{'fraction_non_alphanumeric': 0.02671523982999393, 'fraction_numerical': 0.02185792349726776, 'mean_word_length': 4.971014492753623, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Laser trabecular ablation of human eyes with the erbium:YAG laser: a histopathologic study

We postulated that ablation of trabecular meshwork can be accomplished without damage to Schlemm's canal and adjacent tissue. We performed Erbium:YAG laser trabecular ablation on human autopsy eyes and confirmed the results by histopathologic examination. We used an Erbium:YAG laser (2.94 micrometers ) equipped with a sapphire probe and a quartz tip (350 micrometers diameter). Energy levels of 5, 10, 15, 20, and 40 mJ per pulse were used. The probe was placed directly onto the trabecular meshwork viewed through an operating microscope and focal ablation was performed with single pulses. The tissue was then processed and examined under light and scanning microscopy. The histopathologic study of the trabecular meshwork revealed that a single pulse at an energy level of 15 mJ was optimal for ablating through the trabecular meshwork to Schlemm's canal with a minimal amount of coagulative damage to the surrounding tissue. The mean width of ablated tissue was 150 micrometers +/- 29 micrometers (n equals 18) and the mean depth of ablation was 133 +/- 48 micrometers (n equals 18) at this energy level. The mean width of coagulative damage to adjacent tissue was 16 +/- 8 micrometers (n equals 18). The ablation and coagulative damage increased with increasing energy levels. The Erbium:YAG laser equipped with a contact probe effectively ablates trabecular meshwork with little surrounding coagulative damage. This feature may minimize scarring and result in a high long-term patency rate of outflow channels created by laser trabecular ablation.