EYEMATE IMPLANTABLE TONOMETER

 

The Eyemate system consists of a permanent implantable and biocompatible micro sensor, which provides continuous intraocular pressure (IOP) measurements. The Eyemate-SC, developed by the German company Implandata Ophthalmic Products, is inserted into the suprachoroidal space. The Eyemate-IO is implanted in the ciliary sulcus.

Sulcus implanted wireless telemetric sensors were shown to be generally safe and to provide long-term reliable IOP measurements. However, ciliary sulcus implantation has numerous disadvantages such as iris chafing and atrophy, pupillary distortion and pigment dispersion. The implants are reserved for pseudophakic or cataract patients, which excludes younger patients for whom long-term IOP monitoring is particularly important. Furthermore, the bulky sensor ring needs a large corneo-scleral incision and causes excessive manipulation during sulcus implantation. The ARGOS and ARGOS-02 trials for the Eyemate-IO did show good patient tolerability and provided measurements that closely agreed with manometric pressure measurements.

The Eyemate device consists of eight pressure- and temperature-sensitive capacitors attached to a gold circular antenna, and readings are transmitted through an external handheld device which also charges the Eyemate through electromagnetic coupling.

The IOP measurements are transmitted via a wireless data connection to a secure internet-based database. This enables the treating physician to monitor the IOP and then decide the adjustment of the glaucoma medications.

The Eyemate smartphone app will provide helpful information about the disease status and the therapy success to the patient and a medication schedule can be established, which reminds the patient automatically when he/her has to apply his/her glaucoma medication.

One of the main advantages of IOP sensors is that they are independent of corneal biomechanics. While corneal-surface-based tonometry techniques only measure relative dimensional changes of the eye with questionable validity, intraocular sensors directly measure the absolute IOP.

SURGICAL TECHNIQUE:

To implant the sensor, the suprachoroidal space is accessed either through the window (100% thickness technique) or through a 5mm incision in the remaining scleral lamella (90% thickness technique). The choroid is separated from the sclera by means of OVD, and the EYEMATE-SC implant is carefully inserted into the suprachoroidal space using padded implantation forceps and avoiding contact with the sensor’s ASIC. Afterward, the superficial scleral flap and the conjunctiva are closed and sutured.

COMPLICATIONS:

The most frequent postoperative complication after Eyemate implantation is hyphema. Other complications reported are: superficial punctate keratitis, postoperative leakage, choroidal detachment and hypotony, postoperative photopsia, touch sensitivity, slight pain in the operative area, and intermittent headaches. No serious AEs related to the EYEMATE-SC sensor have been reported.

REFERENCES:

1. Szurman P, Gillmann K, Seuthe AM, Dick HB, Hoffmann EM, Mermoud A, Mackert MJ, Weinreb RN, Rao HL, Mansouri K; EYEMATE-SC Study Group. EYEMATE-SC Trial: Twelve-Month Safety, Performance, and Accuracy of a Suprachoroidal Sensor for Telemetric Measurement of Intraocular Pressure. Ophthalmology. 2023 Mar;130(3):304-312. doi: 10.1016/j.ophtha.2022.09.021. Epub 2022 Oct 3. PMID: 36202141.
2. Szurman P, Mansouri K, Dick HB, Mermoud A, Hoffmann EM, Mackert M, Weinreb RN, Rao HL, Seuthe AM; EYEMATE-SC study group. Safety and performance of a suprachoroidal sensor for telemetric measurement of intraocular pressure in the EYEMATE-SC trial. Br J Ophthalmol. 2023 Apr;107(4):518-524. doi: 10.1136/bjophthalmol-2021-320023. Epub 2021 Nov 12. PMID: 34772665; PMCID: PMC10086291.
3. Koutsonas A, Walter P, Roessler G, Plange N. Implantation of a novel telemetric intraocular pressure sensor in patients with glaucoma (ARGOS study): 1-year results. Invest Ophthalmol Vis Sci. 2015 Jan 22;56(2):1063-9. doi: 10.1167/iovs.14-14925. PMID: 25613949.
4. Choritz L, Mansouri K, van den Bosch J, Weigel M, Dick HB, Wagner M, Thieme H; ARGOS study group. Telemetric Measurement of Intraocular Pressure via an Implantable Pressure Sensor-12-Month Results from the ARGOS-02 Trial. Am J Ophthalmol. 2020 Jan;209:187-196. doi: 10.1016/j.ajo.2019.09.011. Epub 2019 Sep 20. PMID: 31545953.

