Effect of brimonidine tartrate on basophil activation in glaucoma patients.

AIM: To evaluate the mechanism of which brimonidine tartrate 0.15% causes clinical hypersensitivity. METHODS: A prospective case-control study comparing 8 glaucoma patients with clinical hypersensitivity to brimonidine to a control group consisting 13 healthy volunteers. Blood samples were stimulated with brimonidine 0.15%, timolol 0.5% or brimonidine tartrate/timolol maleate 0.2%/0.5%. Premixed antibodies (CD63/FITC and aIgE/PE) were added for direct staining and whole-blood samples were lysed, fixed and analyzed by a flow cytometer. The basophil population was defined by high IgE cell expression. Degranulation was identified by the expression of the activation molecule CD63. RESULTS: Basophil activation was not significant when comparing percent of activated basophils of patients and healthy controls after exposure to brimonidine (2.58%, 2.45%, respectively, P=0.72). There was a significant suppression of basophil activation when a combination of brimonidine-timolol (0.87%) was compared to timolol (2.27%; P=0.012) and to brimonidine alone (2.58%; P=0.017). CONCLUSION: The results of our study do not support the hypothesis that brimonidine induces an immediate allergic reaction. Basophil activation was suppressed by the presence of ß-blockers in patients hypersensitive to brimonidine and in healthy individuals. This finding indicates that timolol suppress brimonidine drug reaction by a different mechanism.

Intracameral tissue plasminogen activator in trabeculectomy: a 1-year prospective, randomized, controlled study.

PURPOSE: To evaluate the safety and the adjunctive effect of intracameral tissue plasminogen activator (tPA) in trabeculectomy for patients with primary open-angle glaucoma (POAG). METHODS: This was a prospective, randomized study consisting of patients with POAG who underwent trabeculectomy in Tel Aviv Medical Center between March 2013 and December 2014. Patients were randomly assigned to two groups: Group 1 underwent mitomycin C (MMC) trabeculectomy and group 2 underwent MMC trabeculectomy with intracameral tPA. Complete and overall success were defined as intraocular pressure (IOP) between 5 and 18 mmHg and at least 30% IOP drop without and with or without anti-glaucoma treatment, respectively. RESULTS: A total of 16 patients (seven females and nine males) were recruited, and eight patients were assigned to each group. IOP at presentation was 27 ± 5.3 mmHg and 25.3 ± 5.1 mmHg, compared to 13.7 ± 4.3 mmHg and 10.6 ± 2.0 at 12 months (p < 0.0001) for groups 1 and 2, respectively. Complete success at 12 months was achieved in 62.5% of group 1 compared to 87.5% of group 2 (p = 0.28). Overall success was achieved in 87% compared to 100% of patients at 12 months (p = 0.33). No evidence of complications attributable to tPA was found. CONCLUSIONS: Augmentation of tPA during MMC trabeculectomy may have better complete and overall success rates, compared to MMC trabeculectomy. The safety profile was similar for both groups.

Intracameral bevacizumab role in trabeculectomy: A 1-year prospective randomized controlled study.

PURPOSE: To evaluate the effect of intracameral Bevacizumab on trabeculectomy success rates. METHODS: A prospective, randomized, interventional clinical trial. Patients with primary open-angle glaucoma were randomly assigned to two groups: trabeculectomy with mitomycin C and trabeculectomy with mitomycin C and intracameral bevacizumab. Complete success is defined as an intraocular pressure (IOP) reduction of at least 30% from baseline IOP to a measured pressure of between 5 and 18 mm Hg without the use of IOP lowering medications. Qualified success is defined as same achievement of reduced IOP, but with the use of IOP lowering medications. Overall success is defined as same achievement of reduced IOP with or without the use of IOP lowering medications. RESULTS: Thirty-three patients in the mitomycin C group and 36 patients in the mitomycin C and bevacizumab group were included in final analyses. The IOP at presentation was 28.3 ± 8 and 28.4 ± 8.6 mm Hg, compared to 10.8 ± 3.4 and 12.3 ± 3.7 mm Hg at 12 months (p < 0.0001) for the mitomycin C group and the mitomycin C and bevacizumab group, respectively. Complete success at 12 months was achieved in 65% of the mitomycin C group compared to 60% of the mitomycin C and bevacizumab group (p = 0.77). Overall success was achieved in 82% compared to 80% of patients at 12 months (p = 0.78). Both groups showed a statistically significant reduction in IOP after 6 and 12 months (p ⩽ 0.001). There were no statistically significant differences in visual acuity and complications. CONCLUSION: Intracameral bevacizumab during mitomycin C trabeculectomy in patients with primary open-angle glaucoma apparently does not improve success rates. The adjuvant use of intracameral bevacizumab is therefore not justified.

