Nikolaos Tr. Stangos

Primary pars plana vitrectomy versus scleral buckle surgery for the treatment of pseudophakic retinal detachment: a randomized clinical trial.

Objective: To compare the anatomical and functional outcome of scleral buckle (SB) surgery with that of pars plana vitrectomy (PPV) alone in the treatment of primary rhegmatogenous pseudophakic retinal detachment (RD). Methods: In this prospective, randomized clinical trial, 150 eyes of 150 patients with pseudophakic RD and proliferative vitreoretinopathy (PVR) stage B or less were randomized to SB surgery (75 eyes) or primary PPV (75 eyes). SB surgery involved break localization, cryotherapy, placement of a circumferential 240 style 2.5-mm solid silicone band, combined with a local buckle when indicated, and transscleral drainage of subretinal fluid. PPV included extensive vitreous removal, perfluoro-n-octane injection or endodrainage of subretinal fluid to flatten the retina, cryopexy treatment of breaks, and fluid/air exchange with injection of 20% SF6. Postoperative follow-up was 1 year. Break diagnosis, operating time, intraoperative and postoperative complications, retinal reattachment rate for single as well as multiple surgeries, axial length changes, and best-corrected visual acuity at 1 year after surgery were the main outcome measures. Results: The number of eyes that were diagnosed with additional breaks interoperatively was higher in the PPV group (P = 0.004, &khgr;2 test). Mean operating time was significantly less (P = 0.0001, t-test) in the PPV group. With a single surgery, the retina was reattached in 62 eyes (83%) in the SB surgery group and in 71 eyes (94%) in the PPV group (P = 0.037, Fisher exact test). With subsequent surgeries, final anatomical reattachment was achieved in 71 cases in the SB surgery group and in 74 cases in the PPV group (P = 0.37, Fisher exact test). Mean axial length change at 1 year was 0.95 mm in the SB surgery group and 0.1 mm in the PPV group (P = 0.0001, t-test). Mean final best-corrected visual acuity (logMAR) was 0.40 in the SB surgery group and 0.33 in the PPV group (P = 0.26, t-test). Conclusions: Primary PPV offers potential advantages over SB surgery in the treatment of pseudophakic RD, including less operating time, accurate diagnosis of breaks, higher reattachment rate with a single surgery, and no postoperative axial length changes. Retinal reattachment rate with multiple surgeries and final visual acuity at 1 year were similar for SB surgery and PPV.

Primary vitrectomy with perfluoro-n-octane use in the treatment of pseudophakic retinal detachment with undetected retinal breaks.

PURPOSE This report describes the results of a prospective trial to evaluate the efficacy of pars plana vitrectomy (PPV) in conjunction with perfluoro-n-octane (PFO) as initial treatment of pseudophakic retinal detachment (RD) with no breaks diagnosed preoperatively. METHODS Fourteen consecutive eyes presenting with pseudophakic RD in which retinal breaks could not be identified preoperatively underwent primary PPV, internal microsurgical identification of the retinal breaks with endoillumination and noncontact wide angle viewing system, PFO retinal reattachment, transscleral cryopexy or endolaser treatment of breaks, PFO-air exchange, and final injection of 20% sulfur hexafluoride. In five eyes, a scleral buckle was also used. Mean follow-up period was 18 months. RESULTS In 13 of the 14 eyes in which no breaks had been identified preoperatively, breaks were diagnosed during surgery. Perfluoro-n-octane retinal attachment facilitated accurate microscopic treatment of retinal breaks. The retina was reattached with a single operation in all eyes. Eleven eyes had final visual acuity of 20/60 or better. Complications were minimal. CONCLUSIONS Pars plana vitrectomy in conjunction with PFO expression of subretinal fluid is effective in the initial treatment of pseudophakic RD with no preoperative diagnosis of retinal breaks.

Macular epiretinal membranes.

Epiretinal membranes (ERM) are a common finding in older patients. Although they may be associated with numerous clinical conditions, most epiretinal membranes occur in the absence of ocular pathology. Patients symptoms range from asymptotic to complaints of severe vision loss and metamorphopsia. Epiretinal membranes are commonly classified according to their density, to the seventy of retinal distortion and to associated biomicroscopic changes. Pars plana vitrectomy has been found to be effective in removing ERM from the macula, improving the visual acuity and decreasing metamorphopsia. Both idiopathic and secondary ERMs do well after surgery, although secondary ERMs showed a greater amount of improvement than idiopathic ones. Complications are frequent including accelerated postoperative nuclear sclerosis, retinal breaks and RD, macular edema, RPE and, occasionally, macular hole and hypotony. However only RD involving the macula have a worsening prognosis on final outcome

Brimonidine 0.2% given two or three times daily versus timolol maleate 0.5% in primary open-angle glaucoma.

