Reproducibility of consecutive automated telemetric noctodiurnal IOP profiles as determined by an intraocular implant.

BACKGROUND: Intraocular pressure (IOP) monitoring in glaucoma management is evolving with novel devices. We investigated the reproducibility of 24 hour profiles on two consecutive days and after 30 days of self-measurements via telemetric IOP monitoring. METHODS: Seven primary patients with open-angle glaucoma previously implanted with a telemetric IOP sensor in one eye underwent automatic measurements throughout 24 hours on two consecutive days ('day 1' and 'day 2'). Patients wore an antenna adjacent to the study eye connected to a reader device to record IOP every 5 min. Also, self-measurements in six of seven patients were collected for a period of 30 days. Analysis included calculation of hourly averages to correlate time-pairs of day 1 versus day 2 and the self-measurements vers day 2. RESULTS: The number of IOP measurements per patient ranged between 151 and 268 on day 1, 175 and 268 on day 2 and 19 and 1236 during 30 days of self-measurements. IOP time-pairs of automatic measurements on day 1 and day 2 were significantly correlated at the group level (R=0.83, p<0.001) and in four individual patients (1, 2, 6 and 7). IOP time-pairs of self-measurements and day 2 were significantly correlated at the group level (R=0.4, p<0.001) and in four individual patients (2, 5, 6 and 7). CONCLUSIONS: Twenty-four hour automatic measurements of IOP are correlated on consecutive days and, though to a lesser degree, with self-measurements. Therefore a virtual 24-hour IOP curve might be constructed from self-measurements. Both options provide an alternative to frequent in-office IOP measurements.

Measurement of intraocular temperature in glaucoma: week-day and seasonal fluctuations.

PURPOSE: To evaluate long-term intraocular temperature (IOT) variations in eyes with primary open-angle glaucoma (POAG) using an intraocular telemetric sensor. METHODS: This prospective, open-label, multicentre observational study analysed the IOT variations in 22 eyes of 22 patients with POAG. All enrolled patients underwent implantation of an intraocular pressure (IOP) sensor during cataract surgery. The telemetric system uses a built-in temperature sensor to control measured IOP for temperature. Each time a patient measures their IOP, both the IOP and IOT are recorded in the reader device. Patients were instructed to self-measure their IOP as often as desired, but at least four times daily. Recorded readings were retrieved and analysed using mixed effect models and pairwise comparisons using Bonferroni correction to assess the statistical significance of average IOT variations between each individual weekday and calendar month. RESULTS: The mean age of patients was 67.8±6.8 years and 36.4% were women. A total of 132 745 readings over 21 102 measurement-days were obtained. On average, IOT was significantly higher on Sundays (34.57°C; 95% CI 34.37 to 34.78) than on any other day of the week (p<0.001). Mean IOT on other weekdays ranged from 34.48°C to 34.51°C. Over the year, IOT followed a clear seasonal pattern, reaching its maximum in July (34.8°C; 95% CI 34.56 to 34.97) and its minimum in January (34.4°C; 95% CI 34.15 to 34.56; p<0.001). CONCLUSIONS: This study demonstrates the feasibility of continual and long-term measurement of IOT using intraocular sensors. The results show significant short-term and long-term fluctuations of IOT. Research is warranted to understand the impact of IOT variations on IOP, ocular perfusion and glaucoma progression.

Safety and performance of a suprachoroidal sensor for telemetric measurement of intraocular pressure in the EYEMATE-SC trial.

AIM: To investigate the safety and performance of a telemetric suprachoroidal intraocular pressure (IOP) sensor (EYEMATE-SC) and the accuracy of its IOP measurements in open angle glaucoma (OAG) patients undergoing simultaneous non-penetrating glaucoma surgery (NPGS). METHODS: Prospective, multicentre, open-label, single-arm, interventional clinical trial. Twenty-four eyes of 24 patients with OAG regularly scheduled for NPGS (canaloplasty or deep sclerectomy) were simultaneously implanted with an EYEMATE-SC sensor. Six-month follow-up on the sensor's safety and performance as well as on the level of agreement between the EYEMATE-SC measurements and IOP measurements with Goldmann applanation tonometry (GAT). RESULTS: The eyes underwent canaloplasty (n=15) or deep sclerectomy (n=9) and achieved successful implantation of the sensor. No device migration, dislocation or serious device-related complications occurred. A total of 367 comparisons were included in the IOP agreement analysis. The overall mean difference between GAT and EYEMATE-SC measurements was 1.31 mm Hg (lower limit of agreement (LoA) 7.55 mm Hg; upper LoA -4.92 mm Hg). The maximum difference of 2.5 mm Hg ±3.96 (LoA 0.30-2.29) was reached on day 10 and continuously improved to an agreement of -0.15 mm Hg ±2.28 (LoA -1.24 to 0.89) after 6 months. Accordingly, the percentage of eyes within an IOP difference of ±5 mm Hg improved from 78% (day 3) to 100% (6 months). CONCLUSIONS: After 6 months, the EYEMATE-SC sensor was safe and well tolerated, and allowed continual IOP monitoring. TRIAL REGISTRATION NUMBER: NCT03756662.

