Brtish Journal of Ophthalmology 1995; 79: 339-342
`
`339
`
`Effect of timolol with and without preservative on
`the basal tear turnover in glaucoma
`
`Esmeralda V M J Kuppens, Chris A de Jong, Thorsten R Stolwijk, Rob J W de Keizer,
`Jaap A van Best
`
`Abstract
`Aimns-The purpose of this study was to
`assess whether the preservative benzal-
`konium chloride (BAC 0.01%) present in
`timolol induced a decrease in basal tear
`turnover and a deterioration ofprecorneal
`tear film in patients with glaucoma and
`ocular hypertension using topical timolol.
`Methods-The basal tear turnover of 20
`patients with open angle glaucoma or
`ocular hypertension was measured by
`computerised objective fluorophotometry
`when using topical timolol preserved
`with BAC and 2 weeks after changing to
`topical timolol containing no preserva-
`tive. Evaluation of the precorneal tear
`film was done by measuring the break up
`time (BUT) before and 2' weeks after
`changing medication.
`Results-The tear turnover ofthe patients
`before the change was 32% lower than that
`of healthy controls (mean tear turnover
`values (SD) (0/olmin): 10*7 (3.0) and 15*6
`(5.4), respectively, p<0.0001). A mean
`increase of 28% (47%/O) in the individual
`tear turnover values was found after the
`change to the preservative-free timolol
`(p=0.04). The BUT values before the
`change of medication did not differ
`significantly from those after the change
`(p=0*5) but both values were significantly
`lower than the values of healthy controls
`(p=0*009 and p=0 003, respectively).
`Conclusion-Preservative-free
`timolol
`solution has a favourable effect on the tear
`turnover of patients with glaucoma and
`ocular hypertension in comparison with
`timolol contining BAC. The integrity
`of the precorneal tear film persisted to
`be affected when using timolol without
`BAC. Timolol without preservative can
`be recommended in those patients who
`have keratoconjunctivitis
`sicca
`or
`a
`borderline tear production since BAC
`may exacerbate a dry eye state.
`(BrJ Ophthalmol 1995; 79: 339-342)
`
`The ingredients timolol, timolol maleate, and
`the preservative benzalkonium chloride (BAC
`- 0 01%) are used successfully worldwide as a
`topical intraocular pressure lowering drug
`('timolol+BAC'). However, side effects like
`superficial
`keratopathy,
`corneal
`punctate
`anaesthesia, and burning or dry eye sensations
`have been reported
`during
`the
`use
`of
`timolol+BAC.1 2 Additionally, benzalkonium
`chloride can influence the tear film stability as
`
`has been showed previously.36 A new product
`('timolol-BAC') has been developed in order
`avoid some of
`the
`side
`effects
`of
`to
`timolol+BAC. Timolol-BAC is identical in
`all respects to timolol+BAC except that it
`lacks a preservative. To guarantee sterility each
`package consists of a hermetically sealed single
`dose unit.
`In a previous study7 we demonstrated a 36%
`lower mean basal tear turnover in patients with
`glaucoma using timolol+BAC in comparison
`with that of healthy controls. The preservative
`BAC is suggested as a possible cause for
`this decrease in tear turnover. The present
`follow up study was initiated to verify this
`assumption.
`In this study the tear turnover and break up
`time (BUT) of the precorneal tear film of
`patients with open angle glaucoma and ocular
`hypertension were evaluated when using
`timolol+BAC and subsequently when using
`timolol-BAC. In this way we expected to find
`out if BAC could be held responsible for a
`decrease in tear production and for a deteriora-
`tion of tear film stability in patients with
`glaucoma who use timolol+ BAC. The study
`was set up in such a way that the same patient
`was measured when using timolol+BAC as
`well as when using timolol-BAC in order to
`avoid the effect ofinterindividual spread in tear
`turnover values. Note that the fluorophoto-
`metric measurement of tear turnover with a
`computer fluorophotometer is a quantitative
`method for the determination of tear produc-
`tion7 and is, because of its objectivity and
`reproducibility,
`suitable
`for unbiased out-
`comes of the measurements. The precorneal
`tear film integrity determined by the tear
`film BUT and the subjective acceptability of
`timolol+BAC and timolol-BAC were also
`assessed.