BRIMONIDINE WITHOUT PRESERVATIVES (ALPHA VISION SINE)

DR JOSEF FLAMMER

ENGLISH VERSION

For the drug therapy of glaucoma, the physicians have various antiglaucomatous drugs with

different mechanisms of action at their disposal. The range of glaucoma therapies is now

being expanded with the market launch of the preservative-free brimonidine (Alpha-Vision®

sine).

Brimonidine is a highly selective α2- adrenoreceptor agonist. Adrenoreceptors are receptors

that are stimulated with epinephrine and norepinephrine and thus transfer information from

the sympathetic nervous system and the adrenal cortex to terminal organs. They play a diverse role, including in the regulation of blood pressure and eye pressure.

Accordingly, pharmacological attempts have been made for a long time to influence these

receptors. Unfortunately, this pharmacology is not so easy to understand. Because there are

different adrenoreceptors (α, β etc.) and even more subtypes (e.g. α1, α2, α3 etc.) and

finally, sub-subtypes (e.g. α2A, α2B, α2C, etc.). These receptors are expressed in different

organs to different degrees and their density is not constant. They are permanently

degraded and newly synthesized. This activity depends on the current demand of the

respective cell and is therefore variable in time [1].

To distinguish: Mode of action of the α2-agonists at pre- and postsynaptic α2-receptors,

α2 receptors occur both presynaptically and postsynaptically. The same agonist acts

inhibiting via the presynaptic receptors and stimulating via the postsynaptic receptors.

In the central nervous system, the presynaptic α2 receptors predominate. Here agonists have

an inhibitory effect, i.e. the release of neurotransmitters is reduced. Therefore, they lead to

analgesia, sedation, blood pressure reduction and hyperthermia.

In the periphery, however, the post-synaptic α2 receptors predominate. Here the agonists

lead to stimulation and thus, among other things, to vasoconstriction [2].

α2-receptor agonists in ophthalmology:

Already in the 1960s, a α2 receptor agonist, namely clonidine, was used for the treatment of

arterial hypertension [2]. In the 1970s, clonidine was also marketed as eye drops for

lowering eye pressure [3, 4]. Because of the side effects, the application remained limited.

Clonidine was particularly popular as premedication before retrobulbar anesthesia because

it also reduced anxiety, pain and blood pressure [5].

In 1988, apraclonidine, an amino derivative of clonidine that is less lipophilic and therefore

crosses the blood-brain barrier less frequently, was introduced to the market. Apraclonidine

thus has fewer central effects such as lowering blood pressure. Unfortunately, however,

allergies are relatively common [4].

Brimonidine followed in 1997, an imidazoline which has less central effects than clonidine

and causes fewer allergies than apraclonidine. It lowers the intraocular pressure by reducing

the production of aqueous humor and improving uveoscleral outflow. In contrast to betablockers, it also lowers intraocular pressure at night [4, 6].

Now there is this new brimonidine free of preservatives with similarly good effects, but

considerably less side effects [7]. The extension of the spectrum of preservative-free

antiglaucomatous agents is positive, because preservatives - especially benzalkonium

chloride - can cause chronic irritation, trigger allergies and aggravate a sicca syndrome [8].

Neuroprotection and vasoconstriction by Brimonidine

α2 agonists have a neuroprotective effect in vitro. Whether this is also the case in vivo in

glaucoma patients are difficult to prove. Visual field studies indicate that this is the case [9]. In

order to have this effect, however, the molecule must pass through the blood-brain or

blood-retina barrier. For this reason, a slightly central sedative and rarely a blood pressure

lowering effect must be accepted for brimonidine [4].

Brimonidine also has a slight vasoconstrictive effect, both in the periphery and the eye. This

is why caution is advised in patients with Raynaud's syndrome [10]. This effect is exploited in

a local application on the skin for the treatment of rosacea [11].

