Atypical presentations of macular holes.

OBJECTIVE: To describe nine cases of macular holes with atypical presentations and propose possible mechanistic explanations. SETTING: The steps leading to typical idiopathic macular hole formation have recently been defined. PATIENTS: Patients included seven with previous retinal detachment and subsequent macular hole formation and two with macular hole formation after vitrectomy for epiretinal membrane removal. CONCLUSIONS: The occurrence of these cases may seem to contradict reported pathogenesis schemes, but they are explainable within reported grading schemes.

Diode endolaser photocoagulation.

Endolaser photocoagulation was applied using a diode laser in 25 patients. Indications were for treatment of complications of proliferative diabetic retinopathy (17 patients), proliferative vitreoretinopathy (four patients), complex retinal detachments (three patients), and a retinal break (one patient). Good retinal and retinal pigment epithelial laser uptake was observed in all cases. The clinical appearance of the burn while it is being made is similar to that with the argon laser, but it is subtly lighter, especially in less-pigmented areas and eyes. Predictable clinical results and no adverse effects have been observed. While the clinical utility of the diode laser is analogous to that of standard argon endolaser systems, numerous logistical advantages are offered by this system.

Dislocated posterior chamber intraocular lens. A new technique of management.

Posterior dislocation of an intraocular lens in the vitreous cavity is an uncommon but serious complication of the standard extracapsular surgical technique for cataract extraction with intraocular lens implantation. Described herein is a new technique for managing this complication by using vitrectomy techniques and scleral fixation sutures of the intraocular lens. This technique allows permanent, controllable relocation of the intraocular lens and avoids trauma to the iris and cornea that previous techniques for intraocular lens repositioning may induce.

Histopathologic characteristics of diode laser-induced chorioretinal adhesions for experimental retinal detachment in rabbit eyes.

A retinal break and localized retinal detachment were induced in 10 rabbit eyes. The retinal break was treated within regions of detached retina using diode laser transscleral retinopexy (four eyes), diode laser indirect ophthalmoscopy (two eyes), or retinocryopexy (two eyes). Two eyes were left as untreated controls. The clinical and histopathologic effects were studied 1 day and 3 weeks after initial treatment. Suitable chorioretinal adhesions were induced with all treatment modalities. The extent of tissue effects was greater in cryopexy and smaller in laser treatment. The histopathologic characteristics of the lesions induced by diode laser indirect ophthalmoscopy were similar to those seen with transscleral diode treatment and were more focal than those seen with cryopexy. Transscleral and transpupillary diode laser photocoagulation were effective in inducing chorioretinal adhesions in detached retina in this experimental model in rabbits.

Histopathologic results of retinal diode laser photocoagulation in rabbit eyes.

Diode laser photocoagulation was applied to rabbit retina simulating scatter treatment using an endolaser probe and in a manner simulating treatment of peripheral retinal breaks using a transscleral retinopexy probe. Clinically appearing mild, moderate, and severe burns were created by altering the burn duration in one eye and by altering the power setting in the fellow eye. Histopathologic results demonstrated the clinically evident dose-response effect with sparing of inner retinal cellular elements with mild burns and full-thickness retinal cell loss with severe burns. Bruch's membrane ruptures were seen in three of 42 endophotocoagulation severe spots placed with high power, but in none of the 42 severe spots placed with long burn duration. Thus, longer burn duration appeared to be a safer way to produce a severe burn than higher power. Burns characteristically bloomed during the several seconds following laser application by both modalities, possibly indicating a deep source of energy absorption. Scleral effects, seen only when high energy levels were used to treat atrophic areas, were mild.

Vitrectomy for macular traction caused by incomplete vitreous separation.

