Characterization of idiopathic macular telangiectasia type 2 by fundus fluorescein angiography in Indian population.

PURPOSE: To characterize the variations in fundus fluorescein angiography (FFA) features in idiopathic macular telangiectasia (IMT) type 2. METHODS: Retrospective observational study. The authors included all the patients with IMT type 2 who underwent FFA during the period from January 2004 to December 2005. The main outcome measures were subretinal neovascularization and number and distance of telangiectasia from the center of the foveal avascular zone. RESULTS: The mean age of 21 patients included in the study was 53.0+/-7.7 years. There were 11 women and 10 men. Six of the 21 patients had a history of diabetes mellitus. Subretinal neovascularization (SRN) was observed in 10 (23.8%) eyes. Subretinal plaque of pigment hyperplasia in the macula was found in 7 (21.9%) eyes, and crystalline yellowish deposits on the retinal surface were seen in 19 (59.4%) eyes. Only one eye had visible retinal telangiectasia. Most had more than 10 telangiectatic lesions in the macular area and the temporal macula was most commonly involved. The mean distance from the center of the foveal avascular zone (FAZ) up to which telangiectasia could be observed was 1340+/-400 microm. The maximum distance from the FAZ at which telangiectasia was identified was 2530 microm. CONCLUSIONS: In IMT type 2, telangiectasia may be seen farther from the parafoveal area.

A comparative study of epiretinal membranes associated with Eales' disease: a clinicopathologic evaluation.

AIM: To study the histopathologic features and clinical correlation of epiretinal membranes (ERM) obtained from patients of Eales' disease and compare with other vasoproliferative disorders. METHODS: Retrospective analysis of epiretinal membranes submitted for histological evaluation between January 1995 and June 2001, from the patients of diabetic retinopathy and vascular occlusions (Group 1; vaso-occlusive disorders) and of Eales' disease (Group 2; vasoinflammatory disorders). Demographics, pre and postoperative visual acuity, and anatomic and histologic characteristics of membranes were studied. Histopathologic features and clinical outcomes were correlated between the groups. The results were analysed statistically by Student's t-test, Fisher's exact test and Kruskal-Wallis test. RESULTS: This study consisted of 42 patients, 24 in Group 1 and 18 in Group 2. Patients in Group 2 (33.0+/-9.2 years) were significantly younger than the patients in Group 1 (49.9+/-7.6 years) (P< or =0.0001). Final visual acuity of >20/400 was attained in 79.2% (19/24) patients in Group 1 and 83.3% (15/18) in Group 2 (P=1.0). Inflammatory membranes were significantly associated with presumed Eales' disease (94.4 vs 0%) (P< or =0.0001) and fibrovascular membranes with Group 1 (70.8% vs 33.3%) (P=0.028). Mast cells and eosinophils were observed as special features in epiretinal membranes of patients with Eales' disease. CONCLUSIONS: Histological features of ERM in Eales' disease are comparable to other vasoproliferative disorders except for features of inflammation. Presence of mast cells and eosinophils in epiretinal membranes of Eales' disease needs further investigation.

Risk factors for and management of dropped nucleus during phacoemulsification.

PURPOSE: To study the risk factors and management of posteriorly dislocated crystalline lenses during phacoemulsification at a teaching institution. SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: This retrospective analysis included all phacoemulsification procedures performed by experienced and inexperienced surgeons over 7 years. The incidence, risk factors for, role of surgical experience, mode of management, and the final outcome of posteriorly dislocated lens nuclei were evaluated. RESULTS: Of a total 11 343 phacoemulsification procedures performed between 1993 and 1999, the nucleus was dropped in 38 eyes (0.3%). Two patients with a dropped nucleus were referred from an outside practice. The incidence of dropped nucleus with experienced surgeons (22/8671; 0.2%) was significantly less than that with inexperienced surgeons (16/2672; 0.6%) (P =.007). Sixteen of the 22 cases of dropped nucleus (72.7%) in the experienced group and 1 of 16 (6.3%) in the inexperienced group had risk factors (P =.0005). Nucleus removal was performed using vitreoretinal procedures in 39 eyes; 1 eye with a dropped epinucleus was managed conservatively. The final best corrected visual acuity was 20/40 or better in 21 eyes (53.8%). CONCLUSIONS: The incidence of dropped nucleus was more frequent with inexperienced surgeons, even though experienced surgeons had more cases with predisposing risk factors. Modern vitreoretinal procedures reduce morbidity and improve the visual outcome.