`
`Material and methods
`
`PATIENTS
`All patients were recruited from the outpatient
`department of the Leiden University Hospital
`Eye Clinic (Leiden, the Netherlands). Patients
`were selected according to
`the following
`criteria: (1) normal aspect of all corneal layers
`upon slit-lamp biomicroscopic examination;
`(2) open angle glaucoma or ocular hyperten-
`sion for at least 6 months; (3) daily instillation
`of two drops of 0-25% or 050% timolol+BAC
`at 12 hour intervals for at least 1 month before
`measurements. Excluded were patients: (1)
`with intraocular pressure (IOP) values above
`Exhibit 1049
`ARGENTUM
`IPR2017-01053
`
`Department of
`Ophthalmology,
`Leiden University
`Hospital, Leiden, the
`Netherlands
`E V M J Kuppens
`C A de Jong
`T R Stolwijk
`R J W de Keizer
`J A van Best
`Correspondence to:
`J A van Best, PhD,
`Departnent of
`Ophthalmology, University
`Hospital Leiden,
`Rijnsburgerweg 10, 2333 AA
`Leiden, the Netherlands.
`Accepted for publication
`16 November 1994
`
`000001
`
`

`

`340
`
`30 mm Hg when using timolol+BAC; (2)
`using other topical ophthalmic medication
`than timolol or using systemic anti-glaucoma
`treatment or 3 blocking medication any time
`before fluorophotometry; (3) wearing contact
`lenses.
`The study was approved by the medical
`ethics committee of the Leiden University
`Hospital. Informed consent was obtained from
`each patient after a verbal and written explana-
`tion of the procedure of the study.
`
`MEDICATION
`Timolol+BAC (Timoptol 0-25% and 0 50%;
`Merck, Sharp & Dohme, Paris, France; avail-
`able in USA as Timoptic, Rahway, NJ).
`Timolol-BAC (Timoptol-Ocudose 0-25%
`and 0 50%; also Merck, Sharp & Dohme).
`Both solutions were identical except for the
`component BAC.
`
`APPARATUS
`Fluorophotometric measurements were carried
`out with the Fluorotron Master (Coherent
`Radiation Inc, Palo Alto, CA, USA) fitted with
`a special lens (anterior segment adapter) for
`detailed scanning of the anterior segment of
`the eye along the optical axis.8 A reduced
`scanning time was used in order to prevent
`blinking during scanning by modifying the
`commercial software.8
`
`FLUOROPHOTOMETRIC PROCEDURE
`The fluorophotometric measurements were
`performed about 5 hours after the last timolol
`instillation. Four fluorophotometric scans of
`each cornea were carried out to determine
`corneal autofluorescence.9 Then 1 1dl of a 2%
`into the
`solution was instilled
`fluorescein
`lateral part of the lower conjunctival fornix of
`each eye via a microcapillary tube according to
`a method described previously.7 10 Hereafter,
`both eyes were alternately scanned every 1.5
`minutes for about 30 minutes. After the
`fluorophotometric measurements the cornea
`was examined by slit-lamp biomicroscopy. The
`precorneal tear film integrity was determined
`by the tear film BUT. BUT values of patients
`and healthy controls were all assessed to be
`shorter or longer than 10 seconds. This time
`represents the interval from the last blink to the
`first dry spot in the tear film while the fluores-
`cein stained tear film is examined by slit-lamp
`biomicroscopy using cobalt light. The IOP was
`measured with applanation tonometry.
`Basal tear turnover is defined as the tear
`turnover at the lowest level of reflex lacrima-
`tion possible under physiological conditions
`(minimally stimulated tears). Assuming that
`fluorescence measured was
`tear
`film
`the
`proportional to the fluorescein concentration
`present in the tear film, the basal tear turnover
`was determined from the decay of fluorescence
`between 5 and 30 minutes after instillation
`of fluorescein since at that time no reflex
`lacrimation was present any more and the
`decay of fluorescein was monophasic.7 These
`
`Kuppens, de _Jong, Stolwijk, de Keizer, van Best
`
`repeated
`procedures
`were
`measurement
`2 weeks after the patient had changed from
`timolol+BAC to timolol-BAC medication
`with an identical percentage of timolol. An
`interval of 2 weeks was chosen because
`this time is required for the 'washout' effect of
`timolol+BAC.1' All patients were asked by
`means of a standard questionnaire whether
`the
`they had any complaints related
`to
`medication and if they preferred one of the two
`medications.
