Long-Term Stability of Keratometry, Scheimpflug-Derived True Net Power, and Total Corneal Refractive Power after Primary Pterygium Excision

Ka Wai Kam, Timothy A. Kuan, Michael W Belin, Alvin L. Young

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Purpose: To evaluate long-term changes in mean keratometry, astigmatism, true net power (TNP), and total corneal refractive power (TCRP) of corneas after primary pterygium excision. Methods: This is a prospective observational series conducted at a tertiary teaching hospital eye center in Hong Kong. A total of 31 eyes of 31 patients with primary pterygium excision were included. Patients with recurrent or double-headed pterygia or a history of corneal scars from previous trauma, infection, or surgery were excluded. Data were collected prospectively at postoperative weeks 1, 4, 12, and month 18. Results: Mean keratometry of the anterior cornea was 44.3 diopters (D) [95% confidence interval (CI): 43.6-44.9 D] at week 1, 44.3 D (95% CI: 43.6-44.9 D, standard error = 0.3) at week 4, 44.3 D (95% CI: 43.7-44.9 D) at week 12, and 44.1 D (95% CI: 43.5-44.7 D) at month 18. Mean astigmatism of the anterior cornea was 1.1 D (95% CI: 0.7-1.4 D), 1.0 D (95% CI: 0.7-1.3 D), 0.9 D (95% CI: 0.6-1.1 D), and 1.0 D (95% CI: 0.7-1.3 D) at postoperative 1, 4, 12 weeks, and 18 months, respectively. Mean keratometry, astigmatism of the anterior and posterior cornea, TNP and TCRP at 2.0-mm, 3.0-mm, 4.0-mm rings and zones remained unchanged on all follow-up visits (P = 1 for all comparisons). Conclusions: Keratometric values including TNP and TCRP were stable as soon as 1 week after pterygium excision. This information might help clinicians in planning subsequent intraocular surgery that requires biometric assessment for intraocular lens implantation.

Original languageEnglish (US)
Pages (from-to)1358-1363
Number of pages6
JournalCornea
Volume36
Issue number11
DOIs
StatePublished - Nov 1 2017

Fingerprint

Pterygium
Confidence Intervals
Cornea
Astigmatism
Intraocular Lens Implantation
Hong Kong
Tertiary Care Centers
Teaching Hospitals
Wounds and Injuries

Keywords

  • corneal scar
  • correspondence
  • keratometry
  • pterygium
  • Scheimpflug image
  • true net power

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Long-Term Stability of Keratometry, Scheimpflug-Derived True Net Power, and Total Corneal Refractive Power after Primary Pterygium Excision. / Kam, Ka Wai; Kuan, Timothy A.; Belin, Michael W; Young, Alvin L.

In: Cornea, Vol. 36, No. 11, 01.11.2017, p. 1358-1363.

Research output: Contribution to journalArticle

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abstract = "Purpose: To evaluate long-term changes in mean keratometry, astigmatism, true net power (TNP), and total corneal refractive power (TCRP) of corneas after primary pterygium excision. Methods: This is a prospective observational series conducted at a tertiary teaching hospital eye center in Hong Kong. A total of 31 eyes of 31 patients with primary pterygium excision were included. Patients with recurrent or double-headed pterygia or a history of corneal scars from previous trauma, infection, or surgery were excluded. Data were collected prospectively at postoperative weeks 1, 4, 12, and month 18. Results: Mean keratometry of the anterior cornea was 44.3 diopters (D) [95{\%} confidence interval (CI): 43.6-44.9 D] at week 1, 44.3 D (95{\%} CI: 43.6-44.9 D, standard error = 0.3) at week 4, 44.3 D (95{\%} CI: 43.7-44.9 D) at week 12, and 44.1 D (95{\%} CI: 43.5-44.7 D) at month 18. Mean astigmatism of the anterior cornea was 1.1 D (95{\%} CI: 0.7-1.4 D), 1.0 D (95{\%} CI: 0.7-1.3 D), 0.9 D (95{\%} CI: 0.6-1.1 D), and 1.0 D (95{\%} CI: 0.7-1.3 D) at postoperative 1, 4, 12 weeks, and 18 months, respectively. Mean keratometry, astigmatism of the anterior and posterior cornea, TNP and TCRP at 2.0-mm, 3.0-mm, 4.0-mm rings and zones remained unchanged on all follow-up visits (P = 1 for all comparisons). Conclusions: Keratometric values including TNP and TCRP were stable as soon as 1 week after pterygium excision. This information might help clinicians in planning subsequent intraocular surgery that requires biometric assessment for intraocular lens implantation.",
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T1 - Long-Term Stability of Keratometry, Scheimpflug-Derived True Net Power, and Total Corneal Refractive Power after Primary Pterygium Excision

AU - Kam, Ka Wai

AU - Kuan, Timothy A.