Retinal pigment epithelial autotransplantation: morphological changes in retina and choroid.

BACKGROUND: Replacement of degenerating retinal pigment epithelial (RPE) cells has been proposed to promote photoreceptor survival in retinal pigment epithelial disease. However, allografts of RPE have a higher rate of immunological rejection. The investigators studied the effects of autotransplantation of RPE on the morphological changes in photoreceptors and choriocapillaris. METHODS: RPE autotransplantation (wound type 1) was performed in 25 rabbits and compared with wounds following debridement of the RPE (wound type 2). Light and electron microscopy and scanning electron microscopy of choroidal vascular casts were performed at 3, 7, 14 and 30 days after surgery. Quantitative analysis of the choriocapillaris bed area was performed by automated image analysis and the results were analyzed by paired Student's t-test. RESULTS: Retinal pigment epithelium was found to be monolayered and ill-differentiated at day 7. Differentiation occurred at day 30, with preservation of photoreceptors and other layers of the neurosensory retina in type 1 wounds. Type 2 wounds showed atrophy of the regenerating retinal pigment epithelium at day 14 and day 30 with loss of overlying photoreceptor cell layer. There was significant choriocapillaris regeneration in type 1 wounds compared to the type 2 wounds at day 7 (P=0.045), day 14 (P=0.028) & day 30 (P=0.06). CONCLUSIONS: Retinal pigment epithelial autotransplantation significantly reduced photoreceptor degeneration and choriocapillaris atrophy associated with loss of retinal pigment epithelium. This procedure supports the hypothesis that RPE autotransplantation may be helpful in geographic atrophy and conditions requiring submacular surgery.

Age-related retinal pigment epithelium and Bruch's membrane degeneration in senescence-accelerated mouse.

PURPOSE: To investigate age-related changes in the retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in the senescence-accelerated mouse (SAM). METHODS: The external and eyecup features and light and electron microscopic findings were examined in three male and two female mice of a senescence-prone mouse strain (SAM P(8)) monthly for 12 months. These results were compared with those in age-matched mice of similar background but senescence resistant (SAM R(1)). Choroidal vascular casts were prepared at 12 months in seven mice each of the SAM P(8) and SAM R(1) strains. Quantitative analysis of area of choriocapillaris was performed by automated image analysis, and the results were analyzed by paired Student's t-test. RESULTS: We found in the SAM P(8) strain that hair loss, coarseness of hair texture, and ulceration of skin appeared and increased as the age advanced (at approximately 5-9 months). Eyecup examination showed no differences. Light and electron microscopy revealed progressively more prominent abnormalities in the RPE and Bruch's membrane mice older than 10 months. Two of the five SAM P(8) mice older than 11 months showed what appeared to be intra-Bruch's membrane choroidal neovascularization. The RPE and Bruch's membrane appeared normal in the SAM R(1) strain. In the SAM P(8), vascular casts of the choriocapillaris showed a mild but significant decrease in vascular area when compared with the SAM R(1) strain at 12 months (P = 0.011). CONCLUSIONS: Senescence accelerated mice develop progressive age-related changes in the RPE-Bruch's-choriocapillaris complex that have features that may be relevant in the study of age-related macular changes in humans.

The surgical management of hypotony.

