We read with interest the article by Blumenkranz, in which he pointed out that the technique of retinal light photocoagulation had been first pioneered by Meyer-Schwickerath in the late 1940s. Nevertheless, we believe that it is only partly true. Effectively, the renowned German ophthalmologist presented three cases of retinal detachment successfully treated by retinal coagulation with sunlight during the meeting of the Deutsche Ophthalmologische Gelleschaft in Hamburg in 1949. However, the Spanish ophthalmologist José Morón (1918–2000) was the author of the first known experience of therapeutic retinal photocoagulation and used a similar technique in rabbit and human eyes in 1945 and 1946. These experiences already appeared in his doctoral dissertation, which was defended in Madrid on November 22, 1946, almost three years before the presentation of Meyer-Schwickerath. Then, he wrote: “(…) the retinal scars produced by sunlight are very variable in intensity, depending on the stational variations, amount of sunlight, moment of the day, atmospheric changes, ophthalmoscopy lens position, (…) pupil size, refractive status of the patient, media transparency, retinal pigmentation, gaze direction, (…)”.

Morón did not publish his results until 1950, when after reading the Meyer-Schwickerath’s essays he decided to report his experiences: “In 1946, I practiced the procedure with an intense white light in four patients with retinal detachment at the Ophthalmological Clinic in Seville. Previous pharmacological mydriasis, and following location of the retinal tear by ophthalmoscopy, the patient kept his gaze in the same direction that of the light, I placed the voltaic arc in the place of the observer. The exposition time was five minutes but the results were unsatisfactory. The patients complained with heating, not much photophobia, but the fixation was not good enough.”

Posteriorly, he tried the same procedure in two patients with retinal tear without retinal detachment: “The first one was a voluntary patient with a blind eye with optic atrophy. After five minutes of exposition, he got an oval lesion in the irradiated area, with slight retinal edema, very similar to the lesion characteristic of central serous chorioretinopathy. The final lesion was not strong enough to close a retinal tear.” Finally, Morón concluded: “The ideal conditions to treat a retinal tear with light photocoagulation is when the retina is not detached, the tear is not peripheral, dark fundus, clean ocular media, emmetropia and good mydriasis.” However, he never treated a case with such favorable conditions. He recognized that “Meyer-Schwickerath was more lucky or more perseverant than me, getting what I was looking for, and resolving three retinal detachment cases with that technique. I hope to repeat the successful experience of the German surgeon, taking into account that Spanish sunlight is more intense than Hamburg sunlight.” It is interesting to mention that Meyer-Schwickerath referenced Morón’s studies in his early papers as a precursor of retinal photocoagulation.

Although Meyer-Schwickerath developed the technique to obtain clinically useful results and is worldwide considered the father of retinal photocoagulation, we would like to note Morón’s earlier experimental studies, which deserve international recognition.