The effect of simulated cataract on the glaucomatous visual field

PURPOSE: The current study is designed to determine the effect of light scattering (simulated cataract) on glaucomatous visual fields. METHODS: Twelve patients with relative scotomas caused by glaucoma underwent the 30-2 threshold test with the Humphrey Visual Field Analyzer twice: once with and once without having a light-diffusing piece of ground glass in front of the eye, which, in previous experiments, has been shown to decrease perimetric threshold by 4.4 decibels (dB) in normal eyes. As controls, 12 patients underwent the same examination with and without a piece of clear glass in front of the eye. In each pair of fields, five points were analyzed within the relative scotoma and compared with five points in a normal area of the opposite hemifield. RESULTS: The diffusing ground glass produced a mean decrease of perimetric threshold of 5.7 dB (standard deviation [SD] = 3.3 dB) within the area of relative scotoma compared with 6.1 dB (SD = 2.4 dB) within the normal area and 4.4 dB (SD = 2.25 dB) at the fovea. The differences between means were not statistically significant. In addition, the diffusing glass did not affect the corrected pattern SD (CPSD) index (6.5 dB with the diffuser and 6.5 dB without). CONCLUSION: Light scattering depresses the glaucomatous visual field diffusely. Relative glaucomatous scotomas and normal areas are depressed equally, expressed as change in decibel of sensitivity. Therefore, in following patients with cataracts and glaucoma, depression of threshold sensitivity in glaucomatous areas out of proportion to normal areas should not be attributed to the light-scattering effect of the cataract, but rather to possible worsening of glaucomatous damage.     

Studies of IFN-induced transcriptional activation uncover the Jak-Stat pathway

PURPOSE: To evaluate the new threshold strategies of the Humphrey Field Analyser, SITA Standard and SITA Fast, in normals and glaucoma patients. METHODS: Fifty healthy volunteers and 50 glaucoma patients were tested twice with three algorithms: Full Threshold, SITA Standard and SITA Fast in two sessions. The second test was taken into account to eliminate learning effect. Glaucoma patients were chosen to cover a large range of deficits. Quantitative analysis of global indexes was performed as well as qualitative comparison of visual fields by a trained optometrist. RESULTS: Compared to Full Threshold, testing time was reduced by 51% in normals and 49% in glaucoma with SITA Standard and by 72% and 69% with SITA Fast, respectively. In glaucoma, mean testing time dropped from 16'01" with Full Threshold to 8'05" with SITA Standard and to 4'55" with SITA Fast. Quantitative comparison showed a high correlation between indexes (MD Full Threshold vs MD SITA Standard: r = 0.98, p < 0.01; PSD Full Threshold vs PSD SITA Standard: r = 0.94, p < 0.01). However SITA Standard and SITA Fast had a tendency to underestimate visual field defects. In glaucomatous subjects, mean MD ameliorated by 1.01 dB with SITA Standard and by 1.71 dB with SITA Fast. Mean PSD ameliorated by 0.04 dB and 0.43 dB, respectively. Qualitative analysis confirmed these last results showing artificial slight or important improvement of visual fields in 21% of the cases with SITA Standard and 30% with SITA Fast, compared to Full Threshold. CONCLUSION: SITA Standard and SITA Fast strategies improve dramatically visual field testing time, by 51% and 72% respectively. However, one should be cautious in comparing results obtained with different algorithms, as these new strategies improve the mean defect and, to a lesser extent, the localized defect.     

Fatty acid use in glaucomatous optic neuropathy treatment

The authors have studied the efficacy of an association of DHA, vitamin E and vitamin B complex (TROFINERV) in glaucomatous patients. The parameters evaluated were computerized visual field (CVF) and retinal contrast sensitivity (RCS). Thirty chronic simple glaucoma patients in good tensional compensation with local therapy were given TROFINERV oral therapy. The results show significant differences after 90 days of treatment both in the perimetric indices (MD, SF, CPSD; p < 0.05) and in the RCS frequency values (p < 0.05). In the light of the results obtained, the authors consider the use of such association to be a useful support in glaucomatous patient therapy for preventing or delaying the progress of damage.     

