Mehmet Akif Acar

Role of the Vitreous in Age-Related Macular Degeneration

PURPOSE To investigate the relationship between posterior vitreous detachment (PVD) and age-related macular degeneration (AMD). METHODS The condition of the vitreous was examined by slit-lamp funduscopy and ultrasonography in 93 eyes of 50 patients with AMD (exudative or dry) and 100 eyes of 50 controls. RESULTS There was complete PVD in 31 of the 93 eyes (33.3%) of 50 patients with AMD and the posterior vitreous was attached in 62 of these eyes (66.6%). In the control group, in 50 eyes (50%) of 50 subjects there was posterior vitreous detachment. The prevalence of PVD in eyes with macular degeneration was significantly lower (P < .05). There was no statistically significant difference between the exudative and the nonexudative groups in respect to PVD. CONCLUSIONS PVD may have a protective role against the development of AMD. Chronic vitreomacular traction and/or continuous exposure to free radicals and cytokines may possibly be one of the causes of AMD in eyes with attached vitreous.

Role of posterior vitreous detachment on outcome of anti-vascular endothelial growth factor treatment in age-related macular degeneration.

Purpose: The aim of this study was to determine the effect of posterior vitreous detachment on outcome of anti–vascular endothelial growth factor injection. Methods: Sixty-one eyes with age-related macular degeneration that had received intravitreal bevacizumab or ranibizumab injections were retrospectively reviewed. The vitreomacular interface was evaluated, and eyes were grouped according to the presence of posterior vitreous detachment (Group 1, n = 25) or vitreomacular adhesion (Group 2, n = 36). All patients received three loading doses of intravitreal anti–vascular endothelial growth factor injections at monthly intervals, and subsequently, pro re nata regimen was performed. Best-corrected visual acuity and central foveal thickness measurement at follow-up were evaluated. The development of posterior vitreous detachment during the follow-up was also reported. Results: The best-corrected visual acuity changes at each visit compared with baseline were significantly better in Group 1 (P = 0.01, 0.02, 0.02, 0.009, 0.009, respectively at third, sixth, ninth, 12th month, and last visit). When best-corrected visual acuity was classified according to the change in visual acuity of 10 letters or more, the rate of improved or stable best-corrected visual acuity was greater in Group 1 (P = 0.02). During the follow-up, 5 eyes (14.3%) developed posterior vitreous detachment. Conclusion: Vitreomacular adhesion seems to have an adverse effect on the visual prognosis of anti–vascular endothelial growth factor treatment for age-related macular degeneration.

Outcome of Complex Retinal Detachment Surgery after Silicone Oil Removal

Background and objective: To evaluate anatomical prognosis after silicone oil removal.Patients and methods: Sixty-eight eyes which underwent silicone oil removal were enrolled into the study. The underlying ocular pathology for pars plana vitrectomy, surgical methods, and time of silicone oil removal were analysed.Results: Sixteen of 68 eyes (23.5%) redetached following the removal of silicone oil. According to etiology redetachment rates: PVR C 9.5% (2/21), PVR D 25% (4/16), trauma without intraocular foreign body 27.3% (3/11), with intraocular foreign body 33.3% (2/6), giant retinal tear 37.5% (3/8), and proliferative diabetic retinopathy with tractional retinal detachment 33.3% (2/6). The rate of redetachment was 22% in patients with encircling band and 27.8% without encircling band. Retina was redetached in the first 10 days in 81.3% of patients after silicone oil removal.Conclusion: The residual vitreoretinal traction especially at the vitreous base is the most likely reason for retinal redetachment after silicone oil removal, which is most commonly seen during the first 10 days.