The Importance of Signal Strength Index in Optical Coherence Tomography Angiography: A Study of Eyes with Pseudoexfoliation Syndrome.

Purpose: To evaluate the effect of the signal strength index (SSI) on a comparison of the vascular and structural OCT measurements between eyes with pseudoexfoliation syndrome (PXF) and healthy controls of Asian-Indian origin. Methods: In this cross-sectional study, 33 eyes of 33 PXF patients and 40 healthy eyes of 40 controls underwent OCT and OCT angiography (OCTA). Eyes with intraocular pressure (IOP) >21mmHg, glaucomatous disc changes, or any other ocular pathology were excluded. Peripapillary vessel density (VD) and retinal nerve fiber layer (RNFL) thickness were determined from the optic disc scans. Parafoveal VD and ganglion cell complex (GCC) thickness were measured from the macular scans. These parameters were compared between the groups using mixed effect models after adjusting for clinical confounders such as IOP, as well as SSI of the scans. Results: The 2 groups were demographically similar. Average RNFL (94µm vs 100µm, p = 0.01) and GCC (91µm vs 95µm, p = 0.03) were thinner in the PXF group compared to controls. The average peripapillary VD appeared lower in the PXF groups compared to controls (58.2% vs 58.8%, p = 0.04), but after adjusting for IOP and SSI, no difference was noted (p = 0.39). After accounting for confounders, parafoveal VD in the PXF group was significantly lower compared to controls (44.3% vs 46.8%, p = 0.008). Conclusion: Peripapillary RNFL thickness, parafoveal GCC thickness and parafoveal VD were decreased in eyes with PXF when compared to controls. VD measurements are associated with the SSI and, therefore, clinicians and researchers evaluating OCTA scans quantitatively must consider the SSI value during analysis and interpretation.

Optic nerve head vessel density in different stages of pseudoexfoliation disease.

PURPOSE: To evaluate the superficial vascular density of the optic nerve head in different stages of pseudoexfoliation disease using optical coherence tomography angiography (OCTA). METHODS: In this cross-sectional study, 57 normal eyes, 41 eyes with pseudoexfoliation syndrome (PXS), 82 eyes with pseudoexfoliation glaucoma (PXG) and 27 non-glaucomatous fellow eyes of PXG (NL-PXG) that had OCTA were included. Circumpapillary RNFL (cpRNFL) thickness and circumpapillary capillary density (cpCD) were compared among the groups after adjusting for confounders using linear-mixed model. RESULTS: PXG eyes had thinner global RNFL and lower cpCD (74.2±14.3 µm and 36.7±10.0%) than control (103.3±8.6 µm and 52.5±2.3%), PXS (96.8±8.8 µm and 51.5±2.3%), and NL-PXG eyes (96.3±11.1 µm and 50.1±3.9%) (p<0.001). After adjustment for age, gender and signal strength index, global cpRNFL thickness was comparable among control, PXS and NL-PXG. NL-PXG had the lowest cpCD (p=0.045) and sectoral cpCD compared to PXS and control eyes. Although cpCD was comparable between control and PXS (p=0.425) eyes, sectoral differences (p=0.009 and 0.004, for inferonasal and temporal-inferior cpCD, respectively) were detectable between the two groups. AUROC for differentiating NL-PXG eyes from normal were better for cpCD (0.78) compared to cpRNLF (0.69). CONCLUSIONS: OCTA can detect reduced capillary density before significant changes in cpRNFL in fellow eyes of PXG patients. This can enable earlier detection of glaucomatous loss in pseudoexfoliation disease and enhance management of the disease.

Weekly and seasonal changes of intraocular pressure measured with an implanted intraocular telemetry sensor.

