Fluctuation of intraocular pressure in glaucoma patients before and after trabeculectomy with mitomycin C.

Joanna Wasielica-Poslednik,Julian Schmeisser,Esther M Hoffmann,Veronika Weyer-Elberich,Norbert Pfeiffer,Katharina Bell,Katrin Lorenz,Sanjoy Bhattacharya

doi:10.1371/journal.pone.0185246

Abstract

PurposeIntraocular pressure (IOP) fluctuation is considered as a risk factor for glaucoma progression. We investigated IOP values and IOP fluctuation before and after trabeculectomy (TE) with mitomycin C (MMC) measured by 48-hour diurnal-nocturnal-IOP-profiles (DNP).MethodsPre- and postoperative DNPs of 92 eyes undergoing primary TE with MMC were analysed. Each 48-hour IOP-profile involved 10 IOP measurements (8:00 a.m., 2:00 p.m., 6:00 p.m., and 9:00 p.m. in sitting and at 00:00 in supine position). The “preoperative DNP” was performed a few weeks before TE. The “postoperative DNP” was performed at least six months (range: 6 months—2 years) after TE. Mean IOP values and IOP fluctuations were calculated.ResultsAfter TE with MMC mean IOP was reduced from 16.94±3.83 to 11.26±3.77 mmHg at daytime and from 18.17±4.26 to 11.76±3.90 mmHg at night. At daytime mean IOP-fluctuation decreased from 8.61±4.19 to 4.92±2.52 mmHg, at night from 3.15±2.95 to 1.99±1.82 mmHg. Mean IOP was lower on the second day of the preoperative DNP. This effect was not present in the postoperative DNP. Preoperatively, IOP was controlled in all eyes with a mean of 3.22±0.94 antiglaucomatous agents. Postoperatively, IOP≤15 mmHg was achieved in 71.7%, IOP≤18 mmHg in 77.1% and a decrease in IOP of >30% in 47.8% without antiglaucomatous therapy. Postoperatively, pseudophakia was associated by a higher mean IOP-fluctuation compared to the phakic eyes.ConclusionsTE with MMC significantly reduces both mean IOP-values and IOP- fluctuations at day and night at least 6 months postoperatively. The effect of TE on the IOP fluctuation was less pronounced in pseudophakic eyes.

Highlights

Reducing intraocular pressure (IOP) is the only evidence-based intervention that can delay the onset and progression of glaucoma, which is sight threatening progressive optic neuropathy [1,2]
The effect of TE on the IOP fluctuation was less pronounced in pseudophakic eyes
We know that rather than having an absolute high IOP above 21 mmHg, many patients suffer from an individual high IOP presenting with normal IOP ranges accompanied by glaucomatous damage and disease progression

Summary

Introduction

Reducing intraocular pressure (IOP) is the only evidence-based intervention that can delay the onset and progression of glaucoma, which is sight threatening progressive optic neuropathy [1,2]. A major risk factor for glaucoma is an elevated IOP which is specified as values measured above 21 mmHg. we know that rather than having an absolute high IOP above 21 mmHg, many patients suffer from an individual high IOP presenting with normal IOP ranges accompanied by glaucomatous damage and disease progression. IOP-fluctuations, defined as the difference between maximal and minimal IOP values measured during a day, are relevant for progression in glaucoma damage [3,4,5,6]. Glaucoma patients can show larger IOP variations ranging from 4.8 to 11 mmHg. According to other studies, IOP-fluctuation was not an independent risk factor of glaucoma or glaucoma progression [8,9,10]. Nocturnal IOP-measurements, which cannot be provided in an outpatient setting but often show nocturnal IOP-peaks, are of special relevance for the therapy of glaucoma patients [12,13]

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