AU - Belin, Michael W

AU - Young, Alvin L.

PY - 2017/11/1

Y1 - 2017/11/1

N2 - Purpose: To evaluate long-term changes in mean keratometry, astigmatism, true net power (TNP), and total corneal refractive power (TCRP) of corneas after primary pterygium excision. Methods: This is a prospective observational series conducted at a tertiary teaching hospital eye center in Hong Kong. A total of 31 eyes of 31 patients with primary pterygium excision were included. Patients with recurrent or double-headed pterygia or a history of corneal scars from previous trauma, infection, or surgery were excluded. Data were collected prospectively at postoperative weeks 1, 4, 12, and month 18. Results: Mean keratometry of the anterior cornea was 44.3 diopters (D) [95% confidence interval (CI): 43.6-44.9 D] at week 1, 44.3 D (95% CI: 43.6-44.9 D, standard error = 0.3) at week 4, 44.3 D (95% CI: 43.7-44.9 D) at week 12, and 44.1 D (95% CI: 43.5-44.7 D) at month 18. Mean astigmatism of the anterior cornea was 1.1 D (95% CI: 0.7-1.4 D), 1.0 D (95% CI: 0.7-1.3 D), 0.9 D (95% CI: 0.6-1.1 D), and 1.0 D (95% CI: 0.7-1.3 D) at postoperative 1, 4, 12 weeks, and 18 months, respectively. Mean keratometry, astigmatism of the anterior and posterior cornea, TNP and TCRP at 2.0-mm, 3.0-mm, 4.0-mm rings and zones remained unchanged on all follow-up visits (P = 1 for all comparisons). Conclusions: Keratometric values including TNP and TCRP were stable as soon as 1 week after pterygium excision. This information might help clinicians in planning subsequent intraocular surgery that requires biometric assessment for intraocular lens implantation.

AB - Purpose: To evaluate long-term changes in mean keratometry, astigmatism, true net power (TNP), and total corneal refractive power (TCRP) of corneas after primary pterygium excision. Methods: This is a prospective observational series conducted at a tertiary teaching hospital eye center in Hong Kong. A total of 31 eyes of 31 patients with primary pterygium excision were included. Patients with recurrent or double-headed pterygia or a history of corneal scars from previous trauma, infection, or surgery were excluded. Data were collected prospectively at postoperative weeks 1, 4, 12, and month 18. Results: Mean keratometry of the anterior cornea was 44.3 diopters (D) [95% confidence interval (CI): 43.6-44.9 D] at week 1, 44.3 D (95% CI: 43.6-44.9 D, standard error = 0.3) at week 4, 44.3 D (95% CI: 43.7-44.9 D) at week 12, and 44.1 D (95% CI: 43.5-44.7 D) at month 18. Mean astigmatism of the anterior cornea was 1.1 D (95% CI: 0.7-1.4 D), 1.0 D (95% CI: 0.7-1.3 D), 0.9 D (95% CI: 0.6-1.1 D), and 1.0 D (95% CI: 0.7-1.3 D) at postoperative 1, 4, 12 weeks, and 18 months, respectively. Mean keratometry, astigmatism of the anterior and posterior cornea, TNP and TCRP at 2.0-mm, 3.0-mm, 4.0-mm rings and zones remained unchanged on all follow-up visits (P = 1 for all comparisons). Conclusions: Keratometric values including TNP and TCRP were stable as soon as 1 week after pterygium excision. This information might help clinicians in planning subsequent intraocular surgery that requires biometric assessment for intraocular lens implantation.

KW - corneal scar

KW - correspondence

KW - keratometry

KW - pterygium

KW - Scheimpflug image

KW - true net power

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