Relationship between Intra Ocular Pressure and Visual Acuity in Port Harcourt, Nigeria

Aim: To determine the relationship between intra ocular pressure and visual acuity among patients attending a private eye clinic in Port Harcourt Nigeria

Methods: This was a retrospective study done in a private hospital in Port Harcourt. The first one hundred patients attending the hospital in 2013 that met the inclusion criteria were recruited for the study. Those with corneal diseases/lesions were excluded. Medical history was recorded, and comprehensive ocular examination done on each of the 200 eyes of 100 subjects (59 males and 41 females). Ocular examination included visual acuity, ophthalmoscopy, visual field and tonometry. Instruments used during the research were Snellen’s charts both literate and illiterate charts for visual acuity assessment, Pen torch for examination of the external structures of the eyes, Keeler ophthalmoscopes for fundus examination, Reichert AT 555 Auto non-contact tonometer for measurement of the intra-ocular pressure. Data analysis was performed using the Statistical Package of Social Sciences (SPSS) version 20.

Results: There were 200 eyes of 100 subjects in this study comprising 59 males and 41 females (M: F=3:2). The mean age was 45.83±20.43years. The mean IOP was 16.18±6.13 for right eye and 16.82±8.22mmHg for left eye. 66.25% of eyes with normal IOP had good vision (VA ≤6/18) while only 3.75% were blind VA >3/60. 50% of eyes with elevated IOP had good vision (VA ≤6/18) while 15% were blind (VA >3/60). Fisher’s exact test =6.022; p-value =0.099. Statistically significant p<0.25 set at bivariate analysis.

Conclusion: This study shows a statistically significant inverse relationship between intraocular pressure and vision, that is, elevated IOP is related to reduced visual acuity.

Keywords: Elevated intra ocular pressure; Visual acuity; Relationship; Port harcourt