The Assessment of Retinal Nerve Fiber Layer Thickness Changing after Glaucoma Surgery by Optical Coherence Tomography, Phramongkutklao Hospial
Sitthinee Maneesang MD*, Ornwasee Jatutong MD*, Wallop Iemsomboon MD**
Affiliation : * Department of Ophthalmology, Phramongkutklao Hospital, Bangkok, Thailand ** Department of Ophthalmology, Phramongkutklao College of Medicine, Bangkok, Thailand
Objective : To assess retinal nerve fiber (RNFL) thickness change in glaucoma patients after glaucoma surgery.
Material and Method: A prospective and cohort study of 19 patients who underwent trabeculectomy with mitomicin C or
combined procedures or glaucoma drainage device surgery in Phramongkutklao Hospital were included. All subjects had
obtained informed consents. Preoperative and 3 month-postoperative IOP and RNFL thickness were determined. Areas of
peripapilllary RNFL thickness were evaluated by Stratus OCT scanning. The relationship between IOP reduction and RNFL
thickness change after glaucoma surgery was analyzed.
Results : Postoperative RNFL thickness analysis found no significant increase in inferior, superior, nasal and temporal
quadrants. The average of preoperative RNFL thickness was 59.58 + 17.59 microns, whereas the average of postoperative
RNFL thickness was 57.19 + 14.97 microns (p = 0.426). Postoperative IOP was decreased significantly from 29.26 + 8.58
mmHg to 12.11 + 4.52 mmHq (p < 0.001). The mean of postoperative RNFL thickness was not significantly correlated with
IOP reduction (r = 0.306, p = 0.250).
Conclusion : Post glaucoma surgery, RNFL thickness was not significantly increased although the IOP had
significantly reduced. No correlation between IOP reduction and RNFL thickness was found.
Keywords : Optical coherence topography (OCT), Retinal nerve fiber layer thickness (RNFL), Intraocular pressure (IOP)
