The PAUL® glaucoma implant: 1-year results of a novel glaucoma drainage device in a paediatric cohort.

PURPOSE: The PAUL® glaucoma implant (PGI) is a novel glaucoma drainage device, which has not been previously reported in paediatric glaucoma management. This study aims to evaluate the safety and effectiveness of the PGI in a paediatric cohort. METHODS: A retrospective evaluation of 25 cases of paediatric PGI surgery (age 8 months to 16 years) was performed at Manchester Royal Eye Hospital between September 2019 and July 2020. Primary outcome measures included failure (intraocular pressure (IOP) > 21 mmHg or < 20% reduction of IOP, removal of the implant, further glaucoma intervention or visual loss. Secondary outcomes included mean IOP, mean number of medications, logMAR visual acuity and complications. RESULTS: Eleven eyes (48%) had a complete success and achieved an unmedicated IOP < 21 mmHg, and 21 eyes (84%) had a qualified success (with or without medications). Four failures were observed, 2 due to hypotony and 2 underwent further surgery (gonioscopy-assisted transluminal trabeculotomy). The mean preop IOP was 30.9 ± 5.9 mmHg (n = 25), falling to 13.5 ± 6.8 mmHg at 1 month, 17.9 ± 7.2 mmHg at 3 months, 13.4 ± 5.1 mmHg at 6 months, 13.2 ± 4.9 mmHg at 12 months and 11.8 ± 4.6 mmHg at 24 months. The mean change in IOP from the preoperative visit to the last visit was a reduction of 19.1 ± 7.7 mmHg. A significant reduction in the number of medications and IOP was demonstrated after PGI (p < 0.0001). Nine patients required removal of the intraluminal Prolene stent from the PGI for further pressure lowering. CONCLUSION: The one- to two-year results demonstrate paediatric PGI has high qualified success rates and effectively reduces IOP and the need for glaucoma medical therapy.

Providing capacity in glaucoma care using trained and accredited optometrists: A qualitative evaluation.

INTRODUCTION: The role of optometrists in glaucoma within primary and secondary care has been well described. Whilst many studies examined safety and clinical effectiveness, there is a paucity of qualitative research evaluating enablers and barriers for optometrists delivering glaucoma care. The aims of this study are to investigate qualitatively, and from a multi-stakeholder perspective whether optometric glaucoma care is accepted as an effective alternative to traditional models and what contextual factors impact upon their success. METHODS: Patients were recruited from clinics at Manchester Royal Eye Hospital and nationally via a Glaucoma UK registrant database. Optometrists, ophthalmologists, and other stakeholders involved in glaucoma services were recruited via direct contact and through an optometry educational event. Interviews and focus groups were recorded and transcribed anonymously, then analysed using the framework method and NVivo 12. RESULTS: Interviews and focus groups were conducted with 38 participants including 14 optometrists and 6 ophthalmologists (from all 4 UK nations), and 15 patients and 3 commissioners/other stakeholders. Themes emerging related to: enablers and drivers; challenges and barriers; training; laser; professional practice; the role of other health professionals; commissioning; COVID-19; and patient experience. CONCLUSION: Success in developing glaucoma services with optometrists and other health professionals is reliant on multi-stakeholder input, investment in technology and training, inter-professional respect and appropriate time and funding to set up and deliver services. The multi-stakeholder perspective affirms there is notable support for developing glaucoma services delivered by optometrists in primary and secondary care, with caveats around training, appropriate case selection and clinical responsibility.

Surgical technique, perioperative management and early outcome data of the PAUL® glaucoma drainage device.

