Validity and limits of the rebound tonometer (ICare®): clinical study

Performance of home-based self-tonometry (iCare HOME (TA022)) for measuring intraocular pressure among healthy and glaucoma patients

Introduction: The purpose of this study was to compare iCare HOME (TA022) with Goldmann applanation tonometer and to evaluate the self-tonometry measurements among the Indian population. Methods: Eligible patients underwent iCare HOME training through guided demonstration (verbal, pictorial, video) and practised self-tonometry measures using iCare HOME. Certification for independent iCare HOME measure was provided if first iCare HOME intraocular pressure (IOP) measurement fell within ± 5 mmHg of Goldmann applanation tonometer (GAT) measurement which was measured by the trained clinician (principal investigator). Certified participants underwent simulated home self-tonometry measurements using iCare HOME, and agreement with GAT IOP measurements was assessed. Results: Seven of 83 participants (8.43%) failed to complete the study due to difficulty in performing the task, leading to non-certification. Patients who could use the iCare HOME had a mean age of 53 ± 15.55years (53% males; 46% females). Only one in 12 subjects did not qualify to use iCare HOME. The overall mean difference between iCare HOME and GAT was 0.83 mmHg (95%, 3.92 and -2.25). At various pressure ranges, 7-16 mmHg, 17-23 mmHg and >23 mmHg, the mean difference between iCare HOME and GAT was 1.22 mmHg (95%, 4.32 and -1.86), 0.77 mmHg (95%,3.69 and -2.19), -0.11 mmHg (95%, 2.52 and -2.74) respectively. The intra-class correlation coefficient of the iCare HOME device was 0.997(95% CI,0.995-0.998). Conclusions: Patients were able to perform self- tonometry using iCare HOME with good reliability and safety. iCare HOME can be used to address the issue of difficulty in acquiring frequent and diurnal IOP measurements by patients doing self-tonometry from home.

Assessment of intraocular pressure measurement between Goldman applanation tonometer, rebound tonometer, non-contact tonometer, and its correlation with central corneal thickness

Purpose

To compare readings of intraocular pressure (IOP) taken with the Goldmann applanation tonometer (GAT), the non-contact tonometer (NCT), and the rebound tonometer (RBT), and to compare their correlation with central corneal thickness (CCT).

Methods

This was a prospective, cross-sectional, observational study to which patients above 18 years of age were enrolled. A total of 400 eyes of 200 non-glaucomatous patients underwent IOP recordings using the GAT, NCT, and RBT, and CCT was also noted. Informed consent of the patients was taken. The IOP readings taken via the three methods were compared and correlated with CCT. Paired t test was used to compare the two devices. Simple and multivariate linear regression analyses were used to study the relationship between factors. A P value less than 0.05 was considered significant. Correlation was determined using the Pearson correlation coefficient, and a Bland-Altman graph was plotted.

Results

Mean IOP measured by the NCT was 15.65 ± 2.80 mmHg, by the RBT was 14.23 ± 3.05 mmHg, and by the GAT was 14.69 ± 2.97 mmHg. The mean CCT was 510.61 ± 33.83 microns. The difference between mean IOP recorded by the NCT and that by the RBT was 1.41 ± 2.39 mmHg, between the NCT and GAT was 0.95 ± 2.03 mmHg, and between the GAT and RBT was 0.45 ± 2.22 mmHg. The difference between the IOP values was statistically significant (P < 0.005). All tonometers showed a statistically significant correlation with CCT, but it was observed that the NCT had a stronger correlation (0.4037).

Conclusion

The IOP readings taken by all the three methods were comparable; however, RBT values were closer to GAT values. CCT did influence the IOP values, and this should be kept in mind while evaluating.

Visual impairment and the need for vision care services amongst older Finnish people receiving home care

AIM

This study aimed to describe visual performance and the need for vision care services among Finnish older people receiving home care. We evaluated the applicability of the Resident Assessment Instrument of Home Care (RAI HC) in identifying visual impairment (VI) and the need for vision care services among older people.

DESIGN

A descriptive quantitative, cross-sectional design.

METHODS

Visual impairment and the need for vision care services for older people receiving home care (N = 70) were determined by an optometrist's screening examination and vision assessment by home care workers using the RAI HC instrument. In this study, the definition of visual impairment was visual acuity (VA) <0.63 (logMAR >0.2).

RESULTS

According to the distance VA measurements, 41% of the participants showed VI (<0.63) of the better eye, while the RAI HC assessment revealed VI among 36% of the participants. The Kappa value for interrater reliability in classifying VI was 0.137. The optometrist's vision screening examination recognized a previously unknown and unmet need for vision care services more than twice as often as the RAI HC assessment.

The analysis of the glaucoma screening event results obtained during the World Glaucoma Week in Zagreb, Croatia

PURPOSE

To report the prevalence of undiagnosed glaucoma, as well as demographic characteristics and risk factors among glaucoma suspects who were detected in a publicly promoted intraocular pressure (IOP) based glaucoma screening event.

METHODS

A total of 2468 subjects older than 18 years participated in the glaucoma screening event in Zagreb, in 2014, which included a medical interview and IOP measurement using Icare tonometer. 256 subjects (10.37%) were identified as glaucoma suspects, out of which 125 (5.06%) subjects underwent further detailed ophthalmic examination and were classified into five diagnostic groups.

RESULTS

The prevalence of all types of newly diagnosed glaucoma was 1.175%, while the prevalence of ocular hypertension (OH), primary open-angle glaucoma (POAG), primary angle closure (PAC) and secondary glaucoma (SG) was 0.16%, 0.89%, 0.16% and 0.12%, respectively. The prevalence of newly diagnosed glaucoma in glaucoma suspects was 23.2%. 17.60% of glaucoma suspects were diagnosed as POAG. Older age was statistically significantly associated with POAG (p = 0.001) and PAC (p = 0.029). At the univariate level, refractive errors were a statistically significant predictor of POAG, and those with hyperopia had more than three times larger odds for POAG. At the multivariate level, none of the predictors reached statistical significance.

CONCLUSION

Successful cooperation between healthcare institutions and media can be a useful way of increasing awareness and detection of individuals at an increased risk for developing glaucoma.

Audit of outcomes following attendance at the City West drive-through IOP glaucoma clinic during the COVID-19 pandemic

BACKGROUND

Glaucoma is the leading cause of irreversible blindness globally. During the COVID-19 pandemic, an enforced reduction in capacity resulted in the deferral of routine outpatient appointments for glaucoma patients.

AIM

This study analyses patient outcomes following the establishment of a drive-through intra-ocular pressure (IOP) clinic during the COVID-19 pandemic to alleviate increased pressure on the tertiary glaucoma services at Royal Victoria Eye and Ear Hospital (RVEEH) and Mater Misericordiae University Hospital (MMUH) between August 2020 and June 2021.

