European Journal of Cardiovascular Medicine

The composition of the normal human ocular surface flora includes Staphylococcus epidermidis, Staphylococcus aureus, and diphtheroids. There are several factors that may alter the composition of ocular surface flora: age, dry eye, immunosuppressive medication and medical illnesses such as diabetes mellitus [1,2]. Patients in the intensive care unit (ICU) frequently have impaired ocular defence mechanisms as a result of metabolic derangements, mechanical ventilation, sedation, paralysis and decreased level of consciousness [2]. The impaired ocular defence mechanisms include poor eyelid closure, inhibition of Bell’s phenomenon, decreased blink reflex, and reduced tear production [3,4]. The ICU also presents an environment rich in pathogens that may contribute to the increased exposure of the ocular surface to micro-organisms with significant antimicrobial resistance resulting from the widespread use of multiple antibiotics [2,5].

Moreover, prolonged eye closure, which occurs in ICU patients, causes a cascade of biochemical, cellular and microbial events culminating in inflammation, hypoxia, and dry eye states [6]. Dry eye is one of the major risk factors of infectious keratitis [7]. Intensive care unit (ICU) patients are susceptible to a number of ophthalmic conditions that may result in visual loss. The eye’s natural protection is composed of the upper and lower lids, lacrimal film and the conjunctiva. The eyelids and tears help flush organisms and abrasive particles from the eye with each blink. The conjunctiva has lymphoid 

It was a prospective observational study was conducted in the Department of Ophthalmology, S.V.R.R.G.G. Hospital, Tirupati over a period of 6 months

This prospective study was conducted on 27 patients, 18-65 years of age, in the Respiratory intensive care unit (RICU) and Neonatal intensive care unit (NICU).

Inclusion Criteria

1. All patients aged 18-65 years admitted to RICU for a time period of>48 hours were included. 2. Neonates in NICU.
3. Prior informed consent was obtained from an attendant authorized to do so.

Exclusion criteria

1. Patients who presented with ocular surface disorders prior to admission to RICU. 2. Patients or authorized attendants not willing to participate in the study.

Materials for Eye examination: The following equipment were used for clinical examination a) For Microbiological examination (if and when required)
• Conjunctival Swab
• Gram stain

• Culture in Sabouraud dextrose Agar

b) For posterior segment examination

• Direct ophthalmoscope(Heine beta 200S ophthalmoscope)

Methodology of data collection: After approval from the Institutional Ethics Committee, S.V. Medical College, Tirupati, the present study was conducted. All patients admitted to ICU within 24 hours between the ages of 18-65 years and neonates were included in this observational study. All patients who were on mechanical ventilation were taken for this study. Mechanically ventilated patients were those patients who were intubated either by Endotracheal tube (ETT) or Tracheostomy tube (TT) and were on mechanical ventilation. Thorough ophthalmic examination, including Pupil size and reaction, Relative afferent pupillary defect by swinging flashlight examination, and External eye examination for conditions like the presence of lagophthalmos, exophthalmos, buphthalmos & deviation of the eyeball. The conjunctival swab was obtained by pulling down the lower lid and exposing the conjunctiva. Gently sweep the sterile swab stick along the lower fornix from the inner to the outer canthus, taking care not to touch the eyelids.

In this study, a total of 28 patients were taken. Among these are 16 males, 4 females and 8 neonates. In this study, 8 cases positive for Gram-positive cocci were seen in singles, pairs, tetrads and clusters in the right eye and 7 cases in the left eye. Coagulase-negative staphylococci were isolated in 6 cases in the right eye and 4 cases in the left eye. The culture was negative for 18 cases in the right eye and 14 cases in the left eye. Micrococci are present in 4 cases in the right eye and 3 cases in the left eye. No bacterial growth or pus cells are seen in 9 cases in the right eye and 1 case in the left eye. No bacterial growth, but pus cells are seen in 10 cases in the right eye and 4 cases in the left eye.

In this study, a total of 28 patients were taken. Within 24 hours, a conjunctival swab was collected and sent to the microbiology department for Gram staining and culture and sensitivity. Among 28 patients, 8 cases were reported to have Gram-positive Coagulase-positive cocci in the right eye and 7 cases in the left eye. In 6 cases, Coagulase-negative staphylococci were isolated from the right eye and, in 4 cases, from the left eye. Micrococci were isolated from 4 cases in the right eye and 3 cases in the left eye. The culture was negative in 18 cases in the right eye and 14 cases in the left eye.

Conjunctival swabs were placed in culture media. There is no bacterial growth or pus cells in 9 cases in the right eye and 10 cases in the left eye. No bacterial growth. But pus cells were seen in one case in the right eye and 4 cases in the left eye.

The composition of the normal human ocular surface flora includes Staphylococcus epidermidis, Staphylococcus aureus, and diphtheroids. There are several factors that may alter the composition of ocular surface flora: age, dry eye, immunosuppressive medication and medical illnesses such as diabetes mellitus [1,2]. Sahin et al.,[9] reported in ICU patients that the most frequently isolated microorganism from the cultures was coagulase-negative Staphylococcus species (n=210/331, 63.5%).