Clinical Evaluation of Unilateral Open-Angle Glaucoma: A Two-Year Follow-Up Study

To evaluate the clinical characteristics of unilateral open-angle glaucoma, patients diagnosed with unilateral open-angle glaucoma from January 2017 to October 2018 were divided into primary open-angle glaucoma and normal-tension glaucoma groups according to the type of glaucoma diagnosed. The glaucoma and the contralateral eyes were compared, and the contralateral eye was analyzed for conversion to glaucoma and its risk factors were assessed during the 2-year follow-up period. Among 99 patients, 36 were diagnosed with primary open-angle glaucoma and 63 with normal-tension glaucoma. When comparing the glaucoma eye with the contralateral eye, the visual field mean deviation value (all p<0.001), peripapillary retinal nerve fiber layer thickness (all p<0.001), macular ganglion cell layer-inner plexiform layer thickness (p<0.001, p=0.003), and optic nerve cup-disc ratio (p=0.005, p<0.001) were significantly different in both the primary open-angle glaucoma and normal-tension glaucoma groups. In normal-tension glaucoma, peripapillary retinal nerve fiber layer thickness was significantly thinner in the glaucoma conversion group than in the glaucoma non-conversion group (p=0.008). It was significantly associated with glaucoma conversion (odds ratio=0.97, p=0.023). In conclusion, in patients with unilateral open-angle glaucoma, the contralateral eye may develop glaucoma. In particular, if the peripapillary retinal nerve fiber layer thickness is decreased in normal-tension glaucoma, the possibility of glaucoma conversion is high; hence, careful examination is required.

Applications of Isolated-Check Visual Evoked Potential in Early Stage of Open-Angle Glaucoma Patients

Background:

Standard automated perimetry does not sufficiently detect early open-angle glaucoma (OAG) in the clinic. New visual function tests for early glaucoma damage are therefore needed. The present study evaluated whether an isolated-check visual evoked potential (icVEP) could be used to detect visual function abnormalities in early-stage OAG and to explore potential related factors.

Methods:

This was a cross-sectional study. Thirty-seven OAG patients with early-stage visual field loss (mean deviation ≥ −6.00 dB) detected by the Humphrey Field Analyzer (30-2 SITA program) and 26 controls were included in this study. Optical coherence tomography (OCT) was used to detect retinal nerve fiber layer (RNFL) defects. The icVEP preferentially evaluates the magnocellular-ON pathway. VEPs were recorded and signal-to-noise ratios (SNRs) were derived based on multivariate analysis. Eyes that yielded an SNR ≤1 were considered abnormal. Receiver operating characteristic (ROC) curve analysis was used to estimate the accuracy of group classification. Correlations between SNRs and related factors were analyzed.

Results:

Based on an SNR criterion of 1, the icVEP had a sensitivity of 62.2% and a specificity of 92.3% for diagnosing early-stage OAG with 74.6% classification accuracy. The ROC curve analysis, however, suggested that an SNR criterion of 0.93 would produce the highest classification accuracy (77.3%). Both RNFL thinning in the temporal superior quadrant on OCT and number of abnormal test points in the central 11° visual field (pattern deviation, P < 0.5%) significantly correlated with the SNR (P < 0.05).

Conclusions:

The icVEP detected visual function abnormalities in approximately 3/5 of eyes with early-stage OAG with greater than 90% specificity. SNR correlated with both a decrease in RNFL thickness and severity of central visual field loss.

Adherence to treatment in patients with open-angle glaucoma and its related factors

INTRODUCTION

Lack of adherence to medical treatments typically lead to burdensome consequences such as progressive visual impairment, blindness, and disabilities. This study aimed to determine the adherence to medication in patients with open-angle glaucoma and related factors in patients referred to the Matini Ophthalmology Hospital in Kashan, Iran.

METHODS

A cross-sectional study was conducted from 23 July 2015 to 20 January 2016 on all patients with open-angle glaucoma referred to the Matini Ophthalmology Hospital in Kashan, Iran. A questionnaire was used to gather data about patients' demographics and factors affecting adherence to medical treatments. The Morisky Medication Adherence Scale was used to evaluate the adherence to glaucoma medication. Results were analyzed using SPSS version 13. Descriptive statistics, chi-square, and logistic regression analysis were used.

RESULTS

In total, 130 patients with a mean age of 55.36 ± 15.54 were studied. Only 34.6% of patients completely adhered to glaucoma medications. The chi-square test showed that age (p=0.007), education (p=0.01), life entourage (p=0.04), place of residence (p=0.06), average monthly income (p=0.005), the interval between medical visits (p=0.007), problem in scheduling the medical visits (p<0.001), number of medications (p<0.001), lifelong using and side-effects of medications (p<0.001), answers of the physician to the patient's questions (p<0.001), financial and traveling problems (p<0.001), lack of skill in using eye drops (p<0.001), lack of awareness of glaucoma complications and symptoms (p<0.001), forgetting, fatigue, impatience, believing in uselessness of medications, and lack of support from family (p<0.001) were associated with patients' adherence. Logistic regression showed that 89% of variance of patients' adherence to glaucoma medications can be predicted by seven factors: problems in traveling and scheduling medical visits, the large number and side effects of medications, impatience, forgetting, and lack of skill in using eye drops.

CONCLUSION

About two-thirds of patients with open-angle glaucoma did not adhere to their own medications. Appropriate patient education and planning a patient follow-up strategy might positively affect the patients' adherence to glaucoma medications.