Dr. K. Konieczka in Basel investigated the effect of glaucoma drugs on corneal temperature.

After brimonidine (but not placebo) the temperature decreased slightly (due to

vasoconstriction in the anterior segment of the eye) for about 90 minutes. Interestingly, this

effect was significantly stronger in patients with Flammer syndrome (FS) than in patients

without FS [12]. This also corresponds to our clinical experience: Patients without FS tolerate

brimonidine significantly better than patients with FS.

In summary, we can say that Alpha-Vision® sine1 twice a day has a good lowering of

intraocular pressure and a possibly neuroprotective effect and can be combined with other

drugs. It has significantly fewer side effects than its predecessor molecules. The central

effects and vasoconstrictions are weak but still present. Therefore, Alpha-Vision® sine1 is

more suitable for glaucoma patients without FS than for glaucoma patients with FS.

Prof. Dr. Med. Josef Flammer

Former head of the eye clinic, University Hospital Basel, Switzerland

EFFECT OF MASSAGE ON IOP

 

DR. SHIBRA FAROOQ

P.G. SCHOLAR

DEPARTMENT OF ILAJ-BIT-TADBEER

AJMAL KHAN TIBBIYA COLLEGE,

ALIGARH MUSLIM UNIVERSITY, INDIA

 

Intraocular pressure (IOP) fluctuates with body position. The IOP is lowest in the sitting posture and increases in the order of supine and lateral decubitus positions.

These changes are attributed to the increase in episcleral venous pressure and choroidal vascular volume. The uveal tissues also develop congestion and expansion from increased venous and arterial pressures in the orbit, contributing to the increased IOP.

Massage is an important component of Ilaj-bit-tadbeer in Unani medicine. Known as dalk, it is done for both prophylactic and therapeutic reasons.

Body massage has also become popular recently as a relaxation technique. Massage parlors and spas are coming up in different places.

In a study from Thailand, participants received muscle relaxing massage and facial lymphatic drainage for 15 minutes. The mean IOP significantly decreased 0.87+1.43 mmHg (p=0.01) for the right eyes. However, no significant difference in the left eyes was seen. [1]

Therefore, massage to relax muscles and lymphatic drainage of muscles around the head and face might reduce IOP.

In a study from the Philippines, 46 volunteers were recruited to have a back massage in the prone position for 30 minutes by a professional masseuse. The IOP was taken before the massage, and after the massage. The IOP uniformly increased in 43 of the 46 participants immediately after the massage. [2]

A study was performed by Patel et al, at Temple University, USA to determine the effect of foot reflexology in primary open-angle glaucoma (POAG) and ocular hypertension (OHT). Patients with glaucoma performed a 5-minute foot massage on a foot massage board. In the POAG patients, the IOP significantly decreased up to 10% of the pre-massage levels. [3]

These studies show that IOP changes with body posture and patients with glaucoma can be informed of the risks of lying in the same posture for long periods. The risk of supine position is greatest and individuals with glaucoma or those at risk of glaucoma should not undergo such massages.

On the contrary, facial massage, and foot massage reduce IOP and can probably be taught to individuals to perform themselves at home.

REFERENCES:

1. Pattaranit, P., Ratanapakorn, T., Limphatcharaporn , J., & Sitthiracha , P. (2022). Immediate Effect of Facial Massage and Lymphatic Drainage Massage on Intraocular Pressure. Journal of Vongchavalitkul University, 35(1), 45–59. Retrieved from https://ph01.tci-thaijo.org/index.php/vujournal/article/view/245503.
2. https://paojournal.com/article/the-effect-of-body-massage-lying-face-down-on-intraocular-pressure-in-normal-eyes/. Last accessed on 07.07.2024
3. Patel D, Henderer JD, Kung P, Cohen D, Krane A, Yu D. The effect of foot reflexology on intraocular pressure in ocular hypertension and primary open-angle glaucoma patients. Invest. Ophthalmol. Vis. Sci. 2021;62(8):2563.

SMARTPHONE USE AND INTRAOCULAR PRESSURE

 

Smartphone and digital device use has become very common. It would be interesting to know the effect of using phones on intraocular pressure (IOP). A few studies have been performed to analyze the effect of using smartphones on IOP.