METHODS

A 1-lane driveway system was established in a marquee on the grounds of City West hotel. IOPs were measured in patients' cars using a hand held iCare100 tonometer. Results were reviewed by a consultant ophthalmologist. At hospital follow-up clinic visits, IOP was measured using the Goldmann applanation tonometer (GAT).

RESULTS

Three hundred one patients of a total of 672 who attended the drive-through clinic have subsequently attended a designated hospital follow-up appointment. In this cohort, the mean drive-through iCare IOP of 19.4 mmHg ± 6.0 was significantly higher (< 0.005) than the mean GAT IOP at the pre-drive through clinic visit (16.3 mmHg ± 3.7) and the post drive-through hospital follow-up visit (17.2 mmHg ± 4.1). Two hundred twenty-six (75%) patients did not need any treatment change, 53 (18%) required eye drop medication changes, 10 (3%) underwent a laser procedure, 4(1%) required surgical intervention, and 8 (3%) were discharged. When patient outcomes were analysed according to IOP grade assigned at the drive-through clinic, those with an iCare IOP < 21 were significantly less likely to require a treatment change. The cohort with iCare IOP ≥ 30 were significantly more likely to have a laser or surgical intervention.

CONCLUSION

The implementation of a drive-through IOP clinic was a safe and effective way to monitor glaucoma patients during COVID-19, and identify those at high risk of poor IOP control or requiring a change in treatment.

The Effects of Sex, Oral Contraception, and Menstrual Cycle Phase on Intraocular Pressure, Central Corneal Thickness, and Foveal Thickness: A Descriptive Analysis

The primary goal of this study was to investigate the effects of sex, oral contraceptive (OC) use, and menstrual cycle phase on common ocular parameters assessed during ophthalmic evaluations, namely intraocular pressure (IOP), central corneal thickness (CCT), and foveal thickness (FT), in young healthy adults. We measured IOP, CCT, and FT in 60 participants (16 men, 16 contraceptive users, and 28 cycling women) over two sessions that characterized the menstrual cycle phase in women. For men in our study, two sessions were separated by two weeks. For women, the two sessions were scheduled during the follicular and luteal phases of the menstrual cycle. There was a trend towards higher IOP in men, and the difference was significant for white, non-Hispanic subjects and for white subjects considered separately. There was also a trend for thicker corneas in women, but men had significantly thicker foveae. CCT and FT were not different between men and OC-users, hinting at a moderating hormonal effect of oral contraceptive use. We found that IOP, CCT, and FT were equivalent between the follicular and luteal phases, which may be owing to the timing of our sessions. However, our findings strongly suggest that clinicians should consider contraceptive use during routine ophthalmic evaluations, as it could inform glaucomatous risk in women.

How to Measure Intraocular Pressure: An Updated Review of Various Tonometers

Intraocular pressure (IOP) is an important measurement that needs to be taken during ophthalmic examinations, especially in ocular hypertension subjects, glaucoma patients and in patients with risk factors for developing glaucoma. The gold standard technique in measuring IOP is still Goldmann applanation tonometry (GAT); however, this procedure requires local anesthetics, can be difficult in patients with scarce compliance, surgical patients and children, and is influenced by several corneal parameters. Numerous tonometers have been proposed in the past to address the problems related to GAT. The authors review the various devices currently in use for the measurement of intraocular pressure (IOP), highlighting the main advantages and limits of the various tools. The continuous monitoring of IOP, which is still under evaluation, will be an important step for a more complete and reliable management of patients affected by glaucoma.

Ocular manifestations in phakomatosis pigmentovascularis: Current concepts on pathogenesis, diagnosis, and management

Phakomatosis pigmentovascularis is a rare congenital multisystemic disease with variable manifestations where a vascular malformation of the skin is associated with a pigmentary nevus. Ocular involvement includes glaucoma, choroidal hemangioma, and pigmentary alterations that predispose to uveal melanoma. Diagnosis is made on clinical grounds, although recent advances in molecular genetics have better clarified the etiopathogenesis of the condition. The advent of improved imaging techniques such as enhanced depth imaging spectral domain optical coherence tomography has provided new insight into the ocular alterations, enabling better follow-up of patients. We review the ophthalmic manifestations of the disease with an update on etiopathogenesis and current management strategies.

Short-Term Effects of Dark Chocolate on Retinal and Choriocapillaris Perfusion in Young, Healthy Subjects Using Optical Coherence Tomography Angiography

(1) Aim: Contrasting results have been published on the effect of dark chocolate on visual function. The aim of this study was to evaluate retinal and choriocapillaris perfusion, using optical coherence tomography angiography (OCT-A), and visual function in healthy subjects following dark chocolate ingestion. (2) Methods: This prospective randomized study was carried out on 18 healthy young subjects at the St. Andrea Hospital, Sapienza, University of Rome. Visual acuity assessment and a complete ophthalmologic examination were carried out at baseline. In session one, each subject was randomized to eat either a 100 g dark chocolate bar or a 100 g white chocolate bar. In session two, the opposite chocolate was given to each participant. OCT-A and best corrected visual acuity (BCVA) were performed before the chocolate was eaten and repeated 1, 2, and 3 h after that. Retinal vessel density and choriocapillaris flow area were assessed. (3) Results: 18 patients with a mean (SD) age of 26.3 (1.5) years were included. No significant differences between dark or white chocolate were found when evaluating foveal density (%), whole density (%), choriocapillaris flow area, and BCVA. (4) Conclusions: Dark chocolate did not result in significant changes in retinal perfusion and choriocapillaris flow area. However, given the results of other studies showing the positive effects of flavonoids on visual function, further studies are warranted using pure chocolate without other components such as caffeine that can potentially affect results. Furthermore, we cannot rule out the possible benefits of higher doses of flavonoids in dietary supplementation over a more extended period and in a larger patient population.

Effect of Near Work on Intraocular Pressure in Emmetropes

Objective

To determine whether accommodation induced by reading alters intraocular pressure (IOP) in healthy, young, emmetropic adults and to document the duration and magnitude of this effect.

Design

Cross-sectional study. Participants. Fifteen healthy, emmetropic young adults.

Methods

Subjects performed 20 minutes of near work (reading at 33 cm) followed by 20 minutes of far work (reading at 520 cm) while IOP was measured using an iCare tonometer at baseline and every 5 minutes thereafter. Statistical analysis was performed using repeated measures ANOVA. Main Outcome Measures. Intraocular pressure.

Results

IOP decreased significantly compared to baseline IOP after 10 minutes of near work (average change of −1.60 ± 2.2 (SD) mm Hg, p < 0.05). IOP remained lower than baseline IOP throughout all subsequent near and far work. The difference in IOP at the end of experimentation compared to baseline IOP was −1.87 ± 1.81 mm Hg (p < 0.05). IOP remained lower than baseline IOP throughout all subsequent near and far work. The difference in IOP at the end of experimentation compared to baseline IOP was −1.87 ± 1.81 mm Hg (

Conclusions

Near work decreases IOP in healthy emmetropes, and this effect is sustained for at least 20 minutes after discontinuing prolonged near work. Providers may need to consider this effect when measuring IOP in clinical practice.

