DCRs) of the Corvis-ST in POAG, OHT and controls, evaluated the correlation between global visual field parameters mean deviation and pattern SD (MD and PSD) and DCRs in the POAG group. METHODS: 156 eyes of 156 patients were included in this prospective, single-centre, observational study, namely 41 HTG and 33 NTG, 45 OHT cases and 37 controls. Central corneal thickness (CCT), GAT-IOP and bIOP were measured, GAT-IOP was also adjusted for CCT (GATAdj). DCRs provided by Corvis-ST were evaluated, MD and PSD were recorded by 24-2 full-threshold visual field. To evaluate the difference in DCRs between OHT, HTG and NTG, a general linear model was used with sex, medications and group as fixed factors and bIOP and age as covariates. RESULTS: There was a significant difference between GAT-IOP, GATAdj and bIOP in NTG and HTG, OHT and controls. NTG corneas were significantly softer and more deformable compared with controls, OHT and HTG as demonstrated by significantly lower values of stiffness parameters A1 and highest concavity and higher values of inverse concave radius (all p<0.05). There was a significant correlation (p<0.05) between MD, PSD and many DCRs with POAG patients with softer or more compliant corneas more likely to show visual field defects. CONCLUSIONS: Corneal biomechanics might be a significant confounding factor for IOP measurement that should be considered in clinical decision-making. The abnormality of corneal biomechanics in NTG and the significant correlation with visual field parameters might suggest a new risk factor for the development or progression of NTG.

Assessment of the Association Between In Vivo Corneal Biomechanical Changes After Corneal Cross-linking and Depth of Demarcation Line.

PURPOSE: To test for an association between stiffening following corneal cross-linking (CXL) and demarcation line depth. METHODS: Sixty-six eyes of 66 patients treated with CXL for progressive keratoconus were included. Dynamic corneal response parameters (DCRs) were measured with the Corvis ST (Oculus Optikgeräte GmbH; Wetzlar, Germany) on the day of CXL and after 1 month. Demarcation line was measured 4 weeks after CXL. A multivariate general linear model was used to test for an association between the change in DCRs and the ratio between demarcation line depth and the postoperative pachymetry. RESULTS: The authors found no significant associations between the change in inverse concave integrated radius (1/R) and the demarcation line ratio (P = .46), age (P = .33), sex (P = .11), preoperative maximum keratometry (P = .10), and laterality (P = .82). Similarly, there was no significant correlation between the change in 1/R and the demarcation line ratio (R2 = .002 and P = .75). However, there was a significant association between the preoperative values of 1/R and the respective change in 1/R (P < .0001). The change in 1/R was inversely proportional to the patient's preoperative 1/R; stiffer corneas (lower values of 1/R) were less affected than less stiff corneas (R2 = .23, P < .0001). CONCLUSIONS: CXL is associated with changes in DCRs, suggesting a change in corneal biomechanics following CXL. These changes do not appear to be associated with the demarcation line depth. [J Refract Surg. 2019;35(3):202-206.].

Bandage contact lens and topical steroids are risk factors for the development of microbial keratitis after epithelium-off CXL.

OBJECTIVE: To 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 ANALYSIS: Patients 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). RESULTS: 1273 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 (p<0.0001). A greater proportion of patients who developed microbial keratitis were atopic (75%, p=0.4). CONCLUSION: The 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.

Refractive outcomes following cataract surgery in patients who have had myopic laser vision correction.

OBJECTIVE: Prediction 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 ANALYSIS: The 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. RESULTS: 22 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 (p<0.01). The mean difference between the intended and postoperative refractive error was relatively small, but its variance was significantly greater among post LVC eyes than control eyes (p<0.01). Among post LVC eyes, there were no significant differences between the mean intended target refraction and between the intended and postoperative refractive error using five biometry formulae (p=0.76). CONCLUSION: Biometry 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.

Biometric calculation of intraocular lens power for cataract surgery following pupil dilatation.

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.

Improving precision for detecting change in the shape of the cornea in patients with keratoconus.

To investigate a method for precision analysis to discriminate true corneal change from measurement imprecision in keratoconus (KC). Thirty patients with KC and 30 healthy controls were included. Coefficients of repeatability and limits of agreement (LOA) were compared using multiple measurements for inter-observer and inter-device agreement with the Pentacam HR, Orbscan IIz, and Tomey Casia SS-1000. Correlation of repeated measurements was evaluated using a linear mixed effect model (also called random effect model). A formula was derived for the theoretical expected change in precision and compared with measured change. Correlation between measurements from the same eye was small (R = 0.13). The 99.73% LOA (3 SD) of the mean of three measurements, provided better precision than 95% LOA (2 SD) of single cut-off values as expected from statistical theory for uncorrelated measurements for evidence of a significant change in corneal shape in patients with keratoconus. This enabled the determination of cut-off values for the detection of true change in corneal shape. The mean of three repeated measurements will provide better precision when there is minimal correlation. Three (rather than two) standard deviations provides a precise estimate of the LOA within or between observers and can be used as a reliable measure for identifying stage-independent corneal shape changes (progression) in keratoconus.