Serum lipid profile in diabetic macular edema

PURPOSE To evaluate the correlation of lipid profile and clinical presentation of macular edema in Type 2 diabetes mellitus (DM) patients. MATERIALS AND METHODS The study included 20 patients with chronic diabetic macular edema and plaque-like hard exudates (Group 1), 20 patients with diabetic macular edema (Group 2), and 20 DM patients but without retinopathy (Group 3). Diabetic retinopathy was classified according to the Early Treatment Diabetic Retinopathy Study grading system. Sample t test was used to evaluate the association between the fasting serum lipid [total cholesterol, triglyceride, low-density lipoprotein (LDL), high-density lipoprotein (HDL)], glycosylated hemoglobin (HbA1c), fasting blood glucose, creatinine levels, and the clinical findings. P values <.05 were considered statistically significant. RESULTS There was no difference between fasting serum lipids and HbA1c levels. Duration of diabetes was shorter in Group 3 than in Groups 1 and 2. Patients in Group 1 had longer duration of diabetes than others (P<.05). Creatinine levels in Group 1 were higher than in other groups (P<.05). Although there was no correlation between fasting blood glucose and HbA1c levels, HbA1c was higher in all three groups from the baseline-normal limits (P<.05). CONCLUSION No correlation was found between serum lipid levels and macular edema severity, but the duration of diabetes was demonstrated as a significant factor in the progression of macular edema. High HbA1c levels in all patients highlight the importance of intense glycemic control in diabetic patients.

Intraocular intrusion of a scleral sponge implant

A patient with intrusion of a scleral sponge implant after retinal reattachment surgery is described. Retinal incarceration occurred during primary retinal reattachment surgery and the patient underwent additional cryopexy and radial sponge implant. However, the retina remained detached and pars plana vitrectomy was performed with silicone oil endotamponade to reattach the retina. The interval between placement of the sderal buckle and development of intrusion was 3 months. The buckle was sutured to the sclera with mattress sutures. During the postoperative follow-up period, the intraocular pressure was elevated and controlled with topical antiglaucomatous medication. The encircling band was cut but left in place to avoid perforation, and the retina remained attached. Intrusion of a buckle after retinal reattachment surgery is a rare complication that usually does not require surgical intervention. Cutting the silicone band without removing it may be a treatment option.

Surgical management of retinal detachment with choroidal coloboma

Purpose To verify the functional and anatomical results of retinal detachments related to choroidal coloboma. Methods Seven eyes with retinal detachment secondary to retinal breaks at the margin of or within a choroidal coloboma were analysed retrospectively. Results Scleral buckling was performed in five of the seven eyes; two needed additional pars plana vitrectomy (PPV) with internal tamponade using silicone oil to reattach the retina. In two eyes PPV with internal tamponade using silicone oil or gas was used as a primary procedure. All seven eyes were reattached. Five eyes (71.4%) showed improvement or had visual acuity of 20/400 or better after surgery, but two remained unchanged. Conclusions Retinal detachment secondary to choroidal coloboma can be treated successfully by scleral buckling or PPV with internal tamponade.

Retinal nerve fiber layer thickness in chronic renal failure without diabetes mellitus.

PURPOSE To evaluate the retinal nerve fiber layer (RNFL) thickness in patients with chronic renal failure (CRF) without diabetes mellitus by using optical coherence tomography (OCT). METHODS Sixty-six eyes of 33 patients with CRF were evaluated. Eighteen patients have been treated with hemodialysis (group 1) and 15 patients have been treated with peritoneal dialysis (group 2). The RNFL thicknesses were assessed before and after the hemodialysis in group 1. None of these patients had diabetes mellitus. Forty eyes of 20 age-matched normal control subjects were assessed in group 3. An RNFL thickness protocol was used to acquire circular scans of 3.4 mm in diameter around the optic nerve. For each eye, RNFL thicknesses were evaluated in 4 quadrants. All of the measurements were automatically calculated by the existing OCT software. All normal subjects and CRF patients underwent comprehensive ophthalmologic examination. The mean and quadrantal RNFL thickness values in patients with CRF were compared with the control group. RESULTS The mean RNFL thickness values in patients with CRF were statistically significantly lower than the control group. Differences between the RNFL thickness values in group 1 and group 2 and the predialysis and postdialysis measurements were not statistically significant. CONCLUSIONS The RNFL thickness in CRF without DM, which was measured by OCT-3, was found to be significantly decreased. The presence of CRF can be a source of false positive results and lead to overestimation of glaucomatous optic neuropathy.

Aqueous humor nitric oxide levels in patients with central retinal artery occlusion.

