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Pseudostigmata — Clinical Guidelines

Overview

Astigmatism is a common refractive error characterized by differences in refractive power between the orthogonal planes of the eye, often leading to distorted vision. It affects a significant portion of the population, with over 60% having more than 0.50 diopters of astigmatism 1.

Diagnosis

Key Diagnostic Criteria: Measurement of refractive error showing significant differences in power between two principal meridians.

Recommended Tests: Keratometry, computerized videokeratography, and autorefractometry for precise measurements 7 9.

Grading: Typically graded by diopters of astigmatism, with specific referral criteria varying (e.g., 1.50D vs. 2.25D for screening in children) 4.

Management

First-Line Treatments: Corrective lenses (eyeglasses or contact lenses) tailored to the degree of astigmatism 5.

Surgical Interventions: Keratotomy techniques such as arcuate incisions (transverse and inverse arcuate) for moderate to high astigmatism 10 11.

Adjunctive Treatments: Scleral surgery for mixed and myopic compound astigmatism, aiming to modify corneal curvature 17.

Special Populations

Pediatrics: Prescribing practices for eyeglasses vary widely among pediatric ophthalmologists based on the degree of astigmatism 5.

Comorbidities: Untreated astigmatism poses additional risks in patients with coexisting conditions like cataract, glaucoma, and dry eye 2.

Key Recommendations

Utilize keratometry and videokeratography for accurate measurement and management of astigmatism to ensure reliable follow-up and treatment adjustments (Evidence: Moderate 7).

Implement age-appropriate referral criteria for vision screening in children to minimize over-referral, considering higher thresholds like 2.25D for astigmatism 4.

Consider surgical interventions such as arcuate keratome incisions for persistent moderate to high astigmatism, balancing efficacy and potential complications (Evidence: Expert opinion 10).

References

1 Kohnen T, Næser K, Holladay JT, Stulting RD, Wang L, Abulafia A et al.. Standards for analyzing astigmatic outcomes: Part I: astigmatism basics. Journal of cataract and refractive surgery 2025. link 2 Zhang J, Wu Y, Sharma B, Gupta R, Jawla S, Bullimore MA. Epidemiology and Burden of Astigmatism: A Systematic Literature Review. Optometry and vision science : official publication of the American Academy of Optometry 2023. link 3 Grzybowski A, Kanclerz P. Beginnings of Astigmatism Understanding and Management in the 19th Century. Eye & contact lens 2018. link 4 Vaughan J, Dale T, Herrera D, Karr D. Oregon Elks Children's Eye Clinic vision screening results for astigmatism. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus 2018. link 5 Harvey EM, Miller JM, Dobson V, Clifford CE. Prescribing eyeglass correction for astigmatism in infancy and early childhood: a survey of AAPOS members. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus 2005. link 6 Kusel R, Oechsner U, Wesemann W, Russlies S, Irmer EM, Rassow B. Light-intensity distribution in eccentric photorefraction crescents. Journal of the Optical Society of America. A, Optics, image science, and vision 1998. link 7 Karabatsas CH, Cook SD, Papaefthymiou J, Turner P, Sparrow JM. Clinical evaluation of keratometry and computerised videokeratography: intraobserver and interobserver variability on normal and astigmatic corneas. The British journal of ophthalmology 1998. link 8 Dunne MC, Elawad ME, Barnes DA. Determination of the influence of effectivity upon residual astigmatism. Acta ophthalmologica Scandinavica 1997. link 9 Dunne MC, Elawad ME, Barnes DA. Measurement of astigmatism arising from the internal ocular surfaces. Acta ophthalmologica Scandinavica 1996. link 10 Thornton SP. Inverse arcuate incision: a new approach to the correction of astigmatism. Journal of refractive and corneal surgery 1994. link 11 Hanna KD, Hayward JM, Hagen KB, Simon G, Parel JM, Waring GO. Keratotomy for astigmatism using an arcuate keratome. Archives of ophthalmology (Chicago, Ill. : 1960) 1993. link 12 Kaye SB, Campbell SH, Davey K, Patterson A. A method for assessing the accuracy of surgical technique in the correction of astigmatism. The British journal of ophthalmology 1992. link 13 Garzia RP, Nicholson SB. Clinical aspects of accommodative influences on astigmatism. Journal of the American Optometric Association 1988. link 14 Saunders H. Changes in the axis of astigmatism: a longitudinal study. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) 1988. link 15 Nordan LT. Quantifiable astigmatism correction: concepts and suggestions, 1986. Journal of cataract and refractive surgery 1986. link80125-0) 16 Grey C, Yap M. Influence of lid position on astigmatism. American journal of optometry and physiological optics 1986. link 17 Arciniegas A, Amaya LE. Corneal curvature modification by scleral surgery: preliminary results. Annals of ophthalmology 1985. link 18 Jensen RP, Jensen AC. Surgical correction of astigmatism by microwedge resection of the limbus. Ophthalmology 1978. link35553-6)

Pseudostigmata