A study was performed by Srivastava et al, to compare the effect on IOP while reading smartphone digital text and printed text in healthy, and in glaucoma patients. The study included 60 healthy and 22 patients who had medically controlled POAG. The participants were asked to perform reading tasks on printed text followed by digital text on a smartphone. The IOP assessment was done at baseline and subsequently at 10, 20, and 30 minutes of reading and 10 and 20 minutes after completing the reading tasks. IOP variations from baseline were measured and compared. The mean baseline IOP in volunteers was 14.58 (±2.91) mmHg, while in POAG patients it was 15.02 (±2.18) mmHg. The IOP was found to rise in all participants (healthy, as well as, glaucoma patients) while reading both printed text and digital text. It returned to normal 20 minutes after stopping the reading. However, there was a relatively marked rise in IOP on reading smartphone text, compared to digital text.

Ha et al, performed a study on healthy volunteers to investigate the effect of reading or writing on a smartphone on IOP changes. The study included 39 healthy volunteers less than 40 years of age. The participants were tasked to conduct standardized work (i.e., read a sample text on a single mobile device and subsequently type it on the same device) under daylight [300 lux] and low-light [100 lux] conditions independently on consecutive days. On each day, three sets of IOP measurements (total: 7) were performed: (1) pre-work (baseline), (2) during smartphone work [5, 15, and 25 minutes], and (3) post-work [5 and 15 minutes].

The study reported that the mean IOP had a persistent rise from baseline under daylight conditions. While the baseline IOP was around 14 mmHg, it increased to around 15 mmHg after 5 minutes of work, then almost 16 mmHg after 15 minutes of work, and persisted over 25 minutes of smartphone use. When the smartphone use was stopped for 5 minutes, the IOP returned to levels even below baseline levels.

The underlying ocular dynamics for these IOP changes during and after smartphone work are unclear, though the following mechanisms are assumed to be involved: 1) Accommodation and convergence; 2) external ocular muscle (EOM) contraction; 3) psychophysiological stress; 4) dry eye; 5) neck-flexion posture.

Therefore, smartphone users concerned about IOP fluctuation are advised to:

1.  Take a break if they read or write on their smartphone for more than 5 minutes, 
2.  Avoid using smartphones wherever possible in dark places.

REFERENCES:

Srivastava, Rajat Mohan; Agrawal, Siddharth; Amrin, Nayani; Bharti, Devanand. Intraocular Pressure Changes While Reading Smartphone Digital Text Versus Printed Text in Healthy Individuals and those with Glaucoma. Journal of Glaucoma 33(3):p 189-194, March 2024. | DOI: 10.1097/IJG.0000000000002314

Ha A, Kim YK, Park YJ, Jeoung JW, Park KH (2018) Intraocular pressure change during reading or writing on smartphone. PLoS ONE 13 (10): e0206061.

 

EXERCISE IN GLAUCOMA: TO DO OR NOT TO DO?

 

DR. ALIYA

P.G. SCHOLAR

DEPT OF ILAJ-BIT-TADBEER

STATE UNANI MEDICAL COLLEGE AND HOSPITAL

PRAYAGRAJ, INDIA

 

Controversy exists among the patients and the healthcare industry about whether exercise, especially certain exercises such as yoga, is useful or harmful for glaucoma patients.

Many articles have shown the positive and negative sides of exercises on glaucoma status.

PROS OF EXERCISE:

Studies have shown that aerobic exercises are particularly useful in glaucoma patients. These exercises improve circulation in the brain and therefore, are useful for the eye, especially in glaucoma patients who have vascular anomalies contributing to glaucomatous damage.

A prominent glaucoma expert, Dr. Robert Ritch recommends 45 minutes of aerobic exercise 3-4 times per week. Walking, swimming, biking, or working out on stationary machines lowers intraocular pressure (IOP) and improves blood circulation to the eye and brain.