Comparison of intraocular pressure measurements using Goldmann tonometer, I-care pro, Tonopen XL, and Schiotz tonometer in patients after Descemet stripping endothelial keratoplasty.

PURPOSE: Post-Descemet stripping endothelial keratoplasty (DSEK) patients are prone for intraocular pressure (IOP) elevations and glaucoma. Corneal characteristics influence various IOP measuring devices in various ways. The aim of this study was to evaluate the agreement between four different IOP measuring devices: Goldmann applanation tonometer (GAT), I-care pro, Tonopen XL, and Schiotz tonometr in patients who underwent DSEK. METHODS: This was a prospective comparative study using a convenience cohort of post-DSEK patients with compact grafts. Post-DSEK patients had IOP measured using GAT, I-care Pro, Tonopen XL, and Schiotz tonometer. Measurements were compared and agreement assessed. Wilcoxon signed-rank test was used for comparison of means as variables did not show a normal distribution. Bland-Altman plots were used for assessing agreement. RESULTS: Thirty eyes of 24 patients were included in the study. Mean time from DSEK surgery was 25.31 ± 13.05 months. Mean IOP with GAT, I-care pro, Tonopen XL, and Schiotz tonometer was 13.99 ± 3.76, 13.92 ± 3.36, 13.31 ± 3.89, and 12.83 ± 4.07, respectively. GAT, I-care pro, and Tonopen XL had similar mean IOP measurements (P = 0.135 and P = 0.551, respectively), while Schiotz tonometry measurements were higher (P = 0.046). Bland-Altman plots show good agreement between GAT, Tonopen XL, and I-care pro. GAT and Schiotz tonometry show less agreement, with large variations in the differences of measured IOP. CONCLUSIONS: IOP measurements in post-DSEK patients showed good agreement between GAT and either Tonopen XL or I-care pro. Schiotz tonometer has large variations in this patient group. IOP measurements and IOP difference between devices were not dependent on central corneal thickness.

Trabeculectomy with Ex-PRESS implant versus Ahmed glaucoma valve implantation-a comparative study.

AIM: To compare the surgical outcomes of trabeculectomy with Ex-PRESS implant and Ahmed glaucoma valve (AGV) implantation. METHODS: Patients who underwent trabeculectomy with Ex-PRESS implants or AGV implantation separately were included in this retrospective chart review. Main outcome measures were surgical failure and complications. Failure was defined as intraocular pressure (IOP) >21 mm Hg or <5 mm Hg on two consecutive visits after 3mo, reoperation for glaucoma, or loss of light perception. Eyes that had not failed were considered as complete success if they did not required supplemental medical therapy. RESULTS: A total of 64 eyes from 57 patients were included: 31 eyes in the Ex-PRESS group and 33 eyes in the AGV group. The mean follow-up time was 2.6±1.1y and 3.3±1.6y, respectively. Patients in the AGV group had significantly higher baseline mean IOP (P=0.005), lower baseline mean visual acuity (VA) (P=0.02), and higher proportion of patients with history of previous trabeculectomy (P<0.0001). Crude failure rates were 16.1%, n=5/31 in the Ex-PRESS group and 24.2%, n=8/33 in the AGV group. The cumulative proportion of failure was similar between the groups, P=0.696. The proportion of eyes that experienced postoperative complications was 32.3% in the Ex-PRESS group and 60.1% in the AGV group (P=0.0229). CONCLUSION: Trabeculectomy with Ex-PRESS implant and AGV implantation had comparable failure rates. The AGV group had more post-operative complications, but also included more complex cases with higher baseline mean IOP, worse baseline mean VA, and more previous glaucoma surgeries. Therefore, the results are limited to the cohort included in this study.

From Georgia to Jerusalem: some Medical Aspects of "The Knight in the Panther's Skin" by Shota Rustaveli.

The Georgian poet Rustaveli wrote his epic poem The Knight in the Panther's Skin around 1200. He knew the works of Hippocrates and Galen, and believed in the unity of body and soul.Thereare many references to health and medicine in the poem, and we shall highlight some of them. In 1185 Rustaveli left Georgia and settled in Jerusalem. There he lived and died at the Monastery of the Cross, where he was buried.