PURPOSE To evaluate the efficacy and safety of brimonidine 0.2% two or three times daily versus timolol maleate 0.5% solution twice daily. METHODS Patients with primary open-angle glaucoma were randomized by Latin square technique to one of the three treatment sequences in this crossover, prospective double-masked trial. Each treatment period consisted of 6 weeks of chronic dosing followed by a diurnal curve for the intraocular pressure measured at 08:00, 10:00, 16:00, 18:00, 20:00, 22:00, and 24:00 hours. Intraocular pressure was measured by applanation tonometry. RESULTS Thirty patients completed this trial. The average diurnal intraocular pressures in the trial were measured for timolol maleate (17.7 +/- 2.7 mm Hg), brimonidine given three times daily (18.0 +/- 2.2 mm Hg), and brimonidine given twice daily (19.2 +/- 2.4 mm Hg). There was a statistical difference between groups (P <.005). When groups were compared by pairs, three times daily dosing with brimonidine and timolol maleate both reduced the pressure more than twice daily brimonidine at every time point past 10:00 hours and for the diurnal curve (P <.05). In contrast, three times daily brimonidine and timolol maleate were statistically similar for the diurnal pressure, and each time point, except timolol maleate, decreased the pressure more at 16:00 (P =.042). Safety was similar between groups. CONCLUSIONS This study demonstrated that both timolol maleate twice daily and brimonidine three times daily provide a similar intraocular pressure reduction to each other. Timolol maleate twice daily and brimonidine three times daily provide a greater decrease in pressure in the late afternoon and nighttime hours, compared with brimonidine twice daily.

Ultrasonographic classification and phacoemulsification of white senile cataracts

OBJECTIVE To classify the white senile cataracts and report the results of phacoemulsification of white cataracts. DESIGN Prospective, noncomparative case series. PARTICIPANTS One hundred eyes were included. INTERVENTION White cataracts were examined biomicroscopically before surgery, and their acoustic structure was analyzed with standardized A-scan echography. White cataract surgery was performed with phacoemulsification via a superior temporal near-limbus corneal approach using a bimanual divide-and-conquer or stop-and-chop technique. Patients were followed after surgery for a period of 9 months. MAIN OUTCOMES MEASURES The A-scan acoustic structure of white cataracts; successful accomplishment of capsulorrhexis; mean phacoemulsification time, power, and energy; intraoperative and postoperative complications of phacoemulsification; and visual acuity at 9 months after surgery. RESULTS White senile cataracts were categorized into three different types. Type I included intumescent, white cataracts with cortex liquefaction and high internal acoustic reflections (44 eyes), type II included white cataracts with voluminous nuclei, little amount of whitish solid cortex, and low internal acoustic reflections (49 eyes), and type III included white cataracts with fibrosed anterior capsule and low internal echospikes (7 eyes). Circular capsulorrhexis was completed in 79 eyes and was significantly less successful in eyes with type I intumescent, white cataracts compared with type II white cataracts (P = 0.0034). Mean phacoemulsification time and energy were higher in type II and type III white cataracts. Posterior capsule rupture occurred in ten eyes, and three of these eyes were complicated by vitreous loss. In 95 eyes, the posterior chamber lens was implanted in the capsular bag and in five eyes in the sulcus. After surgery, a transient corneal edema developed in 31 eyes. At the final 6-month examination, the mean postoperative visual acuity was 20/30. CONCLUSION Current phacoemulsification techniques can safely manage eyes with senile white cataracts. The increased risk of difficulty with continuous capsulorrhexis in type-I and type-III white cataracts and the substantial nuclear hardness in type-II and mainly type-III white cataracts would suggest that current phacoemulsification techniques might not be as successful in these patients as they are in ordinary earlier cataracts.

Perfluorocarbon liquid utilization in primary vitrectomy repair of retinal detachment with multiple breaks.

Purpose To evaluate the efficacy of pars plana vitrectomy in conjunction with intraoperative perfluoro-n-octane (PFO) use as initial treatment of retinal detachment (RD) with multiple breaks located at various distances from the ora serrata. Methods Twenty-two consecutive eyes (15 phakic, 2 aphakic, and 5 pseudophakic) presenting with RD with multiple breaks and tears underwent primary pars plana vitrectomy, PFO retinal reattachment, transcleral cryopexy or endolaser treatment of breaks, PFO/air exchange, and final injection of 18% perfluoropropane (C3F8). Scleral buckles were not used. The mean follow-up period was 29 months. Results Temporary PFO utilization attached the posterior retina and facilitated the safe removal of vitreous at its base and around the retinal tears. Intraoperative complications included new breaks (3 eyes), enlargement of breaks (2 eyes), and a small bubble of subretinal PFO (1 eye). Postoperatively, the retina remained attached during follow-up in 19 eyes. Cataract developed or progressed in 13 phakic eyes. Conclusions Pars plana vitrectomy in conjunction with intraoperative PFO utilization is effective as initial treatment of RDs with multiple breaks. The main limitation of this technique is the postoperative progressive cataract formation in phakic eyes.