A study by Lee et al reported that increased walking, greater time spent doing moderate-to-vigorous physical activity, and more time spent in non-sedentary activity were associated with slower rates of VF loss in a treated population of patients with glaucoma, with an additional 5000 daily steps or 2.6 hours of non-sedentary physical activity decreasing the average rate of VF loss by approximately 10%. [1]

A study by Janicijevic et al reported that low-intensity aerobic exercise had a lowering effect on IOP, being the beneficial effect more accentuated and prolonged in the High-fit group (IOP reduction compared to baseline lasted 30 minutes) than in the Low-fit group (IOP was only reduced at 6 minutes of exercise compared to baseline). [2] 

Ramulu and associates have also found that substantial reductions in physical activity and walking were noted with greater levels of VF loss. [3] 

In experiments on mice, Chrysostomou and collegues reported that exercise almost completely reversed age-related vulnerability of the optic nerve to injury such that exercised aged mice had a similar functional response to injury as non-exercised young (3-month-old) mice. Exercise also abrogated injury-induced astrocytic gliosis and macrophage activation in the aged retina. These data suggest that the known benefits of exercise also extend to the visual system and support further investigation of physical activity as a means of protecting against injury, dysfunction, and degeneration in the aging eye. [4] 

A meta-analysis has found that mild-intensity aerobic exercises are beneficial because of their diverse mechanisms in glaucoma patients. They can help in the transient reduction of IOP and have a beneficial effect on glaucoma severity and progression. [5] 

CONS OF EXERCISE:

A large study from the UK Biobank Eye and Vision Consortium did not find a significant association between exercise and glaucoma. Higher overall physical activity (PA) level and greater time spent in moderate and vigorous exercise were not associated with glaucoma status but were associated with thicker mGCIPL. Associations with IOP were modest and inconsistent. Despite the well-documented acute reduction in IOP after PA, there was no evidence that high levels of habitual PA are associated with glaucoma status or IOP in the general population. [6] 

Certain yoga postures are especially harmful for glaucoma patients. Studies have shown downward facing dog (adho mukha svanasana), standing forward bend (uttanasana), Plow (halasana), and legs up the wall (viparita karani) are especially harmful in glaucoma patients. A study found that the above mentioned four poses raised IOP in both the control group and the glaucoma patients, with the greatest increases associated with downward-facing dog. Once the subjects returned to a seated position, they were tested immediately and 10 minutes later. The IOP returned to baseline levels at these time points.

A study by Liu et al found that arterioles show increased stiffness with aging and it cannot be reversed with exercise.[7] 

CONCLUSION:

It can be inferred from the above studies that light aerobic exercises are useful, but heavy exercises like weight-lifting and certain yoga postures are deleterious for glaucoma patients and should be avoided.

REFERENCES:

1. Moon Jeong Lee, Jiangxia Wang, David S. Friedman, Michael V. Boland, Carlos G. De Moraes, Pradeep Y. Ramulu, Greater Physical Activity Is Associated with Slower Visual Field Loss in Glaucoma. Ophthalmology, Volume 126, Issue 7,2019,Pages 958-964.
2. Janicijevic, D., Redondo, B., Jiménez, R., Garcia-Ramos, A., & Vera, J. (2022). The intraocular pressure lowering-effect of low-intensity aerobic exercise is greater in fitter individuals: a cluster analysis. Research in Sports Medicine, 32(1), 86–97.
3. Pradeep Y. Ramulu, Eugenio Maul, Chad Hochberg, Emilie S. Chan, Luigi Ferrucci, David S. Friedman, Real-World Assessment of Physical Activity in Glaucoma Using an Accelerometer, Ophthalmology, Volume 119, Issue 6, 2012, Pages 1159-1166, https://doi.org/10.1016/j.ophtha.2012.01.013.
4. Chrysostomou V, Kezic JM, Trounce IA, Crowston JG. Forced exercise protects the aged optic nerve against intraocular pressure injury. Neurobiol Aging. 2014 Jul;35(7):1722-5. doi: 10.1016/j.neurobiolaging.2014.01.019. Epub 2014 Jan 23. PMID: 24524967.
5. Gildea, David MB BCh BAO; Doyle, Aoife MB, BCh; O’Connor, Jeremy MB, BCh. The Effect of Exercise on Intraocular Pressure and Glaucoma. Journal of Glaucoma 33(6):p 381-386, June 2024. | DOI: 10.1097/IJG.0000000000002411.
6. Madjedi KM, Stuart KV, Chua SYL, Ramulu PY, Warwick A, Luben RN, Sun Z, Chia MA, Aschard H, Wiggs JL, Kang JH, Pasquale LR, Foster PJ, Khawaja AP; Modifiable Risk Factors for Glaucoma Collaboration and the UK Biobank Eye and Vision Consortium. The Association of Physical Activity with Glaucoma and Related Traits in the UK Biobank. Ophthalmology. 2023 Oct;130(10):1024-1036. doi: 10.1016/j.ophtha.2023.06.009. Epub 2023 Jun 17. PMID: 37331483; PMCID: PMC10913205.
7. Liu C, Kobayashi T, Shiba T, Hayashi N (2022) Effects of aging and exercise habits on blood flow profile of the ocular circulation. PLoS ONE 17(4): e0266684.