BACKGROUND/AIMS: To better understand seasonal and weekday intraocular pressure (IOP) variations, long-term daily IOP measurements were assessed in patients with glaucoma using an intraocular telemetric sensor. METHODS: This prospective, open-label, multicentre observational study analysed the IOP variation patterns in 22 eyes of 22 patients with primary open-angle glaucoma (67.8±6.8 years, 36.4% female) who had undergone placement of an intraocular telemetric sensor at the time of cataract surgery. The telemetric system combines an implantable IOP sensor with a hand-held reading device. Patients were instructed to self-measure their IOP as often as desired, but at least four times daily. Analysis of variance and Tukey multiple-comparison correction were used to assess the statistical significance of average and peak IOP variations between individual weekdays and months. RESULTS: Each enrolled patient recorded daily IOP measurements for an average duration of 721 days. On average, IOPs were highest on Wednesdays and lowest on Fridays (p=0.002). There were significant variations of IOP throughout the year, and IOP showed a seasonal pattern. Between mid-winter (December-January) and mid-summer months, there was a reduction in mean IOP of 8.1% (-1.55 mm Hg, p<0.05). CONCLUSION: This study confirms previously observed seasonal variations of IOP. IOP was significantly higher in winter compared with summer months. Moreover, IOP was lower on Friday than on other days. The explanation for these results is not known.

Referenced scans improve the repeatability of optical coherence tomography angiography measurements in normal and glaucoma eyes.

AIM: To compare the repeatability of peripapillary perfusion density and flux index measurements on referenced and non-referenced optical microangiography (OMAG) scans in normal, glaucoma suspect and glaucoma eyes. METHODS: In a cross-sectional study, 48 eyes (33 subjects) underwent three repeat, non-referenced peripapillary OMAG scans in the same session and 43 eyes (25 subjects) underwent three referenced peripapillary OMAG scans. In the referenced scan group, repeat scans (second and the third scan) were acquired exactly on the baseline (first) scan using the 'track to prior scan' option on the device. Repeatability estimates of the mean and four-sector (temporal, superior, nasal and inferior) OMAG measurements on the non-referenced and referenced scans were assessed using within-subject coefficient of repeatability (CRw) and variation (CVw). RESULTS: CRw (%) of peripapillary perfusion density measurements (range: 2.0-4.1) on non-referenced scans were significantly higher than that on referenced scans (range: 1.4-2.7). CVw (%) on non-referenced and referenced scans ranged from 1.7 to 3.1 and from 1.2 to 2.1, respectively . CRw of flux index on non-referenced and referenced scans ranged from 4.4 to 5.8 and from 3.6 to 4.8, respectively. CVw on non-referenced and referenced scans ranged from 4.1 to 5.2 and from 3.3 to 4.5, respectively. CONCLUSIONS: Repeatability estimates of OMAG measurements were better on referenced scans compared with non-referenced scans. Perfusion density measurements had lower variability than flux index. OCTA-measured perfusion density of referenced scans is preferable for monitoring vascular change in glaucoma.

A comparison of the corneal biomechanics in pseudoexfoliation glaucoma, primary open-angle glaucoma and healthy controls using Corvis ST.

PURPOSE: To compare the corneal biomechanical parameters between pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma (POAG) and healthy controls using Corvis ST. METHODS: A prospective, cross-sectional study was conducted which included 132 treatment-naïve eyes which underwent Corvis ST. The study cohort comprised of 44 eyes with PXG, 42 eyes with POAG and 46 healthy controls. Corneal biomechanical parameters, which included corneal velocities, length of corneal applanated surface, deformation amplitude (DA), peak distance and radius of curvature, were compared between the groups using analysis of variance models. RESULTS: The 3 groups were demographically similar. The mean IOP was 15.7 ±3 mmHg in the control group, 21.3 ±5 mmHg in the POAG group and 25.8 ±7 mmHg in the PXG group (p<0.0001). Corneal pachymetry was similar across the 3 groups. Mean DA was significantly lower (p<0.0001) in the PXG group (0.86 ±0.18 mm) compared to the POAG group (0.97 ±0.14mm) and the control group (1.10 ±0.15mm). Corneal velocities were also found to be statistically significantly different between the groups. However, after adjusting for IOP, there was no difference in any of the biomechanical parameters between the 3 groups. CONCLUSION: Corneal biomechanical parameters measured on Corvis ST are not different between eyes with PXG, POAG and healthy controls after adjusting for IOP.

Steroid-induced glaucoma and blindness in vernal keratoconjunctivitis.

