Tear Film Instability Likely 1 Month After Panretinal Photocoagulation

Retina of diabetic - diabetic retinophaty
Retina of diabetic – diabetic retinophaty
The researchers say that the finding may be due to postoperative damage to the corneal nerves.

Patients with proliferative diabetic retinopathy (PDR) typically receive panretinal photocoagulation (PRP). A study, published in The Ocular Surface, found that PRP affected ocular parameters to varying degrees and may temporarily cause tear film instability.

Patients (N=33; eyes: n=33, mean age 53.9±10.5 years, 17 men) with PDR were recruited at UT Health in Texas. The patients received PRP using a solid-state diode green or yellow laser. Patients were assessed at baseline and 1 and 3 months by a comprehensive ophthalmic evaluation.

Patients received an average of 1.3 (range, 1-3) PRP sessions with 1247 (range, 504-1969) spots per session.

Patients in the study had a diabetes duration of  16.6±8.3 years, with a mean glycated hemoglobin of 8.8%±2.0%. At baseline patients had an Ocular Surface Disease Index (OSDI) score of 26.1±16.9, indicating moderate symptoms of dry eye disease.

PRP had no effect on OSDI (P =.09), Schirmer’s test (P =.16), corneal fluorescein staining (P =.19), or conjunctival lissamine green staining (P =.06).

After PRP, tear breakup time decreased from 7.1±2.4 to 5.4±2.8 s (P =.04) at 1 month, increasing to 7.5±2.6 s (P =.02) at month 3 (overall trend, P =.004).

The investigators concluded that patients with PDR had a differential response to PRP between 1 and 3 months. PDR has previously been associated with dry eye disease, and symptoms of dry eye disease were observed among this patient population. The significant decrease in tear breakup time in the month after PRP treatment likely indicated a temporary tear film instability. Some patients may benefit from enhanced dry eye disease treatment after receiving PRP.

In addition, the study authors speculated that the changes in ocular surface and tear film parameters after PRP may be caused by damage to the corneal nerves during treatment. Additional studies are needed.

This study was limited by its single center, observational design.


Hodson NM, Jiang CC, Uhm SY, Sohn J-H, Johnson DA, Kheirkhah A. Effects of panretinal photocoagulation on the ocular surface and tear film. Ocul Surf. 2021;S1542-0124(21)00118-X. doi:10.1016/j.jtos.2021.10.001