Original and generic latanoprost for the treatment of glaucoma and ocular hypertension: are they really the same?

We compared the intraocular pressure (IOP)-lowering effect and safety profile of latanoprost (Xalatan) with its generic variant, Glautan (Unipharm, Tel Aviv, Israel). After 1 and 4 weeks of treatment, a randomized, prospective, cross-over comparison was carried out that included patients with open-angle glaucoma or ocular hypertension, either naïve or treated and well-controlled, who were attending the Department of Ophthalmology, Tel Aviv Medical Centre, Tel Aviv, Israel, between May 2010 and November 2012. After a 3-week washout period for the medicated subjects, the participants were randomized to 4 weeks of treatment with either Xalatan or Glautan once every evening and then, after a 3-week washout period, crossed-over to the other treatment for an additional 4 weeks. Efficacy was expressed by a change in intraocular pressure at three designated hours of the day after 1 week and 1 month of treatment, and tolerability was determined by ocular side-effects as reported by the patient in a questionnaire. A total of 19 patients (mean age at initial diagnosis 66 ± 9 years, 14 females) were enrolled, of whom 17 had bilateral open-angle glaucoma and two had unilateral disease. Both drugs lowered intraocular pressure after 1 week and 1 month (P = 0.06 and P = 0.04, respectively) of treatment. Xalatan had a tendency of greater efficacy than Glautan both after 1 week and 1 month, but the difference was not statistically significant (P = 0.69 and P = 0.34, respectively). Drug safety was similar for Xalatan or Glautan, but more ocular side-effects were reported after treatment with Glautan (21 vs 12 for Xalatan, P = 0.06).

Standard Trabeculectomy and Ex-PRESS Miniature Glaucoma Shunt: A Comparative Study and Literature Review.

PURPOSE: The aim of this study was to compare the efficacy and safety between standard trabeculectomy and the Ex-PRESS shunt implantation. METHODS: A retrospective review of the records of 100 eyes of 100 patients who underwent trabeculectomy or Ex-PRESS shunt implantation between July 2010 and June 2012 was conducted. Of these, 61 (61%) eyes underwent trabeculectomy and 39 (39%) eyes underwent Ex-PRESS shunt implantation. Demographic information, glaucoma type, surgical details, preoperative, and postoperative data including intraocular pressure (IOP), number of medications, reoperation, and occurrence of any complications were recorded. RESULTS: No differences in IOP reduction or number of postoperative IOP-lowering medications were demonstrated between the 2 procedures. Success rates were 86.9% for trabeculectomy and 84.6% for Ex-PRESS shunt. Rates of failure and hypotony were not significantly different between the groups. No parameter was correlated with success or failure of any procedure. CONCLUSIONS: Standard trabeculectomy and Ex-PRESS shunt have similar efficacy and safety profiles. As the Ex-PRESS shunt is considerably more expensive, its use may be unjustified, especially as a primary procedure.

Evaluation of the retinal, choroidal, and nerve fiber layer thickness changes in patients with toxic anterior segment syndrome.

PURPOSE: To evaluate changes in choroidal, retinal, and nerve fiber layer (NFL) thickness following toxic anterior segment syndrome (TASS). METHODS: Macular and peripapillary choroidal thickness was measured using enhanced depth imaging (EDI) optical coherence tomography (OCT) on the day of the diagnosis and on three follow-up exams (months 1 to 4). A similar OCT analysis of central retinal and NFL thickness was performed. RESULTS: Thirteen TASS patients were included. Average age was 72.8 ± 8.7 years. Macular choroidal thickness in the superior, subfoveal, and nasal macula in the study eye was larger than the control eye and decreased at months 2-4. This was statistically significant only for the superior macula (p = 0.004). Peripapillary choroidal thickness was larger in the study eye at baseline compared with the control eye-significantly so in the nasal (p = 0.026) and inferior (p = 0.033) locations. Peripapillary choroidal thickness peaked at the baseline or 1st month exam and decreased thereafter. Retinal thickness increased significantly with time, peaking at the 2nd month and decreasing thereafter. No changes were found in the NFL. CONCLUSIONS: TASS may have a transient effect on the choroid. Changes in retinal thickness are probably a normal transient postoperative response and not a result of TASS.

Topical bevacizumab for neovascular glaucoma: a pilot study.