Comparability of three intraocular pressure measurement: iCare pro rebound, non-contact and Goldmann applanation tonometry in different IOP group

Background

Measurement of intraocular pressure (IOP) is essential for glaucoma patients. Many factors such as central corneal thickness (CCT) can affect the accuracy of IOP measurement. The purpose of this study was to evaluate the agreement of IOP measured by non-contact tonometer (NCT), iCare pro rebound tonometer (iCare), and Goldmann applanation tonometer (GAT) in different IOP group.

Methods

This was a Hospital-based cross-sectional study. Two hundred subjects were enrolled in this study. All subjects underwent IOP measurement using an NCT–iCare–GAT sequence. Bland-Altman, Pearson correlation and intraclass correlation analysis were performed using SPSS 17.0 software. The influence of CCT on each IOP measurement methods was evaluated by linear regression analysis.

Results

The mean difference (Δ) of NCT–GAT did not differ from (Δ) iCare–GAT in IOP < 10 and 10–21 mmHg group. However, (Δ) NCT–GAT was significantly higher than (Δ) iCare–GAT in IOP 22–30 and > 30 mmHg group (P < 0.05). Bland–Altman analysis showed significant agreement between the three devices (P < 0.01). IOP measurements of the three methods were significantly correlated with CCT (P < 0.01).

Conclusions

ICare pro shows a higher agreement with GAT over a wide range of IOP compared with NCT. The consistency between the three tonometers was similar in a low and normal IOP range. However, NCT shows a greater overestimate of IOP in moderate and higher IOP group. The variability of IOP measurement affected by CCT is NCT > iCare pro > GAT.

Deep topical anesthesia with ropivacaine-soaked sponge for phacoemulsification

PURPOSE

To assess safety and efficacy of deep topical anesthesia with ropivacaine-soaked sponge compared with topical anesthesia with oxybuprocaine in patients undergoing phacoemulsification.

METHODS

This was a retrospective study where records of patients operated for cataract were evaluated. Patients using a visual analogue scale scored pain during surgery, and the surgeon on a questionnaire recorded ease of operation. Medical records were evaluated for patients who received topical anesthesia with multiple administrations of oxybuprocaine 0.4% or those who received deep topical anesthesia with a polyvinyl acetal sponge impregnated with ropivacaine 0.75% and positioned under the eyelid 30 min before surgery.

RESULTS

A total of one hundred patient records, equally divided in patients receiving deep topical anesthesia or topical anesthesia, were included. The visual analogue scale scores among the groups were statistically significant for a lower pain score in patients who received deep topical anesthesia with ropivacaine-soaked sponges (p = 0.0069). The average surgeon score was significantly higher for the deep topical anesthesia group indicating favorable ease of surgery (p = 0.0341). Six patients had major complications during surgery. No additional anesthesia was necessary to manage the complications in four patients in the deep anesthesia group, whereas propofol was used for the induction and maintenance of anesthesia in two patients in the topical anesthesia group.

CONCLUSIONS

Deep topical anesthesia with ropivacaine-soaked sponges performed as well as topical oxybuprocaine regarding safety and efficacy. It provided a lower patient pain score, favorable surgeon satisfaction, and long-lasting anesthesia.

Pigment dispersion syndrome and pigmentary glaucoma: a review and update

INTRODUCTION

Pigment dispersion syndrome (PDS) is a condition where anomalous iridozonular contact leads to pigment dispersion throughout the anterior segment and the released pigment is abnormally deposited on various ocular structures.

CLINICAL PRESENTATION

The clinical presentation of PDS is defined by the presence of pigmented cells on the corneal endothelium, an increase of pigmentation of the trabecular meshwork, and mid-periphery transillumination defects of the iris. This syndrome, more common in myopes, is usually bilateral and can be associated with ocular hypertension or glaucoma. Secondary open-angle pigmentary glaucoma (PG) can develop due to reduction of the outflow of aqueous humour and consequent increase in intraocular pressure leading to glaucomatous optic neuropathy. Diagnosis of PG is commonly between 40 and 50 years of age, occurring more frequently in men. The advent of ultrasound biomicroscopy and anterior segment optical coherence tomography has contributed to enhancing our knowledge on the condition. Typical alterations of the anterior segment are the posterior insertion of the iris and iris concavity. Treatment of PG should be initiated early to hinder disease progression, glaucomatous damage, and vision loss. Management is based on medical therapy, laser iridotomy, selective laser trabeculoplasty, and filtration procedures.

CONCLUSIONS

The differential diagnosis of PDS with other disorders can be challenging and awareness of the condition together with meticulous ophthalmologic examination allows early diagnosis followed by appropriate management strategies. The present review is a comprehensive report on the clinical characteristics, pathogenesis, current management, and status quo of PDS and PG.

Philadelphia Telemedicine Glaucoma Detection and Follow-up Study: Methods and Screening Results

PURPOSE

To describe methodology and screening results from the Philadelphia Telemedicine Glaucoma Detection and Follow-up Study.

DESIGN

Screening program results for a prospective randomized clinical trial.

METHODS

Individuals were recruited who were African-American, Hispanic/Latino, or Asian over age 40 years; white individuals over age 65 years; and any ethnicity over age 40 years with a family history of glaucoma or diabetes. Primary care offices and Federally Qualified Health Centers were used for telemedicine (Visit 1). Two posterior fundus photographs and 1 anterior segment photograph were captured per eye in each participant, using a nonmydriatic, autofocus, hand-held fundus camera (Volk Optical, Mentor, Ohio, USA). Medical and ocular history, family history of glaucoma, visual acuity, and intraocular pressure measurements using the ICare rebound tonometer (ICare, Helsinki, Finland) were obtained. Images were read remotely by a trained retina reader and a glaucoma specialist.

RESULTS

From April 1, 2015, to February 6, 2017, 906 individuals consented and attended Visit 1. Of these, 553 participants were female (61.0%) and 550 were African-American (60.7%), with a mean age of 58.7 years. A total of 532 (58.7%) participants had diabetes, and 616 (68%) had a history of hypertension. During Visit 1, 356 (39.3%) participants were graded with a normal image. Using image data from the worse eye, 333 (36.8%) were abnormal and 155 (17.1%) were unreadable. A total of 258 (28.5%) had a suspicious nerve, 62 (6.8%) had ocular hypertension, 102 (11.3%) had diabetic retinopathy, and 68 (7.5%) had other retinal abnormalities.

CONCLUSION

An integrated telemedicine screening intervention in primary care offices and Federally Qualified Health Centers detected high rate of suspicious optic nerves, ocular hypertension, and retinal pathology.