 

TRANS-LAMINA CRIBROSA PRESSURE DIFFERENCE

 

The lamina cribrosa (LC) is a mechanical barrier between the intraocular compartment, having high pressure, and the intra-orbital space, which has comparatively lower pressure.

In the orbital part of the optic nerve sheath, the dynamics and composition of the cerebrospinal fluid (CSF) are different from the intracranial CSF.

The pressure difference between the intraocular pressure (IOP) and intracerebral pressure (ICP) at the level of the LC is called trans-lamina cribrosa pressure difference (TLCPD). This pressure difference has an important role in the development of cupping seen in glaucoma patients.

The difference between IOP and retrolaminar tissue pressure, divided by the thickness of the LC forms the translamina cribrosa pressure gradient.

The LC is apparently thinner in glaucoma patients compared to normal controls. In NTG patients the ICP is significantly lower than in normal individuals. These features contribute to the increase in the TLCPD and promote glaucomatous cupping.

It is also found that fluctuations in the IOP lead to repeated shear and strain at the level of the LC, increasing the cupping.

High TLCPD causes altered axonal transport, structural changes in the LC, and ischemia.

Therefore, it can be concluded that altered TLCPD plays an important role, singly or in combination with other factors, in the development and progression of glaucomatous optic nerve degeneration.

CLOSED EYE IOP AND EM MONITORING

Normally, intraocular pressure (IOP) exhibits a significant circadian rhythm, typically peaking in the early morning hours before the end of sleep (3–4 mmHg higher than daytime levels), with a trough occurring at the end of the day. This phenomenon is closely associated with changes in body position (supine posture increases episcleral venous pressure by 3–6 mmHg) and fluctuations in glucocorticoid levels.

Furthermore, frequent eye movements during sleep, such as those occurring during rapid eye movement (REM) sleep, can increase resistance to aqueous humor outflow. This is particularly concerning in patients with angle-closure glaucoma, where the risk of acute attacks is 3–5 times higher at night compared to during the day.

Smart contact lenses have emerged as a promising solution for continuous, noninvasive ocular signal monitoring instead of discrete measurements.

While Goldman Appalanation Tonography (GAT) is the ideal method, it requires topical anesthesia and fluorescein instillation before measurement, and the fluorescein concentration can influence accuracy. Furthermore, GAT-like instruments often require a slit lamp examination. Corneal thickness, stiffness, and tear film characteristics can also introduce measurement errors. 

Contact lenses are a practical solution to the problems of continuous monitoring. Gan and colleagues have proposed a stretchable self-decoupled BCL comprising electromagnetic capacitive IOP (CIOP) and neodymium-iron-boron (NdFeB)-MEM components. The design features an NdFeB/polydimethylsiloxane (PDMS) interlayer film that separates double-layered serpentine-geometry spiral copper (Cu) films.

This innovation involves a stretchable bimodal contact lens (BCL) amalgamating self-decoupled electromagnetic capacitive intraocular pressure (CIOP) and magnetic eye movement (MEM) monitoring components. This integrated system offers a non-invasive and comfortable solution for real-time eye health monitoring, providing accurate measurements and continuous tracking of eye status. 

In this way, both IOP and EM can be monitored continuously through closed lids.