BACKGROUND/AIMS: Bevacizumab (Avastin), an anti-vascular endothelial growth factor drug, has been successfully used in recent years to treat ocular pathologies, mostly by intravitreal administration. The aim of this study was to investigate the safety and efficacy of topically applied bevacizumab for the treatment of neovascular glaucoma (NVG). METHODS: Patients with NVG were treated with topical bevacizumab (25 mg/ml) 4 times daily during 2 weeks. The following parameters were evaluated at baseline and on days 3, 7 and 14: visual acuity, slit-lamp examination, intraocular pressure (IOP), heart rate and systemic blood pressure. Iris neovascularization was documented using slit-lamp color photos at baseline and on day 14. RESULTS: Eight eyes of 8 patients with NVG were evaluated. After the 2-week treatment, mean IOP was lowered from 34.9 mm Hg (SD 12.8) at baseline to 28.8 mm Hg (SD 9.9) on day 14, representing a mean reduction of 6.1 mm Hg (17.5%). Three patients had clinical regression of their iris neovascularization. Ocular adverse events were transient and included mild upper eyelid swelling, mild exacerbation of superficial punctate keratitis and mild corneal epithelial bullae in an already edematous cornea. There were no serious systemic adverse events. CONCLUSIONS: Topical application of bevacizumab may lower IOP and result in regression of neovascularization in patients with NVG.

Intraocular pressure reduction using a fixed combination of timolol maleate 0.5% and brimonidine tartrate 0.2% administered three times daily.

BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of a fixed combination of timolol maleate 0.5% + brimonidine tartrate 0.2% (Combigan®) for reduction for intraocular pressure (IOP) in patients with glaucoma when the dose frequency is increased from twice to three times daily. METHODS: The patients included had either primary open angle glaucoma or ocular hypertension. Those who were previously on treatment completed a drug washout period prior to inclusion. IOP was measured at baseline, after 4 weeks of treatment with Combigan twice daily, and again after a further 4 weeks of Combigan three times daily. Blood pressure, heart rate, and oxygen saturation were also recorded at each assessment. RESULTS: Thirty-one eyes from 31 patients were included. Increasing the Combigan dose frequency resulted in a statistically significant (P < 0.001) additional reduction in IOP of 2.25 ± 1.18 mmHg, corresponding to a further 10.3% reduction in IOP from baseline. No local or systemic adverse effects were documented. CONCLUSION: Treatment with Combigan three times daily was more effective in reducing IOP than the twice-daily regimen, with no increase in adverse effects.

Anterior chamber bleeding after laser peripheral iridotomy.

IMPORTANCE: To our knowledge, this is the first study to describe the correlation of anterior chamber bleeding after laser peripheral iridotomy (LPI) and antiplatelet therapy. OBJECTIVE: To determine the incidence and amount of anterior chamber bleeding after laser peripheral iridotomy in patients whose condition is suggestive of primary angle-closure glaucoma (PACS) who continued their antiplatelet or anticoagulant treatment before undergoing LPI compared with when they discontinued treatment. DESIGN AND SETTING: A prospective controlled trial. PATIENTS: Patients with suspected bilateral primary angle-closure and no other ocular disease who take antiplatelet or anticoagulant medications regularly (from January 2010-October 2011) were enrolled. MAIN OUTCOME AND MEASURE: The incidence of anterior chamber bleeding with and without antiplatelet and anticoagulant therapy. RESULTS: A total of 104 patients (208 eyes) participated in the study. Thirty-six eyes (34.6%) in the treated and untreated arms bled. The amount of bleeding did not differ significantly when the patient was on or off antiplatelet or anticoagulant treatment, nor did the immediate postprocedure mean intraocular pressure (P = .13). The type of antiplatelet or anticoagulant, total laser energy, age, sex, or color of irides were not risk factors for increased bleeding (P = .156 for all parameters). CONCLUSIONS: No indication was noted for discontinuing these medications before a high-powered pulsed laser peripheral iridotomy.

Acute calcific band keratopathy: case report and literature review.

UNLABELLED: An 86-year-old patient developed a significant intraocular inflammatory reaction after having phacoemulsification. Topical therapy did not eliminate the inflammation, and tissue plasminogen activator (tPA) was injected into the anterior chamber. A white corneal plaque appeared in the previously clear cornea within days of the injection. The lesion was diagnosed as calcific band keratopathy and successfully treated with ethylenediaminetetraacetic acid chelation. Electron microscopy and elemental analysis of a corneal scraping from the lesion established its composition to be mainly calcium and phosphate, validating the diagnosis. This is the seventh reported case of rapid formation of calcific band keratopathy after tPA injection. The pathogenesis of this rare complication involves multiple factors, including alkalinization of the intraocular pH, increased phosphate concentration, and endothelial dysfunction. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

[Comparison of dynamic contour tonometry, Goldmann applanation Tonometry and tonopen for measuring intraocular pressure in normal tension glaucoma].

