[Retinal nerve fiber layer in OCT 3: prospective study of 53 normal children]. / Évaluation de l'épaisseur de la couche des fibres nerveuses rétiniennes en OCT 3 : étude prospective sur 53 enfants normaux.

PURPOSE: To measure the peripapillary retinal nerve fiber layer thickness (RNFL thickness) in normal children using optical coherence tomography (OCT) and evaluate the effects of several factors on RNFL thickness, in order to complete results of other studies on this topic. MATERIAL AND METHOD: One hundred and four eyes of 53 normal children were investigated using OCT (Stratus OCT 3, Carl Zeiss Meditec, Dublin, CA, USA) measuring the RNFL thickness. These 28 boys and 25 girls had a mean age of 9.68±3.02 years (range, 4-15 years) and a mean refraction in spherical equivalent of +1.79±2.11 diopters (range, -3.50-5.75). The effects of age, sex, and refraction on RNFL thickness were statistically analyzed with the SPSS Package (version 15, Chicago, IL, USA). RESULTS: RNFL thickness was 104.33±10.22 µm (range, 85.87-145.82). RNFL thickness was greatest inferiorly (132.99±16.36 µm) and superiorly (130.72±19.51 µm), thinner nasally (79.01±18.48 µm), and thinnest temporally (73.79±12.61 µm). In univariate regression analysis, age had no significant effect on refraction and RNFL thickness. In univariate and multivariate analysis, refraction had a significant effect only on temporal (p<0.001) RNFL thickness. CONCLUSION: OCT can be used to measure RNFL thickness in children. This study confirms normal children's RNFL thickness data, which can be useful to the clinician in evaluating and treating optic nerve disorders in children.

Relationship between macular hole size and the potential benefit of internal limiting membrane peeling.

AIM: To investigate the relationship between the size of macular holes and the possible benefit of internal limiting membrane (ILM) peeling. METHODS: 84 consecutive cases of idiopathic macular hole followed up for at least 3 months were included in this retrospective study. Surgery comprised pars plana vitrectomy, peeling of any epiretinal membrane, 17% C2F6 (hexafluoroethane) gas filling and 10 days of positioning. 36 eyes had ILM peeling. The main outcome measure was the macular hole closure rate checked by optical coherence tomography. RESULTS: The overall postoperative closure rate was 90.5%. For macular holes > or =400 microm in diameter, the rate was 100% with ILM peeling versus 73.3% without (p = 0.015). For smaller macular holes, the rates were 100% in both groups. Postoperative gain in visual acuity was not significantly different in eyes with ILM peeling and those without. CONCLUSIONS: ILM peeling does not seem to be useful for macular hole <400 mum in diameter. Its likely benefit has to be investigated for larger macular hole sizes, for which the failure rate is higher.

Comparison of optical coherence tomography models OCT1 and Stratus OCT for macular retinal thickness measurement.

AIMS: To compare the values measured for retinal macular thickness with the first and last generations of the optical coherence tomograph (OCT1 and Stratus OCT, Zeiss, Humphrey Division). METHODS: This was a cohort study. 59 eyes were examined: 17 had a normal macula and 42 had a diabetic macular oedema. In each eye, mean retinal thickness (RT) was measured automatically in the nine macular Early Treatment Diabetic Retinopathy Study areas and at the foveal centre, using OCT1 and Stratus OCT. The paired mean RT values for each area and the type and proportion of artefacts were compared. RESULTS: Of the 590 automatic measurements, 505 had no artefact, either with OCT1 or Stratus OCT. The mean difference between the OCT1 and Stratus OCT measurements was 25 (SD 26.2) microm (p<0.0001). With Stratus OCT, RT values were significantly higher, by 8.1% (7.8%), than with OCT1. Artefacts were only observed in cases of diabetic macular oedema and were significantly more frequent with OCT1 than Stratus OCT (10.5% versus 4.4, p<0.0001). CONCLUSION: The macular retinal thickness values measured with Stratus OCT were significantly higher than those measured with OCT1. Stratus OCT has the advantage of producing fewer artefacts than OCT1 in pathological cases.

Retinal thickness in healthy and diabetic subjects measured using optical coherence tomography mapping software.

PURPOSE: To define the normal retinal thickness in healthy subjects using optical coherence tomography (OCT) mapping software and to assess the ability of OCT to detect early macular thickening in diabetic patients. METHODS: Six radial scans centered on the fixation point were done on 60 healthy eyes and 70 eyes of 35 diabetic patients without macular edema on biomicroscopy. Retinal thickness was measured automatically with OCT mapping software. Mean retinal thickness was compared in subgroups of healthy patients based on age, sex, and eye, and in the eyes of diabetic patients and healthy subjects. Thickening was diagnosed if mean retinal thickness of an area was greater than the mean thickness + 2SD in the corresponding area in healthy subjects; or if the difference between right and left eye exceeded the mean difference + 2 SD in a given area in healthy subjects. RESULTS: In healthy subjects, mean retinal thickness in the central macular area 1000 microm in diameter was 170+/-18 microm. There was no significant difference according to age, or left or right eye, but central macular thickness was significantly greater in men than women (p=0.0139). No difference was observed between the eyes of healthy subjects and diabetic patients without macular edema on biomicroscopy, but OCT detected early macular thickening in 12 diabetic eyes. CONCLUSIONS: In this study average retinal thickness and mean local variations in a normal population were defined using a commercially available mapping software. OCT seems a sensitive tool for detecting early retinal thickening.