PURPOSE: To report the clinical features, treatment outcomes and blindness associated with steroid-induced glaucoma in vernal keratoconjunctivitis (VKC). MATERIALS AND METHODS: Records of patients with VKC, who visited our tertiary centre from 1992 and 2009, were reviewed and those with steroid-induced glaucoma were included in the study. Glaucoma was diagnosed based on intraocular pressure (IOP) ≥22 mm Hg on two consecutive visits (ocular hypertension) and/or glaucomatous optic disc damage. Blindness was defined as best corrected visual acuity of ≤20/400 or visual field <10°. RESULTS: Of the 4062 VKC subjects, 91 (157 eyes) had steroid-induced glaucoma (SIG), showing a prevalence of 2.24%. Of these 87% were men. The median (IQR) age at onset of VKC was 12 years (7-17). At presentation, the median duration of VKC was 48 months (24-72) and the median duration of steroid usage was 24 months (12-36). The median cup-to-disc ratio (CDR) was 0.9 (0.7-0.9) and median mean deviation was -21.9 dB (-30.0 to -10.2). IOP was medically controlled in 66% eyes (104/157) and 34% eyes (53/157) needed glaucoma surgery. High presenting IOP (OR: 1.04; p=0.05) and increased duration of steroid usage (OR: 1.07; p=0.02) were significantly associated with need for glaucoma surgery. At presentation, 29/91 subjects (31.8%) were bilaterally blind due to SIG. Higher CDR at presentation was significantly associated with blindness in this cohort (p=0.02). CONCLUSION: In this cohort of VKC with SIG, the disease predominantly affected adolescent males. Glaucoma was severe with one-third needing surgery and one-third blind due to SIG.

Vessel density and retinal nerve fibre layer thickness following acute primary angle closure.

BACKGROUND: To evaluate changes in circumpapillary vessel density (cpVD) and retinal nerve fibre layer (cpRNFL) thickness after a successfully treated episode of acute primary angle closure (APAC) and to identify factors associated with glaucoma progression in these eyes. METHODS: Twenty-six patients successfully treated for a unilateral episode of APAC were included in this prospective study. Optical coherence tomography (OCT) cpRNFL thickness and OCT angiography (OCTA) cpVD were compared between 2 and 8 months after treatment. Multiple logistic regression analysis was conducted to identify factors that influenced cpRNFL outcome. RESULTS: cpRNFL thicknesses was thinner in the affected eye (94.0 µm (95% CI: 87.3 to 100.8)) than in the unaffected fellow eye (103.1 µm (99.3 to 106.9)) at 2 months (p=0.039). The cpRNFL thickness of the affected eye decreased 8 months after remission (89.5 µm (84 to 95)), but was unchanged in the unaffected eye. Although cpVD was significantly lower (p=0.001) in APAC eyes 2 months after treatment (56.7% (53.8 to 59.7)) compared with fellow eyes (62.9% (61.4 to 64.4)), there was no significant change in cpVD of the affected eye between 2 and 8 months. In the multivariable analysis, the only factor that was associated with cpRNFL progression was lower cpVD at 2 months after APAC remission (OR=1.79, p=0.036). CONCLUSION: Early reductions of the vessel density and long-term decrease in cpRNFL thickness were observed during the first 8 months after an APAC attack. A lower vessel density at 2 months was the best predictor of conversion to an abnormal cpRNFL thickness. Glaucomatous progression should be suspected in eyes with lower vessel density even after remission of an episode of APAC.

Prospective study of factors influencing timely versus delayed presentation of preterm babies for retinopathy of prematurity screening at a tertiary eye hospital in India The Indian Twin Cities ROP Screening (ITCROPS) data base report number 6.

Purpose: To evaluate the factors influencing timely versus delayed presentation of preterm babies for ROP evaluation. Methods: Preterm babies (≤35 weeks gestational age, ≤2000 g birth weight) were prospectively included in the study. Timely presentation was defined as babies who presented for the first ROP screening within 30 days of birth and Delayed as more than 30 days of birth. An event survey to assess factors influencing timely vs delayed presentation was administered to parents/guardian of babies after obtaining informed consent. Results: Data of 278 preterm babies (n = 139 timely vs n = 139 delayed presentation) collected in the event surveys were analyzed. The delayed presenters came at a median duration of 6.3 weeks (1st and 3rd quartiles: 5.3 and 9.1) after birth. The odds of any stage of ROP was 2.6 times and the odds of sight threatening ROP was 6.8 times in those presenting delayed compared to those presenting timely. Major Reasons for delayed presentation were not asked to do so/no referral from pediatrician in 64 (46%) participants and unaware of the importance by 46 (33%) participants. Conclusion: Deviation from screening protocol is an important modifiable risk factor in ROP screening. The study findings suggest the need for creating awareness about timely screening and referral guidelines among the pediatricians involved in "care" of preterm infants at risk of developing ROP.