Analysis of depressive symptomatology in mood disorders

BACKGROUND: At this time little information is available about the relationship between glaucomatous visual field defects and impaired blood flow in the optic nerve head. The purpose of this study was to examine blood flow of the juxtapapillary retina and the rim area of the optic nerve head in primary open-angle glaucoma with a borderline visual defect. METHODS: Juxtapapillary retinal and neuroretinal rim area blood flow was measured by scanning laser Doppler flowmetry (SLDF). The visual field was evaluated by static perimetry (Octopus-G1). The optic nerve head was assessed on 15 degrees color stereo photographs. We examined 116 eyes of 91 patients with POAG with controlled IOP and 66 eyes of 44 healthy individuals. The POAG group was divided into eyes with a mean defect lower than 2 dB (POAG group I) and in eyes with a mean defect equal to or greater than 2 dB (POAG group II). The mean age of POAG group I and POAG group II was 55 +/- 11 years and 57 +/- 10 years, respectively. The mean age of the control group was 45 +/- 15 years. The eyes of POAG group I had an average C/D ratio of 0.71 +/- 0.18 with an average mean defect of the visual field of 0.97 +/- 0.68 dB; the eyes of POAG group II had an average C/D ratio of 0.80 +/- 0.17 with an average mean defect of the visual field of 8.2 +/- 6.0 dB. The intraocular pressure on the day of measurement in POAG group I was 18.2 +/- 3.7 mmHg, in POAG group II 17.6 +/- 4.0 mmHg, and in the control group 15.1 +/- 2.5 mmHg. For statistical analysis, age-matched groups of 32 normal eyes of 32 subjects (mean age 52 +/- 10 years) were compared to 18 glaucomatous eyes of 18 patients (POAG group I, mean age 55 +/- 11 years) and 59 glaucomatous eyes of 59 patients (POAG group II, mean age 55 +/- 10 years). RESULTS: In the eyes of POAG group I and POAG group II, both juxtapapillary retinal blood flow and neuroretinal rim area blood flow were significantly decreased compared to an age-matched control group: neuroretinal rim area "flow" POAG group I -65%, POAG group II -66%; juxtapapillary retina "flow" POAG group I -52%, POAG group II -44%. All eyes of the POAG group I (MD < 2 dB) and 56 of 61 eyes of the POAG group II (MD > = 2 dB) showed a retinal perfusion lower than the 90% percentile of normal blood flow. We found no correlation between reduction of juxtapapillary or papillary blood flow and mean defect in POAG eyes. CONCLUSION: Glaucomatous eyes with no defects or borderline visual field defects as well as glaucomatous eyes in an advanced disease stage show significantly decreased optic nerve head and juxtapapillary retinal capillary blood flow.     

Amphetamine increases extracellular concentrations of glutamate in the prefrontal cortex of the awake rat: a microdialysis study

OBJECTIVE: To determine if motion automated perimetry can identify early glaucomatous visual field defects in patients with suspected glaucoma (by disc), those with ocular hypertension, and those with primary open-angle glaucoma. METHODS: Motion automated perimetry, a foveally centered motion test, and standard visual field tests were conducted on one randomly selected eye of normal patients (n = 38), patients with suspected glaucoma (by disc) (n = 28), patients with ocular hypertension (n = 18), and patients with primary open-angle glaucoma (n = 21). Subjects' performance on both motion tests were compared with their performance on standard perimetry. RESULTS: Perimetric motion thresholds significantly distinguished the groups (P< or =.001), while the foveally centered motion test was unable to separate them (P< or =.32). Of the total patients, 90.5% of those with glaucoma, 39.3% of those with suspected glaucoma, 27.8% of those with ocular hypertension, and 5.3% of the normal subjects had abnormal results on motion automated perimetry testing. Perimetric motion thresholds were significantly correlated with standard visual field thresholds (P< or =.001). CONCLUSION: Motion automated perimetry identifies visual field defects in patients who already show standard visual field loss as well as in a moderate percentage of those with suspected glaucoma and ocular hypertension, indicating that the testing of discrete locations might be necessary for increased diagnostic utility.     

Blue-on-yellow visual field and retinal nerve fiber layer in ocular hypertension and glaucoma

