Jacky W. Y. Lee

Retrospective case series on the long-term visual and intraocular pressure outcomes of phacomorphic glaucoma

PurposeTo analyse the long-term visual acuity (VA) and intraocular pressure (IOP) outcomes in phacomorphic glaucoma.Patients and methodsA retrospective analysis of 100 consecutive, acute phacomorphic glaucoma cases from January 2000 to April 2009 was conducted at The Caritas Medical Centre in Hong Kong. All cases underwent cataract extraction after IOP control with medication and/or laser.ResultsDuring a 3.1±2.6-year follow-up, the mean visual improvement was 1.1±0.9 LogMAR units with improvements in 81.7% of cases. A shorter duration from symptoms to cataract extraction resulted in greater visual improvement (r2=0.1, P=0.001). In all, 80.5% of the cases had IOP⩽21 mm Hg without any glaucoma treatment; 19.5% required 1.6±0.7 glaucoma eye drops; and 3.7% required additional laser iridotomy or trabeculectomy for IOP control at 1.8±2.3 years. The vertical cup–disc ratio (VCDR) of the index eye was 0.6±0.3. Gonioscopy revealed an averaged Shaffer grading of 3.0±1.0 and 99±90 degrees of peripheral anterior synechiae (PAS). The Humphrey automated perimetry mean deviation was 5.2±2.7 and the pattern standard deviation was −15.9±10.ConclusionOver 80% of phacomorphic patients had long-term visual improvements and normalization of IOP after cataract extraction. A shorter attack seemed to offer better VA. Post-operatively, most have open angles with some degree of PAS formation, and glaucomatous optic neuropathy is evident from enlarged VCDRs and visual field defects. At least 2 years of follow-up is useful to detect a 20% glaucoma progression possibly requiring additional glaucoma treatments.

Efficacy of selective laser trabeculoplasty for normal tension glaucoma: 1 year results

BackgroundNormal tension glaucoma (NTG) is commonly treated with anti-glaucoma medications. Recently, selective laser trabeculoplasty (SLT) has been demonstrated to lower the intraocular pressure (IOP) and medication use in NTG. The purpose of this study was to investigate the efficacy of a single session of SLT for NTG at 1 year.MethodsThis prospective cohort study recruited NTG patients taking anti-glaucoma medication. Potential subjects were excluded if they had had previous glaucoma surgery or laser and also if intraocular surgery or additional SLT procedures were performed after the first treatment. All subjects underwent a 1-month washout. A 30% IOP reduction was set as the target IOP. A single session of SLT was performed to 360 degrees of the trabecular meshwork. At 1-month after SLT, medication was resumed to achieve the target IOP. The IOP was measured every 3 months, and the number of medications was recorded at 3, 6, and 12 months. Only the right eye was used for statistical analysis.ResultsIn 41 right eyes, the mean pre-study IOP was 14.3 ± 3.4 mmHg while on 1.5 ± 0.8 eye drops. The post-washout IOP was 16.2 ± 2.2 mmHg. A mean of 191.1 ± 26.3 SLT shots at 1.0 ± 0.07 mJ were applied. There was significant IOP reduction at all time intervals following SLT when compared to the post-washout IOP (P < 0.0001). The number of medications was significantly reduced at all time intervals following SLT when compared to the pre-study level (P < 0.0001). At 12 months, the mean IOP was 12.2 ± 2.2 mmHg while on 1.1 ± 0.9 eye drops.ConclusionsA single session of SLT for NTG achieved an additional 15% IOP reduction while using 27% less medication at 1 year compared to pre-study levels.Trial registrationThe Clinical Trials Register of the University of Hong Kong HKCTR1847The European Clinical Trials Database 2014-003305-15 (August 11, 2014) (https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-003305-15)

Corneal changes after a single session of selective laser trabeculoplasty for open-angle glaucoma.

