DefinePK

Research Objective

To compare the effectiveness of contact versus non-contact axial length measurement methods on post-operative mean spherical equivalent in cataract patients.

Methodology

Randomized control trial conducted over six months at the Cataract Clinic, Al Ibrahim Eye Hospital, Karachi. 100 cataract patients were randomly assigned to Group A (non-contact IOL Master) or Group B (contact A-Scan) for axial length measurement. Post-operative mean spherical equivalent was assessed four weeks after surgery. Data were analyzed using SPSS, with t-tests and stratified analysis based on age and gender.

Methodology Flowchart

                        graph TD;
    A[Recruit 100 Cataract Patients] --> B[Random Assignment];
    B --> C[Group A: Non-Contact Biometry IOL Master];
    B --> D[Group B: Contact Biometry A-Scan];
    C --> E[Measure Axial Length];
    D --> E;
    E --> F[Perform Cataract Surgery];
    F --> G[Assess Post-operative Mean Spherical Equivalent 4 weeks];
    G --> H[Data Analysis SPSS, t-tests, Stratification];
    H --> I[Compare Outcomes Between Groups];
    I --> J[Draw Conclusion];                    

Discussion

The non-contact method demonstrated higher precision in axial length measurements and better refractive outcomes post-surgery due to reduced variability and absence of corneal compression. It also offers advantages in patient comfort and reduces risks associated with direct eye contact. While both methods achieved similar visual acuity improvements, the non-contact method's statistical significance in refractive outcomes suggests a slight advantage. Stratification analysis indicated no significant impact of age or gender on outcomes.

Key Findings

The non-contact method (Group A) showed a slightly better post-operative mean spherical equivalent (0.95 ± 0.12 D) than the contact method (1.00 ± 0.20 D), with a statistically significant difference (p = 0.04). Visual acuity improvements were similar in both groups, with 80% in Group A and 76% in Group B achieving 6/12 or better.

Conclusion

The non-contact method for axial length measurement in cataract surgery offers slightly better refractive accuracy post-operatively compared to the contact method. While both methods effectively improve visual acuity, the non-contact approach may enhance precision and patient comfort, making it a preferable choice in clinical settings.

Fact Check

1. Sample Size: 100 cataract patients were included in the study, with 50 patients in each group (Group A: non-contact, Group B: contact).
2. Statistical Significance: A statistically significant difference (p = 0.04) was found between the post-operative mean spherical equivalent of the non-contact and contact groups.
3. Visual Acuity Achievement: 80% of patients in the non-contact group (Group A) achieved a visual acuity of 6/12 or better, compared to 76% in the contact group (Group B).

Mind Map