BACKGROUND AND OBJECTIVE: It has been suggested that the clinically detectable changes of the blue-on-yellow (B/Y) visual field and retinal nerve fiber layer (RNFL) may precede standard white-on-white (W/W) visual field defects in the progression of glaucoma. The aim of this study was to test the relationship between the results of B/Y visual fields and semiquantitative RNFL evaluation in corresponding areas and to determine how the B/Y visual fields and RNFL scores label the normal W/W perimetry hemifields in patients with glaucoma and ocular hypertension. DESIGN: A cohort study. PARTICIPANTS AND METHODS: Monochromatic RNFL photographs of 32 normal subjects and 29 patients with ocular hypertension and different stages of glaucoma were assessed in a masked fashion. The B/Y and W/W visual fields (program 30-2) were examined with a Humphrey perimeter. The results of both visual fields were adjusted for the patients' age and lens transmission index measured with a lens fluorometer. MAIN OUTCOME MEASURE: Mean deviation (MD) of visual field and semiquantitative score of RNFL loss were measured. RESULTS: The total and hemifield MD values of B/Y and W/W visual field showed a statistically significant correlation with diffuse and overall score of RNFL loss in corresponding areas. The hemifield MD values of B/Y perimetry obtained from "normal" W/W hemifields of patients with early glaucoma were well correlated (r = -0.56) with respective RNFL loss scores found to be abnormal in 84% of hemispheres. The difference between the hemifield MD values of B/Y perimetry obtained from normal W/WAN hemifields of patients with ocular hypertension and patients with early glaucoma was not statistically significant (analysis of variance). The respective B/Y hemifield data of normal subjects were statistically significantly different from the data of patients with ocular hypertension and early glaucoma. CONCLUSIONS: The hemifield MD values of B/Y perimetry correlate well with semiquantitative scores of RNFL loss obtained from the corresponding hemisphere. The B/Y perimetry as well as RNFL assessment may show glaucomatous defects in a hemifield found to be normal on W/W perimetry. In subjects with ocular hypertension, the functional damage detected by B/Y perimetry may, in some cases, precede RNFL defects on conversion to glaucoma.     

Laser scanning tomography of the optic nerve head in ocular hypertension and glaucoma

BACKGROUND: This study evaluated the ability of laser scanning tomography to distinguish between normal and glaucomatous optic nerve heads, and between glaucomatous subjects with and without field loss. METHODS: 57 subjects were classified into three diagnostic groups: subjects with elevated intraocular pressure, normal optic nerve heads, and normal visual fields (n = 10); subjects with glaucomatous optic neuropathy and normal visual fields (n = 30); and subjects with glaucomatous optic neuropathy and repeatable visual field abnormality (n = 17). Three 10 degrees image series were acquired on each subject using the Heidelberg retina tomograph (HRT). From the 14 HRT stereometric variables, three were selected a priori for evaluation: (1) volume above reference (neuroretinal rim volume), (2) third moment in contour (cup shape), and (3) height variation contour (variation in relative nerve fibre layer height at the disc margin). Data were analysed using analysis of covariance, with age as the covariate. RESULTS: Volume above reference, third moment in contour, and mean height contour were significantly different between each of the three diagnostic groups (p < 0.001). Height variation contour showed no significant difference among the three diagnostic groups (p = 0.906). CONCLUSIONS: The HRT variables measuring rim volume, cup shape, and mean nerve fibre layer height distinguished between (1) subjects with elevated intraocular pressures and normal nerve heads, and glaucomatous optic nerve heads, and (2) glaucomatous optic nerve heads with and without repeatable visual field abnormality. This study did not directly assess the ability of the HRT to identify patients at risk of developing glaucoma. It is hypothesised that the greatest potential benefit of laser scanning tomography will be in the documentation of change within an individual over time.     

Thoracic outlet syndrome after motor vehicle accidents in a Canadian pain clinic population

Trabeculotomy ab externo has been demonstrated to be effective in controlling intraocular pressure (IOP) in adult patients with either primary open-angle glaucoma or pseudoexfoliation syndrome. We evaluated the surgical outcome of 60 eyes with either primary open-angle glaucoma or pseudoexfoliation syndrome that underwent combined trabeculotomy ab externo and cataract extraction. All patients were at least 40 years old, and were followed for at least 1 year. At the final examination, IOP was well controlled (21 mm Hg or less) in 54 (90%) of the 60 eyes, with or without medication. Also, "overall success" (ie, stabilization of IOP, visual field, and optic nerve status) was achieved in 49 (81.7%). Complications included fibrin exudation (22%), transient IOP elevation (17%), early perforation of the probe into the anterior chamber (10%), and detachment of Descemet's membrane (5%). We recommend combined trabeculotomy ab externo and cataract extraction in selected cases of glaucoma with coexisting cataract. For cases in which the target IOP level is in the low teens, or for patients who may not tolerate postoperative fluctuations in IOP, we do not recommend trabeculotomy ab externo. Also, in eyes that have normal-tension glaucoma, or that have already sustained severe damage to the optic nerve, visual dysfunction caused by glaucomatous changes may progress even after successful combined trabeculotomy ab externo and cataract extraction.     