OBJECTIVES: To describe a surgical technique and early post-operative outcomes for a novel glaucoma drainage device-the PAUL® glaucoma implant (PGI). METHODS: A consecutive cohort study of subjects who had PGI surgery between February 2019 and May 2020 with a minimum of 6-month follow-up. Primary outcome measures included failure (intraocular pressure (IOP) > 21 mmHg or a <20% reduction of IOP, removal of the implant, further glaucoma intervention or visual loss to no light perception). Secondary outcomes included mean IOP, mean number of medications, logMAR visual acuity (VA) and complications. RESULTS: Ninety-nine eyes of 97 patients had a preoperative IOP (mean ± standard deviation) of 28.1 ± 9.0 mmHg, falling to 18.2 ± 6.8 mmHg at 1 month, 17.9 ± 6.7 mmHg at 3 months and 13.6 ± 4.7 mmHg at 6 months. 52 patients had a 12-month mean IOP of 13.3 ± 4.4 mmHg. The mean change in number of medications was a reduction of 2.38 ± 1.48. A significant reduction in the number of medications and intraocular pressure was demonstrated after PGI (p < 0.0001). No significant change was demonstrated in VA (p = 0.1158). A total of nine cases were deemed failures (six had <20% IOP reduction from baseline and three had IOP >21 mmHg). Thirty-eight (38.4%) of eyes had complete success and achieved an unmedicated IOP <21 mmHg. Ninety (90.1%) of eyes were qualified successes (with or without topical medications). Seventy-four (74.7%) eyes have achieved an intraocular pressure of <15 mmHg. Two cases of hypotony were observed. CONCLUSION: This study presents a safe surgical technique, which significantly reduces IOP and number of medications with minimal complications.

Randomized clinical trial to evaluate the effects of Pascal panretinal photocoagulation on macular nerve fiber layer: Manchester Pascal Study report 3.

PURPOSE: To investigate the effects of panretinal photocoagulation (PRP) on macular thickness and macular nerve fiber layer thickness in eyes with proliferative diabetic retinopathy. METHODS: Single-center, randomized clinical trial (n = 40 eyes). Proliferative diabetic retinopathy was treated with 1,500 burns given as Pascal 20-millisecond single-session PRP (SS-PRP) or as multiple-session PRP (100 milliseconds, MS-PRP) over a 4-week period. The main outcome measures included optical coherence tomography measurements of total retinal thickness and nerve fiber layer at the macula, visual acuity, and proliferative diabetic retinopathy regression and were recorded at baseline, 4 weeks, and 12 weeks. Optic disk photographs were graded by masked a glaucoma specialist. RESULTS: At 12 weeks, in the SS-PRP group, there was no significant change in total nerve fiber layer thickness from baseline (4 weeks; +7.2 µm, P = 0.78; 12 weeks, -1.8 µm, P = 0.95). There was a significant increase in total retinal thickness for the MS-PRP group at 4 weeks from baseline (96 ± 17 µm; P < 0.001) and at 12 weeks (56 ± 21 µm; P = 0.0167). After 4 weeks in the MS-PRP group, total nerve fiber layer thickness increased significantly by 31 ± 54 µm (P = 0.029) from baseline, with a significant reduction at 12 weeks from baseline (35 ± 63 µm; P = 0.034). There was no change among groups for optic nerve appearance postlaser. At 12 weeks, the mean visual acuity was 81 ± 6 letters (SS-PRP group), compared with 77 ± 15 letters in the MS-PRP group (95% confidence interval, 5.2 to 9 letters; P = 0.286). For the SS-PRP group, a positive effect on proliferative diabetic retinopathy regression was observed in 74% of eyes compared with 53% of the eyes in the MS-PRP group (P = 0.31). CONCLUSION: Compared with 20-millisecond SS-PRP, eyes treated with conventional 100-millisecond single-spot delivered over multiple sessions showed increased total macular thickness at 4 weeks, with a thinning of macular nerve fiber layer at 12 weeks.

Outcomes of Primary Trabeculectomy From Two Same-centre Cohorts 10 Years Apart.