`All measurements were carried out by
`the same investigators and with the same
`equipment as in the previous study.7 The
`measurements were done in the same darkened
`room without a direct connection with the
`Temperature and humidity were
`outside.
`regulated and the air movement was restricted
`to a minimum. Also the slit-lamp biomicro-
`scopic examination, the BUT assessment, and
`IOP measurements were done by the same
`clinician who was not aware of the outcomes of
`the fluorophotometric measurements.
`Previous studies'2 13 showed that BAC can
`induce an increase in the comeal epithelial
`permeability. An increased penetration of
`fluorescein in the cornea might result in an
`apparently lower tear turnover value since
`fluorescence of the tear film is measured simul-
`taneously with the fluorescence of the cornea
`as a result of the limited spatial resolution of
`the fluorophotometer. In order to check for
`corneal penetration of the instilled fluorescein,
`the tear turnover measurements were repeated
`in three patients when using timolol+BAC to
`determine the amount of fluorescein in the
`cornea. This was done by washing the eye with
`eyebaths containing saline 25-30 minutes after
`the instillation of fluorescein and hereafter
`measuring the concentration of fluorescein
`present in the cornea.
`
`STATISTICAL ANALYSIS
`The paired Student's t test was used for
`statistical analysis of the tear turnover values
`before and after the change of medication.
`The normality of tear turnover value distribu-
`tion was assessed in the patients by using
`d'Agostino's test for departure from normal-
`ity.'4 The values of the patients were com-
`pared with those of 27 healthy controls
`measured by the same investigators in a
`previous study7 (mean age 58 (11) years). For
`evaluation of the BUT values Fisher's exact
`test was used and a BUT value shorter than
`10 seconds was considered not normal. '5
`
`Results
`Twenty patients with open angle glaucoma or
`ocular hypertension participated in the study
`(mean age 60 (SD 13) years; mean duration of
`using timolol before first fluorophotometric
`measurements 3-5 years).
`Basal tear turnover values of patients when
`using timolol+BAC versus the values when
`using timolol-BAC are presented in Figure 1.
`The tear turnover values increased signifi-
`cantly after the change of medication (mean
`
`000002
`
`

`

`Effect of timolol with and without preservative on the basal tear turnover in glaucoma
`
`341
`
`Table 1
`
`Basal tear turnover, intraocular pressure, and tearfilm break up time
`
`Patients* when using timolol+BAC
`Patients* when using timolol-BAC
`Healthy controlst
`
`Tear turnover
`Mean (SD)
`(%/a/min)
`10-7 (3 0)
`13-2 (5-1)
`15-7 (5 3)
`
`IOP
`Mean (SD)
`(mm Hg)
`17-7 (2-0)
`18-1 (3 0)
`14-7 (2 9)
`
`Number ofsubjects with
`tearfilm break up time
`<10 seconds
`>10 seconds
`
`4
`5
`0
`
`16
`15
`27
`
`*Open angle glaucoma or ocular hypertension patients. tMeasure in a previous study.7
`
`patients;
`they all
`preferred using timolol
`-BAC. One patient preferred using timo-
`lol+BAC. The remaining 10 patients did not
`give any preference for either timolol+BAC or
`timolol-BAC.
`Tear turnover measurements were repeated
`in three patients when using timolol+BAC in
`order to check for corneal penetration of
`fluorescein. The total fluorescein mass in the
`cornea amounted from 0-02% to 2-3% of that
`present in tear film 25-30 minutes after the
`fluorescein
`instillation. The 2-3% value
`was found in a patient with evident corneal
`dystrophy which was confirmed by slit-lamp
`biomicroscopy after the measurements.
