Evaluation of a retinal oximetry image quality indicator in patients with cataract.

PURPOSE: To evaluate a new automated retinal oximetry image quality indicator with cataract as a clinical model. METHODS: Sixty-one eyes in 61 patients were imaged by the Oxymap T1 Retinal Oximeter at baseline and 25 eyes were also examined 3 weeks after cataract surgery. Image quality (0-10 on a continuous scale) was compared with standardized AREDS cataract grading and Pentacam lens densitometry. Associations with retinal oximetry measurements and visual acuity were examined. RESULTS: Image quality correlated with total, nuclear and posterior subcapsular cataract grades (ANOVA, p < 0.05), tended to be associated with lens densitometry and it improved from 4.3 ± 1.4 to 5.7 ± 1.0 (p < 0.05) after cataract surgery. Very low image quality, below 3, led to vessel detection failure in retinal oximetry images. Higher image qualities were linearly associated with higher measured retinal oxygen saturations (r = 0.52 in arteries and r = 0.46 in veins; p < 0.001). CONCLUSION: Retinal oximetry image quality deteriorated with increasing cataract density and improved after cataract surgery, supporting its use as a measure of optical clarity. The numerical quality indicator demonstrated a threshold below which images of poor optical quality should be discarded. Image quality affects the estimates of retinal oximetry parameters and should therefore be included in future analyses.

Biometry and corneal aberrations after cataract surgery in childhood.

BACKGROUND: To report long-term biometric and refractive outcomes in a group of Danish children after surgery for childhood cataract. METHODS: Children between 7 and 18 years who had undergone uni- or bilateral cataract surgery at the Department of Ophthalmology, Rigshospitalet, Denmark, were examined in this cross-sectional study. Swept source optical coherence tomography (OCT) based optical biometry (IOLmaster 700) and anterior tomography (Pentacam) was performed. Healthy fellow eyes from those with unilateral cataract were used as controls. RESULTS: We included 56 children in the study with a median age at surgery of 43.8 months (1.6-137.6). The amount of higher order aberrations was significantly increased in operated eyes (median root mean square 0.461 µm [range 0.264-1.484]) compared with non-operated eyes (median root mean square 0.337 µm [range 0.162-0.498], p < 0.001). Younger age at surgery was positively associated with more higher order aberrations at follow-up (p < 0.001), but we found no significant associations between the amount of higher order aberrations and visual acuity or contrast vision. Longer axial length was associated to glaucoma while shorter axial length was associated to strabismus (p < 0.001). CONCLUSIONS: Eyes operated for childhood cataract have higher order aberrations compared with non-operated eyes. Higher order aberrations are complex refractive errors that cannot be corrected by normal lenses and may contribute to poor visual outcomes for the children. We found an association between young age at surgery and higher order aberrations.

Associations between visual function and ultrastructure of the macula and optic disc after childhood cataract surgery.

PURPOSE: To investigate the association between visual function and ultrastructural characteristics of the retina and optic disc in children operated for cataract and factors influencing this relationship. METHODS: We included 56 children aged 7-18 years who had been operated for bilateral or unilateral cataract. Three-dimensional swept source OCT scans of the macula and the optic disc were obtained using the Triton OCT (Topcon, Corporation, Tokyo, Japan). Best corrected distance visual acuity was measured using the HOTV 3 Meter visual chart. Contrast vision was evaluated using the Freiburg Visual Acuity Contrast Test (FrACT). Healthy fellow eyes of the unilateral group were used as control eyes. RESULTS: We did not find any associations between visual acuity or contrast sensitivity and structural retinal parameters. Shorter axial length, the presence of glaucoma and pseudophakia (opposed to aphakia) were all significant predictors of greater mean macular thickness in a multiple regression analysis, (p = 0.039). Two children had foveal hypoplasia, and one child had a right eye with a thin, disorganized retina. CONCLUSIONS: Children with pseudophakia have a thicker macula but this does not seem to be related to visual function. Obtaining high quality OCT scans of the macula and optic disc in severely visually impaired children with glaucoma and/or nystagmus is challenging. We found structural macular changes which contributed to poor vision but most eyes with very reduced vision were difficult to image, and the prevalence of structural changes may be underestimated.

Visual outcomes after surgery for childhood cataracts.

PURPOSE: To describe long-term objective and subjective visual outcomes in a group of Danish children after cataract surgery. METHODS: Follow-up examination of 56 children aged 7-18 years who had undergone uni- or bilateral cataract surgery. Subjective visual function was assessed using the Cardiff Visual Ability Questionnaire for Children (CVAQC) and compared to objective visual acuity for distance and near, contrast vision and stereopsis. RESULTS: Better visual acuity on the better seeing and contrast vision on worst seeing eye were significant predictors of increased subjective visual function in a multivariate analysis, p = 0.024. Children in the unilateral group had a significantly better CVAQC ratio compared to children in the bilateral group, median of 0.88 (range 0.50-1.00) versus 0.80 (range 0.55-0.98), p = 0.027. Reading small print, playing ball games and seeing friends in the playground were the most difficult CVAQC items in the unilateral group and reading small print, seeing the board in the classroom and seeing friends in the playground were the most difficult in the bilateral group. CONCLUSION: Children with unilateral disease often have a healthy eye to support the operated eye, why they overall have better subjective visual function. Many of the most difficult visual tasks were related to academic activities which might hamper future academical capabilities.