PRECIS: Trabeculectomy can effectively lower intraocular pressure (IOP). A more junior surgeon profile is emerging. Mitomycin C (MMC) has replaced 5-fluorouracil (5-FU) intraoperatively with comparable success rates and a decrease in postoperative antimetabolite administration. PURPOSE: We compare 2-year outcomes for primary trabeculectomy in 2 cohorts, 10 years apart, performed at a large UK teaching hospital. METHODS: Consecutive case series of trabeculectomies at Manchester Royal Eye Hospital between 2004-2005 (Cohort 1/C1) and 2014-2015 (Cohort 2/C2). Preoperative and postoperative data was collected for IOP outcomes and complications. Success was defined as IOP ≥6 and ≤21, ≤18, ≤16, ≤14, or ≤12 mm Hg with/without a ≥20% decrease from preoperative IOP. The need for and absence of postoperative antihypertensive medication defined qualified and complete success, respectively. RESULTS: A total of 186 cases were analyzed [52 (C1), 134 (C2)]. Mean preoperative IOP was 24±10 mm Hg (C1) and 21±7 mm Hg (C2) (P=0.01). Overall, 34 (79%), 33 (77%), 33 (77%), 29 (67%), and 25 (58%) patients in C1 and 88 (70%), 82 (65%), 73 (58%), 64 (51%), and 40 (32%) patients in C2 achieved complete success for IOP ≤21 mm Hg (P=0.33), ≤18 mm Hg (P=0.22), ≤16 mm Hg (P=0.04), ≤14 mm Hg (P=0.09), or ≤12 mm Hg (P=0.004). Similarly, 43 (93%), 40 (87%), 40 (87%), 35 (76%), and 27 (59%) in C1 and 123 (98%), 116 (92%), 106 (84%), 87 (69%), and 58 (49%) in C2 achieved qualified success (P=0.34, 0.37, 0.83, 0.48, and 0.19). In all, 32 (74%), 31 (72%),31 (72%), 28 (65%), and 24 (56%) in C1 and 64 (51%), 63 (50%), 61 (48%), 54 (43%), and 39 (31%) in C2 achieved complete success with ≥20% reduction from preoperative IOP and IOP of ≤21 mm Hg (P=0.01), ≤18 mm Hg (P=0.02), ≤16 mm Hg (P=0.01), ≤1 mm Hg (P=0.02), or ≤12 mm Hg (P=0.006). By same definition, 37 (80%), 36 (78%), 36 (78%), 33 (72%), and 26 (57%) in C1 and 94 (75%), 93 (74%), 90 (71%), 75 (60%), and 58 (46%) in C2 achieved qualified success (P=0.55, 0.69, 0.48, 0.20, and 0.30). Mean IOP at 2 years was 13±5 mm Hg (C1) and 13±4 mm Hg (C2) (P=0.35). Overall, 62% had intraoperative 5-FU in C1; only MMC was used in C2 (P<0.0001). Postoperative 5-FU was administered in 54% versus 22% in C1 and C2, respectively (P<0.0001). Needling rates were not statistically different [42% (C1), 54% (C2)] (P=0.22). CONCLUSIONS: Trabeculectomy is effective in lowering IOP with success comparable across various definitions. MMC replaced 5-FU as intraoperative antimetabolite resulting in reduced need for postoperative antimetabolite but not increased complications.

Spontaneous Resolution of a Rapidly Formed Dense Cataract Following Nd: YAG Laser Peripheral Iridotomy in a Case of Pigmentary Glaucoma.

A 54-year-old man was referred for a senior opinion. His vision had acutely dropped in his right eye from 6/6 to hand movements following Nd:YAG laser peripheral iridotomy for treatment of pigmentary glaucoma. A dense rosette posterior subcapsular cataract had formed in his right eye rapidly after surgery. Within 4 weeks the cataract resolved spontaneously and his vision returned to 6/6. It is hypothesized that a dual mechanism caused the rapidly formed cataract. Shockwaves stemming from Nd:YAG laser resulted in a reversible misalignment of the lenticular fibers, and localized direct damage to capsule caused osmotic imbalance and fluid collection between lamellae. Restoration of the osmotic balance, repair, and formation of lens fibers and clearing of vacuoles led to the resolution of the cataract. The proximity of the concave iris to the lens equator in pigmentary glaucoma was a predisposing factor. This highlights the importance of exercising great caution in using laser peripheral iridotomy in cases of pigmentary glaucoma, particularly if a higher laser power is used and considering initial conservative management of this complication.

Care pathways for glaucoma detection and monitoring in the UK.