`
`intraindividual increase 28%
`(47%), range
`-34% to 141%; paired Stu
`dent's
`t
`test
`p=0 04). Mean basal tear turn
`over and IOP
`values before and after the
`change from
`timolol+BAC to timolol-BAC
`are presented
`in Table 1. The mean tear turnol
`ver value when
`using timolol+BAC was signi:
`ficantly lower
`than the value of healthy cc
`)ntrols7 (32%
`decrease; Table 1; Student's t tes
`st, p<00001).
`tear turnover
`On the other hand the mean
`did not differ
`value when using timolol-BAC
`significantly from that of heE
`althy controls
`irnover values
`(p=0 1; Table 1). The tear tu
`were not significantly correlated
`with the dura-
`tion of timolol+BAC medicat
`ion (r<-0-4,
`p>005). The mean difference
`between the
`intraindividual IOP values befor
`e and after the
`significant
`change of medication was n
`Lot
`'2); p=0 6).
`(mean difference 0 4 mm Hg (3-
`The BUT values of all patients
`s are presented
`in Table 1. The BUT values
`s when using
`iificantly from
`timolol+BAC did not differ sigr
`,AC (Fisher's
`those when using timolol-B
`T values were
`exact test: p=05) but both BU
`f healthy con-
`significantly lower than those o:
`trols (p=0 009 and p=0 003,
`respectively).
`None of the 20 patients showe4
`d a superficial
`punctate keratopathy on final sli
`it-lamp biomi-
`of
`examination
`after
`the
`croscopic
`use
`timolol+BAC or after the uz
`se of timolol
`-BAC. Ten patients complainec
`i ofburning or
`dry eye sensations when using t
`timolol+BAC.
`ir disappeared
`These complaints diminished c
`after changing to timolol-B
`AC in
`nine
`
`Discussion
`The mean basal
`tear turnover values in
`patients with open angle glaucoma and ocular
`hypertension
`increased
`from
`10-7
`to
`13 20/o/minute when these patients changed
`from
`preservative-free
`timolol+BAC to
`timolol. This indicates an improvement of
`tear production towards normal values (mean
`tear turnover value in healthy controls is
`15 60/o/minute). A close inspection of Figure 1
`reveals that a distinct improvement of the tear
`turnover (> + 10%) occurred in nine patients
`(average +70%) and a distinct deterioration of
`tear turnover (<-1 0%) occurred in three
`patients (average -28%). Complaints about
`burning or dry eye sensations diminished or
`even disappeared in nine of the 10 patients
`after the change in medication. Six of them
`were nine patients showing a tear turnover
`improvement of 70% (see Figure 1). Note that
`the assessment of acceptability was subjective
`and biased since each patient knew when he
`was using the preservative-free timolol solu-
`tion'6; this is in contrast with the fluorophoto-
`metric
`which
`allowed
`measurements
`an
`objective evaluation.'
`In a previous study4 it was demonstrated that
`the chronic application of timolol containing
`benzalkonium chloride (BAC) by glaucoma
`..patients resulted in an impairment of the
`aqueous layer production rate. The increase in
`tear turnover values in our patients when
`changing from timolol+BAC to timolol-BAC
`medication corroborates these findings and
`demonstrates that the component BAC causes
`impairment of the aqueous tear flow. BAC is
`known to affect the superficial lipid layer of the
`precorneal tear film.17 A defective lipid layer
`results in an increased evaporation of the tear
`fluid. Consequently, the rate of disappearance
`of fluorescein will be diminished as less tear
`fluid is available for washing out the instilled
`fluorescein.
`Exaggerated use of BAC can also induce
`epithelial damage'2 and lead to an increased
`corneal
`epithelial
`permeability.'3 Such an
`increased permeability can increase the corneal
`penetration of fluorescein and might then
`result in unreliable tear turnover measure-
`ments. The tear turnover values in our study
`are not likely to result from an increased
`corneal penetration of fluorescein. The mass of
`fluorescein in the cornea was at most 2-3% of
`
`30
`
`,.Z'
`
`o
`
`a0.