PurposeTo investigate the changes in endothelial cell count, central corneal thickness (CCT), and refractive error after a session of selective laser trabeculoplasty (SLT) for open angle glaucoma (OAG).MethodsThis prospective cohort study recruited 111 eyes of 66 consecutive subjects with OAG. Subjects received SLT to 360° of the trabecular meshwork. Endothelial cell count, CCT, and spherical equivalent were measured at baseline before SLT as well as at 1 week and 1 month post SLT. A repeated measure nested ANOVA with Tukey’s multiple comparison test was performed to compare the outcome measures before and after SLT.ResultsIn 111 eyes of 66 subjects, the mean number of laser applications per treatment was 166.9±41.4 with a mean energy level of 1.0±0.07 mJ. The mean endothelial cell count decreased significantly from 2465.0±334.0 cells/mm2 at baseline to 2355.0±387.0 cells/mm2 at 1 week (P=0.0004) but increased to baseline levels at 1 month post SLT (2424.0±379.4 cells/mm2, P=0.3). The CCT, which decreased from a baseline of 549.4±37.6 to 543.9±40.2 μm at 1 week post SLT (P=0.02), also returned to the baseline level by 1 month (P=0.2). The spherical equivalent was static from baseline. A positive correlation was found between total laser energy and CCT at 1 month post treatment (r=0.3, P=0.005).ConclusionThe transient reductions in endothelial cell count and CCT following SLT returned to baseline levels 1 month after the procedure. Patients undergoing SLT should be aware of the risk of potential corneal changes.

Prospective study on the efficacy of treating normal tension glaucoma with a single session of selective laser trabeculoplasty.

Purpose:The purpose of this study was to investigate the efficacy of selective laser trabeculoplasty (SLT) in the treatment of normal tension glaucoma (NTG). Methods:This prospective cohort study recruited consecutive cases of NTG on antiglaucoma medication. Cases were excluded for previous glaucoma surgery or laser. All patients underwent a 1-month washout of medication followed by a mean baseline intraocular pressure (IOP) measured at 9 AM, 1 PM, and 5 PM. A 30% reduction from baseline was set as the target IOP. A single session of SLT was performed to 360 degrees of the trabecular meshwork. IOP phasing was repeated at 1 month after SLT and medication was resumed to achieve the target IOP. Patients were followed up to 6 months after SLT. Results:In 83 eyes of 46 subjects, the mean prestudy IOP was 14.2±3.1 mm Hg when on 1.5±0.9 antiglaucoma medication. The mean baseline IOP without medication was 16.1±2.2 mm Hg. The mean SLT shots applied was 187.8±27.5 using a mean energy of 1.0±0.07 mJ. At 1-month post-SLT, the IOP was 12.7±2.0 mm Hg (21.6% IOP reduction) from baseline without medication (P<0.05). The 6-month IOP was 11.4±1.6 mm Hg when on 1.1±1.0 medications, representing a 19.7% reduction from prestudy IOP, a 29.6% reduction from baseline IOP, and a 26.7% reduction in antiglaucoma medication (all P<0.05). A higher baseline IOP was correlated with greater IOP reduction with SLT (r=0.3, P=0.009). Conclusions:A single session of SLT for NTG achieved an additional 20% reduction in IOP with 27% less medication at 6 months compared with prestudy levels while maintaining a 30% reduction from baseline IOP.

Twenty-Four-Hour Intraocular Pressure Related Changes Following Adjuvant Selective Laser Trabeculoplasty for Normal Tension Glaucoma

AbstractTo investigate intraocular pressure (IOP) related patterns before and after selective laser trabeculoplasty (SLT) for normal tension glaucoma (NTG).In this prospective cohort study, 18 NTG patients underwent SLT. Success was defined as IOP reduction ≥20% by Goldmann applanation tonometry. 24-hour IOP-related pattern recording with a contact lens sensor (CLS) (SENSIMED Triggerfish®, Sensimed, Switzerland) was done before (baseline) and 1 month after SLT. A cosine function was fitted to the mean CLS patterns for each individual in the SLT success and non-success groups and the amplitude before and after SLT was calculated. Diurnal, nocturnal, and 24-hour CLS pattern local variability was determined for pre- and post-SLT sessions. Cosine amplitude and variability were compared before and after SLT by group using paired t-tests, with &agr; = 0.05.Patients (11 women, 7 men) had a mean age of 65.1 ± 13.7 years. Mean IOP was 15.3 ± 2.2 mm Hg at baseline and was reduced by 17.0% to 12.7 ± 1.8 mm Hg 1 month after SLT (P = 0.001). SLT was successful in 8 patients (44%). The amplitude of the fitted cosine was reduced by 24.6% in the success group, but displayed an amplitude increase of 19.2% post-SLT in the non-success group. Higher diurnal local variability of the CLS pattern was observed after SLT in non-success subjects (P = 0.002), while nocturnal variability showed no significant change. The increase in diurnal variability in the non-success group led to an increase in 24-hour variability in this group (P = 0.001). No change in local variability (diurnal, nocturnal, and 24-hour) was seen in the success group.The IOP-related pattern cosinor amplitude was reduced in NTG patients with a successful SLT treatment whereas the non-success group exhibited an increase of cosine amplitude. Higher diurnal and 24-hour CLS pattern variability was observed in non-success patients 1 month post-SLT.