Unilateral testing of utricular function

PURPOSE: To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma. METHODS: In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression. RESULTS: Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02). CONCLUSION: Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.     

Design of low cost glaucoma screening

In 1991 the Netherlands Glaucoma Patient Association organized a glaucoma screening survey. This survey was designed to evaluate the effectiveness of a low cost screening setting. During a screening period of 8 days, 1259 subjects over the age of 49 years were examined by a team of non-ophthalmologically trained students. The following screening methods were used: visual field analysis (Henson CFS3000 perimeter), retinal nerve fiber layer photography (Canon non-mydriatic camera), intraocular pressure measurement (Pulsair non-contact tonometer) and determination of the peripheral anterior chamber depth (slitlamp biomicroscope, the van Herick method). In a later stage, subjects with glaucomatous abnormalities in the visual field and/or the photograph were re-examined by a glaucoma specialist using applanation tonometry, gonioscopy, ophthalmoscopy and Humphrey 30-2 visual field analysis. The time taken to conduct the individual screening tests in a subject varied from 1 to 5 min: perimetry took 5 min, photography 2 min, tonometry 3 min and angle-width determination 1 min. Fifty-six (4.4%) subjects showed glaucomatous defects in perimetry and/or photography. Thirty-seven could be re-examined and glaucoma was diagnosed in 16 subjects. Visual field defects and glaucomatous abnormalities in the photograph were confirmed by Humphrey perimetry in 72.7% and 35.7% respectively. Sixty-seven (5.3%) subjects had an intraocular pressure above 21 mm Hg, while no cases of angle closure glaucoma were found in this population. The costs of this screening setting were estimated at F1. 48,60 per screen. A future low cost screening survey might be limited to non-contact tonometry and visual field analysis with the Henson CFS3000 perimeter or a similar device, using suprathreshold testing with a limited number of points. Screening might be performed by non-medically trained employees. The costs of such a screening program may be estimated at F1. 16,- per screen and F1. 1.989,- per glaucoma case using a mobile screening unit (addendum).     

Cataract and high-pass resolution perimetry

The present study describes the influence of cataract on high-pass resolution perimetry results. Twenty-five otherwise healthy patients were examined before and after cataract surgery. Their preoperative visual acuities ranged from 0.1 to 0.8 and their mean resolution thresholds from 3.9 to 12.3 dB. Both elevated mean thresholds and local visual fields defects were observed. In patients with low-grade cataract, i.e. preoperative visual acuity 0.3 to 0.65, the mean improvement in perimetric results after operation was approximately 1 dB. In patients with higher degrees of lens opacity, visual acuity 0.1 to 0.25, the difference between pre- and postoperative perimetry results showed a wide range, 1.4-6.2 dB. In conclusion, cataract induced different types of visual field defects. The general threshold increase due to low-grade cataract (VA > or = 0.3) could be compensated for by subtracting 1 dB from the measured value.     

Visual field progression: comparison of Humphrey Statpac2 and pointwise linear regression analysis

BACKGROUND: Humphrey Statpac2 "glaucoma change probability analysis' is a widely available analysis technique to aid the clinician in the diagnosis of glaucomatous visual field deterioration. A comparison of this technique with the more recently described pointwise linear regression analysis (PROGRESSOR) is given. METHODS: Series of visual field data from a group of nine eyes of nine patients with normal-tension glaucoma were selected. Each series had 16 fields with mean follow-up of 5.7 years (SD 0.6 years). Statpac2 "glaucoma change probability analysis' was used to define test locations that had unequivocally deteriorated in the last three fields of each series. The accuracy of both Statpac2 and PROGRESSOR in providing early detection of these deteriorated locations was assessed. RESULTS: The sensitivity and specificity of the two techniques in predicting deteriorated locations were similar when a rate of luminance sensitivity loss of faster than 1 dB/year (2 dB/year for outer locations beyond 15 deg of eccentricity) with a slope significance of P < 0.10 was used as the regression definition of deterioration. The difficulties of comparing two techniques in the early diagnosis of field progression without a true external standard for field loss are illustrated. CONCLUSIONS: PROGRESSOR closely emulates the performance of Statpac2 in detecting sensitivity deterioration at individual test locations. This new technique, which uses all available data in a field series and gives the rate of sensitivity loss at each location, may provide a clinically useful method for detecting field progression in glaucoma.     