OBJECTIVE: To study the effect of dissecting epiciliary proliferative tissue in eyes that are hypotonous. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Eight patients (nine eyes). MAIN OUTCOME MEASURES: Normalization of intraocular pressure and preservation of vision. METHODS: A chart review was conducted to locate all surgical procedures performed primarily for hypotony. Nine procedures on eight eyes of eight patients seen in the vitreoretinal service of the Wilmer Ophthalmological Institute were identified and included in this study. Six of these eyes had undergone prior surgery for retinal detachment in association with proliferative vitreoretinopathy, one had undergone surgery for retinal detachment in the setting of a ruptured globe, and two had undergone cataract surgery and coined the diagnoses of uveitis (juvenile rheumatoid arthritis and sarcoid). Dissection and removal of the epiciliary proliferative tissue and lens capsule was undertaken by two surgeons (EdJ and MSH) using either a pars plana or limbal approach. The main outcome measures were intraocular pressure (IOP) and visual acuity after an average follow-up of 26 months (range, 9-48 months). RESULTS: In the immediate postoperative period, all patients showed an increase in IOP (average increase of 6.3 mm Hg; range, 3-14 mmHg). This average increase in IOP decreased to 5.2 mmHg at 6 months and 4.2 mm Hg at 12 or more months of follow-up. The rate of the IOP decrease appeared to lessen with time, suggesting long-term stabilization. Visual acuity remained stable in all patients, although the final level of vision was low. CONCLUSIONS: Surgical intervention for hypotony with greater than 1 year follow-up continues to show elevated IOP in some patients, despite the fact that the large initial increase in IOP is not sustained. No eye had phthisis develop or became painful. However, no eye had marked improvement in vision. Further study is needed to uncover the main contributing factors that result in hypotony before IOP can be maintained for prolonged periods in more hypotonous eyes and before these eyes can regain more vision.

Changes in choriocapillaris and retinal pigment epithelium in age-related macular degeneration.

Retinal pigment epithelial cells (RPE) and the choriocapillaris are on opposite sides of Bruch's membrane and control transport in and out of the retina. In age-related macular degeneration (AMD), they may also be responsible for deposition of material in and on Bruch's membrane and the formation or regression of choroidal neovascularization (CNV). Indocyanine green (ICG) angiography can be used to visualize the choroidal vasculature and CNV. Filling of the choriocapillaris with ICG was delayed in subjects older than 50 years of age, and areas of hypofluorescence were observed in maculas of AMD subjects, often associated with CNV. Laser Doppler flowmetry of the choriocapillaris in the macula demonstrated that choroidal blood flow and volume are reduced in subjects older than 46 years of age and further decreased in subjects with AMD. The human choriocapillaris can be histologically studied in two dimensions by incubating the tissue for alkaline phosphatase activity, flat-embedding it in transparent polymer and sectioning it. Using this technique, choriocapillaris dropout was found to be associated with deposition of material in Bruch's membrane in diabetic subjects. When RPE are removed from Bruch's membrane, the choriocapillaris degenerates; the regeneration of choriocapillaris can be blocked by Genistein, a tyrosine kinase inhibitor. Finally, RPE cells may produce substances that both stimulate the formation and regression of CNV in animal models. These studies suggest that there may be a reduction in choriocapillaris flow in AMD, and this loss of choriocapillaris can be associated with the Bruch's membrane deposits that are hallmarks of AMD. Furthermore, RPE may stimulate the formation and regression of CNV and RPE loss can result in loss of choriocapillaris.

Surgically induced degeneration and regeneration of the choriocapillaris in rabbit.

BACKGROUND: Retinal pigment epithelium (RPE) and choriocapillaris play an important role in maintaining the outer retina. Clinical and experimental studies have shown that there is a close relationship between them. To examine the relationship between RPE and choriocapillaris we developed an animal model in which degeneration and regeneration of the choriocapillaris can be created easily and reproducibly. METHODS: Using pigmented rabbits a retinal detachment (about 7 disk diameters) was created in the eye and the detached retina was surgically removed. A half area of the exposed RPE was mechanically debrided using a silicone brush. The other half area remained untouched. The eyes were morphologically examined at 3, 7, and 14 days and 4 and 8 weeks after the surgery using scanning or transmission electron microscopy. Changes in the choriocapillaris after the RPE debridement were also evaluated by corrosion vascular casts. RESULTS: The debrided area was resurfaced with elongated RPE in 7 days after surgery. The replaced RPE was dedifferentiated but it gradually recovered cell polarity by 4 weeks after surgery. The choriocapillaris beneath the debrided area underwent degeneration; however, it regenerated by 4 weeks after surgery, corresponding to the timing of the morphologic recovery of the replaced RPE. CONCLUSION: This animal model of surgically induced degeneration and regeneration of the choriocapillaris may be useful to clarify the relationship between RPE and choriocapillaris and to study potential treatments for choroidal vascular diseases.

Long-term histological and electrophysiological results of an inactive epiretinal electrode array implantation in dogs.