Repeatability and comparability of peripapillary vessel density measurements of high-density and non-high-density optical coherence tomography angiography scans in normal and glaucoma eyes.

AIMS: To compare the peripapillary vessel density (VD) measurements of high-density (HD) and non-HD optical coherence tomography angiography (OCTA) scans in normal and glaucoma eyes, and to evaluate the intrasession repeatability of VD measurements of HD scans. METHODS: In a cross-sectional study, 46 normal (33 subjects) and 89 glaucoma (64 patients) eyes underwent 3 HD and 1 non-HD optic nerve head OCTA scans in the same session. Agreement in VD measurements between HD and non-HD scans was assessed using Bland and Altman analysis. Repeatability of the VD measurements of HD scans was assessed using within-subject coefficient of repeatability (CRw) and variation (CVw). RESULTS: The mean difference in the VDs ranged between 0.7% (temporal sector VD) and 2.0% (inferonasal sector VD), with HD scans showing significantly greater VD values than non-HD scans. The 95% limits of agreement (LoA) in glaucoma eyes ranged between -2.0% and 5.0% for whole enface VD and between -4.8% and 9.6% for superotemporal VD. CRw (%) and CVw (%) of VD measurements of HD scans ranged from 3.0 to 4.9 and from 2.0 to 3.1 in normal eyes. The same ranged from 3.2 to 6.7 and from 2.6 to 4.8, respectively, in glaucoma eyes. CONCLUSIONS: VD of HD scans was higher than that of non-HD scans. The wide 95% LoA indicates that the VD measurements of HD and non-HD scans cannot be used interchangeably. Test-retest repeatability of VDs on HD scans was as high as 6%. These results should be considered while using OCTA for longitudinal evaluation of glaucoma.

25G PARS PLANA VITRECTOMY AND IRIDO-ZONULO-HYALOIDO-VITRECTOMY IN THE MANAGEMENT OF MALIGNANT GLAUCOMA IN PHAKIC EYES FOLLOWING TRABECULECTOMY.

PURPOSE: To describe a new surgical technique in the management of malignant glaucoma in phakic eyes. METHODS: We performed 25-gauge pars plana vitrectomy with anterior irido-zonulo-hyaloido-vitrectomy in 2 young phakic patients with malignant glaucoma after trabeculectomy. This technique allowed posteroanterior aqueous communication, relieved aqueous misdirection, helped restoring anterior chamber depth, normalized the intraocular pressure and most importantly helped to preserve the crystalline lens. RESULTS: At 8 months follow-up, both patients have stable visual acuity, normal intraocular pressure, well-functioning blebs, and clear crystalline lens. CONCLUSION: One can consider 25-gauge pars plana vitrectomy with anterior irido-zonulo-hyaloido-vitrectomy as a safe and effective treatment option for the management of malignant glaucoma in phakic eyes.

Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma.

BACKGROUND: Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma. PURPOSE: To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma. DESIGN: Cross-sectional analysis. METHODS: 35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations. STATISTICAL ANALYSIS: Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR). RESULTS: Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P < 0.001 for all comparisons). AUCs of all HD-OCT ONH parameters (0.90-0.97 in perimetric and 0.62-0.71 in preperimetric glaucoma) were comparable (P > 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma. CONCLUSIONS: ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma.

A study of prevalence and risk factors of diabetic retinopathy in patients with non-arteritic anterior ischemic optic neuropathy (NA-AION).