REFERENCE:

Gan, X., Yao, G., Li, C. et al. Closed-eye intraocular pressure and eye movement monitoring via a stretchable bimodal contact lens. Microsyst Nanoeng 11, 83 (2025). https://doi.org/10.1038/s41378-025-00946-y

HEAD ELEVATION AND GLAUCOMA

Several nighttime events including increased IOP, decreased ocular perfusion pressure (OPP), and possibly obstructive sleep apnea (OSA) contribute to the development and progression of glaucomatous optic neuropathy. These events may explain the occurrence and progression of glaucomatous disease in the setting of seemingly controlled office-measured IOP. [1]

A study by Buys et al., has shown the 30-degree head-up sleeping position lowers IOP compared with the flat position. Although this effect varies between individual patients, mean IOP was 20% lower in one third of patients in this series.[2]

Several studies have shown that raising the bed head by 30-degrees significantly lowers IOP compared to the supine position. However, the method applied to elevate the head plays a significant role in IOP reduction. For example, while bed head elevation (BHE) is useful, resting on multiple pillows (MP) does not appear to offer the same IOP reduction in glaucoma patients.[3]

Some researchers studied the effect of sleeping in a head-up position using a wedge pillow in glaucoma patients, and healthy subjects. They have demonstrated reduction of mean IOP by 1.5–3.2 mm Hg in the head-up position compared with the flat position.[3]

Lazzaro et al also studied the effect of sleeping in a 20° head-up position in 15 glaucoma patients and 15 non-glaucoma patients. They demonstrated lower nocturnal IOPs (−1.5 mm Hg) with head-up position as compared with the head-flat position in patients with and without glaucoma.[4]

However, Natasha G reported that lying down increases IOP but also improves ocular blood flow. This could affect progression of glaucomatous optic nerve degeneration.[5]

REFERENCES:

1. Aref AA. What happens to glaucoma patients during sleep? Curr Opin Ophthalmol. 2013 Mar;24(2):162-6.
2. Buys YM, Alasbali T, Jin YP, Smith M, Gouws P, Geffen N, Flanagan JG, Shapiro CM, Trope GE. Effect of sleeping in a head-up position on intraocular pressure in patients with glaucoma. Ophthalmology. 2010 Jul;117(7):1348-51.
3. Yeon DY, Yoo C, Lee TE, Park JH, Kim YY. Effects of head elevation on intraocular pressure in healthy subjects: raising bed head vs using multiple pillows. Eye (Lond). 2014 Nov;28(11):1328-33. 
4. Lazzaro EC, Mallick A, Singh M, Reich I, Elmann S, Stefanov DG, et al. The effect of positional changes on intraocular pressure during sleep in patients with and without glaucoma. J Glaucoma. 2014;23:282–287.
5. https://www.medscape.com/viewarticle/night-shift-should-patients-glaucoma-sleep-their-head-raised-2025a10005rn

TAFLUTAN

 

Tafluprost 0.0015% is a prostaglandin analogue which was co-developed by Santen with Asahi Glass Co., Ltd (Tokyo, Japan) for the treatment of glaucoma and elevated intraocular pressure (IOP). Unit-dose, preservative- free eyedrops and in combination with timolol are now also available.  

The recommended dose is one drop of tafluprost in the conjunctival sac of the affected eye(s) once daily in the evening.

PHARMACOLOGY:

Mechanism of action=

Tafluprost acid is a fluorinated prostaglandin F2α (PGF2α) analogue. Tafluprost is a prodrug of the active substance, tafluprost acid, a structural and functional analogue of PGF2α. Tafluprost acid is a selective agonist at the prostaglandin F-receptor, increasing outflow of aqueous humor via the uveoscleral pathway and thus lowering IOP.

Other PGF2α analogues with the same mechanism of action include latanoprost and travoprost.

Pharmacokinetics=

Tafluprost is a prodrug ester prostaglandin F2α-analog designed to expedite the corneal penetration of the drug, which is then hydrolyzed by corneal esterases to produce the carboxylic acid active metabolite. The product, tafluprost acid, can then be taken up by the aqueous humor to therapeutically relevant levels.

Onset of action is 2 to 4 hours after application, the maximal effect is reached after 12 hours, and ocular pressure remains lowered for at least 24 hours.

