R. Joseph Olk

Modified grid laser photocoagulation for diffuse diabetic macular edema : long-term visual results

The authors reviewed the records of 302 eyes of 185 patients with diffuse diabetic macular edema with or without cystoid macular edema treated with modified grid laser photocoagulation between the years 1981 and 1990. Three years after initial grid treatment, visual acuity was improved in 14.5%, unchanged in 60.9%, and worse in 24.6% of eyes. The average number of treatments per eye was 1.9. These results show that in assessing long-term visual outcome, modified grid laser photocoagulation is an effective modality in maintaining or improving visual acuity in eyes with diffuse diabetic macular edema. The effectiveness demonstrated in this study is without comparison with control subjects with no treatment or comparison with other treatment techniques.

Modified Grid Argon (Blue-Green) Laser Photocoagulation for Diffuse Diabetic Macular Edema

One hundred sixty eyes of 92 patients with diffuse diabetic maculopathy with or without cystoid macular edema were enrolled in a prospective randomized clinical trial to determine the efficacy of modified grid argon (blue-green) laser photocoagulation. At the 12- and 24-month follow-ups, visual acuity significantly improved in treated eyes (P = 0.00007 and P = 0.00031, respectively) compared to the observation group. In addition, at the 12- and 24-month follow-ups, visual acuity significantly worsened in observation eyes (P = 0.00007 and P = 0.0007, respectively) compared to the treatment group. The following factors did not statistically alter the visual prognosis: a history of systemic hypertension (P = 0.2921); systemic vascular disease (P = 0.5324); cystoid macular edema (P = 0.1010); and initial poor visual acuity (P = 0.3032).

Factors Associated With a Poor Visual Result in Endophthalmitis

In a retrospective study of 82 cases of endophthalmitis treated between 1976 and 1982 at Barnes Hospital-Washington University, St. Louis, Missouri, 51 (62%) cases were culture-proven. Forty-nine (60%) were associated with cataract extraction, 16 cases (20%) were associated with trauma, and 17 cases (20%) were associated with other events. Sixty-four patients (78%) had undergone neither anterior chamber nor vitreous paracentesis before referral. Seventeen of the 51 culture-proven cases were initially thought to be sterile inflammatory responses and not infectious by the referring ophthalmologist. A poor visual result (visual acuity of less than 20/400) was associated with positive cultures, accidental trauma, virulent organisms, poor initial visual acuity, or a combination of these.

Vitrectomy for Premacular Fibroplasia: Prognostic Factors, Long-term Follow-up, and Time Course of Visual Improvement

Two hundred seventy eyes with premacular fibroplasia consecutively treated by pars plana vitrectomy and membrane peeling were reviewed. This study is among the largest series with long-term follow-up reported to date. Visual improvement of two or more lines was achieved in 43% of eyes at 6 to 12 months, in 54% at 1 to 2 years, in 60% at 2 to 3 years, and in 58% at 3 to 5 years. Overall, complications occurred in 34 eyes (13%). Cataract progression after vitrectomy was noted in 106 (57%) of phakic eyes at 3 to 5 years, and 43 of these eyes underwent subsequent cataract extraction. Mean time to best visual acuity after vitrectomy was slightly less than 1 year for all eyes unless they had cataract worsening with subsequent cataract extraction (1.9 years). Significant factors affecting visual outcome were: preoperative lens status, visual acuity before vitrectomy, duration of preoperative symptoms of distortion and/or blurred vision, and the occurrence of intraoperative complications.

Vitrectomy Without Scleral Buckling for Primary Rhegmatogenous Retinal Detachment

Trans pars plana vitrectomy with air-fluid exchange was performed on 29 selected cases of primary rhegmatogenous retinal detachment in which scleral buckling would be the usual surgical approach. The group contained 20 phakic eyes, two aphakic eyes, and seven pseudophakic eyes; the macula was detached preoperatively in 17 eyes (66%). The reattachment rate after one operation was 79% (23 of 29 eyes); after two operations this increased to 93% (27 of 29 eyes). Visual acuities of 20/50 or better were achieved in 22 of 27 successfully treated cases (81%). Vitrectomy without scleral buckling may allow retinal reattachment with excellent visual results in selected cases of primary rhegmatogenous retinal detachment.