Pars plana vitrectomy was performed in 16 eyes to release vitreomacular traction. All patients had a symptomatic preoperative decrease in visual acuity, most often to 20/200. Partial detachment of the posterior vitreous surface was associated with vitreoretinal attachment remaining in the area of the macula and sometimes to the optic nerve head. The posterior vitreous traction on the macula was released by tangential traction on the posterior vitreous surface, causing it to separate from the retina. The postoperative vision was the same or improved in each case. No operative complications occurred, but progressive nuclear sclerosis developed postoperatively in five of the 15 phakic eyes.

Simulated treatment of recurrent choroidal neovascularization in primate retina. Comparative histopathologic findings.

We simulated the treatment of recurrent choroidal neovascular membranes (CNVM) by applying two courses of laser treatment to monkey retinas. Argon green, argon blue-green, and krypton red lasers (KRLs) were used in juxtafoveal, papillomacular bundle, and nonmacular areas. The effects were examined clinically and histopathologically. Results of once-treated control eyes were consistent with those of previous studies. Repeat treatment, however, resulted in full-thickness retinal destruction or necrosis with all laser modalities and in all fundus locations. These results are consistent with the absorptive characteristics of xanthophyll and melanin and suggest only limited advantages to the KRL when treatment of recurrent CNVM is performed in a previously treated area of the fundus. However, treatment of recurrent CNVM is still probably most successful with a KRL, because recurrent CNVM is usually at a border of a photocoagulation scar, where the retina is still untreated, and because histologic studies have demonstrated inner retinal sparing with a KRL in juxtafoveal areas.

Comparison of krypton and argon laser photocoagulation. Results of stimulated clinical treatment of primate retina.

We compared the clinical and histological effects of argon blue-green laser (ABGL), argon green laser (AGL), and krypton red laser (KRL) photocoagulation on the primate retina. Burns were produced in juxtafoveal and papillomacular bundle and in nonmacular areas in a manner simulating treatment of a choroidal neovascular membrane (NVM). In the juxtafoveal and papillomacular bundle areas, ABGL photocoagulation caused extensive inner retinal damage while KRL photocoagulation spared inner retinal structures. The effects of AGL photocoagulation in the fovea were intermediate in extent between KRL and ABGL photocoagulation. Axonal transport studies also showed differential effects of these wavelengths on retinal ganglion cell function. Nonmacular effects were similar for all three modalities. These results suggest that the krypton red wavelength may be more suitable than the argon green or argon blue-green wavelengths in treating choroidal NVMs near the fovea.

Refractive changes after scleral buckling surgery.

Pneumatic retinopexy is increasingly recommended to treat some patients with retinal detachment to avoid the complication of induced refractive changes sometimes associated with scleral buckling procedures. Prospective evaluation of refractive changes after scleral buckling procedures was performed in 75 eyes of 69 patients. Encircling scleral buckles caused an average increased axial length of 0.99 mm and average induced myopia of 2.75 diopters. Induced astigmatism was likely to occur in patients undergoing scleral buckling surgery, but it was not related to whether a radial element was used.

Cell proliferation after laser photocoagulation in primate retina. An autoradiographic study.

Argon blue-green laser and krypton red laser (KRL) photocoagulation were applied to primate retinas at intervals ranging from two to 23 days before the animals were killed. An injection of tritiated thymidine was given intravitreally three days before death. Argon blue-green laser photocoagulation induced cell proliferation in the retina and retinal pigment epithelium seven days after treatment, with quiescence at 23 days. Krypton red laser photocoagulation induced similar cell proliferation not only in the retina and retinal pigment epithelium but also around choroidal vessels and in the stroma of the choroid. Peak thymidine uptake occurred seven days after KRL treatment. There was less uptake at two and 11 days and no uptake at 23 days. Thymidine uptake in the retina and choroid also was detected with low levels of KRL treatment. True cell hyperplasia (cell division) occurred after laser treatment; only KRL treatment induced cellular reaction in the choroid.

Transforming growth factor beta. A biologic chorioretinal glue.