Tafluprost acid is inactivated by beta oxidation to 1,2-dinortafluprost acid, 1,2,3,4-tetranortafluprost acid, and its lactone, which are subsequently glucuronidated or hydroxylated. The cytochrome P450 liver enzymes play no role in the metabolism.

ADVERSE EFFECTS:

The most common side effect of tafluprost is conjunctival hyperemia, which occurs in 4 to 20% of patients. Less common side effects include stinging of the eyes, headache, and respiratory infections. Rare side effects are dyspnea (breathing difficulties), worsening of asthma, and macular oedema.

Tafluprost causes changes to pigmented tissues, leading to increased pigmentation of the iris, periorbital tissue (eyelid) and eyelashes. Before treatment is initiated, patients should be informed of the possibility of eyelash growth, darkening of the eyelid skin and increased iris pigmentation. Some of these changes may be permanent, and may lead to differences in appearance between the eyes when only one eye is treated.

Usually, the eyelash and pigmentary changes resolve after discontinuation of the drug.

To reduce the risk of darkening of the eyelid skin patients should blot off any excess solution from the skin. Nasolacrimal outflow occlusion or gently closing the eyelid after administration may reduce the systemic absorption of products administered via the ocular route.

Contact lenses should be removed prior to the administration of tafluprost, and may be reinserted 15 minutes following administration.

Caution is recommended in patients with known risk factors for iritis/uveitis and should generally not be used in patients with active intraocular inflammation.

Macular edema, including cystoid macular edema, has been reported during treatment with prostaglandin F2α analogues. These side-effects usually occur in aphakic patients, pseudophakic patients with a torn posterior lens capsule or anterior chamber lenses, or in patients with known risk factors for macular edema. Therefore, caution is recommended when using tafluprost in these patients.

STUDIES:

In a review performed by Keating, tafluprost was at least as effective as latanoprost ophthalmic solution 0.005 % in Asian patients with primary open-angle glaucoma or ocular hypertension. The efficacy of tafluprost ophthalmic solution 0.0015 % was maintained in the longer term. [1]

A study by the Tafluprost Multi-center Study Group and others, found the agent to be effective in lowering IOP in normal-tension glaucoma (NTG) patients. Mean IOP changes from baseline were -4.0 +/- 1.7 mmHg in tafluprost administered patients and -1.4 +/- 1.8 mmHg in Placebo administered patients at 4 weeks, with a statistically significant difference (p<0.001). [2]

A study by Nakano et al., to evaluate the efficacy and safety of tafluprost in NTG with IOP of 16 mmHg or less, found the IOP in the study eyes versus fellow eyes were 10.2 ± 1.6 versus 12.1 ± 1.5 mmHg at week 12 of treatment. The IOP difference between the study eyes and the fellow eyes was statistically significant (P < 0.0001, Student's t test). [3]

Hoy has reported good IOP control with the tafluprost/timolol combination (Taptiqom). [4]

REFERENCES:

1. Keating GM. Tafluprost Ophthalmic Solution 0.0015 %: A Review in Glaucoma and Ocular Hypertension. Clin Drug Investig. 2016 Jun;36(6):499-508. doi: 10.1007/s40261-016-0413-z. PMID: 27225879.
2. Kuwayama Y, Komemushi S; Tafluprost Multi-center Study Group. [Intraocular pressure lowering effect of 0.0015% tafluprost as compared to placebo in patients with normal tension glaucoma: randomized, double-blind, multicenter, phase III study]. Nippon Ganka Gakkai Zasshi. 2010 May;114(5):436-43. Japanese. PMID: 20545217.
3. Nakano T, Yoshikawa K, Kimura T, Suzumura H, Nanno M, Noro T. Efficacy and safety of tafluprost in normal-tension glaucoma with intraocular pressure of 16 mmHg or less. Jpn J Ophthalmol. 2011 Nov;55(6):605-13. doi: 10.1007/s10384-011-0082-7. Epub 2011 Aug 27. PMID: 21874307.
4. Hoy SM. Tafluprost/Timolol: A Review in Open-Angle Glaucoma or Ocular Hypertension. Drugs. 2015 Oct;75(15):1807-13. doi: 10.1007/s40265-015-0476-9. PMID: 26431840.