Cindy Tromans

Quality of life in myopia

BACKGROUND The safety and predictability of refractive surgery for all degrees of myopia is now becoming established. It is therefore appropriate to evaluate whether there is a patient driven demand for such treatments and, if so, to establish guidelines for its provision within the National Health Service (NHS). METHODS A comparative study was designed to assess the effect of degree of myopia on quality of life (“high” (n = 30) –10.00D, worse eye; “moderate” (n = 40) –4.00 to –9.75D, worse eye; “low” (n = 42) <–4.00D, worse eye) compared with a group of patients with keratoconus (n = 30) treated by optical correction. Data collection included binocular logMAR visual acuity, Pelli-Robson low contrast letter sensitivity, questionnaires to assess subjective visual function (VF-14) and effect on quality of life (VQOL), and semi-structured interviews. RESULTS There were no significant differences in any of the measures between patients with a high degree of myopia and those with keratoconus, or between those with a low and those with a moderate degree of myopia. However, those with a high degree of myopia had highly significantly poorer logMAR, VF-14, and VQOL scores than those with low and moderate myopia (p<0.001). Interview data supported these findings with patients with a high degree of myopia and those with keratoconus reporting that psychological, cosmetic, practical, and financial factors affected their quality of life. CONCLUSION Compared with low and moderate myopia, patients with a high degree of myopia experience impaired quality of life similar to that of patients with keratoconus. Criteria should therefore be identified to enable those in sufficient need to obtain refractive surgical treatment under the NHS.

Management of pellucid marginal corneal degeneration

Purpose A retrospective study to ascertain the management of pellucid marginal corneal degeneration (PMCD).Method and results Sixteen patients (average age 42.6 years) presented with PMCD. PMCD was bilateral in 13 and unilateral in 3 patients. Eight eyes underwent surgery. Nineteen eyes were managed non-surgically. Surgery involved corneal wedge excision (WE) (6 eyes), penetrating keratoplasty (PK) (3 eyes) and lamellar thermo-keratoplasty (LTK) (1 eye). Immediate pre-operative average visual acuity (VA) was 6/24, 6/10 and 6/60 with an average pre-operative astigmatism of 11.40 D, 9.75 D and 20.5 D for WE, PK and LTK respectively. After an average post-operative follow-up of 57 months, 66 months and 1 year, the average astigmatism was 8.90 D, 4.63 D and 6.00 D with an average final VA of 6/19, 6/15 and 6/6 for WE, PK and LTK respectively. In the nonsurgical group, at presentation, 40% of eyes had a VA of 6/12 or better. After an average follow-up period of 32.3 months, 80% of eyes had a visual acuity of 6/12 or better. Optical correction was achieved with spectacles and or contact lenses.Conclusions Surgical correction for PMCD provides poor long-term reduction of astigmatism. Patients with PMCD may be adequately corrected in the long term by the use of scleral fitted gas-permeable contact lenses.

Visual performance and optical quality with soft lenses in keratoconus patients

Citation information: Jinabhai A, Radhakrishnan H, Tromans C & O’Donnell C. Visual performance and optical quality with soft lenses in keratoconus patients. Ophthalmic Physiol Opt 2012, 32, 100–116. doi: 10.1111/j.1475‐1313.2011.00889.x

Reduction in Corneal Volume with Severity of Keratoconus

Purpose: To compare the corneal volume in keratoconic and normal eyes to improve our understanding of the tissue distribution associated with the disease. Materials and Method: The Oculus Pentacam tomographer (Oculus Inc., Wetzlar, Germany) was used to analyze the corneal volume contained within discs with diameters of 3, 5, 7, and 10 mm in 21 patients with keratoconus and 21 matched healthy control subjects. Results: Corneal volume was significantly decreased in the keratoconus group (keratoconus vs. control group: 3.44 ± 0.39 vs. 4.05 ± 0.29 mm3, 10.34 ± 0.95 vs. 11.79 ± 0.84 mm3, 22.80 ± 1.73 vs. 25.26 ± 1.74 mm3, and 57.17 ± 3.94 vs. 61.90 ± 4.12 mm3 for the 3-, 5-, 7-, and 10-mm diameter discs, respectively; p < 0.001). As the corneal disc diameter analyzed increased, fewer differences were found between the control corneas and keratoconic corneas at different stages of the disease. Within the 3-mm and 5-mm diameter discs, significant differences were detected between the control group, moderate keratoconus, and the severe keratoconus groups (p < 0.05). However, within the 10-mm discs, differences were only detected between the control group and the severe keratoconus group (p = 0.005). Conclusions: Corneal volume was significantly decreased in keratoconus, particularly in the central and paracentral area. The decrease in corneal volume in moderate and severe keratoconus as detected by the Pentacam tomographer, may be explained by loss of corneal tissue. In the early stages of the disease, the altered metabolic activity may cause tissue stretching and, as the disease progresses, this stretching is then accompanied by tissue loss.