BACKGROUND: Normal tension glaucoma (NTG) is a chronic progressive optic neuropathy, characterized by relatively normal intraocular pressure (IOP) measurements. This study utilized three modalities in the measurement of lOP: dynamic contour tonometry (Pascal-DCT), Goldmann applanation tonometry (GAT) and Tonopen XL. OBJECTIVES: To compare the lOP measurements of the three devices in eyes with NTG. METHODS: This retrospective study of thirty-three NTG patients (66 eyes) who underwent lOP measurements using the three devices was approved by a local ethics committee. The lOP measurements were stratified according to central corneal thickness (CCT) and corneal curvature (CC). RESULTS: The mean DCT IOP was higher (16.22 +/- 3.04 mmHg) than the mean GAT IOP (13.14 +/- 2.83 mmHg, P < 0.0042). The mean Tonopen XL lOP was lower than the mean GAT IOP (12.76 +/- 3.11 mmHg, P < 0.001). GAT and DCT measurements were significantly infLuenced by corneal curvature (P = 0.004 and P < 0.0001, respectiveLy). CONCLUSIONS: lOPs measured by GAT or Tonopen XL were consistently lower than by DCT. CC significantly influenced GAT and DCT results.

The efficacy of selective laser trabeculoplasty versus argon laser trabeculoplasty in pseudophakic glaucoma patients.

INTRODUCTION: This study evaluated and compared the efficacy of selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT) in terms of intraocular pressure (IOP)-lowering effects in pseudophakic patients at various time points after treatment. The primary aim was to compare the efficacy of SLT and ALT in reducing the IOP of pseudophakic glaucoma patients who recently underwent successful cataract extraction surgery. The secondary endpoint was to determine the percentage of SLT and ALT patients whose IOP was successfully reduced by at least 15% from baseline. PATIENTS AND METHODS: This study was a follow-up of a prospective randomized clinical trial. Fifty-two eyes from 52 glaucoma patients with uncontrolled IOP who had previously undergone successful phacoemulsification-assisted cataract excision surgery with intracapsular lens implantation were randomly assigned to treatment with either ALT (n = 30) or SLT (n = 22). Fifteen patients were excluded due to adverse events encountered during the study, leaving a total of 18 and 19 patients in the ALT and SLT groups, respectively. IOP measurements were carried out at scheduled intervals until 12 months post-laser treatment. RESULTS: There were no significant differences in the IOP-lowering effects between the two methods at any time point during the follow-up period. The greatest differences between the two groups were observed at 1 week posttreatment and at the 3-month time point, but neither reached a level of significance. At the final checkup, the mean IOP reduction from baseline was 3.23 mmHg in the ALT group and 4.30 mmHg in the SLT group (P = 0.269). At that visit, six (35.3%) patients in the ALT group and 15 (75%) patients in the SLT group had a reduction of ≥15% from their baseline IOP. CONCLUSION: SLT and ALT are equally effective in their IOP-lowering capabilities in new pseudophakic glaucoma patients during the first 12 months after treatment.

Intraocular pressure measurements with Goldmann applanation tonometry and dynamic contour tonometry in eyes after IntraLASIK or LASEK.

BACKGROUND AND METHODS: Myopic photorefractive surgery induces a reduction in central corneal thickness, which may lead to underestimation of intraocular pressure. This retrospective clinical study compared intraocular pressure measurements obtained by Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT-Pascal) in eyes undergoing myopic intralaser-assisted in situ keratomileusis (IntraLASIK) or laser-assisted subepithelial keratomileusis (LASEK). RESULTS: Of a total of 51 eyes, 21 underwent LASEK and 30 underwent IntraLASIK. By GAT, mean preoperative intraocular pressure was 16.2 ± 1.99 mmHg and postoperatively was 10.84 ± 1.45 mmHg. By DCT, mean preoperative intraocular pressure was 15.9 ± 2.08 mmHg and postoperatively was 16.1 ± 2.3 mmHg. Both preoperative and postoperative differences between measurements made by GAT and DCT were found to be statistically significant (P < 0.04 and P < 0.01, respectively). GAT and DCT readings were unaffected by type of surgery (P = 0.74 and P = 0.46, respectively). CONCLUSION: Postoperative GAT measurements were lower than those obtained by DCT. The difference between preoperative and postoperative DCT measurements was minimal, so DCT may be preferable for the measurement of intraocular pressure in eyes undergoing myopic IntraLASIK or LASEK.