Background/Purpose: There is increasing evidence suggesting that nitric oxide (NO) is implicated in the pathogenic process of ischemic disease. The purpose of this study was to quantify the aqueous humor NO levels in patients with central retinal artery occlusion (CRAO) and in age‐matched controls. Methods: Aqueous humor specimens were obtained from seven patients who had been diagnosed with CRAO; the sampling was done within 12 to 24 hours of diagnosis. All specimens were obtained by paracentesis, which was performed as a therapeutic intervention. Samples of aqueous humor were also collected from 15 age‐matched healthy patients undergoing cataract surgery, to be used as controls. For each sample, we assayed the amount of nitrite, which is the stable metabolite of NO, using the spectrophotometric method based on the Griess reaction. Results: There were detectable levels of nitrite in the aqueous humor from five of seven patients with CRAO (mean level, 0.32 ± 0.08 μmol/L). The levels in the control group were below the detection limit in all cases (<0.08 μmol/L). There was a statistically significant difference between the aqueous humor nitrite levels in the CRAO group and the controls (P = 0.0008). Conclusions: Our study shows that patients with CRAO present with elevated levels of NO in the aqueous humor. These findings may provide insight into the role that NO plays in CRAO.

Primary and Secondary Implantation of Scleral‑Fixated Posterior Chamber Intraocular Lenses in Adult Patients

Purpose: The purpose of this study is to evaluate and to compare the results of primary and secondary scleral-fixated posterior chamber intraocular lens (PCIOL) implantations in adult patients. Materials and Methods: A retrospective analysis of scleral-fixated PCIOLs-implanted during (primary group) or after (secondary group) cataract surgery was performed. The median follow-up time of 96 patients was 6 months (minimum: 6; maximum: 35 months). Outcome measures were indications, corrected distance visual acuity (CDVA), change in visual acuity and complications. Results: A total of 37 patients (38.5%) had primary implantations and 59 (61.5%) had secondary implantations. Penetrating keratoplasty was combined with secondary implantation in 13 cases. The median post-operative CDVA was 0.5 in decimal notation in both groups (P = 0.576). The CDVA improved by at least one Snellen line or remained unchanged in 35 eyes (94.6%) in the primary group and in 52 eyes (88.1%) in the secondary group (P = 0.263). Eyes with CDVA of 0.5 or higher were 62.2% (n = 23) in the primary group and 67.8% (n = 40) in the secondary group post-operatively (P = 0.066). The difference in early and late complications were not statistically significant between groups (P = 0.637, P = 0.154, respectively). Regarding late complications, 30 eyes (81%) in the primary group and 40 eyes (67.9%) in the secondary group had no complications (P = 0.154). Conclusion: Both primary and secondary scleral-fixated PCIOL implantations can provide favorable visual outcomes with lower complication rates. An important consideration is the appropriate timing for scleral fixation, taking into account the patients characteristics and the course of the operation.

Penetration of topically applied diclofenac and ketorolac into the aqueous humour and subretinal fluid: randomized clinical trial

OBJECTIVE To determine the level of intraocular penetration of diclofenac sodium and ketorolac tromethamine into the aqueous humour and subretinal fluid. DESIGN Prospective randomized clinical trial. PARTICIPANTS Twenty eyes scheduled for retinal detachment surgery and 17 eyes scheduled for cataract surgery. METHODS Patients with retinal detachment were randomly assigned to receive either topical ketorolac (n = 11) or topical diclofenac (n = 9). Subretinal fluid samples were collected 30-60 minutes after the administration of the last dose. In addition, 17 patients with cataract were randomly assigned to receive topical ketorolac (n = 9) or topical diclofenac (n = 8). The aqueous humour samples were collected 30 minutes after the administration of the last dose. Drug concentrations were determined by high-performance liquid chromatography fluorescence. RESULTS The mean diclofenac concentration in the subretinal fluid was 42.31 (SD 24.89) ng/µL. Ketorolac was undetectable in the subretinal fluid in all patients who received it because ketorolac tromethamine levels were under the limit of detection. In the aqueous humour, mean diclofenac concentration was 4.98 (SD 4.56) ng/µL, and mean ketorolac concentration was 20.17 (SD 12.21) ng/µL. Topical administration of diclofenac sodium yielded 8.4 times greater drug concentration in the subretinal fluid than in the aqueous humour. Aqueous humour concentrations of ketorolac were higher than those of diclofenac (p = 0.019). CONCLUSIONS The concentration in the subretinal fluid of topically applied diclofenac was higher than that of ketorolac; and topical ketorolac penetrated into the aqueous humour better than diclofenac did. This suggests that diclofenac can be used more effectively in events related to posterior segment and ketorolac in anterior segment events.