PURPOSE: Short-term pattern electrical stimulation of the retina via multielectrode arrays in humans blind from photoreceptor loss has shown that ambulatory vision and limited character recognition is possible. To develop an implantable retinal prosthesis that would provide useful vision, these results need to be sustained over a prolonged period of retinal electrical stimulation. As a first step toward this goal, the biocompatibility and the feasibility of surgically implanting an electrically inactive electrode array onto the retinal surface was tested. METHODS: A 5 x 5 electrode array (25 platinum disc-shaped electrodes in a silicone matrix) was implanted onto the retinal surface using retinal tacks in each of the 4 mixed-breed sighted dogs. Color fundus photography, fluorescein angiography, electroretinography, and visual evoked potentials were obtained preoperatively, at 1-week intervals for 2 weeks postoperatively, then at 2-week intervals up to 2 months postoperatively, and thereafter at 1-month intervals. One dog was killed at 2 months after implantation and a second dog after 3 months of implantation. Histologic evaluation of the retinas was performed. The remaining two dogs continue to be followed beyond 6 months after the implantation surgery. RESULTS: No retinal detachment, infection, or uncontrolled intraocular bleeding occurred in any of the animals. Retinal tacks and the retinal array remained firmly affixed to the retina throughout the follow-up period. Hyperpigmentation of the retinal pigment epithelium was observed only around the site of retinal tack insertion. No fibrous encapsulation of the implant or intraocular inflammation was visible. A- and b-wave amplitudes of the electroretinogram were depressed at the first postoperative week testing but recovered over the ensuing 1 week and were not statistically different from the normal unoperated fellow eye throughout the postoperative period. N1 and P1 wave amplitudes of the visual evoked potentials were not significantly different from the normal fellow eyes at any of the postoperative test intervals. Fluorescein angiography showed that the entire retina including the area under the electrode array remained well perfused. Similarly, histologic evaluation revealed near total preservation of the retina underlying the electrode array. CONCLUSIONS: Implantation of an electrode array on the epiretinal side (i.e., side closest to the ganglion cell layer) is surgically feasible, with insignificant damage to the underlying retina. The platinum and silicone arrays as well as the metal tacks are biocompatible. With the success of implanting an electrically inactive device onto the retinal surface for prolonged periods, the effects of long-term retinal electrical stimulation are now ready to be tested as the next step toward developing a prototype retinal prosthesis for human use.

Microbiologic spectrum and susceptibility of isolates: part I. Postoperative endophthalmitis. Endophthalmitis Research Group.

PURPOSE: To present the microbial spectrum and susceptibilities of isolates in postoperative endophthalmitis. METHOD: Isolates from 206 eyes of 206 patients who underwent vitrectomy for postoperative endophthalmitis were examined. RESULTS: One-hundred twelve (54.4%) of 206 vitreous samples were culture positive and 14 (12.5%) of 112 culture-positive cases were polymicrobial, yielding a total of 126 isolates. Isolates included 59 (46.8%) gram-positive cocci, eight (6.3%) gram-positive bacilli, 33 (26.2%) gram-negative organisms, five (4.0%) Actino-mycetes-related organisms, and 21 (16.7%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported. CONCLUSIONS: This is the largest, single-center, prospective series on microbial susceptibilities in postoperative endophthalmitis. We report a high prevalence of gram-negative species and fungi, suggesting that empiric therapy should include coverage for gram-negative pathogens and for fungal pathogens in appropriate settings.

Microbiologic spectrum and susceptibility of isolates: part II. Posttraumatic endophthalmitis. Endophthalmitis Research Group.

PURPOSE: To present the microbial spectrum and susceptibilities of isolates in posttraumatic endophthalmitis. METHOD: Isolates from 182 eyes of 182 patients who underwent vitrectomy for posttraumatic endophthalmitis were examined. RESULTS: One hundred thirteen (62.1%) of 182 vitreous samples were culture-positive, and 23 (20.4%) of 113 culture-positive cases were polymicrobial, including three (2.7%) trimicrobial cases, yielding a total of 139 isolates. Isolates included 63 (45.3%) gram-positive cocci, 24 (17.3%) gram-positive bacilli, 25 (18.0%) gram-negative organisms, seven (5.0%) Actinomycetes-related organisms, and 20 (14.4%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported. CONCLUSIONS: This study represents a large series on microbial spectrum and susceptibilities in posttraumatic endophthalmitis. We report a high prevalence of gram-positive bacilli species and polymicrobial infections containing gram-negative species, underscoring the importance of broad-spectrum, combination antibiotics in the empiric treatment of posttraumatic endophthalmitis.

