Autofluorescence imaging of cystoid macular edema in diabetic retinopathy.

AIM: Our purpose was to assess fundus autofluorescence (FAF) images in patients with diabetic retinopathy and cystoid macular edema (CME) and their correlation with fluorescein angiography (FA) and optical coherence tomography (OCT) findings. METHODS: Sixty-eight eyes of 34 consecutive patients with diabetic retinopathy were examined with autofluorescence imaging using a confocal scanning laser ophthalmoscope, FA and OCT. The eyes were divided into 2 groups, group 1 with CME and group 2 without. RESULTS: In the 44 eyes of group 1 (65% of the series), we identified 3 patterns of FAF: (1) multicystic increased FA (57%), (2) a single cyst of increased FAF (16%), (3) combined single- and multicystic increased FAF (27%). FA and OCT gave a positive correlation between cystic increased FAF and CME (r = 0.95; p = 0.001). Visual acuity loss was not correlated with the size of the cystic area (p = 0.83), but it was related to significant macular thickening (p = 0.007). CONCLUSIONS: Confocal scanning laser ophthalmoscopy can selectively visualize autofluorescent, multilobulated spaces in eyes with diabetic CME. Even if OCT remains preferable for evaluating macular thickening and cysts, FAF might be another useful easy test to rapidly distinguish this entity noninvasively and with no risk.

Far and near visual acuity with multifocal intraocular lenses in an optomechanical eye model with imaging capability.

PURPOSE: To compare the quantitative and qualitative visual performances of different multifocal intraocular lenses (IOLs) in an experimental model of the human eye. SETTING: University Hospital San Raffaele, Milan, Italy. METHODS: Five multifocal IOLs and 1 monofocal IOL were implanted in an optomechanical eye model with imaging capability. The comparative optical characterization of the imaging performance included aberrometry, simulated visual acuity testing at variable contrast for far and near distance, glare tests, and image records of optotype charts. RESULTS: The maximum recorded far visual acuity for the monofocal IOL was between 20/12.5 and 20/16; the multifocal IOLs decreased visual acuity by 1 to 2 lines. The difference tended to increase at reduced contrast. Full-contrast near visual acuity with multifocal IOLs ranged between 20/63 and 20/25; the near distance performance of the monofocal IOL without an additional correcting lens was worse by 1 to 3 lines of acuity with large pupils but was comparable with small pupils. Multifocal IOLs of different designs showed marked differences as a function of contrast, which tended to balance between far and near behaviors. CONCLUSIONS: Multifocal IOLs of different optical designs were well characterized and distinguished by simulated contrast acuity testing in an experimental eye model, allowing quantitative comparison. Their overall visual performance, averaged over contrast and distance, was not superior to the performance of a monofocal IOL without an additional correcting lens.

Optomechanical eye model with imaging capabilities for objective evaluation of intraocular lenses.

PURPOSE: To develop an in vitro procedure providing data on the visual performance obtainable with intraocular lenses (IOLs), for objective comparison between IOL models and direct correlation with the relative visual performance attainable in vivo. SETTING: University Hospital San Raffaele, Milan, Italy. METHODS: An optomechanical eye model was developed to allow simulated in vivo testing of IOLs. The experimental eye mimics the optics and geometry of the Gullstrand's eye model, with an aspheric poly(methyl methacrylate) cornea, variable pupil, and IOL holder. Its detection system is designed to reproduce the mean resolution of the human fovea. The imaging capabilities of the model eye were measured using monofocal IOLs. The tests included qualitative information, such as appearance of optotype chart images, and quantitative information, such as simulated visual acuity tests for far and near distance at variable contrasts. RESULTS: Objective numerical IOL evaluation was made possible on the basis of the visual acuity recorded with the eye model. The maximum recorded far acuity for the monofocal IOLs was about 20/14 at full contrast, progressively decreasing for reduced contrast. Best corrected near acuity ranged between 20/14.7 and 20/15.4. CONCLUSIONS: The optomechanical eye model provided objective grading of IOLs through the evaluation of simulated visual acuity, which can be scaled usefully to human vision. The eye model also allowed the qualitative visualization of IOL imaging properties, making it potentially useful in characterizing and distinguishing different IOL types.

Optical coherence tomography findings in adult-onset foveomacular vitelliform dystrophy.

