Posterior Corneal Surface Changes After Pterygium Excision Surgery

Abstract

Purpose: To evaluate the effect of pterygium excision on the posterior corneal surface and analyze the factors associated with those changes. Methods: A prospective, interventional study including 33 eyes of 31 patients who underwent pterygium excision at the Tel Aviv Medical Center (Tel Aviv, Israel). Exclusion criteria included corneal dystrophy, pseudopterygium, corneal scarring, or previous ocular surgery in the treated eye. Data were obtained by using the Galilei dual Scheimpflug analyzer. Recorded posterior corneal data included steep keratometry, flat keratometry, mean keratometry, corneal astigmatism, best-fit sphere, and the squared eccentricity index (e2). Posterior surgically induced astigmatism (SIA) was calculated to demonstrate the astigmatic effect of surgery. Anterior-segment high resolution optical coherence tomography was used to measure pterygium dimensions (depth and horizontal/vertical size). Results: The mean age was 53.7 ± 16.7 years. Posterior corneal SIA was 0.9 ± 1.1 D (P < 0.001) and was significantly correlated with age (r = 0.568, P = 0.002), horizontal pterygium size (r = 0.387, P = 0.046), and preoperative posterior astigmatism (r = 0.688, P < 0.001). In a multivariable analysis, only age (coefficient = 0.010, P = 0.038) and preoperative posterior astigmatism (coefficient = 0.648, P = 0.002) remained significant. Pterygium dimensions were not significantly associated with SIA magnitude. Flat keratometry steepened by 0.5 ± 1.1 D (P = 0.019), mean keratometry steepened by 0.3 ±0.6 D (P = 0.035), posterior astigmatism was reduced by 0.4 ± 1.2 D (P = 0.072), and e2 decreased by 5.1 ± 17.3 (P = 0.021). Conclusions: Pterygium excision has a significant astigmatic effect on the posterior corneal surface. The astigmatic effect increases with age and with higher preoperative posterior astigmatism. Pterygium depth and size are not associated with the degree of surgical astigmatic effect.

Earlier Corneal Topographical Changes After Different Pterygium Surgical Techniques: a Comparative Pentacam Scheimpflug Imaging Study

“…Moreover, substantial reduction in pterygium-induced astigmatism after different surgical techniques has been reported before. [17][18][19] The current study investigated and compared post-operative corneal topographical parameters between baseline and one-month data. Similar to Ozdemir et al, 16 there were early signi cant changes in pterygium-induced corneal topographical parameters.…”

Pterigión: conceptos y manejo Actual

“…Las principales molestias referidas por los pacientes son ardor, prurito ocular, resequedad, lagrimeo, sensación de cuerpo extraño y enrojecimiento (1). Aparte de estos, también puede haber afectación de la visión, lo cual es causado por compromiso del eje visual por el mismo pterigión, astigmatismo inducido y la disrupción de la película lagrimal (14). El compromiso astigmático, según mencionan Levinger et al, puede ser tanto regular o irregular; de esta manera aumentan las aberraciones de alto orden, principalmente coma y trefoil (14).…”

The effect of limbal autograft location at primary pterygium excision on anterior and posterior corneal astigmatism: a comparative prospective study

“…In pterygium, surgery is planned due to closure of the visual axis of the brovascular structure, decreased vision with the changes in topographic, refractive and wavefront analysis, recurrent in ammation, and cosmetic deformity. At the same time, pterygium excision is performed to obtain more accurate biometry values before cataract surgery [3][4][5][6][7][8][9]. Bare sclera excision, conjunctival transposition, mitomycin C or Beta radiation application added techniques were performed in pterygium treatment [1].…”

“…Bare sclera excision, conjunctival transposition, mitomycin C or Beta radiation application added techniques were performed in pterygium treatment [1]. However, contemporarily the more secure than the other methods and accepted as 'golden standard' method is 'Conjunctival Autograft' [2][3][4][5][6][7][8][9][10].…”