Sturge-Weber Syndrome Associated with Monolateral Ocular Melanocytosis, Iris Mammillations, and Diffuse Choroidal Haemangioma

We present the case of a 12-year-old boy with Sturge-Weber syndrome and ocular melanocytosis who presented with bilateral naevus flammeus of the face and hyperpigmentation of the right iris associated with ipsilateral iris mammillations. The patient had glaucoma and a diffuse choroidal haemangioma of the right eye. Optical coherence tomography of the anterior segment confirmed iris hyper-pigmentation and did not show abnormalities of the chamber angle structures. B-scan ultrasonography and enhanced depth imaging optical coherence tomography were performed and showed a marked difference in thickness and reflectance between the right and left choroid. Visual field examinations with perimetry showed early defects in the right eye. Peripapillary optical coherence imaging showed borderline values of retinal nerve fibre layer thickness reduction in the right eye. Sturge-Weber syndrome associated with ocular melanocytosis and iris mammillations is an extremely rare condition. This paper highlights the role of multi-imaging methods in the enhanced evaluation of rare diseases towards choosing the most appropriate management strategies and improving the follow-up of patients over time.

Agreement among Goldmann applanation tonometer, iCare, and Icare PRO rebound tonometers; non-contact tonometer; and Tonopen XL in healthy elderly subjects

PURPOSE

To evaluate the inter-device agreement among the Goldmann applanation tonometer (GAT), iCare and Icare PRO rebound tonometers, non-contact tonometer (NCT), and Tonopen XL tonometer.

METHODS

Sixty healthy elderly subjects were enrolled. The intraocular pressure (IOP) in each subject's right eye was measured thrice using each of the five tonometers. Intra-device agreement was evaluated by calculating intraclass correlation coefficients (ICCs). Inter-device agreement was evaluated by ICC and Bland-Altman analyses.

RESULTS

ICCs for intra-device agreement for each tonometer were >0.8. IOP as measured by iCare (mean ± SD, 11.6 ± 2.5 mmHg) was significantly lower (p < 0.05) than that measured by GAT (14.0 ± 2.8 mmHg), NCT (13.6 ± 2.5 mmHg), Tonopen XL (13.7 ± 4.1 mmHg), and Icare PRO (12.6 ± 2.2 mmHg; Bonferroni test). There was no significant difference in mean IOP among GAT, NCT, and Tonopen XL. Regarding inter-device agreement, ICC was lower between Tonopen XL and other tonometers (all ICCs < 0.4). However, ICCs of GAT, iCare, Icare PRO, and NCT showed good agreement (0.576-0.700). The Bland-Altman analysis revealed that the width of the 95% limits of agreement was larger between the Tonopen XL and the other tonometers ranged from 14.94 to 16.47 mmHg. Among the other tonometers, however, the widths of 95% limits of agreement ranged from 7.91 to 9.24 mmHg.

CONCLUSION

There was good inter-device agreement among GAT, rebound tonometers, and NCT. Tonopen XL shows the worst agreement with the other tonometers; therefore, we should pay attention to its' respective IOP.

CLINICAL TRIAL REGISTRATION

Japan Clinical Trials Register; number: UMIN000011544.

Comparison of ICare and IOPen vs Goldmann applanation tonometry according to international standards 8612 in glaucoma patients

AIM

To compare IOPen and ICare rebound tonometry to Goldmann applanation tonometry (GAT) according to International Standards Organization (ISO) 8612 criteria.

METHODS

Totally 191 eyes (n=107 individuals) were included. Criteria of ISO 8612 were fulfilled: 3 clusters of IOP, measured by GAT, were formed. The GAT results were given as mean±standard deviation.

RESULTS

GAT (19.7±0.5 mm Hg) showed a significant correlation to ICare (19.8±0.5 mm Hg) (r=0.547, P<0.001) and IOPen (19.5±0.5 mm Hg) (r=0.526, P<0.001). According to ISO 8612 criteria in all 3 IOP groups the number of outliers (of the 95% limits of agreement) exceeded 5% for ICare and IOPen vs GAT: No.1 (n=68) 29.4% and 22.1%, No.2 (n=62) 35.5% and 37.1%, No.3 (n=61) 26.2% and 42.6%, respectively.

CONCLUSION

The strict requirements of the ISO 8612 are not fulfilled in a glaucoma collective by ICare and IOPen at present. As long as the Goldmann tonometry is applicable it should be used first of all for reproducible IOP readings. ICare and IOPen tonometry should be considered as an alternative tool, if application of Goldmann tonometry is not possible.

Wound stability and surgically induced corneal astigmatism after transconjunctival single-plane sclerocorneal incision cataract surgery

PURPOSE

To compare intraocular pressure (IOP) immediately after cataract surgery, and surgically induced corneal astigmatism (SIA) and corneal shape changes between eyes with transconjunctival single-plane sclerocorneal incisions (TSSIs) and eyes with clear corneal incisions (CCIs).

METHODS

Bilateral eyes of 64 patients undergoing phacoemulsification were randomized to undergo 2.4-mm temporal TSSI or CCI. IOP was measured preoperatively, and in the immediate postoperative periods. SIA was determined using vector analysis, and corneal shape changes and irregular astigmatism were evaluated using a videokeratography preoperatively, and in the early postoperative periods.

RESULTS

Wound hydration was performed in 23 eyes (35.9 %) of the TSSI group and in 60 (93.8 %) of the CCI group (P < 0.0001). Mean IOP was significantly higher in the TSSI group than in the CCI group at 30, 60, and 120 min postoperatively (P ≤ 0.0179). SIA tended to be smaller in the TSSI group than the CCI group, but the difference was not significant. The higher order irregular astigmatism was smaller in the TSSI group than in the CCI group at 2 days (P = 0.0312). The videokeratography revealed a wound-related flattening postoperatively in both groups; this change disappeared within 4 weeks in the TSSI group, whereas it persisted until 12 weeks in the CCI group.

CONCLUSION

IOP was significantly higher immediately after TSSI than after CCI and required less wound hydration, suggesting better stability with TSSI. Higher order irregular astigmatism and wound-related corneal flattening were smaller after TSSI than after CCI in the early periods, suggesting that fewer corneal shape changes with TSSI.

Glaucoma Management in Carotid Cavernous Fistula

Carotid cavernous fistulas (CCF) are vascular communications between the carotid artery and the cavernous sinus. Ophthalmologists are called to diagnose and manage the condition in cases that present with ocular features. A 73-year-old female was referred to our glaucoma center clinic. Eight years before, she had started receiving medication for glaucoma and had undergone laser iridotomy, but a satisfactory management of intraocular pressure (IOP) had not been achieved. The patient was complaining of intermittent diplopia, bilateral proptosis, and conjunctival chemosis over the past 6 months. Best-corrected visual acuity in the right (OD) and left eye (OS) was 9/10 and 10/10, respectively. Visual field testing showed slight paracentral field defects mostly in OS. IOP was 20 mm Hg in OD and 34 mm Hg in OS. We referred the patient to neuroradiology, and MRI angiography revealed a CCF with angiographic classification of Cognard grade 2. Closure of the CCF by transarterial embolization was performed in the neuroradiology department. One week following the procedure, the clinical signs of diplopia, proptosis, and conjunctival chemosis had greatly improved, and IOP was reduced to 12 mm Hg OD and 19 mm Hg in OS. Glaucoma treatment was maintained with topical brimatoprost, brinzolamide, and timolol. Owing to the risk of vision loss associated with vascular stasis, retinal ischemia, and high IOP, ophthalmologists must be aware of the clinical features of CCF and should request appropriate imaging studies such as MRI angiography in order to confirm the diagnosis and plan multidisciplinary treatment.

