EDITORIAL

Ocular Surface Disease: An Integral Part of

Glaucoma Management

Aysha Salam¹

¹Consultant Ophthalmologist, Royal Liverpool Hospital, United Kingdom

Glaucoma has been a silent and symptomless disease-

cells absorb BAK, which has damaging effects similar

to those in bacterial cells. They are cumulative and

become more severe with more concentrated and

frequent exposures. The inflammatory changes induce

permanent damage to the conjunctival goblet cells,

which can seriously compromise the success of any

future filtration procedures.^3,4,5

causing relentless loss of vision requiring lifelong

treatment. It is often hard to gain patient acceptance

for a condition, the treatment for which does not

manifest in the form of any direct visual gains. This is

in turn is compounded by the adverse effects of

medication. These are most commonly poor tolerance

and preservative toxicity in addition to the active

ingredient which in itself can compromise a vulnerable

ocular surface.^1,2Glaucoma patients are presumably at

a much higher risk of developing ocular surface

disease and one of the commonest reasons for that is

being treated with preservative-containing medications

over a prolonged period.^1,2This editorial will highlight

some of the common risk factors and possible

remedies in glaucoma patients manifesting with ocular

surface disease.

In order to fully analyse the histological and

morphological changes in patients treated with BAK

containing glaucoma drops, a prospective, double-

masked, placebo-controlled study was performed by

Barabino et al who assessed corneal thickness, goblet

cell density and conjunctival immunohistochemistry

using CD45 detection in rats at day 7 of treatment.⁶

The study revealed higher incidence of punctate

fluorescein staining in BAK treated eyes as compared

to the control group although the changes in corneal

thickness were not statistically significant. The BAK-

treated eyes showed a significantly lower number of

Goblet cells than those in all control groups (*P <

0.05), whereas it induced a significant increase in the

CD45 expression in the bulbar conjunctiva showing an

increase in the inflammatory activity.⁶

Preservative toxicity is a well-known concept but

is still under diagnosed and poorly managed in most

patients. Benzalkonium Chloride (BAK) is the most

commonly used preservative, in most ophthalmic

preparations. The other preservatives used are

Polyquad and peroxide derivatives.³The main benefit

of using preservatives is to prevent bacterial

contamination along with the requirement by the

regulatory authorities for a safe dispensing of the

medication.^4,5However, the BAK is known to induce

necrosis (at conc. of 0.05 – 0.1%) and cellular

apoptosis (at conc. of 0.01%) by disturbing cellular

membrane in bacterial cells. Human ocular surface

The significance of this is further endorsed in a

study by Agnifil et al⁷, who analysed the pre-operative

conjunctival goblet cell density (GC), MUC5AC

which is the main mucin product of GC, and HLA-DR

in glaucomatous patients undergoing trabeculectomy,

using laser scanning confocal microscopy (LSCM) and

impression cytology (IC). They divided their patients

into three groups. The group with complete success

revealed good population of goblet cells with scattered

How to Cite this Article: Salam A. Ocular Surface

Disease: An Integral Part of Glaucoma Management.

Pak J Ophthalmol. 2020; 36 (2): 194-196.

Doi: 10.36351/pjo.v36i3.1064

microcysts showing

functioning bleb. The

impression cytology also confirmed MUC5AC being

significantly over expressed compared to failed

surgeries along with a better IOP control. The groups

with qualified success and failed trabeculectomies had

much lower Goblet cell densities and MUC5AC

concentrations although the inflammatory component

Correspondence to: Aysha Salam

Consultant Ophthalmologist, Royal Liverpool Hospital

Email: Aysha.salam320@gmail.com

194

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (3): 194-196

Ocular Surface Disease: An Integral Part of Glaucoma Management

HAL-DR was not statistically different in the three

groups.⁷

surface disease¹¹. A detailed history is therefore

crucial.

The study establishes the most important myths

behind a successful filtration procedure which would

appear to be a favourable density of the goblet cells

which could in future be used as a biomarker to predict

the chances of success of surgery and post-operative

bleb management. A decrease in the concentration of

Goblet cells with increase in mast cells, squamous

metaplasia, dendritic cell proliferation and fibroblasts

would be the most likely progenitors for scarring and

surgical failure.^6,7.

Medical illnesses include Collagen Vascular

disorders, Chronic Graft Versus Host Disease (GVHD)

after stem cell transplantation only seen in Allogenic

transplantation, Androgen insufficiency, Iatrogenic

factors including; Chemotherapy and Immuno-

suppressive

therapy,

Anti-Histamines

and

Antidepressants, Beta-blockers, Anti-Androgens,

Isotretinoin, Radiation therapy and any Ocular surgery

can spark dry eye disease.

It is recommended to discontinue BAK containing

medicines and substitute with preservative free

Medications or in severe cases, stop medications

altogether and substitute with oral Acetazolamide.

Glaucoma is common in the elderly and due to

chronicity, is more likely to require more frequent use

of multiple topical medications which precipitate the

risk of Ocular surface disease. The underlying

pathophysiology includes functional changes with

reduced function of the lacrimal glands causing

aqueous tear deficiency with under function of the

meibomian glands as well as reduced number of

conjunctival goblet cells. There is often secondary

inflammation of the ocular surface as a result of

meibomian gland dysfunction which can in turn blunt

the effect of glaucoma medications causing poor

control and intolerance to glaucoma drops. The ageing

of the ocular Adenexa with lid laxity, pump failure and

conjunctivochalasis are other risk factors common in

this age group, which further predispose to ocular

surface disease⁸.

Take home message is liberal use of preservative

free medications, early SLT or Primary treatment,

consider early surgery where there is disc damage and

progression, pre-perimetric glaucoma progression,

poor compliance, poor response to treatment and poor

ocular surface.

It is evident that protecting the integrity of the

ocular surface is as crucial as is treating glaucoma

because without a healthy ocular surface, glaucoma

management is bound to fail. Glaucoma care pathway

is essentially incomplete without the ocular surface

optimization. Early detection and treatment will

predict a smoother journey with a successful long term

outcome.

Early onset glaucoma most commonly requires

surgical intervention as it is more aggressive and

harder to treat. However, given that the disease

process persists through an extended period of time,

younger patents are likely to be exposed to topical

medications for longer length of time and are more

likely to suffer from cumulative toxicity of the

preservatives⁹.

Conflict of Interest

Author declared no conflict of interest

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Aysha Salam

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^.…^….

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