Glaucoma presents considerable challenges in providing clinically and cost-effective care pathways. While UK population screening is not seen as justifiable, arrangements for case finding have historically been considered relatively ineffective. Detection challenges include an undetected disease burden, whether from populations failing to access services or difficulties in delivering effective case-finding strategies, and a high false positive rate from referrals via traditional case finding pathways. The enhanced General Ophthalmic Service (GOS) in Scotland and locally commissioned glaucoma referral filtering services (GRFS) elsewhere have undoubtedly reduced false positive referrals, and there is emerging evidence of effectiveness of these pathways. At the same time, it is recognised that implementing GRFS does not intrinsically reduce the burden of undetected glaucoma and late presentation, and obvious challenges remain. In terms of diagnosis and monitoring, considerable growth in capacity remains essential, and non-medical health care professional (HCP) co-management and virtual clinics continue to be important solutions in offering requisite capacity. National guidelines, commissioning recommendations, and the Common Clinical Competency Framework have clarified requirements for such services, including recommendations on training and accreditation of HCPs. At the same time, the nature of consultant-delivered care and expectations on the glaucoma specialist's role has evolved alongside these developments. Despite progress in recent decades, given projected capacity requirements, further care pathways innovations appear mandated. While the timeline for implementing potential artificial intelligence innovations in streamlining care pathways is far from established, the glaucoma burden presents an expectation that such developments will need to be at the vanguard of future developments.

Long-Term Outcomes and Complications of Baerveldt Glaucoma Drainage Implants in Adults with Glaucoma Secondary to Uveitis.

Purpose: This study investigated the efficacy and safety of Baerveldt glaucoma implants (BGI) in adults with uveitic glaucoma (UG) at the Manchester Uveitis Clinic.Methods: This was a retrospective study of 42 patients with UG who underwent BGI implantation between 2006 and 2015. Primary outcome measures were intraocular pressure (IOP) reduction and number of medications at 5-year follow-up. Three IOP success criteria were chosen: 1.IOP ≤21 mmHg and ≥20% reduction from baseline 2.IOP ≤17 mmHg and ≥20% reduction from baseline and 3.IOP ≤14 mmHg.Results: The mean pre-operative IOP was 29.5 ± 9.5 mmHg on 3.9 antiglaucoma drops. At 5-year follow-up, IOP reduced to 14.4 ± 7.0 mmHg (p < 0.005) on 1.4 drops. The cumulative probability of failure at 5 years based on criteria 1, 2, and 3 was 24.3%, 39.6%, and 56.3%, respectively.Conclusion: This study demonstrated that BGI are safe and effective in refractory UG, especially in younger adults with complex uveitis.

Clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme.

BACKGROUND: Glaucoma referral filtering schemes have operated in the UK for many years. However, there is a paucity of data on the false-negative (FN) rate. This study evaluated the clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme (GERS), estimating both the false-positive (FP) and FN rates. METHOD: Outcome data were collected for patients newly referred through GERS and assessed in 'usual-care' clinics to determine the FP rate (referred patients subsequently discharged at their first visit). For the FN rate, glaucoma suspects deemed not requiring referral following GERS assessment were invited to attend for a 'reference standard' examination including all elements of assessment recommended by National Institute for Health and Care Excellence (NICE) by a glaucoma specialist optometrist. A separate 33 cases comprising randomly selected referred and non-referred cases were reviewed independently by two glaucoma specialist consultant ophthalmologists to validate the reference standard assessment. RESULTS: 1404 patients were evaluated in GERS during the study period; 651 (46.3%) were referred to the Hospital Eye Service (HES) and 753 (53.6%) were discharged. The FP rate in 307 assessable patients referred to the HES was 15.5%. This study reviewed 131 (17.4%) of those patients not referred to the HES through the GERS scheme; 117 (89.3%) were confirmed as not requiring hospital follow-up; 14 (10.7%) required follow-up, including 5 (3.8%) offered treatment. Only one patient (0.8%) in this sample met the GERS referral criteria and was not referred (true FN). There were no cases of missed glaucoma or non-glaucomatous pathology identified within our sample. CONCLUSION: The Manchester GERS is an effective glaucoma filtering scheme with a low FP and FN rate.

