Effect of different eye speculums on intra ocular pressure

To measure the difference in intraocular pressure with use of two different types of eye speculums.

The study was conducted at the Department of Ophthalmology, Abbasi Shaheed Hospital, Karachi, from November 2011 to May 2012. Through probability convenience sampling, hundred patients were selected and divided into two equal groups. Complete history and ocular examination was done. Intraocular pressure was measured using Goldmann Applanation tonometer on slit lamp. It was again measured with Barraquer wire speculum inserted in the eyes of 50 patients, and Universal eye speculum in the other 50 patients with the help of Goldmann Applanation. SPSS 16 was used for statistical analysis.

There were 63 (65%) males and 34 (35%) females with an overall mean age of 45 +/- 14.09 years. The mean age baseline intraocular pressure of the right eye without speculum was 15.04 +/- 3.83 mmHg and that of the left eye was 15.48 +/- 4.00 mmHg. With Barraquer wire speculum, the value for the right eye was 22.21+/- 4.99, and that of the left eye was 23.08 +/- 5.41. With Universal eye speculum, the value for the right eye was 25.51 +/- 3.02, and for the left eye it was 25.78 +/- 3.64.There was a statistically significant difference in baseline and post-speculum measurements (p < 0.0001). Paired sample t-test was also conducted for values of the two speculums and the result was statistically significant (p < 0.0001).

Barraquer wire speculum caused less increase in intraocular pressure compared to the Universal eye speculum. It should be preferred for intraocular surgeries to avoid increase in pressure during surgery and prolapse of ocular contents. Not only the effect of speculum, but also the type of speculum should be kept in mind when measuring intraocular pressure during examination under anaesthesia.