An Update on the Ophthalmologic Features in the Phakomatoses

Neurofibromatosis type 1, tuberous sclerosis complex, and Von Hippel-Lindau disease, historically classified as the phakomatoses, are hereditary multisystem disorders characterized by the presence of hamartoma, which carry the risk of malignant transformation. The alteration of tumor suppressor genes seems to be at the basis of their pathophysiogenetic mechanism. Lisch and choroidal nodules in neurofibromatosis type 1, retinal astrocytomas in tuberous sclerosis complex, and retinal capillary hemangioma in Von Hippel-Lindau disease are the principal ophthalmic hamartomatous manifestations. The advent of novel imaging techniques such as near infrared reflectance and optical coherence tomography has provided unprecedented insight on the choroidal and retinal features of these diseases. These methods have improved early diagnosis and the ongoing surveillance in these conditions. Among an array of treatment modalities, antivascular endothelial growth factor therapy has been used in the management of retinal hamartomas but results have been varied. This review is an update on the pathophysiogenetic mechanisms, ophthalmic manifestations, and novel treatment strategies in the phakomatoses with emphasis on the role of imaging techniques.

The Icare HOME (TA022) Study: Performance of an Intraocular Pressure Measuring Device for Self-Tonometry by Glaucoma Patients

PURPOSE

To evaluate the Icare HOME (TA022) device (Icare Oy, Vanda, Finland) for use by glaucoma patients for self-tonometry.

DESIGN

Prospective performance evaluation of a medical device.

PARTICIPANTS

One hundred eighty-nine participants with glaucoma or suspected glaucoma were recruited from the Wilmer Eye Institute, Baltimore, Maryland, between July 2014 and April 2015.

METHODS

Participants had standardized training and had to be able use the Icare HOME device independently. Subjects also had to be able to obtain the first intraocular pressure (IOP) measurement within 5 mmHg of Goldmann applanation tonometry (GAT). Those certified obtained 3 IOP measures using the HOME device, and these were compared with Icare TA01i and GAT IOP measurements.

MAIN OUTCOME MEASURES

The agreement between Icare HOME and reference tonometers was used to assess precision. The intraclass correlation coefficient was used to assess within-patient reliability for the HOME device.

RESULTS

Eighteen of 189 recruited patients were ineligible to take part in the study. Forty-four of 171 patients (25.7%) started but failed to complete the study: 7 stopped because of time concerns, 10 of 171 patients (6%) stopped because of difficulty using the device during certification, and 27 of 171 patients (16%) failed to be certified based on IOP. The HOME and GAT measurements agreed within 5 mmHg in 116 of 127 participants (91.3%); 2 participants (1.6%) had a difference of more than 7 mmHg. The mean difference between the Icare HOME and GAT measurements was -0.33 mmHg (standard deviation, 3.11 mmHg). The overall intraclass correlation coefficient for the HOME device was 0.92 (95% confidence interval, 0.89-0.95).

CONCLUSIONS

Not all participants could learn how to use the Icare HOME device, but for those who could, most were able to obtain measurements similar to those obtained by GAT. The Icare HOME device is safe and reliable for self-tonometry, but nearly 1 in 6 individuals may fail to certify in use of the device based on large differences in IOP when comparing GAT with the Icare HOME measurements. The device has the potential to address an unmet need by providing more frequent IOP measurements in a patient's day to day life.

Evaluation of Agreement between HRT III and iVue OCT in Glaucoma and Ocular Hypertension Patients

Purpose. To determine the agreement between Moorfields Regression Analysis (MRA), Glaucoma Probability Score (GPS) of Heidelberg retinal tomograph (HRT III), and peripapillary nerve fibers thickness by iVue Optical Coherence Tomography (OCT). Methods. 72 eyes with ocular hypertension or primary open angle glaucoma (POAG) were included in the study: 54 eyes had normal visual fields (VF) and 18 had VF damage. All subjects performed achromatic 30° VF by Octopus Program G1X dynamic strategy and were imaged with HRT III and iVue OCT. Sectorial and global MRA, GPS, and OCT parameters were used for the analysis. Kappa statistic was used to assess the agreement between methods. Results. A significant agreement between iVue OCT and GPS for the inferotemporal quadrant (κ: 0.555) was found in patients with abnormal VF. A good overall agreement between GPS and MRA was found in all the eyes tested (κ: 0.511). A good agreement between iVue OCT and MRA was shown in the superonasal (κ: 0.656) and nasal (κ: 0.627) quadrants followed by the superotemporal (κ: 0.602) and inferotemporal (κ: 0.586) sectors in all the studied eyes. Conclusion. The highest percentages of agreement were found per quadrant of the MRA and the iVue OCT confirming that in glaucoma damage starts from the temporal hemiretina.

Intradevice and Interdevice Agreement Between a Rebound Tonometer, Icare PRO, and the Tonopen XL and Kowa Hand-held Applanation Tonometer When Used in the Sitting and Supine Position

PURPOSE

The aim of the study was to investigate the agreement between a new portable tonometer, Icare PRO, and the Tonopen XL and Kowa hand-held applanation tonometers (HAT).

METHODS

The right eyes of 127 healthy subjects were enrolled. Intraocular pressure (IOP) was measured in both sitting and supine positions using the Icare PRO, Tonopen XL, and Kowa HAT tonometers. The repeatability of the IOP measurements was evaluated by calculating intraclass correlation coefficients. Between-method agreements of tonometer measurements were evaluated using Bland-Altman analysis.

RESULTS

Intradevice agreement: The intraclass correlation coefficients (sitting, supine) of Icare PRO, Tonopen XL, and Kowa HAT were (0.863, 0.656), (0.845, 0.819), and (0.957, 0.956), respectively.Interdevice agreement: The Bland-Altman analysis revealed that, in the sitting position, the mean differences between Icare PRO and Tonopen XL, and between Icare PRO and Kowa HAT were -0.43 and 0.43 mm Hg, respectively (95% limits of agreement: -6.24 to 5.34 mm Hg, -4.04 to 4.90 mm Hg). In the supine position, the corresponding mean differences were -0.88 and 0.14 mm Hg (95% limits of agreement: -5.66 to 3.91 mm Hg, -4.06 to 4.33 mm Hg). IOP differences between Icare PRO and the other tonometers were unaffected by central corneal thickness.