Pharmacokinetics of vancomycin following intracameral bolus injection in patients undergoing phacoemulsification cataract surgery.

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.

Interobserver reliability when using the Van Herick method to measure anterior chamber depth.

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.

In Vivo Early Corneal Biomechanical Changes After Corneal Cross-linking in Patients With Progressive Keratoconus.

PURPOSE: To report early corneal biomechanical changes after corneal cross-linking (CXL) in patients with keratoconus. METHODS: Thirty-four eyes of 34 patients undergoing CXL for progressive keratoconus were included in this prospective clinical study. Dynamic corneal response (DCR) parameters obtained with the Corvis ST (OCULUS Optikgeräte GmbH; Wetzlar, Germany) were assessed at baseline (day of CXL) and after 1 month of follow-up; conversely, corneal tomography with the Pentacam (OCULUS Optikgeräte GmbH) was assessed at baseline and at 1, 3, and 6 months after CXL. RESULTS: At the last follow-up visit (123.7 ± 69.6 days), all morphological parameters including steepest point (Kmax) and thinnest corneal thickness (ThCT) indicated stabilization of keratoconus (P > .05). Comparative analyses showed a rise of corneal stiffness demonstrated by a significant increase of Stiffness Parameter A1 (SP-A1) and Highest Concavity (SP-HC) and a significant decrease of Inverse Concave Radius (1/R) and Deformation Amplitude Ratio (DA Ratio) (P < .05). There was a significant correlation between the preoperative keratoconus characteristics (Kmax, Belin/Ambrósio final D value [BAD-D], and ThCT) and the DCR parameters (P < .05). Kmax and BAD-D showed a significant positive correlation with DA Ratio, Deflection Amplitude (DefA), and 1/R and a significant negative correlation with SPA1 and SP-HC. ThCT showed a significant positive correlation with SP-A1 and SP-HC and a significant negative correlation with DA Ratio, DefA, and 1/R. CONCLUSIONS: This study suggests that the new DCR parameters of the Corvis ST are able to detect early changes in biomechanics following CXL and those that are measurable before corneal shape modifications take place. Based on these results, the authors suggest the use of these metrics to assess the early efficacy of cross-linking. [J Refract Surg. 2017;33(12):840-846.].

Preparation of ultrathin grafts for Descemet-stripping endothelial keratoplasty with a single microkeratome pass.

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.

Corneal topographic features in a family with nanophthalmos.

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.

Femtosecond Laser-Assisted Lamellar Keratectomy for Corneal Opacities Secondary to Anterior Corneal Dystrophies: An Interventional Case Series.

PURPOSE: To report results of femtosecond laser-assisted lamellar keratectomy (FLK) for corneal opacities secondary to anterior corneal dystrophies. METHODS: Patients with a clinical diagnosis of Reis-Bücklers corneal dystrophy, granular corneal dystrophy, lattice corneal dystrophy, and macular corneal dystrophy were treated. FLK was performed to remove a central corneal free cap of 9.5 mm in diameter at a depth of 110 to 140 µm on which histological analysis was undertaken. Preoperative and postoperative refraction, best spectacle-corrected visual acuity, corneal topography results, and color photographs were recorded. Postoperative in vivo confocal microscopy of the cornea was performed. Changes in uncorrected visual acuity and best spectacle-corrected visual acuity, keratometry, refractive error, corneal irregularity, residual or recurrent central corneal opacities, and corneal haze were used to assess the outcome. RESULTS: Eight eyes of 6 patients were treated. The clinical diagnosis was confirmed histologically in all cases. Visual acuity improved significantly from 0.49 ± 0.2 logMAR to 0.14 ± 0.13 logMAR after a mean follow-up of 29 ± 14 (range 8-54) months. Residual central stromal opacities were noted in 5 of 8 eyes immediately postoperatively. Clinically significant recurrence of disease was noted in 1 eye. Keratometry and refraction remained stable, and no further surgical intervention was needed. Patients with stromal corneal dystrophies had worse outcome than those with Reis-Bücklers corneal dystrophy. CONCLUSIONS: In this case series, FLK provided both therapeutic and diagnostic intervention, delaying more invasive surgery. In vivo confocal microscopy showed signs of postoperative corneal stromal neuropathy.

Automated imaging technologies for the diagnosis of glaucoma: a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study).

BACKGROUND: Many glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population. OBJECTIVES: To assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma. DESIGN: Within-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care. SETTING: Secondary care. PARTICIPANTS: Adults referred from the community to hospital eye services for possible glaucoma. INTERVENTIONS: Heidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement. MAIN OUTCOME MEASURES: (1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is 'discharge' or 'do not discharge'. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY). RESULTS: Data from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs. CONCLUSIONS: Automated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective. FUTURE WORK: There are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Suppression of thrombospondin 1 and 2 production by herpes simplex virus 1 infection in cultured keratocytes.

PURPOSE: 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. METHODS: 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. RESULTS: 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 (p<0.002), and were absent from 24 h ai (p<0.001). 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. CONCLUSIONS: 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.

Bullous keratopathy and corneal decompensation secondary to iridoschisis: a clinicopathological report.

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.