Transforming growth factor beta (TGF-beta) stimulates fibrosis. We studied its possible role as a bioactive substance for inducing localized chorioretinal wound healing along the edge of a retinal tear. The TGF-beta was applied to induced retinal tears that were examined histopathologically. One day after surgery, neither control nor TGF-beta-treated eyes developed chorioretinal wound healing. Four days, two weeks, and two months after surgery, the control eyes still had not developed chorioretinal wound healing. In contrast, the edges of the retinal tear treated with TGF-beta were adherent to the underlying Bruch's membrane via localized fibrous tissue without apparent effects elsewhere. These results demonstrate intraocular in vivo bioactivity of TGF-beta and suggest that TGF-beta may have a potential role as an alternative means for inducing a chorioretinal adhesion in the treatment of retinal tears.

Vitrectomy in the management of diabetic retinopathy.

According to the Early Treatment Diabetic Retinopathy Study, at least 5% of eyes receiving optimal medical treatment will still have progressive retinopathy that requires laser treatment and pars plana vitrectomy. During the past decade, improvements in instrumentation and surgical techniques have allowed more difficult cases of diabetic retinopathy to be candidates for vitrectomy. However, although the thresholds for performing surgery within established indicated situations have been lowered, only a few additional indications have been established. Although vitrectomy improves the prognosis for a favorable visual outcome, preventive measures, such as improved control of glucose levels and timely application of panretinal photocoagulation, produce better results. The authors review the indications, techniques, and results of vitrectomy in the management of diabetic retinopathy.

Vitrectomy in the management of diabetic eye disease.

Vitrectomy techniques including endolaser photocoagulation allow visual rehabilitation in many eyes that are otherwise untreatable. Discerning the indications and timing for diabetic vitrectomy is increasingly important as the treatment of complications of diabetic retinopathy continues to undergo modification and redefinition. The most common indications for diabetic vitrectomy include: 1) severe nonclearing vitreous hemorrhage; 2) traction retinal detachment recently involving the macula; 3) combined traction and rhegmatogenous detachment; 4) progressive fibrovascular proliferation; and 5) rubeosis iridis and vitreous hemorrhage for eyes in which the media opacity has prevented adequate laser photocoagulation. Other less common indications in selected cases include dense premacular hemorrhage, ghost cell glaucoma, macular edema with premacular traction, cataract preventing treatment of severe, proliferative diabetic retinopathy, anterior hyaloidal fibrovascular proliferation, and fibrinoid syndrome with retinal detachment. The rationale and surgical objectives are discussed and results are summarized.

Acrylic intraocular lens placement in conjunction with pars plana vitrectomy.

PURPOSE: To report the results of placing a foldable acrylic intraocular lens through a clear cornea incision in eyes undergoing pars plana vitrectomy. METHODS: This interventional case series is a retrospective report of 15 eyes of 15 consecutive patients undergoing foldable (acrylic) intraocular lens insertion in conjunction with pars plana vitrectomy in a single academic institution. Outcome measures included visual acuity and complications. RESULTS: The intraocular lens was successfully implanted and retained in position in all 15 cases. The intraocular lens did not pose difficulty in examining the fundus or cause any vitreoretinal complications. With mean follow-up of 4.5 months (range, 1--10 months), final median postoperative visual acuity range was 20/200 (range, 20/40--2/200) and consistent with the level of vitreoretinal disease. CONCLUSION: Acrylic intraocular lenses may be safely implanted in conjunction with pars plana vitrectomy in selected cases.

Outcomes of macular hole surgery in severely myopic eyes: a case-control study.