Precipitants of 5-Fluorouracil in Trabeculectomy Bleb Management: A Comparative Laboratory Study.

AIM: Concerns regarding 5-Fluorouracil (5-FU) corneal toxicity have resulted in various ways of reducing its corneal exposure during post-operative trabeculectomy bleb manipulation. This study investigates the properties of various topical agents used to induce the precipitation of this compound. MATERIALS AND METHODS: This is a double-blind, descriptive, laboratory study comparing five different potential precipitants of 5-FU (proxymetacaine (proxy), oxybuprocaine (oxy), ametho-caine (ameth), fluorescein (flor), proxymetacaine + fluorescein (proxy-flor) to a control group (normal saline). A 0.01 mL of each anonymized agent was applied next to a clear round comparison marker in a transparent sterile container set on a dark background. 5-FU (0.01 mL of 50 mg/mL) was subsequently applied to each agent. The induced changes in transparency were imaged and compared to the transparency of the central marker. For each application, pH changes were also noted. RESULTS: Proxy, flor and proxy + flor did not result in any discernible 5-FU precipitation. Oxy resulted in a moderate visible change, and ameth produced very significant precipitation. Application of proxy, oxy, ameth, and proxy + flor resulted in the neutralization of the 5-FU's alkaline pH. CONCLUSION: We propose using a cotton-tipped bud dipped in ameth applied at the injection site as the recommended method to avoid 5-FU corneal exposure in these cases. CLINICAL SIGNIFICANCE: Practitioners should be aware of the differences in precipitation of 5-FU by different types of topical anesthetics and modify techniques of anesthesia and 5-FU administration accordingly.How to cite this article: Mercieca KJ, Fenerty CH, Steeples LR, Drury B, Bhargava A. Precipitants of 5-Fluorouracil in Trabeculectomy Bleb Management : A Comparative Laboratory StudyJ Curr Glaucoma Pract 2018;12(2):64-66.

Influence of cyclical mechanical strain on extracellular matrix gene expression in human lamina cribrosa cells in vitro.

PURPOSE: The mechanical effect of raised intraocular pressure is a recognised stimulus for optic neuropathy in primary open angle glaucoma (POAG). Characteristic extracellular matrix (ECM) remodelling accompanies axonal damage in the lamina cribrosa (LC) of the optic nerve head in POAG. Glial cells in the lamina cribrosa may play a role in this process but the precise cellular responses to mechanical forces in this region are unknown. The authors examined global gene expression profiles in lamina cribrosa cells exposed to cyclical mechanical stretch, with an emphasis on ECM genes. METHODS: Glial fibrillary acid protein negative primary LC cells were generated from the optic nerve head tissue of three normal human donors. Confluent cell passages (n=4) were exposed to 15% stretch at 1 Hz or static conditions for 24 h using the Flexercell system. Gene expression was assessed using Affymetrix U133A microarrays with pooled RNA. Expression levels were normalized using robust multi-chip average (RMA). Expression data was annotated using NIH DAVID software. ECM-related gene expression was validated in an independent experiment using quantitative real-time PCR and protein synthesis was measured using ELISA and immunohistochemistry. RESULTS: Compared with static controls, 805 genes were upregulated and 644 were downregulated by +/-1.5 fold in stretched LC cells. Gene ontologies included ECM, cell proliferation, growth factor activity, and signal transduction. Differentially expressed ECM genes included elastin, collagens (IV, VI, VIII, IX), thrombospondin 1, perlecan, and lysl oxidase. Quantitative PCR demonstrated that the expression of TGF-beta2, BMP-7, elastin, collagen VI, biglycan, versican, EMMPRIN, VEGF, and thrombomodulin were reproducible and consistent with the microarray data. VEGF and TGF-beta2 protein levels were also significantly (p<0.05) increased in stretched cell media supernatants. Immunohistochemistry demonstrated increased EMMPRIN (an extracellular matrix metalloproteinase inducer) protein in human POAG optic nerve head tissue compared to nonglaucomatous controls. CONCLUSIONS: These findings demonstrate that LC cells respond to mechanical stimuli in vitro by transcription of several components and modulators of the ECM. Some of the upregulated ECM genes identified are novel in the context of glaucomatous optic neuropathy (biglycan, versican, EMMPRIN, and BMP-7). The LC cell may represent both an important pro-fibrotic cell type in the optic nerve head and an attractive target for novel therapeutic intervention in POAG.