Combined cataract extraction and thermal sclerostomy versus combined cataract extraction and trabeculectomy

We performed either a combined cataract extraction and trabeculectomy or a combined cataract extraction and thermal sclerostomy on 43 eyes. All eyes had chronic open angle glaucoma or chronic angle closure glaucoma, or a combination of the two. In our cataract/trabeculectomy group, 74% had improvement in visual acuity, 91% had normalized intraocular pressure without anti-glaucoma medications, 31% had transient postoperative hyphemas. In our cataract/thermal sclerostomy group, 61% had improvement in visual acuity, 61% had normalization of intraocular pressures without antiglaucoma medications, 17% had transient postoperative hyphemas. We could not correlate any of the complications of surgery with poor intraocular pressure results in either groups. The mechanism for the higher success rate with a combined cataract extraction and trabeculectomy as compared with a combined cataract extraction and thermal sclerostomy was not obvious after analyzing these patients.     

Abnormal motion displacement thresholds are associated with fine scale luminance sensitivity loss in glaucoma

This study tests the hypothesis that abnormal motion displacement thresholds coexist with scotomas on a finer spatial scale than is measurable by conventional Humphrey perimetry. Eighteen patients with primary open angle glaucoma in one eye, and 18 age matched normal controls underwent motion displacement threshold testing and high spatial resolution perimetry. The motion displacement thresholds were significantly elevated in the glaucoma eyes, in 73% this exceeded normal limits. Ten glaucoma eyes had normal Humphrey 24-2 field nearest the motion test site: of these seven had abnormally elevated motion displacement thresholds and six had fine scale threshold depressions detected with high spatial resolution perimetry. This result suggests that glaucomatous elevations of motion displacement threshold may be present in areas of normal Humphrey 24-2 field, and this may coexist with measurable scotomas beyond the resolution of conventional Humphrey perimetry in some, but not all patients.     

Clinical PET: Aesop''s tortoise?

58 eyes of 58 patients underwent cataract surgery with IOL implantation. The density of cataract was quantified by the Opacity Lensmeter 701 before operation and the visual field by program G1 of Octopus 201 before and after operation. The visual fields showed that there was significant difference in the mean defect (MD) before and after operation, but not in the corrected loss variance (CLV), indicating that cataract only caused diffuse visual field damage. This was also confirmed by the parallel shift of the mean cumulative defect curve after surgery. The preoperative lens opacity reading and the visual acuity were correlated with the difference between the pre- and post-operative MD, showing that measurement of OLM 701 and visual acuity permitted assessment of the influence of cataract on the visual field.     

Visual field damage proximal to fixation in normal- and high-tension glaucoma eyes

To compare in more detail the central visual field damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) eyes, a pointwise inner-group comparison of the data obtained with the Humphrey 10-2 was carried out in 68 NTG cases with maximum intraocular pressure (IOP) of < or = 21 mmHg and 62 HTG cases with maximum IOP of > or = 25 mmHg. All eyes had the usual field defects, with a mean deviation of > or = -15 dB (MD, STATPAC). Age, refraction and MD were matched between the two groups. Total deviation (TD, STATPAC), the difference between the measured threshold and the age-corrected normal reference at each test point of the 10-2 program, was used for pointwise inter-group comparisons. The data were analyzed with Wilcoxon rank-sum test and logistic discriminant analysis. The latter method was also applied to the data of the 30-2 program to confirm the results obtained with the 10-2 program. The comparisons using the different methods and programs gave consistent results. For a given amount of overall visual field damage in the two types of glaucoma, a superior arcuate area extending down to the horizontal meridian just nasal to the fixation point was significantly more depressed and an area inferior to the horizontal meridian and inferior temporal to the fixation point significantly less depressed in NTG eyes. HTG eyes were significantly more diffusely damaged in the central 10-degree visual field. NTG and HTG may have unique patterns of central visual field damage. These differences may implications in following NTG patients and studying the pathogenesis of this glaucoma.     

Association between watershed zone and visual field defect in normal tension glaucoma

In order to evaluate the association between the watershed zone and glaucomatous optic damage, we performed indocyanine green fluorescence angiography with a scanning laser ophthalmoscope in 54 eyes of 27 patients with normal tension glaucoma. The visual field indices were measured with a Humphrey Field Analyzer. We identified 8 eyes (14.8%) of 7 patients with a watershed zone not including the optic nerve head (type I), 32 eyes (59.3%) of 20 patients with the zone partially including the optic nerve head (type II), and 14 eyes (26.0%) of 10 patients with the zone including the optic nerve head (type III). Of the total of 27 patients, 10 patients (37.0%) had different types in each eye. In these patients, the mean deviation (MD) of visual field indices was worse in the eye with the watershed zone which included a larger part of the optic disc than in the contralateral eye (p < 0.05). Conversely, the eye with worse MD than the contralateral eye had a watershed zone which included a larger part of the optic disc than the other eye (p < 0.05). The location of watershed zone appeared to influence the progression of the visual field defect.     