Reproducibility of retinal mapping using optical coherence tomography.

OBJECTIVE: To assess the reproducibility of retinal thickness measurement using commercially available mapping software of optical coherence tomography (OCT). METHODS: Six radial scans, 6 mm long and centered on the fixation point, were performed on 10 eyes of 10 healthy volunteers and 10 eyes of 10 diabetic patients with clinically significant macular edema. Retinal thickness was measured automatically using the mapping software of OCT in the 9 macular Early Treatment Diabetic Retinopathy Study areas and in a central area 500 microm in diameter. Measurement reproducibility was tested by means of 3 series of scans performed by 2 different observers on 2 different days. Results were assessed by their repeatability and intraclass correlation coefficients (ICCs). RESULTS: In healthy subjects, intraobserver, interobserver, and intervisit reproducibility of retinal thickness measurements were excellent, with a repeatability coefficient of less than 7 microm and ICCs of greater than 0.89. In diabetic patients, the repeatability coefficient was less than 21 microm in all areas of the macula except one, with an ICC of greater than 0.98. Relative variations in measurements were small in both healthy and diabetic subjects, with reproducibilities of +/- 5% and +/- 6%, respectively. CONCLUSION: Retinal mapping software of OCT allows reproducible measurement of retinal thickness in both healthy subjects and diabetic patients with macular edema.

Foveal pseudocyst as the first step in macular hole formation: a prospective study by optical coherence tomography.

OBJECTIVE: To establish the natural history of a series of impending macular holes presenting as foveal pseudocysts using optical coherence tomography (OCT). DESIGN: In a prospective observational case series, patients exhibiting a foveal pseudocyst on biomicroscopy were examined with OCT and were followed up for 3 to 26 months (mean, 9.4 months) PARTICIPANTS: Twenty-two eyes of 20 consecutive patients examined for a macular hole in the fellow eye or reporting visual symptoms in only one eye, in whom a foveal pseudocyst was diagnosed on OCT. METHODS: In all cases, fundus biomicroscopy and OCT findings were compared. MAIN OUTCOME MEASURES: Biomicroscopic fundoscopy, OCT scans, and visual acuity. RESULTS: Eight foveal pseudocysts occurred in the fellow eye of an eye with a macular hole, and 14 were diagnosed in patients with unilateral visual symptoms. In four of the 22 eyes, the macula was considered normal on biomicroscopy. In the 18 others, biomicroscopy detected a foveal pseudocyst, radial striae, a yellow spot or ring, or a combination of these findings. No posterior vitreous detachment was seen on biomicroscopy in any of the eyes. On OCT, the cystoid space occupied the inner part of the foveal tissue in the stage 1A impending hole; a stage 1B impending hole corresponded to a cystoid space that extended posteriorly, disrupting the outer retinal layer. During the follow-up period, three pseudocysts evolved into full-thickness macular holes, four turned into lamellar holes, seven resolved completely after detachment of the posterior hyaloid, and eight remained unchanged for a long time. CONCLUSIONS: Foveal pseudocysts are a specific entity occurring either as a primary ocular involvement or in the fellow eye of an eye with a macular hole. Foveal pseudocysts are the first step of full thickness macular hole formation, but they also may evolve into a lamellar hole, may persist unchanged for months, or may resolve completely. Foveal pseudocyst formation may be the result of the incomplete separation of the vitreous cortex at the foveal center and the particular structure of the foveal Müller cells.

Optical coherence tomography of idiopathic macular epiretinal membranes before and after surgery.

PURPOSE: To examine the preoperative and postoperative anatomical features of the macula using optical coherence tomography in patients who underwent surgery for epiretinal membrane and to correlate these features with functional results. METHODS: In a noncomparative interventional series, 62 eyes of 62 consecutive patients operated on for an idiopathic epiretinal membrane were followed up using a standardized protocol. Preoperative and postoperative examination included best-corrected visual acuity using an Early Treatment Diabetic Retinopathy Study chart, biomicroscopy of the fundus with a contact lens, fundus photography with blue and green filters, fluorescein angiography, and optical coherence tomography. RESULTS: Median preoperative visual acuity was 20/60 (range, 20/32 to 20/320). Median postoperative visual acuity was 20/40 (range, 20/20 to 20/160). Fifty-one eyes (82%) obtained visual acuity of 20/50 or better. Preoperatively, all eyes had increased macular thickness (mean, 419 +/- 105 microm; range, 265.5 to 689 microm), with disappearance of the foveal pit. An epiretinal membrane was visible on optical coherence tomography scans in 26 cases (42%). Intraretinal cystic spaces were present in the thickened macular tissue in 15 cases but corresponded to cystoid macular edema on fluorescein angiography in only three. Postoperatively, mean macular thickness decreased to 300 +/- 65 microm (range, 185 to 511 microm) but returned to normal in only three eyes. The foveal pit reappeared in 20 eyes. Preoperatively, visual acuity correlated with macular thickness (r = 0.56, P <.0001), but not postoperatively (r = 0.12, P =.37). CONCLUSION: Macular thickness decreases after epiretinal membrane surgery, but the macular profile rarely returns to normal. However, this does not preclude satisfactory improvement of visual acuity.