CONCLUSIONS

The repeatability of Icare PRO was slightly lower in the supine position than in the sitting position. Although Icare PRO underestimated IOP values in eyes with higher IOP when compared with Tonopen XL and Kowa HAT in both positions, we observed good interdevice agreement between Icare PRO and both Tonopen XL and Kowa HAT.

Twelve-Month Results of a Single or Multiple Dexamethasone Intravitreal Implant for Macular Edema following Uncomplicated Phacoemulsification

The clinical efficacy of one or two intravitreal injections of a continued deliverance dexamethasone 700 μg implant in ten patients with persistent macular edema following uncomplicated phacoemulsification was evaluated. Complete ophthalmological examination and spectral domain optical coherence tomography were carried out. Follow-up was at day 7 and months 1, 2, 4, 6, 8, and 12. At baseline mean best corrected visual acuity was 62 Early Treatment Diabetic Retinopathy Study Chart letters, which showed statistically significant improvement at each follow-up, except at month 6, to reach 79 letters at month 12 (P = 0.018). Prior to treatment mean central foveal thickness was 622 μm, which showed statistically significant improvement at each follow-up to reach a mean value of 282 μm (P = 0.012) at month 12. Five patients received a second dexamethasone implant at month 7. Two patients were excluded from the study at months 4 and 8. Intraocular pressure remained stable during the study period with the exception of mild increase in two patients requiring topical therapy. In conclusion there was statistically significant improvement of best corrected visual acuity and mean central foveal thickness with one or two intravitreal dexamethasone implants over 12 months.

Pediatric Glaucoma: A Literature's Review and Analysis of Surgical Results

The purpose of this paper is to review the surgical options available for the management of pediatric glaucoma, to evaluate their advantages and disadvantages together with their long-term efficacy, all with the intent to give guidelines to physicians on which elements are to be considered when taking a surgical decision. Currently there is a range of surgical procedures that are being used for the management of pediatric glaucoma. Within these, some are completely new approaches, while others are improvements of the more traditional procedures. Throughout this vast range of surgical options, angle surgery remains the first choice in mild cases and both goniotomy and trabeculotomy have good success rates. Trabeculectomy with or without mitomycin C (MMC) is preferred in refractory cases, in aphakic eyes, and in older children. GDIs have a good success rate in aphakic eyes. Nonpenetrating deep sclerectomy is still rarely used; nevertheless the results of ongoing studies are encouraging. The different clinical situations should always be weighed against the risks associated with the procedures for the individual patients. Glaucomatous progression can occur many years after its stabilization and at any time during the follow-up period; for this reason life-long assessment is necessary.

Rare Diseases Leading to Childhood Glaucoma: Epidemiology, Pathophysiogenesis, and Management

Noteworthy heterogeneity exists in the rare diseases associated with childhood glaucoma. Primary congenital glaucoma is mostly sporadic; however, 10% to 40% of cases are familial. CYP1B1 gene mutations seem to account for 87% of familial cases and 27% of sporadic cases. Childhood glaucoma is classified in primary and secondary congenital glaucoma, further divided as glaucoma arising in dysgenesis associated with neural crest anomalies, phakomatoses, metabolic disorders, mitotic diseases, congenital disorders, and acquired conditions. Neural crest alterations lead to the wide spectrum of iridocorneal trabeculodysgenesis. Systemic diseases associated with childhood glaucoma include the heterogenous group of phakomatoses where glaucoma is frequently encountered in the Sturge-Weber syndrome and its variants, in phakomatosis pigmentovascularis associated with oculodermal melanocytosis, and more rarely in neurofibromatosis type 1. Childhood glaucoma is also described in systemic disorders of mitotic and metabolic activity. Acquired secondary glaucoma has been associated with uveitis, trauma, drugs, and neoplastic diseases. A database research revealed reports of childhood glaucoma in rare diseases, which do not include glaucoma in their manifestation. These are otopalatodigital syndrome, complete androgen insensitivity, pseudotrisomy 13, Brachmann-de Lange syndrome, acrofrontofacionasal dysostosis, caudal regression syndrome, and Wolf-Hirschhorn syndrome.

Ganglion Cell Complex Evaluation in Exudative Age-Related Macular Degeneration after Repeated Intravitreal Injections of Ranibizumab

Purpose. To detect the effects of intravitreal ranibizumab injections on GCC in patients with wet AMD. Methods. 32 wet AMD eyes were selected and submitted at three ranibizumab injections. RTVue-OCT GCC and MM5 protocol were performed before treatment and twenty days after each injection. Results. At baseline mean GCC thickness was 93.9 ± 18.5 μm. Twenty days after each intravitreal injection it was, respectively, 85.8 ± 10.1, 86.5 ± 9.3, and 91.1 ± 11.5 μm, without statistical significance. A significant improvement in visual acuity (P = 0.031) and a reduction of mean foveal (P = 0.001) and macular thickness (P = 0.001) were observed. Conclusion. The clinical results confirm therapeutic efficacy of intravitreal injections of ranibizumab in wet AMD. A contemporary not statistically significant reduction of GCC thickness suggests that the loading phase of ranibizumab does not have any toxic effects on ganglion cell complex.

Unusual case of angle closure glaucoma in a patient with neurofibromatosis type 1

We report the case of a 29-year-old female patient who presented with an acute onset of anisocoria, blurred vision, nausea and severe left-sided headache. There was no history of trauma, drug abuse, or instillation of topical mydriatic compounds. The ocular history was negative for similar events. On presentation, her visual acuity was 0.2 in the left and 1.0 in the right eye with a +2.5 dpt sph. correction. Slit-lamp examination demonstrated a shallow anterior chamber as well as the presence of iris nodules in both eyes. These nodules were identified as Lisch nodules as the patient referred to the previous diagnosis as being neurofibromatosis type 1. A third nerve palsy was considered, but a brain MRI showed normal results. Her ocular motility was normal, but the left pupil was mydriatic and poorly reacting to light, with an associated raised intraocular pressure (IOP) of 38 mm Hg. An examination of the fellow eye was normal, with the IOP measuring 18 mm Hg. Gonioscopy of the right eye showed a narrow angle. On further anamnestic investigation, the patient revealed that the pain and the blurred vision begun in the morning while she was helping her mother in the garden. Finally, after showing the patient a picture of Datura flowers, which she recognized immediately, we made the unusual diagnosis of angle closure glaucoma by Datura, a well-known toxic plant with mydriatic properties. The patient was successfully treated with systemic acetazolamide and topical pilocarpine.

Intravitreal injection of dexamethasone implant and ranibizumab in cystoid macular edema in the course of irvine-gass syndrome

PURPOSE

To evaluate the efficacy of 2 dexamethasone intravitreal implants and 1 ranibizumab intravitreal injection after a bilateral postoperative complication of cataract surgery as pseudophakic cystoid macular edema.