Vitrectomy for Prevention of Macular Holes: Results of a Randomized Multicenter Clinical Trial

PURPOSE: The purpose of this study is to assess the benefit of vitreous surgery in preventing full-thickness macular holes in patients with impending (stage 1) macular holes. METHODS: A prospective randomized multicenter clinical trial was conducted on patients with full-thickness macular holes in their first eye (stage 3 or 4) and signs and symptoms of stage 1 macular holes in their fellow eye (study eye). The study eye was randomized to vitreous surgery or observation. Outcome was assessed by standardized measurement of visual acuity, detailed clinical examination, fundus photographs, and fluorescein angiography. RESULTS: A full-thickness macular hole developed in 10 (37%) of 27 patients in the vitrectomy group compared with 14 (40%) of 35 patients randomized to observation (P = 0.81). This difference of 3% has a 95% confidence interval of (-21%, 27%). CONCLUSION: The study was terminated because of low recruitment. The authors were unable to prove (or disprove) the benefit of vitreous surgery in patients with stage 1 macular holes. The authors can state, however, that should a beneficial effect from vitrectomy exist, it would probably be minimal. Considering the cost and morbidity of vitreous surgery, a conservative approach for stage 1 macular hole might be appropriate.Purpose: The purpose of this study is to assess the benefit of vitreous surgery in preventing full-thickness macular holes in patients with impending (stage 1) macular holes. Methods: A prospective randomized multicenter clinical trial was conducted on patients with full-thickness macular holes in their first eye (stage 3 or 4) and signs and symptoms of stage 1 macular holes in their fellow eye (study eye). The study eye was randomized to vitreous surgery or observation. Outcome was assessed by standardized measurement of visual acuity, detailed clinical examination, fundus photographs, and fluorescein angiography. Results: A full-thickness macular hole developed in 10 (37%) of 27 patients in the vitrectomy group compared with 14 (40%) of 35 patients randomized to observation ( P = 0.81). This difference of 3% has a 95% confidence interval of (-21%,27%). Conclusion: The study was terminated because of low recruitment. The authors were unable to prove (or disprove) the benefit of vitreous surgery in patients with stage 1 macular holes. The authors can state, however, that should a beneficial effect from vitrectomy exist, it would probably be minimal. Considering the cost and morbidity of vitreous surgery, a conservative approach for stage 1 macular hole might be appropriate.

Modified Grid Laser Photocoagulation for Diabetic Macular Edema: The Effect on the Central Visual Field

Modified grid laser photocoagulation has been shown to stabilize visual acuity in patients with diabetic macular edema, but the effect on extrafoveal visual function is uncertain. Automated static threshold perimetry was performed on 64 eyes of 36 patients before and after modified grid therapy with the argon green or krypton red laser. Twenty-eight eyes underwent two grid treatments for persistent macular edema. For all eyes tested, average threshold sensitivity in the central 5 degrees dropped 3.44 dB (standard deviation [SD], 3.79 dB) after the first treatment and 6.86 dB (SD, 5.02 dB) cumulatively after the second treatment. Qualitatively, the grayscale displays of the central visual field were darker after treatment, but the scotomata from laser photocoagulation could not be distinguished from those due to macular edema. The foveal threshold showed no significant change. In a subgroup of patients tested, color vision was not significantly improved and nearly all patients exhibited a tritan defect before and after treatment. No difference was detected between the argon and krypton groups. This suggests that with modified grid laser photocoagulation visual acuity and foveal threshold are preserved at the expense of generalized loss of threshold sensitivity across the central 10 degrees of the visual field.

Subfoveal and juxtafoveal Subretinal Neovascularization in the Presumed Ocular Histoplasmosis Syndrome: Visual Prognosis

The visual prognosis of 148 eyes in patients with an active subfoveal or juxtafoveal subretinal neovascular membrane (SRNVM) in the presumed ocular histoplasmosis syndrome (POHS) was reviewed. Average follow-up was 39 months. One hundred twenty of 148 eyes (81.1%) had a final visual acuity worse than 20/40. One hundred three of 148 eyes (69.6%) had a final visual acuity equal to or worse than 20/200. Systemic and/or periocular steroids had no effect on final visual outcome. Factors affecting final visual outcome are described and prognosis in the fellow eye is discussed.