Intraocular pressure reduction of fixed combination timolol maleate 0.5% and dorzolamide 2% (Cosopt) administered three times a day.

PURPOSE: To evaluate the safety and efficacy in intraocular pressure (IOP) reduction of increasing Cosopt dosage from twice to three times a day. METHODS: The study included patients with primary open-angle glaucoma or ocular hypertension. After a washout period, IOP was measured at baseline, after 4 weeks of treatment with Cosopt twice a day, and after another 4 weeks of treatment with Cosopt three times a day. Blood pressure, heart rate, and oxygen saturation levels were also recorded. RESULTS: Twenty-nine eyes of 29 patients were included. Increasing Cosopt dosage resulted in a statistically significant (P < 0.001) additional reduction in IOP of 2.2 ± 1.58 mmHg (10.69% ± 7.49% of the baseline IOP values). There were no local or systemic adverse effects. CONCLUSION: Treatment with Cosopt three times a day was more effective in reducing IOP than twice a day, with no effect on safety.

Effect of brimonidine tartrate 0.10% ophthalmic solution on pupil diameter.

PURPOSE: To evaluate the effect of brimonidine tartrate 0.10% ophthalmic solution on pupil diameter under light and dark luminance conditions. SETTING: Ophthalmology Department, Tel Aviv Medical Center, Tel Aviv, Israel. DESIGN: Case series. METHODS: The pupil diameter was measured with a Colvard pupillometer in eyes of healthy volunteers under light (5.0 candelas [cd]/m(2)) and dark (0.0 cd/m(2)) luminance conditions before brimonidine 0.10% instillation and after 30 minutes, 3 hours, and 6 hours. RESULTS: The mean age of the 26 volunteers (52 eyes) was 34.73 years (range 19 to 60 years). Under light conditions, the mean pupil diameter was 4.98 mm ± 0.83 (SD) before instillation of brimonidine 0.10% and 4.64 ± 0.82 mm after instillation. The difference was not statistically significant, with 13.4% of eyes having a clinically significant reduction (>1.0 mm) in pupil diameter after 6 hours. Under dark conditions, the mean pupil diameter was 6.76 ± 1.08 mm before instillation of brimonidine 0.10% and 5.30 ± 0.85 mm after instillation; the difference was statistically significant (P<.001). There was a clinically significant reduction in pupil diameter after 6 hours in 90.4% of eyes. The antimydriatic effect under dark luminance conditions was more pronounced in eyes with light irides. CONCLUSIONS: Brimonidine 0.10% ophthalmic solution had an antimydriatic effect under dark luminance conditions and had a negligible effect on pupil diameter under light luminance conditions. The effect was similar to that reported in studies using higher concentrations of brimonidine.

Intraocular pressure measurements in relation to head position and through soft contact lenses: comparison of three portable instruments.

BACKGROUND AND OBJECTIVE: to compare the reproducibility of three portable instruments-the Tono-Pen tonometer (Reichert Ophthalmic Instruments, Depew, NY), the Phosphene tonometer (Bausch & Lomb, Rochester, NY), and the TERT (Through Eyelid Russian Tonometer; Rjazan State Instrument Making, Rjazan, Russia)-in the measurement of intraocular pressure (IOP) with and without soft contact lenses and in different head positions. PATIENTS AND METHODS: twenty-six eyes of healthy volunteers were examined by the three instruments while the subjects were sitting, recumbent, and hyperextending their heads, and with and without contact lenses. IOP measurements were compared and the effects of head position and presence of contact lenses on the resultant values were analyzed. RESULTS: the average difference between the recumbent and sitting positions was 3.56, 2.68, and 2.62 mm Hg for the Tono-Pen tonometer, Phosphene tonometer, and TERT, respectively. There was an increase of 5.60, 2.78, and 2.63 mm Hg in hyperextension compared to sitting for the Tono-Pen tonometer, Phosphene tonometer, and TERT, respectively. The difference in the IOP values obtained in the presence and absence of therapeutic contact lens for the three instruments in the three positions was between -1.23 and +1.47 mm Hg. CONCLUSION: IOP measurements of bedridden patients are only slightly higher than those of sitting patients except for the Tono-Pen tonometer in the hyperextension position. The presence of contact lenses does not affect IOP values obtained by the three evaluated instruments.