`
`. '
`00
`
`o.O
`
`30 r
`
`20
`
`10o
`
`m -
`
`co
`5
`
`E C
`
`D2
`'3 E
`-c
`
`C (
`
`1
`
`,,
`
`0
`
`10
`
`Tear turnover when using
`
`20
`timolol + BAG
`
`(%Imin)
`,ressed in per cent
`Figure 1
`Basal tear turnover values exp
`rlar hypertension
`per minute in open angle glaucoma or ocu
`the values in the
`patients when using timolol+BAC versus
`same patients when using timolol-BACf
`ean valueeof both
`broken line represents equal values. The n;
`zover values were
`eyes was used since left and right tear turn
`correlated (r>0-5, p<0-05).
`
`000003
`
`

`

`342
`
`that present in tear film about 25-30 minutes
`after instillation of fluorescein even in a patient
`with an evident corneal dystrophy.
`The effect of BAC can be expected to occur
`particularly in patients using a BAC containing
`medication several times a day for a long
`period as in, for instance, dry eye syndrome
`and glaucoma.7 1318 On the other hand, it
`can be postulated that the effect of BAC on
`the basal tear turnover is presumably an
`immediate and reversible effect because (1) no
`significant correlation was found between tear
`turnover values and the duration of instilling
`BAC containing timolol in this study, and (2)
`removal of BAC from timolol restored the tear
`turnover towards normal values within 2 weeks
`even in glaucoma patients who have been using
`daily timolol+BAC for several years (mean
`duration of timolol+BAC medication in this
`study 3-5 years).
`The BUT values of the glaucoma patients in
`this study did not differ significantly when
`changing from timolol+ BAC to timolol-BAC
`medication. Note that the five patients with a
`decreased BUT value did not correspond to
`those with a decreased tear turnover value. All
`the patients had good eyelid hygiene and no
`evident pathology of their lacrimal apparatus.
`The reduction of the BUT could have been
`induced by the fluorescein used to determine
`the BUT since fluorescein itself can affect tear
`stability.19 Yet, the BUT results of
`film
`patients and healthy controls were obtained
`using the same method, thus making compari-
`son possible.
`The BUT values did not disagree with those
`in a previous study3 in which only a small
`increase of the values (about 2 seconds) could
`be found in similar patients after changing
`from timolol+BAC to timolol-BAC medi-
`cation. Our results suggest that timolol (timo-
`lol-BAC) itself can impair the tear film
`stability but no direct supportive evidence is
`is possible that the
`available. However, it
`BUT is still impaired by BAC. BAC has been
`shown to affect the BUT by reducing the pro-
`duction of the tear film mucous layer.4 Active
`concentrations of BAC in the comeal epithe-
`lium and conjunctiva could be detected up to
`7 days after instillation of a single drop.20
`After 2 weeks of instilling timolol-BAC, it
`can be expected that depots of BAC are still
`the
`conjunctiva
`of glaucoma
`in
`present
`patients who have instilled multiple doses of
`BAC containing timolol for several years.
`Timolol-BAC was found to be as effective
`as timolol+BAC in lowering the IOP in the
`patients
`participating
`this
`in
`study.
`Timolol-BAC can
`be recommended in
`patients who need IOP lowering and who have
`keratoconjunctivitis sicca or borderline tear
`
`Kuppens, de _rong, Stolwijk, de Keizer, van Best
`
`production and in glaucoma patients who have
`subjective complaints about dry eye sensation
`when using timolol+BAC. In these cases it
`may be BAC that is contributing to a decreased
`tear production and exacerbating a dry eye
`state. The improved comfort of this frequently
`used topical drug can promote compliance
`with treatment for patients with glaucoma and
`ocular hypertension, who are often obliged to
`instil timolol twice a day for life.
`
`The authors thank Chibret, MSD, for supplying timolol-BAC
`(Timoptol Ocudose). This study was supported in part by
`grants from the 'Leids Oogheelkundig Ondersteunings Fonds',
`'Haags
`the
`Netherlands
`and
`from
`Wassenaar,
`the
`Oogheelkundig Fonds', Wassenaar, the Netherlands.
`
`1 Van Buskirk EM. Corneal anaesthesia after timolol maleate
`therapy. Am J Ophthalmol 1979; 88: 739-43.
`2 McMahon CD, Shaffer RN, Hoskins HD, Heteringhton J
`Jr. Adverse effects experienced by patients taking timolol.