PURPOSE: To estimate prevalence and risk factors for diabetic retinopathy (DR) in diabetic patients with Non-Arteritic Anterior Ischemic Retinopathy (NA-AION). METHODS: This was a retrospective chart review of patients with diabetes diagnosed with NA-AION. Patients with clinical anomalies affecting the optic nerve, diabetic papillopathy, and features suggestive of arteritic AION (raised erythrocyte sedimentation rate/positive temporal artery biopsy) were excluded. Clinical diagrams, notes, and fundus photographs, if available, were evaluated for optic disc edema, optic disc atrophy, presence or absence of small discs, retinal vessel abnormalities, presence of DR, and the presence of sight-threatening DR (STDR). RESULTS: A total of 153 eyes of 109 subjects were included in the study. 82 subjects (75.2%) were men. Mean age of the subjects was 55 ± 9 years. 58 subjects (53.7%) had hypertension and 21 (19.3%) were insulin-dependent. 80 subjects (52.3%) had a duration of diabetes of five years or greater. DR with NA-AION was seen in 46 eyes (30.1%, 95% CI: 22.7 to 37.4) and STDR with NA-AION was seen in 20 eyes (13.1%, 95% CI: 7.7 to 18.5). Logistic regression analysis revealed the duration of diabetes to be significantly associated with both the presence of DR (OR: 1.07, 95% CI: 1.01 to 1.14, p = 0.02) and STDR (OR 1.08, 95% CI: 1.02-1.15, p = 0.01). CONCLUSIONS: Prevalence of DR and STDR in eyes with NA-AION was 30.1% and 13.1%, respectively. Duration of diabetes was an important risk factor for both presence and severity of DR in subjects with NA-AION.

Effect of cataract extraction on Visual Field Index in glaucoma.

PURPOSE: : To determine the effect of cataract on the Visual Field Index (VFI) in glaucoma patients. METHODS: : Reliable visual fields (VFs) of 53 patients (53 eyes) with primary glaucoma who underwent phacoemulsification either alone or combined with trabeculectomy were analyzed before and after surgery. All patients had VFs within a period of 15 months before and after surgery. VFI, mean deviation (MD), and pattern standard deviation (PSD) before surgery were compared with those after surgery. RESULTS: : Median (25th and 75th percentiles) MD after cataract surgery [-10.52 dB (range, -19.25 to -4.86 dB)] was significantly better (P=0.003) than that before surgery [-11.74 dB (range, -20.61 to -7.15 dB)]. Median PSD after surgery [4.76 dB (range, 2.48 to 9.83)] was worse (P=0.01) than that before surgery [3.50 dB (range, 1.93 to 8.20 dB)] when eyes with MD better than -20 dB were considered (41 eyes). VFI after surgery [80% (range, 44% to 94%)] was similar (P=0.92) to that before surgery [77% (range, 37% to 92%)]. MD improved while VFI remained unchanged in both nuclear sclerotic (n=41) and posterior subcapsular cataracts (n=12). CONCLUSIONS: : MD and PSD were significantly affected, whereas VFI was not affected by cataract. VFI may be a more robust measure of VF damage than MD or PSD in glaucomatous eyes with coexisting cataracts.

LV Prasad Eye Institute Glaucoma Epidemiology and Molecular Genetic Study (LVPEI- GLEAMS). Report 1: study design and research methodology.

PURPOSE: In the developing world, more than 90% of glaucoma is undetected due to the lack of appropriate screening methods. The LV Prasad Eye Institute Glaucoma Epidemiology and Molecular Genetic Study (LVPEI-GLEAMS) is a population-based study which aims to estimate the prevalence of, along with clinical, systemic and genetic risk factors for glaucoma in a rural population sampled from the state of Andhra Pradesh, India. The study aims to develop community screening strategies to diagnose glaucoma. This article describes the methodology adopted in LVPEI-GLEAMS. METHODS: A sample of 3833 participants aged 40 years and older has been estimated to be enrolled using a compact segment sampling method with probability proportionate to size. Each participant will undergo a complete medical history and comprehensive eye examination including slit lamp photography, imaging of anterior and posterior segment, frequency doubling technology and standard automated perimetry. Additionally, glycosylated hemoglobin will be measured and a genetic profile based on candidate gene analysis will be undertaken. Clinical, biochemical and genetic data will be stored in a computerized database and analyzed. The novelty of this study lies in the fact that it is conducted at a vision center (primary eye care center serving a population of 50,000) by a vision technician (high school educated rural youth trained in basic ophthalmic techniques for a year). CONCLUSION: Information from the diagnostic techniques of the study will be used to develop effective community-level screening strategies, and insights from risk factors associated with glaucoma will help develop appropriate detection and management strategies.

Evidence-based approach to glaucoma management.

Evidence-based medicine is an evolving new paradigm. With the advent of numerous new diagnostic techniques and therapeutic interventions, one needs to critically evaluate and validate them by appropriate methods before adopting them into day-to-day patient care. The concepts involved in the evaluation of diagnostic tests and therapy are discussed. For delivering the highest level of clinical care, evidence alone is not sufficient. Integrating individual clinical experience and patients' perspectives with the best available external evidence is essential.