تلخیص
OBJECTIVE: To study changes in retinal nerve fiber layer (RNFL) measured on
optical coherence tomography (OCT) after panretinal photocoagulation (PRP)
in patients with proliferative diabetic retinopathy (PDR).
METHODS: This quasi experimental study was conducted at Department of
Ophthalmology, Lahore General Hospital, Lahore from 1-4-2017 to 30-3-2018.
All patients (n=38) diagnosed with PDR requiring PRP were included. Patients
having any coexisting ocular pathology hindering the OCT measurement were
excluded. Pre-operatively, RNFL thickness in four quadrants and signal strength
was measured on OCT and visual acuity (VA) on Snellen's chart. Postoperatively, patients were followed-up after one-month and three-months and
VA was measured and OCT performed.
RESULTS: The mean age of patients was 60.66±5.51years with 23(60.5%)
males. PRP was performed in right-eye of 22 patients. Pre-laser VA in 28
patients was 6/60. Pre-laser total RNFL was 84.32±4.78µm reduced to
83.74±4.61µm one-month and 81.89±4.40µm three-months post-laser
(p<0.001). Pre-laser, superior RNFL thickness was 84.97±4.13µm, reduced to
84.39±3.95µm one-month and to 82.21±3.84µm at three-months post-laser
(p 0.024). Pre-laser inferior RNFL thickness was 84.89±4.68µm, reduced to
84.00±4.44µm one-month and to 81.71±4.50µm three months post-laser
(p=0.032). Pre-laser temporal RNFL thickness was 83.26±3.47µm, reduced
to 82.34±3.44µm one-month and to 80.21±3.49µm three-months post-laser
(p<0.001). Pre-laser nasal RNFL thickness was 85.16±3.78µm, reduced to
84.26±3.88µm one-month post-laser and to 82.08±3.74µm at three-months
post-laser (p=0.043). Pre-laser, signal strength on OCT was 8.26±0.69 and
8.66±0.48 after one-month post-laser and 8.55±0.50 at three-months laser
(p=0.009).
CONCLUSION: PRP leads to a decrease in thickness of RNFL after one month
and three months as compared to pre-laser RNFL thickness.