Corneal nerve structure and function in keratoconus: a case report.

Purpose. To investigate corneal nerve structure and function in a 24-year-old patient with keratoconus and prominent corneal nerves. Methods. Corneal nerve appearance was assessed by using a corneal confocal microscope, and corneal nerve function was assessed by using a Cochet–Bonnet aesthesiometer. Findings were compared to those of an age-matched control subject without keratoconus. Results. The patient with keratoconus was found to have thicker nerve fiber bundles in the stroma (keratoconus vs. control, 9.8 ± 5.0 &mgr;m vs. 5.4 ± 2.7 &mgr;m) and reduced nerve fiber density in the subepithelial plexus (keratoconus vs. control, 269.7 ± 145.6 &mgr;m vs. 1,258 ± 254.8 &mgr;m) compared to the control subject. The patient with keratoconus was found to have reduced corneal sensitivity compared to the control subject (keratoconus vs. control 0.39 gr/mm2 vs. 1.59 gr/mm2). Conclusions. Corneal confocal microscopy proved to be a useful in vivo technique for assessing corneal nerve structure in this patient with keratoconus. Although the total number of stromal nerve fiber bundles was reduced in the patient with keratoconus versus the control subject, the increased tortuosity and increased nerve fiber diameter may explain why the corneal nerves appear more visible in this patient with keratoconus.

Optical quality and visual performance with customised soft contact lenses for keratoconus

This study investigated how aberration‐controlling, customised soft contact lenses corrected higher‐order ocular aberrations and visual performance in keratoconic patients compared to other forms of refractive correction (spectacles and rigid gas‐permeable lenses).

Scope of practice of optometrists working in the UK Hospital Eye Service: a national survey.

The role of the optometrist in the Hospital Eye Service (HES) has undergone significant development in recent years to include extended areas of clinical practice more traditionally undertaken by ophthalmologists, commensurate with a growing demand for increased capacity in ophthalmic services. In this report, we present the findings from a national survey of the scope of practice of optometrists working in the UK HES.

Optical Quality & Visual Performance with Customised Lenses for Keratoconus

Purpose: This study investigated how aberration- controlling soft contact lenses (ACCLs) corrected ocular aberrations and visual performance in keratoconic patients compared to other forms of refractive correction. Method: Twenty-two patients (16 RGP contact lens wearers and 6 spectacle wearers) were fitted with standard toric soft lenses (TCLs) and customised ACCLs (designed to correct 3rd-order coma). In the RGP lens- wearing patients, aberrations were measured without lenses, with the patient?s habitual lenses and with the study lenses (using Hartmann-Shack aberrometry). In the spectacle-wearing patients, aberrations were measured both with and without the study lenses. LogMAR visual acuity (high-contrast and low-contrast) was evaluated with the patient wearing their habitual correction (of either spectacles or RGP lenses) and with the study lenses. Results: In the contact lens-wearing patients, the habitual RGP lenses and ACCLs provided significant reductions in uncorrected 3rd-order coma root-mean-square (RMS) error, 3rd-order RMS and higher-order RMS (HORMS) error (p?0.004). In the spectacle-wearing patients, both the TCLs and ACCLs significantly reduced uncorrected 3rd- order RMS and HORMS errors (p?0.005). The spectacle- wearing patients showed no significant differences in visual performances with their habitual spectacles versus the study lenses. In contrast, the habitual RGP lenses and TCLs provided significantly better high- contrast acuities compared to the ACCLs (p?0.006). Conclusions: In this group of keratoconic patients, ACCLs provided substantial reductions in higher-order aberrations; however, the poor visual performances achieved with the study lenses are most likely to be due to small on-eye lens decentrations.