Hypodermic needles: a new source of penetrating ocular trauma in Indian children.

PURPOSE: To study the clinico-microbiologic profile and visual prognosis of ocular injuries caused by disposable hypodermic needles used by children to squirt water. METHODS: We analyzed 19 consecutive cases of hypodermic needle injury seen at our institute. RESULTS: The average age of the patients was 10.3 years (range, 4-20 years). A small self-sealed corneal or scleral laceration was seen in 11 eyes; in 8 eyes, the site of injury was occult. Initial visual acuity was no light perception (3 eyes) or hand motion or light perception (16 eyes). Surgery in 18/19 eyes included vitrectomy with intraocular antibiotic injections for endophthalmitis (14 eyes), evisceration for panophthalmitis (2 eyes), and cataract extraction for traumatic cataract (2 eyes). Final visual acuity was no light perception or light perception only in 10 eyes, 20/400-20/60 in three eyes, and 20/40 or better in six eyes. CONCLUSIONS: Severe ocular morbidity may result from improper disposal of hypodermic needles.

Inhibition of choriocapillaris regeneration with genistein.

PURPOSE: To test the effects of genistein on choriocapillaris regeneration and retinal pigment epithelial (RPE) wound healing in a surgical model in the rabbit. METHODS: Intravitreal injections of either 0.1 ml of a 90-microM concentration of genistein, dimethyl sulfoxide (DMSO; negative control), or 2 microg cycloheximide (positive control) were given 24 hours before surgical debridement of RPE in rabbits. Scanning electron microscopy (EM) of choroidal vascular casts and the RPE wounds and histologic evaluation by light microscopy and EM of the disturbed areas were performed at days 1, 7, and 30 after surgery. Quantitative analysis of the area of the choriocapillaris bed and RPE was performed by automated image analysis, and the results were analyzed by paired Student's t-test. RESULTS: Loss of RPE caused a rapid initial atrophy followed by slower subsequent revascularization of the choriocapillaris, which paralleled the RPE wound healing. Choriocapillaris regeneration appeared nearly normal by day 30 in the DMSO group. Inhibition of choriocapillaris revascularization by genistein was significant at day 30 when compared with the DMSO-treated negative control (P = 0.013). There was a strong trend toward inhibition in the cycloheximide-treated positive control group (P = 0.062), which reached significance at day 7 compared with the DMSO group (P = 0.02). RPE covered the wound area by day 7 in all groups. CONCLUSIONS: Intravitreal injection of genistein was found to cause significant inhibition of choriocapillaris regeneration without apparent effect on RPE wound healing. Tyrosine kinase inhibitors such as genistein may be useful as a pharmacologic approach in the treatment of choroidal neovascularization.

Glaucoma after pars plana vitrectomy and silicone oil injection for complicated retinal detachments.