Foveal dysfunction and central visual field loss in glaucoma

OBJECTIVE: To determine whether foveal function distal to the ganglion cell layer is an independent predictor of central visual field function in glaucoma. SETTING: University affiliated hospital and private practice. PARTICIPANTS: Twenty-seven eyes (27 patients) with normal-pressure glaucoma, 10 eyes (10 patients) with primary open-angle glaucoma, and 47 eyes of 47 matched normal volunteers. INTERVENTION AND MAIN OUTCOME MEASURES: Foveal cone electroretinogram (ERG) amplitude, relative optic cup to disc area and their relations to Humphrey full-threshold 30-2 visual field central 4-point mean total deviation (C4MTD) and pattern deviation (C4MPD). RESULTS: Foveal cone ERG amplitude was subnormal in 14 (37.8%) of the 37 glaucomatous eyes and lower in the glaucoma group compared with normal eyes (P<.01). The C4MTD and C4MPD were lower in glaucomatous eyes with subnormal amplitudes compared with those with normal amplitudes (P<.01 and P<.05, respectively). Amplitude was directly correlated with C4MTD (P<.01) and C4MPD (P<.01). Relative optic cup to disc area was inversely correlated with C4MTD (P<.001) and C4MPD (P<.001). Partial correlation analysis revealed that amplitude and relative optic cup to disc area were independent predictors of C4MTD and C4MPD. CONCLUSION: Foveal function distal to the ganglion cell layer and optic disc cupping independently predict central visual field function in glaucoma.     

The role of early trabeculectomy in the control of chronic simple glaucoma

Seventy patients of bilateral chronic simple glaucoma with a mean age of 59.7 years, an intra-ocular pressure over 25 mmg Hg, optic disc cupping, and without visual field loss were selected. The eye with higher intra-ocular pressure or the larger optic disc cup was treated by early trabeculectomy while the other eye of the same patient was subjected to medical therapy with topical beta blockers for 3 years (without any surgical treatment). Both the eyes of 70 patients were compared after 3 years. Eyes which had undergone trabeculectomy had a mean intra-ocular pressure of 11.7 mm Hg against 18 mm Hg in the medically treated eyes. Surgically treated eyes had decrease in the mean cup : disc ratio (from 0.54 : 1 to 0.48 : 1) whereas medically treated eyes showed an increase from 0.41:1 to 0.51: 1. Visual field loss occurred in 3/70 operated eyes and in 27/70 medically treated eyes. Twenty-one of 70 treated eyes developed cataract and 12 of these required cataract surgery. Only 18/70 medically treated eyes developed cataracts but none of these required cataract surgery. Early trabeculectomy in cases of chronic simple glaucoma resulted in a large reduction of intra-ocular pressure and consequently reduced the size of optic disc cup and the chances of visual field loss.     

Sensitivity and specificity of optic disc variables and analysis of a new variable (MP/D) for glaucoma diagnosis with the Glaucoma-Scope

AIM: In an attempt to use the quantitative optic disc measurements of the Glaucoma-Scope (OIS Sacramento, CA, USA) to distinguish glaucomatous from normal optic discs, a new variable was investigated, the mean disc corrected for the disc size by dividing by the disc area: MP/D. METHODS: Glaucoma-Scope disc evaluation was performed on 81 eyes of 51 patients split into the following groups based on Humphrey 24-2 visual field and clinical criteria of glaucoma: chronic glaucoma n = 27 (including only early, n = 17, and low tension glaucoma, n = 10), ocular hypertension n = 24, pseudoglaucomatous large discs, n = 12, and normal eyes, n = 18. Classic optic disc variables (the vertical and horizontal c/d ratios, and the c/d area) were compared with the new MP/D index calculating receiver operating characteristic curves. RESULTS: The MP/D ratio was able to identify the glaucomatous eyes more easily than other ratios. Areas under the curves were: 0.91 (MP/D); 0.87 (c/d area); 0.85 (c/d vertical); and 0.80 (c/d horizontal). The MP/D index was also correlated with the mean deviation (r = 0.466; p = 0.001). CONCLUSION: MP/D may prove useful in detecting glaucomatous optic nerve damage and could be an interesting screening tool for primary open angle glaucoma.