Predictors of success in selective laser trabeculoplasty for chinese open-angle glaucoma

Aim:To investigate the determinants of success of selective laser trabeculoplasty (SLT) in Chinese open-angle glaucoma patients. Methods:This prospective cohort study sequentially recruited Chinese subjects with unilateral or bilateral primary open-angle glaucoma (POAG) or normal tension glaucoma (NTG). All subjects received a single session of 360-degree SLT treatment. Success was defined as IOP reduction ≥20%. The following were analyzed in univariate and multivariate regression analyses for association with SLT success: type of glaucoma, age, sex, lens status, presenting IOP, pre-SLT IOP, day 1 IOP, 1-week IOP, number and type of anti-glaucoma medications, number of SLT shots and energy, retinal nerve fiber layer (RNFL) thickness, Visual Field Index, endothelial cell count, central corneal thickness, Snellen visual acuity, and spherical equivalent. Results:In 111 eyes of 65 subjects, there were 51 POAG eyes and 60 NTG eyes. The overall success was 53.15% with a mean IOP reduction of 19.81±15.93%. In univariate analysis, a thinner RNFL [coefficient=−0.027; odds ratio (OR)=0.95; P=0.017] was associated with success. In multivariate analysis, a lower day 1 IOP (coefficient=−0.29; OR=0.75; P=0.049) and using topical carbonic anhydrase inhibitors (CAI) (coefficient=2.92; OR=18.63; P=0.0020) were associated with success. In both univariate and multivariate analyses, a higher pre-SLT IOP significantly predicted success (coefficient=0.20/0.46; OR=1.23/1.58; P=0.0017/0.0011) and using 3 anti-glaucoma medications (coefficient=−1.08/−3.74; OR=0.3/0.024; P=0.037/P=0.0081) was associated with SLT failure. Conclusion:The positive predictors of SLT success included: higher pre-SLT IOP, use of topical CAI, thinner RNFL, and lower day 1 IOP. Using 3 anti-glaucoma medications was associated with failure.

Novel Parameter of Corneal Biomechanics That Differentiate Normals From Glaucoma.

Purpose:To identify novel corneal biomechanical parameters differentiating glaucomatous from normal eyes. Patients and Methods:Sixty subjects with varying degrees of glaucoma severity and 61 normal controls underwent corneal biomechanical measurements including corneal deformation amplitude, inward and outward applanation length and velocity, and highest concavity time in 1 eye per subject at Queen Mary Hospital, Hong Kong. Measurements were taken with the Corvis ST device, a noncontact tonometer coupled with a high-speed Scheimpflug camera. The intraocular pressure (IOP) and central corneal thickness (CCT) were also measured. Results:Significant findings included differences in outward applanation velocity (glaucoma: −0.37±0.01 m/s; control: −0.32±0.01 m/s; P=0.001), peak distance (glaucoma: 2.37±0.03 mm; control: 2.30±0.02 mm; P=0.005), and highest concavity time (glaucoma: 16.75±0.08 ms; control: 17.05±0.07 ms; P=0.002) between the 2 groups, after correcting for IOP, CCT, and age. Both outward applanation velocity and peak distance were moderately correlated with IOP and CCT. However, highest concavity time was not correlated with either IOP or CCT (R2=0.0140 and 0.000055, respectively). Age was not correlated with any of the 3 parameters. Conclusions:Glaucomatous eyes have a greater mean outward applanation velocity and peak distance, but shorter time to highest concavity than eyes without glaucoma. The difference in time to highest concavity does not correlate with age, IOP, or CCT, suggesting that this parameter may be a marker of increased pressure susceptibility that is independently associated with glaucoma risk.