`Am Y Ophthalmol 1979; 88: 736-8.
`3 Marquardt R, Schubert T. Beeinflussung der Tranenfilm-
`aufreisszeit (BUT) durch Betablocker-augentropfen ohne
`Konservierungsstoffe. Klin Monatsbl Augenheilkd 1991;
`199: 75-8.
`4 Herreras JM, Pastor JC, Calonge M, Asensio VM. Ocular
`surface alteration after long-term treatment with an
`1992;
`99:
`antiglaucomatous
`drug.
`Ophthalmology
`1082-8.
`5 Strempel I. The influence of topical a-blockers on the
`breakup time. Ophthalmologica 1984; 189: 110-5.
`6 Wilson WS, Duncan AJ, Jay JL. Effect of benzalkonium
`chloride on the stability of the precorneal tear film
`in rabbits and man. Br J Ophthalmol 1975;
`59:
`667-9.
`7 Kuppens EVMJ, Stolwijk TR, de Keizer RJW, van Best JA.
`Basal tear turnover and topical timolol in glaucoma
`patients and healthy controls by fluorophotometry. Invest
`Ophthalmol Vis Sa 1992; 33: 3442-8.
`8 De Kruijf EJFM, Boot JP, Laterveer L, van Best JA,
`Ramselaar JAM, Oosterhuis JA. A simple method for
`of comeal epithelial
`determination
`permeability
`in
`humans. Curr Eye Res 1987; 6: 1327-34.
`9 Stolwijk TR, van Best JA, Boot JP, Oosterhuis JA. Corneal
`autofluorescence in diabetic and penetrating keratoplasty
`patients as measured by fluorophotometry. Exp Eye Res
`1990; 51: 403-9.
`Gasset
`Klyce Jr SD, Baum JL.
`S,
`A,
`10 Misihima
`Determination of tear volume and tear flow. Invest
`Ophthalmol Vis SCi 1966; 5: 264-76.
`11 Steinert RF, Thomas JV, Boger III WP. Long-term drift
`and continued efficacy after multiyear timolol therapy.
`Arch Ophthalmol 1981; 99: 100-3.
`12 Berdy GJ, Abelson MB, Smith LM, George MA.
`Preservative-free artificial tear preparations; assessment of
`comeal epithelial toxic effects. Arch Ophthalmol 1992;
`110: 528-32.
`13 G6bbels M, Spitznas M. Corneal epithelial permeability of
`dry eyes before and after treatment with artificial tears.
`Ophthalmology 1992; 99: 873-8.
`14 Zar JH. The normal distribution.
`In: Kurtz B, ed.
`Biostatistical analysis. New Jersey: Englewood Cliffs,
`Prentice-Hall Inc, 1984: 79-96.
`15 Lemp MA, Chacko B. Diagnosis and treatment of tear defi-
`ciencies. In: Tasman W, Jaeger EA, eds. Duane's clinical
`ophthalmology. Rev ed. Philadelphia: Harper & Row,
`1993; vol 4, chapter 14.
`16 Vogel R. Surface toxicity of timolol [Letter]. Ophthalmology
`1993; 100: 293-4.
`17 Burstein NL. Basic science of ocular pharmacology. In:
`Bartlett JD, Jaanus SD, eds. Clinical ocular pharmacology.
`2nd ed. Stoneham MA: Butterworths, 1989: 20-2.
`18 G6bbels M, Spitznas M. Influence of artificial tears on
`corneal epithelium in dry-eye syndrome. Graefes Arch Clin
`Exp Ophthalmol 1989; 227: 139-41.
`19 Mengher LS, Bron AJ, Tonge SR, Gilbert DJ. Effect of flu-
`orescein instillation on the pre-corneal tear film stability.
`Curr Eye Res 1985; 4: 9-12.
`20 Champeau EJ, Edelhauser HF. Effect of ophthalmic
`preservatives on the ocular surface: conjunctival and
`corneal uptake and distribution of benzalkonium chloride
`and chlorhexidine digluconate. In: Holly FJ, ed. The
`preocular tear film. Lubbock: Dry Eye Institute, 1986:
`292-302.
`
`000004
`
`