PATIENTS AND METHODS

A 70-year-old male patient with systemic hypertension developed a progressive cystoid macular edema (CME) in both eyes starting between 10 and 20 days after cataract surgery. Two intravitreal dexamethasone implants and 1 ranibizumab injection were administered; first in the right eye (RE) and then in the left eye (LE). The patient was checked for 1 whole week and then once a month for 5 months after the injections.

RESULTS

One month after the first dexamethasone implant in his RE, the spectral domain optical coherence tomography (SD-OCT) showed a progressive reduction of the foveal thickness until a complete resolution of the CME occurred, which was associated with an improvement of visual acuity. After 3 months, the SD-OCT showed a relapse of the CME, which was then treated with 1 injection of ranibizumab. One month after this injection, there was a complete resolution of the CME. A new CME in his RE was diagnosed 2 months after the last ranibizumab injection; it was treated with a new dexamethasone implant. A complete resolution of the CME was obtained; a normal foveal profile was still present 5 months after the last injection, and the best-corrected visual acuity was 20/20. His LE developed a CME 40 days after surgery. One intravitreal injection of ranibizumab was first administered in his LE, with a complete resolution of the CME at SD-OCT 2 weeks later. As observed in his RE, 40 days after the ranibizumab injection, there was a relapse of the CME that was treated with 1 intravitreal injection of dexamethasone implant. Five months later, the patient showed a worsening of the CME, but it was completely resolved with a second dexamethasone injection. After 3 months, the foveal thickness was back to normal with a BCVA of 20/20.

CONCLUSION

Treatment with dexamethasone implants (Ozurdex(®)) and ranibizumab injections (Lucentis(®)) induced a progressive reduction of our patient's CME after cataract surgery (Irvine-Gass syndrome) until a complete normal foveal thickness was restored and his visual function was improved despite the order of injections.

Intraocular pressure and wound status in eyes immediately after scleral tunnel incision and clear corneal incision cataract surgery

PURPOSE

To compare intraocular pressure (IOP) and wound architecture immediately after cataract surgery using a scleral tunnel incision or clear corneal incision.

DESIGN

Prospective randomized clinical trial.

METHODS

Bilateral eyes of 64 patients undergoing phacoemulsification were randomized to 2 groups: 2.4 mm scleral tunnel incision or 2.4 mm clear corneal incision. IOP was adjusted upon completion of surgery to between 15 and 30 mm Hg. The wound was hydrated in 87.5% of eyes in the clear corneal incision group. IOP was measured using a rebound tonometer preoperatively; at the conclusion of surgery; and at 5, 10, 15, 30, and 60 minutes postoperatively. The Seidel test and anterior segment optical coherence tomography (AS OCT) were performed at 30 minutes postoperatively.

RESULTS

In the scleral tunnel incision group, mean IOP decreased to the preoperative level within 15 minutes postoperatively and did not change significantly for up to 60 minutes. In the clear corneal incision group, IOP decreased to lower than the preoperative IOP at 30 minutes postoperatively. Mean IOP was significantly higher in the scleral tunnel incision group than in the clear corneal incision group throughout the postoperative period (P≤.0339). Hypotony (<10 mm Hg) was observed in 7 eyes (10.9%) that underwent clear corneal incision and in no eyes that underwent scleral tunnel incision (P=.0131). Wound leakage and loss of wound coaptation were not observed in any eyes.

CONCLUSIONS

IOP was significantly higher immediately after scleral tunnel incision without hydration than after clear corneal incision with hydration, and both incisions closed within 30 minutes postoperatively without leakage based on AS OCT.

Immediate effect of intravitreal injection of bevacizumab on intraocular pressure

Purpose

To investigate the immediate effect of intravitreal injection of bevacizumab on intraocular pressure (IOP).

Methods

This was a prospective and nonrandomized study. A total of 291 eyes with macular edema or active choroidal neovascularization were submitted to a single 1.25 mg (0.05 mL) bevacizumab intravitreal injection. Intraocular pressure was measured with an Icare^® tonometer immediately before and after injection in a seated position. The presence of subconjunctival reflux was recorded. The fellow eye served as the control.

Results

Mean preoperative IOP was 18.0±5.9 mmHg in the treated eye versus 16.9±6.0 mmHg in the fellow eye. Mean postoperative IOP was 42.1±14.5 mmHg in the treated eye versus 17.5±6.0 mmHg in the fellow eye. The IOP variation was statistically significant in both cases and controls (P<0.001 and P=0.003, respectively), and this increase was higher in cases than in controls (P<0.001). Postoperative IOPs higher than 50 mmHg were achieved in 32.0% of the eyes. Subconjunctival reflux was present in 21.3% and determined a lower IOP rise (P<0.001). Tested variables (glaucoma, phakic status, and sex) did not have a statistically significant effect on IOP rise or subconjunctival reflux.

Conclusion

IOP increases with intravitreal bevacizumab injection, reaching 50 mmHg or more in about one third of patients. A higher IOP is expected if no subconjunctival reflux occurs. The baseline IOP does not influence the incidence of subconjunctival reflux. The clinical relevance of these facts has yet to be clarified.

Test-retest reliability of retinal oxygen saturation measurement

PURPOSE

To determine intrasession and intersession repeatability of retinal vessel oxygen saturation from the Oxymap Retinal Oximeter using a whole image-based analysis technique and so determine optimal analysis parameters to reduce variability.

METHODS

Ten fundus oximetry images were acquired through dilated pupils from 18 healthy participants (aged 22 to 38) using the Oxymap Retinal Oximeter T1. A further 10 images were obtained 1 to 2 weeks later from each individual. Analysis was undertaken for subsets of images to determine the number of images needed to return a stable coefficient of variation (CoV). Intrasession and intersession variability were quantified by evaluating the CoV and establishing the 95% limits of agreement using Bland and Altman analysis. Retinal oxygenation was derived from the distribution of oxygenation values from all vessels of a given width in an image or set of images, as described by Paul et al. in 2013.

RESULTS

Grouped in 10-μm-wide bins, oxygen saturation varied significantly for both arteries and veins (p < 0.01). Between 110 and 150 μm, arteries had the least variability between individuals, with average CoVs less than 5% whose confidence intervals did not overlap with the greater than 10% average CoVs for veins across the same range. Bland and Altman analysis showed that there was no bias within or between recording sessions and that the 95% limits of agreement were generally lower in arteries.

CONCLUSIONS

Retinal vessel oxygen saturation measurements show variability within and between clinical sessions when the whole image is used, which we believe more accurately reflects the true variability in Oxymap images than previous studies on select image segments. Averaging data from vessels 100 to 150 μm in width may help to minimize such variability.

Immediate changes in intraocular pressure after clear corneal micro-incision versus small-incision cataract surgery

PURPOSE

We sought to examine changes in intraocular pressure (IOP) in the immediate period after clear corneal micro-incision cataract surgery (MICS) and after small-incision cataract surgery (SICS).