Effect of cyclical mechanical stretch and exogenous transforming growth factor-beta1 on matrix metalloproteinase-2 activity in lamina cribrosa cells from the human optic nerve head.

PURPOSE: Extensive remodeling of the lamina cribrosa extracellular matrix occurs in primary open angle glaucoma. The transforming growth factor-beta (TGF-beta) and matrix metalloproteinase (MMP) protein families are implicated in this process. The authors investigated (a). the effect of cyclical mechanical stretch on TGF-beta1 mRNA synthesis, TGF-beta1 protein secretion, MMP-2 protein activity and (b). the effect of exogenous TGF-beta1 on MMP-2 protein activity in human lamina cribrosa cells in vitro. METHODS: Primary human lamina cribrosa cells grown on flexible and rigid plates were exposed to cyclical stretch (1Hz, 15%) or static conditions for 12 and 24 hours. Cells grown on 100-mm plates were exposed to human TGF-beta1 (10 ng/ml) or vehicle (4 mM HCl/1% BSA) for 24 hours. TGF-beta1 mRNA synthesis in stretched and static cells was measured using real-time polymerase chain reaction. TGF-beta1 protein secretion in stretched and static cell media was measured using enzyme linked immunosorbent assay. Gelatin zymography measured MMP-2 activity in stretched, static, TGF-beta1- treated and vehicle-treated cell media. RESULTS: Cyclical stretch induced significant increases in TGF-beta1 mRNA synthesis after 12 hours (**P < 0.01) and TGF-beta1 protein secretion after 24 hours (*P < 0.05). Cyclical stretch significantly (*P < 0.05) increased MMP-2 activity in cell media after 24 hours. Exogenous TGF-beta 1 induced a significant (**P < 0.01) increase in cell media MMP-2 activity after 24 hours. CONCLUSIONS: These results suggest that cyclical stretch and TGF-beta1 modulate MMP-2 activity in human lamina cribrosa cells. TGF-beta 1 and MMP-2 release from lamina cribrosa cells may facilitate matrix remodeling of the optic nerve head in primary open angle glaucoma.

A study to assess the feasibility of undertaking a randomized controlled trial of adherence with eye drops in glaucoma patients.

BACKGROUND: Adherence with therapy could influence the progression of glaucoma and ultimately affect the onset of visual impairment in some individuals. This feasibility study evaluated the measures to be used for a future randomized controlled trial assessing the effects of group-based education on adherence with eye drops. METHODS: People diagnosed with glaucoma within the previous 12 months attending a regional ophthalmology clinic in the North West of England were recruited. A two-session education program delivered one week apart had been devised as part of a previous project. A combined adult learning and health needs approach to education was taken. Outcomes measured were knowledge of glaucoma, self-report of adherence, illness perception, beliefs about medicines, patient enablement, and general health (Short Form-12). Adherence was also measured objectively using a Medical Events Monitoring System device. RESULTS: Twenty-six participants consented to undertake the educational program and 19 produced analyzable data. Knowledge of glaucoma, illness perception, beliefs about medicine, and patient enablement all showed statistically significant improvements after education. Mean adherence with eye drops was maintained above 85% before and for 3 months after attendance at the educational program. Self-report exaggerated adherence by at least 10% when compared with the objective Medical Events Monitoring System data, and in fact the kappa agreement was zero. CONCLUSION: All questionnaires other than the Short Form-12 were considered to be valuable measures and use of a Medical Events Monitoring System device was considered to be an objective surrogate measure for adherence with eye drops. A multicenter, randomized, controlled equivalence trial of group versus individualized education using adherence as the primary outcome is the next step.

Relationships between visual field sensitivity and spectral absorption properties of the neuroretinal rim in glaucoma by multispectral imaging.