PURPOSE: To evaluate the outcomes of macular hole surgery in highly myopic eyes and to compare these outcomes with a control group of eyes that were not severely myopic. METHODS: The study design was a matched, case-control, retrospective chart review. The participants included 26 eyes of 24 patients who had vitreous surgery for macular holes. The eyes were divided into two groups: 13 consecutive eyes with severe myopia (defined as -6.00 diopters of refractive error or greater) and 13 control eyes without severe myopia that were operated on immediately before or after each study eye, with the most recently operated eye chosen. The main outcome parameters were preoperative and final follow-up visual acuity, macular hole closure rates, reoperation rates, duration of preoperative symptoms, and follow-up time. RESULTS: Using the Snellen equivalent of logarithm of minimal angle of resolution (logMAR) units, visual acuity improved after macular hole surgery in severely myopic eyes from 20/152 to 20/89 (P =.041) and in control eyes from 20/152 to 20/47 (P <.001). At final follow-up, visual acuities were lower in severely myopic eyes compared with control eyes (P =.048). Macular hole closure rates, reoperation rates, duration of pre-operative symptoms, and follow-up intervals were not significantly different statistically between groups. CONCLUSIONS: Macular hole surgery results in anatomical and visual improvements in severely myopic eyes but generally yields poorer visual acuity outcomes compared with eyes that are not severely myopic.

Laser energy and dye fluorescence transmission through blood in vitro.

PURPOSE: Because of the potential usefulness of evaluating and treating choroidal neovascularization obscured by blood, we designed this study to quantify the transmission of dye fluorescence and laser energy through blood. METHODS: Blood preparations anticoagulated with ethylenediaminetetraacetic acid with hematocrits of 0% (plasma), 46%, and 99% were placed in open cuvettes with path lengths of 100, 200, or 500 microns and were exposed for one minute to either 100% oxygen or 100% carbon dioxide. Each cuvette was then sealed. Photographs of the cuvettes of blood in front of a flask of fluorescein or indocyanine green solution were decoded and used to calculate the percent transmission of fluorescence through blood. Cuvettes of blood were also placed in the path of argon, krypton, and diode lasers for energy transmission measurements. RESULTS: Plasma transmission of fluorescein and indocyanine green fluorescence and argon, krypton, and diode laser energy was 89% to 100% for all samples tested. Transmission of fluorescein fluorescence and argon laser energy through 99% hematocrit samples were both less than 5%. Transmission of indocyanine green fluorescence through 100-, 200-, and 500-microns-thick cuvettes filled with 99% hematocrit blood was 57%, 34%, and 4%. Transmission of krypton laser energy was 50%, 25%, and 6%; and transmission of diode laser energy was 60%, 35%, and 12% through 99% hematocrit blood. Intermediate transmission values were obtained for 46% hematocrit samples. CONCLUSIONS: Krypton and, to a slightly greater degree, diode laser energy penetrate a thin film of blood. Indocyanine green fluorescence also penetrates a thin film of blood. If a layer of blood appears thinner than 500 microns, then indocyanine green angiography may be useful in imaging underlying pathologic features. If a lesion can be imaged with indocyanine green, then it can probably be treated with a krypton or diode laser.

Visual acuity and macular hole size after unsuccessful macular hole closure.

PURPOSE: To evaluate the visual acuity, change in macular hole size, and change in subretinal fluid cuff size after unsuccessful macular hole closure. METHODS: Forty-two consecutive eyes with macular hole and unsuccessful surgery for macular hole were studied. Preoperative and postoperative best-corrected visual acuities were tested according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, and changes were compared. Preoperative and postoperative fundus photographs were analyzed on a photograph documenter for changes in diameter of the macular hole and surrounding subretinal fluid cuff. RESULTS: Mean visual acuity decreased from 20/133 preoperatively to 20/154 postoperatively (mean loss, 0.79 ETDRS line). Mean diameter of the macular hole enlarged 22%; mean diameter of the visible surrounding subretinal fluid cuff enlarged 36%. A decrease in best-corrected visual acuity postoperatively was correlated with better preoperative visual acuity, earlier macular hole stage, and shorter duration. Enlargement in the diameter of the macular hole and fluid cuff did not correlate with better preoperative best-corrected visual acuity, earlier macular hole stage, or shorter duration. In 23 eyes that had failed previous surgery, macular hole surgery was anatomically successful in 17 (65%) (mean improvement, 3.7 ETDRS lines; mean best-corrected final visual acuity, 20/74). CONCLUSION: After macular hole surgery, anatomically unsuccessful closure of the hole correlates with small enlargements in the diameter of the macular hole and its surrounding subretinal fluid cuff, and with a slight decrease in visual acuity. Macular hole closure after repeat surgery improves visual acuity outcome in the majority of retreated eyes.

