Belkacem Haouchine

OPTICAL COHERENCE TOMOGRAPHY FOR EVALUATING DIABETIC MACULAR EDEMA BEFORE AND AFTER VITRECTOMY

PURPOSE To report the use of optical coherence tomography (OCT) for evaluation of diffuse diabetic macular edema (DME) before and after vitrectomy. DESIGN Interventional case series. METHODS A retrospective study was made of 15 consecutive eyes of 13 patients that had vitrectomy for diffuse DME and OCT preoperatively and postoperatively. In seven eyes of six patients (group 1), vitrectomy was performed because of vitreomacular traction observed on biomicroscopy or OCT. In the other eight eyes of seven patients (group 2), vitrectomy was performed for DME not responsive to laser photocoagulation, with no vitreomacular traction on biomicroscopy or OCT. RESULTS Mean +/- standard deviation (SD) follow-up after vitrectomy was 18 +/- 10 months (range, 6 to 33 months). In group 1, mean +/- SD retinal thickness decreased significantly from 661 +/- 181 microm preoperatively to 210 +/- 32 microm at the end of follow-up (P =.018). Median best-corrected visual acuity (BCVA) improved from 20/100 before surgery (range, 20/250 to 20/50) to 20/80 at the end of follow-up (range, 20/250 to 20/25; P =.046). In one eye in group 1, vitreomacular traction was only observed on OCT and not on biomicroscopy. In group 2, mean +/- SD retinal thickness decreased from 522 +/- 103 microm preoperatively to 428 +/- 121 microm at the end of follow-up (P =.2). Median BCVA was 20/100 before vitrectomy (range, 20/320 to 20/63) and 20/200 at the end of follow-up (range, 20/250 to 20/63; P =.78). CONCLUSIONS Vitrectomy was beneficial in eyes with diffuse DME combined with vitreomacular traction but not in eyes without traction. Optical coherence tomography allowed diagnosis of subtle vitreomacular traction and provided precise preoperative and postoperative assessments of macular thickness.

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.

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.

Intravitreal triamcinolone for refractory pseudophakic macular edema

PURPOSE To evaluate the efficacy of intravitreal triamcinolone in refractory pseudophakic cystoid macular edema. DESIGN A prospective, interventional case series. METHODS Three eyes of three patients with longstanding pseudophakic cystoid macular edema following uncomplicated cataract surgery, refractory to any medication, were treated with 8 mg of intravitreal triamcinolone. All three eyes were evaluated before injection and throughout follow-up with the Early Treatment Diabetic Retinopathy Studys visual acuity chart, fluorescein angiography, and macular mapping using optical coherence tomography. RESULTS A month after intravitreal triamcinolone injection, a dramatic decrease in macular thickness was noted by optical coherence tomography in all three eyes (from a mean of 502-233 microm). Mean improvement in visual acuity was 3.7 Snellen lines. Two to 4 months after triamcinolone injection, however, the edema recurred in all cases, to the same degree as before the injection, combined with a decrease in vision. Two eyes underwent a second injection of triamcinolone, and macular thickness decreased, but the edema again recurred 3 months after injection. CONCLUSION Intravitreal injection of triamcinolone induces striking regression, within 1 month, of chronic refractory macular edema. This regression appears to be transient, however, even after a second injection.

Dome-Shaped Macula in Eyes with Myopic Posterior Staphyloma

PURPOSE To describe an unusual feature in myopic eyes responsible for visual loss, which we call a dome-shaped macula. DESIGN Retrospective, observational case series. METHODS After observing isolated cases of dome-shaped macula, we analyzed optical coherence tomography (OCT) scans of 140 highly myopic eyes present in our OCT database to find similar cases. Fifteen eyes of 10 patients had a dome-shaped macula. These patients all had undergone fluorescein angiography (FA), indocyanine green angiography (ICGA), and B-scan ultrasonography examinations. RESULTS The mean refractive error of the affected eyes was -8.25 diopters (D; range, -2 to -15 D). Median visual acuity was 20/50. Recent visual impairment was noted in 11 of the 15 eyes studied, and metamorphopsia was noted in eight eyes. Four eyes were asymptomatic. FA showed atrophic changes in the macular retinal pigment epithelium (RPE) in all eyes, combined with focal points of leakage in seven of the 15 eyes. The dome-shaped appearance of the macula was visible on both B-scan ultrasonography and OCT: a characteristic bulge of the macular retina, RPE, and choroid within the concavity of the moderate posterior staphyloma was present in all eyes. In 10 eyes, OCT also showed a shallow foveal detachment at the top of the dome-shaped macula. CONCLUSIONS A dome-shaped macula within a myopic staphyloma is an unreported type of myopic posterior staphyloma. The dome-shaped macula often is associated with RPE atrophic changes and foveal retinal detachment, which may explain the visual impairment in these eyes.

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 ⩾400 μm 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 μm in diameter. Its likely benefit has to be investigated for larger macular hole sizes, for which the failure rate is higher.

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.

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) μm (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.

Nouvelles techniques d’imagerie de la rétine

La degenerescence maculaire liee a l’âge (DMLA) represente aujourd’hui la premiere cause de cecite des personnes âgees dans les pays occidentaux. Aujourd’hui, nous avons la possibilite de realiser des observations de la retine in vivo qui permettent une meilleure evaluation des maladies retiniennes et aussi de la DMLA. Cet article recense l’ensemble des techniques d’imagerie les plus recentes (incluant la tomographie en coherence optique, l’autofluorescence du fond d’œil, l’analyse de diametre des vaisseaux retiniens, l’imagerie a haute resolution a l’aide de l’optique adaptative). Les principes ainsi que les caracteristiques d’imagerie y sont decrits. La description des avantages potentiels dont pourra beneficier le medecin dans son travail clinique quotidien, mais aussi certains aspects des futures recherches sur la DMLA y sont presentes.