Uncorrected Visual Acuity In Eyes Research Articles

Evaluation of Distance-Specific Uncorrected Visual Acuity in Eyes Implanted with Extended Depth-of-Field Intraocular Lenses

Evaluation of Distance-Specific Uncorrected Visual Acuity in Eyes Implanted with Extended Depth-of-Field Intraocular Lenses

Characteristics of Uncorrected Visual Acuity in Eyes Implanted with Monofocal Intraocular Lens

Characteristics of Uncorrected Visual Acuity in Eyes Implanted with Monofocal Intraocular Lens

Contrast sensitivity measured by two different test methods in healthy, young adults with normal visual acuity.

This study reports contrast sensitivity (CS) reference values obtained by two different test methods in a strictly selected population of healthy, young adults with normal uncorrected visual acuity. Based on these results, the index of contrast sensitivity (ICS) is calculated, aiming to establish ICS reference values for this population and to evaluate the possible usefulness of ICS as a tool to compare the degree of agreement between different CS test methods. Military recruits with best eye uncorrected visual acuity 0.00 LogMAR or better, normal colour vision and age 18-25 years were included in a study to record contrast sensitivity using Optec 6500 (FACT) at spatial frequencies of 1.5, 3, 6, 12 and 18 cpd in photopic and mesopic light and CSV-1000E at spatial frequencies of 3, 6, 12 and 18 cpd in photopic light. Index of contrast sensitivity was calculated based on data from the three tests, and the Bland-Altman technique was used to analyse the agreement between ICS obtained by the different test methods. A total of 180 recruits were included. Contrast sensitivity frequency data for all tests were highly skewed with a marked ceiling effect for the photopic tests. The median ICS for Optec 6500 at 85 cd/m2 was -0.15 (95% percentile 0.45), compared with -0.00 (95% percentile 1.62) for Optec at 3 cd/m2 and 0.30 (95% percentile 1.20) FOR CSV-1000E. The mean difference between ICSFACT 85 and ICSCSV was -0.43 (95% CI -0.56 to -0.30, p<0.00) with limits of agreement (LoA) within -2.10 and 1.22. The regression line on the difference of average was near to zero (R2=0.03). The results provide reference CS and ICS values in a young, adult population with normal visual acuity. The agreement between the photopic tests indicated that they may be used interchangeably. There was little agreement between the mesopic and photopic tests. The mesopic test seemed best suited to differentiate between candidates and may therefore possibly be useful for medical selection purposes.

Evaluation of a toric intraocular lens with a Z-haptic

To evaluate the efficacy and rotational stability of the MicroSil 6116TU foldable 3-piece silicone toric intraocular lens (IOL) (HumanOptics). Department of Ophthalmology, Hillingdon Hospital, Uxbridge, Middlesex, United Kingdom. This prospective observational study included 21 eyes of 14 consecutive patients with more than 1.50 diopters (D) of preexisting corneal astigmatism having cataract surgery. Phacoemulsification was performed, and a MicroSil 6116TU toric IOL was inserted through a 3.4 mm temporal corneal incision. LogMAR uncorrected visual acuity (UCVA), best corrected visual acuity, refraction, keratometry, and cylinder axis of the toric IOL were measured. The mean preoperative refractive and keratometric astigmatism was 3.52 D +/- 1.11 (SD) and 3.08 +/- 0.76 D, respectively. Six months postoperatively, the logMAR UCVA in eyes without ocular comorbidity (n = 14) was 0.20 +/- 0.15 (Snellen 20/32). Seventy-nine percent (11 eyes) had a visual acuity of 0.24 (Snellen 20/35) or better. The mean refractive astigmatism at 6 months was 1.23 +/- 0.90 D. Vector analysis using the Holladay-Cravy-Koch method showed a mean reduction in refractive astigmatism of 2.16 +/- 2.33 D. The mean difference between intended and achieved cylinder axis at 6 months was 5.2 degrees (range 0 to 15 degrees). No IOL rotated more than 5 degrees during the follow-up period. The MicroSil 6116TU toric IOL reduced visually significant keratometric astigmatism and increased spectacle independence. The IOL was stable in the capsular bag, showing no significant rotation up to 6 months postoperatively.

Twelve year follow-up of unfenestrated polysulfone intracorneal lenses in human sighted eyes

Purpose: To evaluate unfenestrated polysulfone intracomeal lenses (ICLs) in human sighted eyes 12 years after their implantation and to assess eyes that had the ICLs explanted.Setting: A department of clinical ophthalmology at a general hospital and the Department of Pathology at the National Institute of Ophthalmology, London, Great Britain.Methods: In this retrospective study, seven eyes were evaluated 12 to 14 years after ICL implantation. Case notes were scrutinized for preoperative ophthalmic history, and patients were interviewed and examined to establish outcome of the ICL implantation. Histopathological correlates were made for two study patients who had had ICL explantation and penetrating keratoplasty (PKP).Results: Uncorrected visual acuity in eyes retaining the ICL ranged between hand motion and 20/40, improving to 20/32 with correction. Corneal clarity varied between complete lucency to extensive opacity on each ICL surface. No corneal vascularization, endothelial decompensation, or uveitis was seen in eyes with clear ICLs. Acuity in eyes in which the ICL was explanted was between 20/20 corrected and finger counting in cases of PKP and between 20/200 and hand motion in eyes after lamellar keratoplasty.Conclusion: Despite satisfactory surgical technique in some eyes, unfenestrated polysulfone appears to be associated with color change and varying degree of stromal opacity in eyes evaluated 12 years postoperatively and thus cannot be considered clinically acceptable.

Transverse incisions for mixed and myopic idiopathic astigmatism

Purpose: To determine the efficacy and safety of the Casebeer transverse nomogram for correcting idiopathic astigmatism using transverse incisions (T-incisions) with variable optical zones.Setting: Rancho Bernardo Eye Center, San Diego, California.Methods: This retrospective study comprised 173 eyes of 100 consecutive patients who had T-incisions according to the Casebeer transverse nomogram to correct mixed or myopic astigmatism. Preoperative cylinder ranged from 0.75 to 6.00 diopters (D). The nomogram was modified for eyes with preoperative cylinder from 1.75 to 6.00 D. Principal outcome measures were net residual astigmatism for all eyes and uncorrected visual acuity in eyes with the highest preoperative cylinder (3.25 to 6.00 D).Results: A comparison of preoperative astigmatism (mean 3.07 D ± 1.53 [SD]) and net residual astigmatism showed significant reduction in all diopter categories. Enhancements were done in 16.2% of eyes, mostly those with high preoperative cylinder. Patient age did not seem to affect results. No patient, including those with smaller optical zones, lost two or more Snellen lines of best corrected visual acuity.Conclusion: Use of the Casebeer transverse nomogram with T-incisions and variable optical zones effectively and safely reduced most idiopathic astigmatism between 0.75 and 5.50 D. Modifications to the nomogram yielded similar results in eyes with a higher preoperative cylinder.