Differentiating macular holes from macular pseudoholes.

Surgical treatments of macular holes have become increasingly effective in inducing resolution of the cuff of surrounding subretinal fluid, resulting in increased vision in many patients. However, for many conditions that mimic a macular hole, either surgery is not indicated or different surgical manipulations are necessary. Differentiating macular holes from some forms of macular pseudoholes can be difficult or impossible based solely on clinical examination. Adjunctive tests that may enhance the accuracy of diagnosis are either not feasible or not available to most clinical practices. We evaluated three clinic-based tests for their value in allowing the differentiation between macular holes and macular pseudoholes: Amsler grid testing, Watzke-Allen sign, and laser aiming beam test. These tests were evaluated in three groups of clinically defined patients: those with full-thickness macular holes, those with macular pseudoholes, and those who had previously undergone successful macular hole treatment. Although the Amsler grid testing was sensitive in correlating with clinically defined macular holes, it was not specific. The Watzke-Allen sign and, to a greater extent, the laser aiming beam test were extremely sensitive and specific in correlating clinically defined full-thickness macular holes and pseudoholes. These tests improve the accuracy of diagnosis of full-thickness macular holes.

Vitrectomy for diabetic macular edema associated with a thickened and taut posterior hyaloid membrane.

PURPOSE: To evaluate the surgical results in a series of patients with diabetic macular edema associated with traction from a thickened and taut posterior hyaloid membrane and to identify features associated with better visual outcome. METHODS: We reviewed the clinical records of ten consecutive patients who underwent pars plana vitrectomy in one eye for diabetic macular edema that was preoperatively attributed to thickening and traction of the posterior hyaloid membrane. RESULTS: Best-corrected, preoperative visual acuity was 20/200 in seven eyes, 20/300 in one eye, and 20/400 in two eyes. Intraoperatively, seven patients were found to have an attached posterior hyaloid membrane which was thickened and taut. Among these seven patients, postoperative best-corrected visual acuity improved by six lines in two eyes, by five lines in one eye, by two lines in one eye, and remained within one line of preoperative visual acuity in three eyes. The other three patients had an epiretinal membrane simulating an attached and thickened posterior hyaloid membrane. CONCLUSIONS: Vitrectomy effectively improved visual acuity in some eyes with diabetic macular edema associated with traction from a thickened and taut posterior hyaloid membrane. Despite careful preoperative examination with a fundus contact lens, however, in some patients it may be difficult to assess how the posterior hyaloid membrane contributes to the macular edema. In selected patients, early surgical intervention may be associated with better visual outcome.

Acute retinal necrosis caused by reactivation of herpes simplex virus type 2.

Acute retinal necrosis is a severe form of necrotizing retinitis. Acute retinal necrosis has been demonstrated to be caused by varicella-zoster virus and herpes simplex virus type 1. We treated three patients with acute retinal necrosis apparently caused by recrudescence of latent herpes simplex virus type 2. Primary viral infection was probably congenital, with documented perinatal herpes simplex virus type 2 infection in two patients. Bilateral chorioretinal scars were present in two patients, neither of whom had a history of ocular herpetic infection, suggesting that earlier subclinical chorioretinitis had occurred. In each case, periocular trauma preceded the development of retinitis by two to three weeks. These cases are evidently caused by trauma-induced reactivation of latent virus rather than the onset of a primary infection.