Visual Outcomes Of Phototherapeutic Keratectomy With 193-Nm Excimer Laser In Patients With Macular Corneal Dystrophy

To evaluate the visual outcomes and recurrence rate of patients diagnosed with Macular Corneal Dystrophy and have undergone phototherapeutic keratectomy.

A chart review of all patients diagnosed with macular corneal dystrophy and have undergone phototherapeutic keratectomy from the period of 2000 to 2020 was carried out. The socio-demographic and pre-operative, operative and post-operative data were collected, including UCVA, BCVA, spherical equivalent (SE), topographic data, ablation depth, optical zone, duration of mitomycin C application, post-operative complications, recurrence of macular dystrophy, and the need of subsequent surgery. The primary outcome measures included UCVA, BCVA. Secondary outcome measures were spherical equivalent, keratometric central power, keratometric astigmatism, recurrence rate, and necessity of subsequent penetrating keratoplasty (PK).

Forty-one eyes of 29 patients have met the inclusion criteria for this study. The average pre-operative uncorrected visual acuity improved from 0.57 (+/-0.44) to 0.55 (+/-0.55) (p = 0.004) at 12 to 24 months post-operatively, and best corrected visual acuity improved from 0.41 (+/-0.17) to 0.30 (+/-0.16) (p = 0.007) post-operatively. Ten out of 41 eyes (25%) had recurrence of macular dystrophy deposits within the stroma, the average time from PTK until recurrence was observed is 33.4 months (range, 5.5-115.4 months). The overall success rate of PTK at 2 years was 44.8%. Only 9 eyes (21.9%) required subsequent surgery after PTK at an average of 39 months post-operatively.

PTK is an effective tool to improve vision, reduce glare and provide faster visual recovery in macular corneal dystrophy. PTK can be considered as a treatment modality for younger patients to defer keratoplasty to a later stage. The application of MMC following PTK is associated with lower recurrence rate of MCD.