Macular hole formation in diabetic retinopathy: the role of coexisting macular edema

The aim of this study was to characterise different etiologies for the development of macular holes in diabetic retinopathy. We examined 8 eyes of 8 patients with known diabetic retinopathy who had developed a macular hole. These were classified as follows: related to macular edema (4 eyes), non-related to macular edema (2 eyes), intraoperative (1 eye) or postoperative (1 eye) after pars plana vitrectomy for proliferative diabetic retinopathy. In three patients the macular holes were treated with pars plana vitrectomy and fluid air exchange.In diabetic eyes with macular edema, macular holes may develop because of intraretinal exudation combined with increased vitreomacular attachments and tractions. The mechanism of macular hole formation in diabetic eyes without macular edema probably results from the same increased tangential vitreous traction which is seen in idiopathic age-related macular holes. Iatrogenically induced macular holes during pars plana vitrectomy for proliferative diabetic retinopathy may be also due to intraoperative vitreoretinal tugging. Finally, macular holes developing after vitrectomy may have an etiology not related to vitreous tractions or attachments.

Mitomycin C therapy for conjunctival-corneal intraepithelial neoplasia.

Purpose. To evaluate the efficacy and safety of topical mitomycin C (MMC) for conjunctival-corneal intraepithelial neoplasia (CCIN). Methods. One patient with primary CCIN received seven applications for 3 minutes of mitomycin C 0.02%, for 2 weeks, on alternative days. The size of the CCIN before and after the treatment and ophthalmic mitomycin C related complications were evaluated. Results. The lesion started to regress during the second month after the last application of mitomycin C, and by the third month it disappeared completely. The patient remains disease free after 36 months follow up. The complications of mitomycin C included a mild tearing and a slight conjunctival hyperemia that resolved 7 days after the end of the therapy. Conclusion. Multiple applications of mitomycin C could be an effective treatment for selected cases of CCIN.

Posterior capsule rupture and vitreous loss during phacoemulsification with or without the use of an anterior chamber maintainer

Purpose: To compare the incidence of posterior capsule rupture and vitreous loss during phacoemulsification with and without the use of an anterior chamber maintainer (ACM) Setting: Aristotle University Eye Clinic, Thessaloniki, Greece. Methods: The surgical records of patients who had phacoemulsification by experienced surgeons over a 2‐year period were reviewed. The cases were divided into 2 groups: surgery performed without the use of an ACM (no‐ACM group) and surgery performed with the use of an ACM (ACM group). Results: The no‐ACM group comprised 231 cases and the ACM group, 312 cases. Posterior capsule rupture occurred in 19 cases (8.22%) and 22 cases (7.05%), respectively. Of the patients with posterior capsule rupture, 6 (31.57%) in the no‐ACM group and 16 (72.72%) in the ACM group had vitreous loss and required an anterior vitrectomy; the difference between the 2 groups was statistically significant (P = .03). Conclusions: The use of an ACM in phacoemulsification provided a consistently deep anterior chamber and approximately the same rate of complications as with a standard technique in the hands of experienced surgeons. However, when posterior capsule rupture occurred, the incidence of vitreous loss was significantly higher in eyes with an ACM.

A-scan quantitative echography of senile cataracts and correlation with phacoemulsification parameters.

Purpose. To study the echographic appearance of various types of senile cataracts using a-scan quantitative echography and correlate these findings with phacoemulsification parameters indicating surgical lens hardness. Methods. The study involved 71 eyes with senile cataracts and 20 additional eyes with normal human lenses. Cataract and clear lenses were studied using A-scan quantitative echography and with a tissue sensitivity gain setting of 74 db. We assessed the lens internal reflectivity in the A-scan echograms within a range of 0% to 100%, and calculated the mean of all spikes. All eyes with cataract underwent clear corneal phacoemulsification. At the end of the operation we recorded the phacoemulsification time and mean percent power. We determined the correlations of echographic and phacoemulsification data. Results. Quantitative echography in the 71 studied eyes with cataract revealed acoustic reflections having various configurations according to the biomicroscopic type of cataract, i.e. cortical, nuclear, corticonuclear, brunescent, white intumescent. The mean of all echographic spikes within the cataract lenses varied from 3% (in some brunescent very sclerotic lenses) to 53%. Echographic reflections were not observed in the A-scan echograms of 20 additional eyes with normal human lenses. The mean of internal lens spikes correlated negatively with phacoemulsification time (p < 0.001; r = -0.703) and mean percent phacoemulsification power (p < 0.001; r = -0.57). Conclusions. The results indicate that A-scan quantitative echography may be used as an adjunctive tool in the preoperative evaluation of cataracts, particularly in cases with compromized visualization of the lens (small pupil, corneal opacities).