PURPOSE: To investigate the relationship between neuroretinal rim (NRR) differential light absorption (DLA, a measure of spectral absorption properties) and visual field (VF) sensitivity in primary open-angle glaucoma (POAG). METHODS: Patients diagnosed with (n = 22) or suspected of having (n = 7) POAG were imaged with a multispectral system incorporating a modified digital fundus camera, 250-W tungsten-halogen lamp, and fast-tuneable liquid crystal filter. Five images were captured sequentially within 1.0 second at wavelengths selected according to absorption properties of hemoglobin (range, 570-610 nm), and a Beer-Lambert law model was used to produce DLA maps of residual NRR from the images. Patients also underwent VF testing. Differences in NRR DLA in vertically opposing 180° and 45° sectors either side of the horizontal midline were compared with corresponding differences in VF sensitivity on both decibel and linear scales by Spearman's rank correlation. RESULTS: The decibel VF sensitivity scale showed significant relationships between superior-inferior NRR DLA difference and sensitivity differences between corresponding VF areas in 180° NRR sectors (Spearman ρ = 0.68; P < 0.0001), superior-/inferior-temporal 45° NRR sectors (ρ = 0.57; P < 0.002), and superior-/inferior-nasal 45° NRR sectors (ρ = 0.59; P < 0.001). Using the linear VF sensitivity scale significant relationships were found for 180° NRR sectors (ρ = 0.62; P < 0.0002) and superior-inferior-nasal 45° NRR sectors (ρ = 0.53; P < 0.002). No significant difference was found between correlations using the linear or decibel VF sensitivity scales. CONCLUSIONS: Residual NRR DLA is related to VF sensitivity in POAG. Multispectral imaging may provide clinically important information for the assessment and management of POAG.

Extension of retracted glaucoma drainage tube using a 22-gauge intravenous catheter in complex pediatric glaucoma.

PURPOSE: To describe the use of the readily available, sterile, and economical 22-gauge intravenous catheter (Venflon) as a preferable option for extending the tube of glaucoma drainage devices in cases of tube retraction in complex pediatric cases. METHODS: A report of noncomparative retrospective evaluation of 2 pediatric cases with tube retraction treated with the extension of the tube. The tube of the drainage devices (1 Baerveldt and 1 Molteno) was extended using a segment of a 22-gauge intravenous catheter (Venflon). The available follow-up for both the cases is 8.5 months. RESULTS: In both cases an adequate length of the tube was obtained in the anterior chamber. In the first case an excellent drainage bleb formed over the plate and the intraocular pressure (IOP) reduced from 28 to 11 mm Hg. In the second case only a 25% reduction of IOP (from 40 to 30 mm Hg) and a shallow bleb was seen for a few weeks only as extensive fibrosis over the plate limited the drainage. There has been no displacement of the tube in the follow-up period. CONCLUSIONS: The readily available, sterile, and economical 22-gauge intravenous catheter (venflon) segment is a structurally and functionally appropriate, and cost effective option for extension of both Baerveldt and Molteno drainage implants in complex pediatric cases. However other factors limiting drainage from tube, such as extensive scarring over the plate may limit the reduction of IOP.

Technical Note: grading the vertical cup:disc ratio and the effect of scaling.

PURPOSE: To evaluate the effect of scaling on sensitivity to change for grading the vertical cup:disc ratio (CDR). METHODS: Vertical CDR was assessed by six observers (three ophthalmologists and three optometrists) on 43 stereo disc photographs. Repeated observations were made for both 0.1 and 0.05 interval scales. Paired differences were calculated for all observers and each observer separately. Mean and standard deviation of differences and agreement statistics were used to compare scales. RESULTS: Five observers demonstrated a reduction in the spread of differences (mean difference 0.19 to 0.15) and all observers demonstrated a reduction in concordance using the finer scale (mean concordance 54% to 39%). CONCLUSION: The use of a finer scale reduces test-retest variability and increases sensitivity to change when estimating the vertical CDR. Use of this scale does not require any additional resource and it may be easily implemented in routine clinical practice.