Abstract
Purpose :
Panretinal photocoagulation (PRP) can contribute to superior visual field (SVF) loss (Int Ophthalmol 1998;22:313-9). It is hypothesized that patients with prior PRP and eyelid ptosis have less potential for SVF improvement after eyelid lifting surgery. Many insurers consider medical necessity when the SVF defect is one or both of the following: (1) > 30%, (2) > 12°. We quantify SVF defects in patients with eyelid ptosis and prior PRP in the context of these criteria.
Methods :
Goldmann SVF testing (stimulus size III-4e) was performed before and after upper eyelid taping on 21 eyes of 19 individuals (mean age = 64.3 ± 2.7 years) with ptosis and prior 360° PRP for diabetic retinopathy, who had no other causes for visual field loss. SVF defect percentage (area under SVF curve with tape minus area under curve at baseline, divided by area under SVF curve with tape) were calculated on Goldmann charts using the Apple iPhone application Ptosis Calc (OPRS 2014;30:141-5). Baseline and post-taping SVF height (degrees of field at the 90° meridian) were also recorded.
Results :
At baseline, mean upper lid margin reflex distance (MRD1) was 1.8 ± 0.4 mm (range: 0 – 3 mm), with a mean percentage SVF defect of 56.2 ± 3.6% (range: 39.8 – 77%; Fig 1, representative example). Mean loss of SVF angle was 9.4 ± 0.7° (32.2 ± 3.9° with tape versus 22.9 ± 3.7° at baseline; P < 0.001). This mean degree change of 9.4 ± 0.7° corresponded to a large effect size (Cohen’s d = 2.4). In all subjects, SVF defects met insurance criteria in percent defect (based on areas under the curve) but not in degrees of field change.
Conclusions :
Ptosis SVF in the presence of PRP was associated with small losses in the angle (degrees) of obstructed field yet large percent field vision loss. These data suggest that SVF may yet significantly improve after ptosis repair in the setting of prior peripheral retinal destruction and corroborate experiential data of functional visual improvement after ptosis repair in diabetic patients who have had prior PRP. Current third party payer medical necessity language for ptosis repair may not adequately account for PRP and potentially other subsets of patients with pre-existing superior field vision loss.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.