Water‐drinking test in primary angle‐closure suspect before and after laser peripheral iridotomy

Abstract

Background: This study aimed to investigate whether performing a laser peripheral iridotomy in primary angle-closure suspects had an effect on the intraocular pressure response during the water-drinking test.Design: Prospective study in a hospital setting.Participants: Primary angle-closure suspects scheduled for a laser peripheral iridotomy.Methods: Primary angle-closure suspects were evaluated before the laser peripheral iridotomy and 2 weeks after. On each visit, subjects underwent the waterdrinking test. Intraocular pressure was measured every 15 min within a 1-h period.Main Outcome Measures: Intraocular pressure fluctuations during the water drinking test.Results: Twenty patients were enrolled. The mean age was 58.1 years (±10.2 SD), predominantly female (n = 14, 70%). Average intraocular pressure range (maximum-minimum) during the waterdrinking test increased significantly from 2.6 ± 1.1 mmHg before the laser peripheral iridotomy to 3.5 ± 1.5 mmHg after (P = 0.04). The mean difference between peak and last intraocular pressure measurements increased after the laser peripheral iridotomy was performed, from 2.5 mmHg (±1.27 SD) to 3.3 mmHg (±1.66 SD), (P = 0.057). There was no change in mean peak intraocular pressure (maximum-baseline) before and after the laser peripheral iridotomy (P = 0.87).Conclusions: Primary angle-closure suspects who underwent the water-drinking test had a slightly more pronounced recovery of intraocular pressure after the laser peripheral iridotomy was performed, which may be attributed to increase in the area of exposed trabecular meshwork following treatment. Differences in intraocular pressure curves before and after laser peripheral iridotomy were minimal, and therefore, the water-drinking test had limited value as a provocative test in this patient population.

Water drinking test: new applications

“…By reporting on the rate of IOP recovery rather than the peak IOP or average IOP, Waisbourd et al highlight an interesting and important feature of the WDT not previously described. In doing so, they also provide evidence of another aspect to the underlying physiological response.…”

“…When trabeculectomy and medical therapy are compared, the former appears better at blunting the WDT response . To this we can now add the findings of Waisbourd et al, which suggest a role for the WDT in assessing response to peripheral laser iridotomy. Although no significant change in peak WDT IOP was reported before and after treatment of primary angle closure suspect eyes, a more rapid recovery in the WDT IOP curve was seen post‐treatment.…”

“…In this issue of Clinical and Experimental Ophthalmology, Waisbourd et al report the outcome of the water drinking test (WDT) before and after peripheral laser iridotomy for primary angle closure suspect eyes. This study highlights a potential new role for the WDT in glaucoma management and provides further insight into the physiology underlying the WDT response.…”

Applications of the water drinking test in glaucoma management

“…To this, we can now add the findings of Waisbourd et al which suggest a role for the WDT in assessing response to peripheral laser iridotomy. Although no significant change in peak WDT IOP was reported before and after treatment of primary angle closure suspect eyes, a more rapid recovery in the WDT IOP curve was seen post‐treatment.…”

Reprodutibilidade do teste de sobrecarga hídrica em portadores de glaucoma de ângulo aberto sob tratamento clínico

“…Outros estudos compararam a eficácia da redução da PIO entre fármacos ou o benefício de adicionar fármacos a um regime terapêutico pré-existente e os mecanismos de ação dos medicamentos hipotensores (45,46,9,47) . A isso podemos acrescentar os achados de Waisbourd et al (48) O TSH foi realizado como se segue: a PIO foi medida antes da ingestão de água (PIO basal) e após o paciente beber 800 ml de água da torneira em menos de cinco minutos (49) . situou-se entre -1,37 e + 0,19 mmHg.…”