OBJECTIVE: To determine the incidence and associations of glaucoma after pars plana vitrectomy (PPV) and silicone oil injection (SOI) for complicated retinal detachments and the response to treatment. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: A total of 150 eyes of 150 patients who had completed a minimum of 6 months of follow-up were included in this study. Analysis included clinical records of all consecutive cases of complicated retinal detachment that underwent PPV with SOI between July 1991 and February 1996. INTERVENTION: Surgical intervention for vitreoretinal pathology included standard three-port PPV and additional procedures as appropriate for the retinal pathology, and SOI. Procedures for the control of glaucoma were silicone oil removal (SOR), trabeculectomy with mitomycin C, cyclocryotherapy, semiconductor diode laser contact transscleral cyclophotocoagulation (TSCPC) and anterior chamber tube shunt to encircling band (ACTSEB). MAIN OUTCOME MEASURES: Presence of glaucoma (predefined as intraocular pressure [IOP] > or = 24 mmHg, which also was > or = 10 mmHg over the preoperative level, sustained for > or = 6 weeks) and the result of medical and surgical management were the main outcome measures. Demographic, preoperative, intraoperative, and postoperative parameters including the age of the patient, etiology of retinal detachment, refractive status, pre-existing glaucoma, aphakia, diabetes mellitus, presence of silicone oil (SO) in the anterior chamber, emulsification of SO, rubeosis iridis, and anatomic success were evaluated by univariate and multivariate logistic regression analyses to assess their predictive value in the causation of glaucoma and to determine factors prognosticating response to treatment. RESULTS: The main indications for PPV+SOI were proliferative vitreoretinopathy (57%; 85 of 150), proliferative diabetic retinopathy (15%; 23 of 150), and trauma (14%, 21 of 150). Glaucoma occurred in 60 eyes (40%) at 14 days median (range, 1 day-18 months). Elevation of IOP could be attributed directly to SO in 42 (70%) eyes. Glaucoma was controlled in 43 (72%) of 60 eyes on treatment (with medicines alone in 30%; SOR and medicines in 25%; trabeculectomy with mitomycin C/ACTSEB/cyclocryotherapy or TSCPC in 17%); 28% (17 of 60) remained refractory. Independent predictive factors for glaucoma on multivariate analysis were rubeosis iridis (odds ratio, 10.76), aphakia (odds ratio, 9.83), diabetes (odds ratio, 6.03), SO in anterior chamber (odds ratio, 4.74), and anatomic failure (negative risk factor; odds ratio, 0.11). Poor prognostic factors for the control of glaucoma were SO emulsification (odds ratio, 15.34) and diabetes (odds ratio, 6.03). CONCLUSION: Glaucoma is a frequent and often a refractory complication of PPV with SOI and has a multifactorial etiology. Aggressive medical and surgical management with SOR, trabeculectomy with mitomycin C, glaucoma shunts, and cyclodestructive procedures shows modest success in controlling IOP.

Role of intravitreal dexamethasone in exogenous fungal endophthalmitis.

PURPOSE: To determine the effects of intravitreal dexamethasone in patients with exogenous fungal endophthalmitis. METHODS: Twenty cases of culture-proven exogenous fungal endophthalmitis following cataract surgery (11/20) and trauma (9/20) were retrospectively analysed for pre- and postoperative visual acuity, anterior chamber and vitreous inflammation and media clarity. All patients were managed with pars plana vitrectomy with intravitreal amphotericin B and oral ketoconazole with (steroid plus group) or without (steroid minus group) intravitreal dexamethasone. Results were analysed by Fisher's exact test. RESULTS: Following vitrectomy 9 of 20 patients (45%) achieved a visual acuity better than counting fingers at 3 m. No statistically significant difference was observed in anatomical and visual outcome between the steroid plus and steroid minus groups, though the number of patients with favourable visual outcome was greater in the steroid plus group. Rate of clearance of inflammation was better in the steroid plus group (40 +/- 15.5 vs 55 +/- 8.6 days). All patients (6/20) with pre-operative vision better than counting fingers showed good anatomical and visual outcome in both groups. CONCLUSIONS: The results of our retrospective study suggest that steroids may be beneficial in promoting faster clearance of inflammation in fungal endophthalmitis. Sensitivity of the fungi to antifungals, dose and timing of steroid and institution of effective antifungal medication prior to the use of steroids are the essential factors which need to be examined further in a prospective manner.

Significance of refractive status in branch retinal vein occlusion. A case-control study.

PURPOSE: To evaluate the significance of refractive error in cases of branch retinal vein occlusion. METHODS: Of 354 patients with branch retinal vein occlusion who attended our clinic between 1989 and 1995, 75 patients with unilateral branch retinal vein occlusion were compared with an equal number of matched controls with similar inclusion and exclusion criteria. The spherical equivalents of the refractive errors of patients in both groups were compared using the chi-square test, student's t test, and multivariate logistic regression. RESULTS: Hypermetropia was present in 53 patients with branch retinal vein occlusion (70.7%) and in 33 control patients (44.0%; P = 0.0001). Myopia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 30 controls (40.0%; P = 0.0005). Emmetropia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 12 controls (16.0%; P = 0.820). The odds ratio of developing branch retinal vein occlusion among patients with hypermetropia was 3.42 (95% Confidence Interval [CI], 1.62-7.2; P = 0.001) when compared with patients with no hypermetropia and 5.3 (95% CI, 2.1-13.3; P = 0.0003) when compared with patients with myopia alone. CONCLUSION: Hypermetropia is significantly more common in patients with branch retinal vein occlusion than in the general population, whereas myopia is significantly less common in these patients.