ABSTRACT

Panretinal photocoagulation (PRP) is a standard treatment for proliferative diabetic retinopathy. Conventional laser (CL) therapy is performed in one or more sessions in single spot mode. Visual disabilities have been reported after treatment with CL, including central vision loss due to macular edema and peripheral visual field loss resulting from extensive inner retinal scarring. Multispot laser (MSL) photocoagulation has recently been introduced to clinical practice. Studies comparing PRP conducted with MSL and CL have reported that MSLs resulted in less retinal tissue damage and pain, and greater patient comfort compared to CL. The aim of this review was to compare the efficacy and side effects of MSLs and CLs for diabetic retinopathy treatment.

Introduction

Panretinal laser photocoagulation (PRP) has been the gold standard for the management of proliferative diabetic retinopathy (PDR) since its efficacy was demonstrated in the Diabetic Retinopathy Study (DRS).¹PDR is performed with conventional laser (CL) over multiple sessions under local or topical anesthesia. The procedure is painful and time-consuming, which is tiring for both patients and physicians. As it requires multiple visits to an outpatient clinic, it also creates an additional load on retina clinics. Automated laser systems were developed in order to speed the photocoagulation process.^2,3However, the lack of constant physician control was also a disadvantage of these devices. A more recent innovation is the semiautomated multispot laser (MSL). These instruments allow multiple laser shots with a single pedal push, use frequency-doubled 532 nm Nd:YAG laser and are fully controlled by the physician.^4,5The aim of this review is to present an evaluation of the implementation, efficacy and side effects of the most recent generation of lasers currently in use.

Conclusion

PRP has been the gold standard in PDR treatment since it was proven effective in the DRS.¹PRP may be completed over MS conducted at intervals of 1-2 weeks. Completion in a SS is less common due to the need for more local anesthesia to manage the higher pain levels and the higher incidence of side effects such as macular edema, angle closure, and exudative retinal detachment. However, completion in MS requires a physician to spend more time per patient, requires the patient to make multiple trips to the hospital, and increases the economic burden of treatment. It also means that treatment remains incomplete in more patients due to poor patient compliance. SS CL therapy is not preferred by many physicians due to the higher incidence of side effects, the need for peribulbar anesthesia in most patients and possible complications related to anesthesia. However, dividing treatment into MS may delay the onset of treatment effect, particularly in high-risk PDR eyes. Complications of PDR may occur during the treatment period or before treatment takes effect. Because the complications that frequently arose due to CL MS-PRP are not a problem with new generation lasers, 20-ms SS-PRP with these lasers may be a favorable alternative to both SS and MS CL therapy. However, these patients must be followed and monitored in case further treatment is required.

The consensus among previous studies is that SS therapy with short duration MSL results in shorter treatment time and less pain compared to single spot therapy. However, as is evident from the above studies, it has not yet been determined whether the ETDRS-recommended number of burns is still applicable or whether more burns are required when applying 20-ms laser treatment with PASCAL® and similar systems like Valon®, Visulas VITE® and Navilas®. Patients who have undergone SS therapy with short duration MSL should also be monitored for treatment effect, and physicians should not hesitate to provide additional therapy when necessary.