Pseudophakic Retinal Detachments in the Presence of Various IOL Types

A series of 600 pseudophakic retinal detachments in 578 patients undergoing surgical repair between 1974 and 1984 was reviewed. Patients with previous retinal surgery of less than six months follow-up were excluded. The series included 395 iris-fixated (IF) lenses, 130 anterior chamber (AC) lenses, and 75 posterior chamber (PC) lenses. The overall success rate for retinal detachment was 88% but was significantly better in the PC lens group and significantly worse in the AC lens group. Forty-one percent of all cases achieved 20/40 visual acuity or better, although the AC lens group did worse (28%), while the PC lens group did significantly better (48%). Risk factors that were predictive of failure also were identified. Many of these factors occurred more frequently in the AC lens group and probably are related to the overall worse outcome in eyes with AC lens implants. The implications of these results for retinal and cataract surgeons are discussed.

Therapeutic benefits of infrared (810-nm) diode laser macular grid photocoagulation in prophylactic treatment of nonexudative age-related macular degeneration: Two-year results of a randomized pilot study

OBJECTIVEnThis pilot study collected preliminary information on the effectiveness and safety of infrared (810-nm) diode laser macular grid photocoagulation in patients with nonexudative age-related macular degeneration (AMD). Results from this pilot study were used in designing a larger, multicenter, randomized clinical trial.nnnDESIGNnA multicenter, randomized, controlled, clinical trial.nnnPARTICIPANTSnA total of 229 eyes of 152 patients with AMD were enrolled in the pilot study. Seventy-five patients with 1 eye eligible (75 eyes) were enrolled in the unilateral arm of the study; 77 patients with both eyes eligible (154 eyes) were enrolled in the bilateral arm of the study. In the unilateral study arm, 32 eyes were randomized to the observation group, 27 eyes were treated with visible endpoint burns, and 16 eyes were treated with invisible endpoint (subthreshold) lesions. In the bilateral study arm, 77 eyes were in the observation group, 36 eyes were treated with visible burns, and 41 eyes were treated with subthreshold (invisible) lesions.nnnINTERVENTIONnEyes were treated with infrared (810-nm) diode laser macular grid photocoagulation using either visible burns or subthreshold (invisible) lesions and compared to eyes receiving no treatment.nnnMAIN OUTCOME MEASURESnReduction of drusen, change in visual acuity, and rate of choroidal neovascularization (CNV) membrane formation.nnnRESULTSnAt 12 months after treatment, 62% of eyes treated with visible burns had a clinically significant reduction in drusen, whereas this proportion (65%) was reached in 18 months for eyes treated with subthreshold lesions. At 24 months follow-up, treated eyes had a significant reduction in drusen compared to observation eyes (P < 0.0001). Visual acuity was significantly improved in treated eyes at 12, 18, and 24 months compared to observation eyes (P < 0.001). Choroidal neovascularization formation was similar in treated and observation eyes through 24 months follow-up. Complications included CNV associated with six eyes treated with visible burns and a juxtafoveal laser scar in one eye treated with visible burns.nnnCONCLUSIONSnInfrared (810-nm) diode laser macular grid photocoagulation in patients with nonexudative AMD significantly reduces drusen levels (P < 0.0001) and significantly improves visual acuity (P < 0.001) when either visible endpoint burns or subthreshold endpoint lesions are used. Complications were fewer using subthreshold endpoint lesions. A larger, multicenter, prospective clinical trial with longer follow-up is needed to determine the efficacy of treatment in reducing the rate of CNV formation. Data from this clinical pilot study have been used to design the Prophylactic Treatment of AMD Trial (PTAMD), a multicenter, randomized, prospective clinical trial currently in progress comparing subthreshold (invisible) treatment to observation in eyes with nonexudative AMD.