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[Comparison between Lenstar LS 900 non-contact biometry and OcuScan RXP contact biometry for task delegation]
H El Chehab1, J-M Giraud, A Le Corre
1Service d'ophtalmologie, hôpital d'instruction des armées Desgenettes, 108, boulevard Pinel, 69003 Lyon, France. elchehab_hussam@hotmail.fr
Journal Francais D'Ophtalmologie
|January 25, 2011
Summary
Non-contact biometry offers advantages for cataract surgery, allowing delegation to orthoptists. While generally reliable, differences in axial length and anterior chamber depth require careful consideration for intraocular lens power calculation.
Area of Science:
- Ophthalmology
- Biometry
- Surgical Technology
Background:
- Non-contact biometry devices offer advantages in clinical settings, including task delegation to allied health professionals like orthoptists.
- Evaluating the reliability of non-contact measurement techniques compared to traditional contact methods is crucial for surgical planning.
Purpose of the Study:
- To compare the reliability of non-contact biometry measurements with contact biometry and ultrasound pachymetry.
- To assess the impact of measurement differences on intraocular lens (IOL) power calculations in phacoemulsification surgery.
Main Methods:
- Comparative measurements were performed on 86 eyes of 45 patients undergoing phacoemulsification.
- Non-contact (Lenstar LS 900) and contact (OcuScan RXP, TONOREF II) biometry techniques were used by experienced orthoptists.
- Axial length, pachymetry, anterior chamber depth, and keratometry were analyzed using paired comparisons.
Main Results:
- Non-contact biometry was ineffective in 5.8% of cases due to conditions like Parkinson's disease or dense cataracts.
- Statistically significant differences were observed in non-contact pachymetry (higher), axial length (longer), and anterior chamber depth (greater).
- These differences, exceeding 0.3mm in 25.9% of patients, impacted the calculated intraocular lens power.
Conclusions:
- Non-contact biometry, exemplified by Lenstar, provides a safe and delegable method for ophthalmic measurements, reducing infection risk.
- The technique aids in optimizing refractive outcomes for a significant portion of patients undergoing refractive cataract surgery.
- Careful analysis of measurement discrepancies is necessary to ensure accurate IOL selection and desired refractive outcomes.