Predictors of success in selective laser trabeculoplasty for primary open angle glaucoma in Chinese

Purpose To determine the predictors of success for adjuvant selective laser trabeculoplasty (SLT) in Chinese primary open angle glaucoma (POAG) patients. Methods This prospective study recruited Chinese subjects with unilateral or bilateral POAG currently taking medication to reduce intraocular pressure (IOP). All subjects received a single session of 360° SLT treatment and continued their medications for 1 month. SLT success was defined as IOP reduction ≥20% at 1 month. The following covariates were analyzed in both groups via univariate and multivariate analyses: age, sex, lens status, initial IOPs, post-SLT IOPs, number and type of medications, SLT shots and energy, and pre-SLT investigations. Results In 51 eyes of 33 POAG subjects, the success rate of SLT was 47.1%. Certain groups of patients were associated with greater success using univariate analysis. These groups included the following: older age (coefficient =0.1; OR: 1.1; P=0.0003), a higher pre-SLT IOP (coefficient =0.3; OR: 1.3; P=0.0005), using four types of antiglaucoma medication (coefficient =2.1; OR: 8.4; P=0.005), a greater degree of spherical equivalent (coefficient =2.1; OR: 8.4; P=0.005), and the use of a topical carbonic anhydrase inhibitor (coefficient =1.7; OR: 6.0; P=0.003). None of the covariates were significant using multivariate analysis. Conclusion Older age, a higher pretreatment IOP, using multiple antiglaucoma medications especially topical carbonic anhydrase inhibitor, and higher refractive errors were associated with greater SLT success.

A randomized control trial to evaluate the effect of adjuvant selective laser trabeculoplasty versus medication alone in primary open-angle glaucoma: preliminary results

Background The objective of this study was to investigate the effects of adjuvant selective laser trabeculoplasty (SLT) versus medication alone on intraocular pressure (IOP) control, medication use, and quality of life in patients with primary open-angle glaucoma. Methods This prospective, randomized control study recruited 41 consecutive primary open-angle glaucoma subjects with medically-controlled IOP ≤21 mmHg. The SLT group (n=22) received a single 360-degree SLT treatment. The medication-only group (n=19) continued with their usual treatment regimen. In both groups, medication was titrated to maintain a target IOP defined as a 25% reduction from baseline IOP without medication, or <18 mmHg, whichever was lower. Outcomes, which were measured at baseline and at 6 months, included the Glaucoma Quality of Life-15 (GQL-15) and Comparison of Ophthalmic Medications for Tolerability (COMTOL) survey scores, IOP, and the number of antiglaucoma medicines. Results The baseline IOP was 15.8±2.7 mmHg and 14.5±2.5 mmHg in the SLT and medication-only groups, respectively (P=0.04). Both groups had a comparable number of baseline medication (P=0.2), GQL-15 (P=0.3) and COMTOL scores (P=0.7). At 6 months, the SLT group had a lower IOP (P=0.03) and required fewer medications compared with both baseline (P<0.0001) and with the medication-only group (P=0.02). There was no statistically significant difference in the 6-month GQL-15 or COMTOL score as compared to baseline (P≥0.4) or between the two treatment groups (P≥0.2). Conclusion A single session of adjuvant SLT provided further reductions in IOP and medication without substantial changes in quality of life or medication tolerability at 6 months.

Corneal collagen cross-linking for infectious keratitis: an update of clinical studies

Collagen cross‐linking (CXL) with ultraviolet light‐activated riboflavin is a corneal surface procedure developed for the treatment of keratoconus and corneal ectasia. With the known microbicidal and corneal stiffening effects of ultraviolet irradiation and photoactivated riboflavin, it has recently been introduced for the management of infectious keratitis, especially for ulcers resistant to antimicrobial therapy or associated with corneal melting. Various authors have attempted to use CXL as an adjunctive, salvage or even as the sole treatment for infectious corneal ulcers. The aim of this review was to provide a summary of the clinical studies in the literature. It is worth noting that there is still no consensus on the treatment protocol of CXL against infectious keratitis. The disparities in outcome measures, treatment protocol and study design can confound the interpretation and hamper the generalization of the study results. Based on current evidence, the role of CXL in infectious keratitis remained unclear despite the reported success in some clinical cases. Further investigations are warranted concerning the efficacy and safety of treating infectious keratitis with CXL.