Macular hole formation: new data provided by optical coherence tomography.

OBJECTIVE: To establish the sequence of events leading from vitreofoveal traction to full-thickness macular hole formation. METHODS: Both eyes of 76 patients with a full-thickness macular hole in at least 1 eye were examined by biomicroscopy and optical coherence tomography. RESULTS: Sixty-one fellow eyes had a normal macula. Optical coherence tomograms showed central detachment of the posterior hyaloid over the posterior pole in 19 cases (31%) and a perifoveal hyaloid detachment not detected on biomicroscopy in 26 cases (42%). In the 4 impending macular holes, optical coherence tomography disclosed various degrees of intrafoveal split or cyst, with adherence of the posterior hyaloid to the foveal center and convex perifoveal detachment. In the 14 stage 2 holes, eccentric opening of the roof of the hole was observed, and in the 24 stage 3 holes, the posterior hyaloid was detached from the entire posterior pole. CONCLUSIONS: In fellow eyes of eyes with macular holes posterior hyaloid detachment begins around the macula, but the hyaloid remains adherent to the foveolar center, indicating the action of anteroposterior forces. This results in an intraretinal split evolving into a cystic space, and then to the disruption of the outer retinal layer and the opening of the foveal floor, thus constituting a full-thickness macular hole.

Visual outcome of surgery for epiretinal membranes with macular pseudoholes.

OBJECTIVE: To evaluate the effect of macular pseudohole on visual results after epiretinal membrane (ERM) surgery. DESIGN: Retrospective case-control study. PARTICIPANTS: The postoperative results for 50 eyes with ERMs combined with pseudohole were compared with the results for a paired series of idiopathic ERMs without pseudohole operated on during the same period. INTERVENTION: All patients underwent standard three-port pars plana vitrectomy, including core vitrectomy, and removal of the membrane. MAIN OUTCOME MEASURES: Anatomic and functional evaluations were performed before and after surgery. Main outcome measures were postoperative visual acuity and the persistence or disappearance of the pseudohole. RESULTS: For the patients with pseudohole, median preoperative visual acuity was 20/63 (range, 20/32-20/860) and median postoperative visual acuity was 20/40 (range, 20/20-20/860). Vision improved by 2 or more lines in 31 (62%) of 50 eyes. Forty eyes (80%) reached visual acuity of 20/50 or more. Pseudohole persisted in 22 eyes (44%) 3 months after surgery and in 15 eyes (30%) at 6 months. There was no difference in visual acuity, whether or not the pseudohole persisted. For the patients without pseudohole, median preoperative visual acuity was 20/63 (range, 20/32-20/860). Median postoperative visual acuity was 20/40 (range, 20/20-20/860). Vision improved by 2 or more lines in 37 eyes (74%). In 36 eyes (72%), it was 20/50 or more. Neither preoperative nor postoperative visual acuity differed significantly in the groups with and without pseudohole. CONCLUSION: After surgery for idiopathic ERMs combined with pseudohole, visual outcome is good, and pseudohole has no adverse prognostic value. Pseudohole disappears inconstantly after surgery, but its persistence does not preclude good postoperative visual recovery.

[Results of surgery of vitreomacular traction syndromes]. / Résultats de la chirurgie des syndromes de traction vitréo-maculaire.

PURPOSE: The vitreomacular traction syndrome is a rare entity in which partial posterior vitreous detachment is combined with persistent macular adherence, thus causing macular traction. In most cases, an epimacular membrane is associated with this vitreomacular traction. We evaluate here the results of vitreous surgery for this syndrome. METHODS: We reviewed 18 consecutive eyes that had undergone vitrectomy and posterior epiretinal membrane stripping, to define the visual results and complications of surgery for the vitreomacular traction syndrome. Minimum follow-up was 3 months. RESULTS: Patients' average age was 63.5 years. All had evidence of cystic macular changes on biomicroscopic examination. Sixteen patients had an epiretinal membrane, and two, a full-thickness macular hole. Cystoid macular edema was present in 7 eyes on fluorescein angiography. The release of vitreomacular traction improved vision in 72% of eyes, with six patients obtaining 20/40 visual acuity or better. Complications of surgery included progression of nuclear sclerosis, and epiretinal membrane formation. CONCLUSION: Vitrectomy for vitreomacular traction syndrome may improve visual acuity, but the visual prognosis remains poor.