METHODS

Sixty-eight eyes of 34 patients scheduled for coaxial phacoemulsification were randomized into one of two groups: (a) eyes that were to undergo a 2.0-mm MICS, and (b) a 2.65-mm SICS. At the conclusion of surgery, the IOP was adjusted to the range between 15-40 mmHg with stromal hydration. The IOP was measured using a rebound tonometer preoperatively, at the conclusion of surgery, and at 3, 6, 9, 12, and 15 min postoperatively. The Seidel test and anterior segment-optical coherence tomography were performed at 20 min postoperatively.

RESULTS

Mean IOP at the conclusion of surgery was 27.7 ± 4.7 mmHg in the MICS group and 29.7 ± 5.1 mmHg in the SICS group (p = 0.1239). In both groups, mean IOP decreased to the preoperative level within 9 min postoperatively and did not change significantly for up to 15 min. Mean IOP was similar between the MICS and SICS groups throughout the observation period (p ≥ 0.1239). Hypotony (≤10 mmHg), positive Seidel test, and loss of wound coaptation were not detected in all eyes.

CONCLUSIONS

After adjusting the IOP to a relatively high level at the conclusion of surgery, the IOP decreased within 9 min and was stable within 15 min without hypotony. The IOP was comparable between eyes after MICS and SICS, and both incisions virtually closed within 20 min postoperatively.

Ganglion Cell Complex Evaluation in Exudative Age-Related Macular Degeneration after Repeated Intravitreal Injections of Ranibizumab

Purpose. To detect the effects of intravitreal ranibizumab injections on GCC in patients with wet AMD.Methods. 32 wet AMD eyes were selected and submitted at three ranibizumab injections. RTVue-OCT GCC and MM5 protocol were performed before treatment and twenty days after each injection.Results. At baseline mean GCC thickness was 93.9 ± 18.5 μm. Twenty days after each intravitreal injection it was, respectively, 85.8 ± 10.1, 86.5 ± 9.3, and 91.1 ± 11.5 μm, without statistical significance. A significant improvement in visual acuity (P= 0.031) and a reduction of mean foveal (P= 0.001) and macular thickness (P= 0.001) were observed.Conclusion. The clinical results confirm therapeutic efficacy of intravitreal injections of ranibizumab in wet AMD. A contemporary not statistically significant reduction of GCC thickness suggests that the loading phase of ranibizumab does not have any toxic effects on ganglion cell complex.

Intraocular pressure during femtosecond laser pretreatment of cataract

PURPOSE

To analyze the course of intraocular pressure (IOP) during femtosecond laser pretreatment to cataract surgery.

SETTING

Launceston Eye Institute, Tasmania, Australia.

DESIGN

Interventional prospective study.

METHODS

Femtosecond laser pretreatment was performed using the Catalys Precision Laser System with Liquid Optics Interface. The IOP was measured using a rebound tonometer (iCare PRO) during different stages of surgery and analyzed by number of docking attempts, vacuum time, treatment time, and central corneal thickness (CCT).

RESULTS

The mean baseline IOP in the 25 eyes was 17.5 mm Hg ± 2.4 (SD). During vacuum application, the mean IOP rise was 11.4 ± 3.3 mm Hg. Peak IOPs were recorded immediately after laser capsulotomy and lens fragmentation (mean 36.0 ± 4.4 mm Hg; mean increase from baseline 18.5 ± 4.7 mm Hg) and remained above baseline 2 minutes after the procedure (26.6 ± 4.0 mm Hg) (P<.001). Multiple regression analysis found no association between IOP rise and number of docking attempts, vacuum time, treatment time, or CCT.

CONCLUSION

Femtosecond laser pretreatment was associated with a mean peak increase in IOP of 18.5 mm Hg from baseline and appeared to be safe and well tolerated.

Evaluation of the Icare-ONE rebound tonometer as a self-measuring intraocular pressure device in normal subjects

PURPOSE

To compare Icare ONE rebound self-tonometer (ICRBT) measurements with Goldman applanation tonometry (GAT).

METHODS

A trained examiner instructed each of 60 normal subjects on use of the ICRBT. Each subject then took two measurements of his/her own pressure using the ICRBT. Finally, a different examiner, who was masked to the earlier readings, measured IOP by GAT. Bland–Altman limits of agreement (LOA), intraclass correlation coefficients (ICCs), Kappa values, and paired t-test were used to assess the agreement between the two methods. Pearson’s correlation coefficient was used for correlation analysis.

RESULTS

All of the subjects were able to obtain correct measurements with ICRBT after three attempts. The mean intraocular pressure with ICRBT and GAT measurements were 16.0 ± 3.3 mmHg and 13.7 ± 2.5 mmHg respectively. The mean difference between patient’s ICRBT and technician’s GAT measurements was 2.3 mmHg (p < 0.001). In 63% (38/60) of the cases the IOP difference (ICRBT − GAT) was within ± 3 mmHg. The weighted Kappa for the IOP measurements of the two methods was 0.49 (95% CI: 0.30–0.68, p < 0.001), indicating acceptable agreement. A significantly positive correlation was found between ICRBT IOP measurements and central corneal thickness (CCT) (r = 0.48, p < 0.001). In addition, the difference in IOP measurements (ICRBT − GAT) between the two methods was positively correlated with CCT (r = 0.31, p = 0.015), indicating that greater thickness is associated with greater differences between the two methods.

CONCLUSION

The ICRBT was reliable in the hands of normal subjects, and may be used for self-monitoring of IOP. ICRBT measurements generally overestimated GAT measurements.

[Comparison of the iCare tonometer with the Goldmann tonometer in Malawi]

BACKGROUND

The risk for glaucoma is 4-5 times higher in patients from sub-Saharan Africa. Thus, especially in developing countries an easy and effective method for assessing the intraocular pressure (IOP) is needed.

METHODOLOGY

In this hospital-based survey 150 eyes were divided into 3 groups concerning the IOP (group I < 16 mmHg, group II 16-23 mmHg and group III > 23 mmHg) and underwent examination with ultrasound pachymetry followed by iCare tonometry (ICT) and Goldmann applanation tonometry (GAT). Agreement of the measurements by two tonometers was assessed with the Bland-Altman method and the influence of the central corneal thickness (CCT) on the ICT measurements was determined.

RESULTS

The mean difference between the IOD measured with GAT and ICT was 0.84 ± 2.63 mmHg. The differences were similar in all three groups (0.77-0.97 mmHg), however, the standard deviation in group III (4.04 mmHg) was greater than in groups I (1.98 mmHg) and II (1.79 mmHg). The mean CCT was 513.51 ± 36.22 µm.

CONCLUSIONS

The agreement of measurements by GAT and ICT was good for lower IOP values but less accurate in patients with higher IOP values (group III). A dependency of the CCT on the ICT measurements was observed. In comparison to other countries the lowest CCTs were found in Malawian patients.