PURPOSE: The purpose of this article is to analyze cross-sectional images of a subretinal macular lesion, using optical coherence tomography (OCT) in eyes with adult-onset foveomacular vitelliform dystrophy (AOFVD), to compare thickness of the neurosensory retina over the lesion with best-corrected visual acuity (BCVA) of each eye, and to compare OCT tomograms of AOFVD patients with OCT of Best disease. DESIGN: Observational case series. METHODS: This is a retrospective study which took place in a clinical practice. Forty-three patients (72 eyes) with AOFVD and 12 patients (24 eyes) with Best's disease were studied. The observation procedures used were biomicroscopic fundus examination, fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). The main outcome measures were a description of the typical picture of AOFVD in OCT tomograms, the relationship between the neurosensory retinal thickness over the lesion, the BCVA expressed in decimal terms, and a comparison with description of OCT in Best disease. RESULTS: Of the 43 patients affected by AOFVD, 29 had bilateral macular lesions. Fluorescein angiography showed a central hypofluorescent spot surrounded by an irregular hyperfluorescent ring in 65 of the 72 eyes. Indocyanine green angiography demonstrated a central nonfluorescent spot and a hyperfluorescent area surrounding the central spot in 22 of 27 eyes examined. In all 72 eyes of 43 patients, OCT showed a well-defined central region of thickening in the reflective band representing the retinal pigment epithelium (RPE). The relationship between the thickness of neurosensory retina over the lesion and BCVA was significant (P =.001, r(2) = 0.61). Optical coherence tomography in all 24 eyes with Best disease showed a well-defined central serous retinal detachment. CONCLUSION: In the 72 eyes with AOFVD, FA and ICGA presented different features. Instead, OCT tomograms showed a well-defined subretinal thickening of the RPE in all the eyes. The lack of difference in OCT patterns between cases with or without the hypofluorescent spot on angiography was useful for confirming the diagnosis of AOFVD. Moreover, a reduced visual acuity was evident in patients with a thinner neurosensory retinal layer over AOFVD lesion. Finally, OCT images were also useful for distinguishing AOFVD from Best disease.

Intrasurgical plasmin enzyme in diabetic macular edema.

PURPOSE: To evaluate in a prospective study the efficacy of intrasurgical autologous plasmin enzyme (APE) in producing posterior vitreous detachment. DESIGN: Consecutive, interventional case series. METHODS: A group of 12 eyes of 11 patients with diabetic macular edema secondary to posterior vitreous cortex contraction was considered. A quantity of 0.1- to 0.2-ml containing 0.8 to 1.2 IU of APE prepared by our Coagulation Service was injected into the vitreous body 25 minutes before surgery. The efficacy of the APE was subjectively evaluated. A control group of 10 eyes with the same clinical characteristics underwent the same surgery without APE injection. Complete eye examinations, including optical coherence tomography, were performed on all patients before surgery and during the 1-year follow-up period. RESULTS: During surgery in the APE-treated group, the posterior vitreous cortex was judged adherent in three cases, partially detached in six cases, and totally detached in three cases. In two cases a complete collapse of the vitreous body was observed. During surgery in the non-APE-treated group, the posterior vitreous cortex was judged still adherent in nine of 10 eyes and partially detached in 1 eye. Comparing the postoperative results between the APE-treated group and the non-APE-treated group, we found no significant differences in final postoperative retinal thickness (P = .2552), whereas we found a significant difference in final visual acuity (P = .0121). CONCLUSIONS: Autologous plasmin enzyme was useful in inducing a pharmacologic posterior vitreous detachment and in facilitating surgery. It did not seem to interfere with the final retinal thickness, and it ameliorates the final visual acuity.

Concomitant effect of topical ubiquinone Q10 and vitamin E to prevent keratocyte apoptosis after excimer laser photoablation in rabbits.

PURPOSE: To investigate in vivo whether ubiquinone Q10 together with vitamin E protects rabbit corneas from keratocyte apoptosis after excimer laser irradiation. METHODS: Photorefractive keratectomy (PRK) was performed in both eyes of three New Zealand white rabbits. During 3 days before surgery, each right eye received four-times-daily instillation of an eye-drop solution containing ubiquinone Q10 0.20% and vitamin E 0.04%; each left eye was treated with a solution that did not contain ubiquinone or vitamin E. The central cornea was analyzed after surgery using the in situ end labelling (ISEL) technique of nicked DNA to detect DNA fragmentation. To determine the number of ISEL positive nuclei, an average of 70 random microscopic fields (five for each de-epithelialized tissue section) of 138,000 mu2 were examined in the right and left cornea samples at 250X by two different observers. RESULTS: Light microscopic examination of the sections from corneas treated before PRK showed that cells committed to apoptosis by PRK were about 50% compared to those of untreated controls. CONCLUSION: Treatment of rabbit eyes before PRK with ubiquinone Q10 lowered the number of apoptotic events.

Viscocanalostomy in patients with glaucoma secondary to uveitis: preliminary report.

PURPOSE: To assess the efficacy of viscocanalostomy in eyes with uncontrolled glaucoma secondary to uveitis. SETTING: Immunology and Uveitis Service, Department of Ophthalmology and Visual Sciences, University Hospital San Raffaele, Milan, Italy. METHODS: All consecutive patients with glaucoma secondary to uveitis and inadequate intraocular pressure (IOP) control (IOP >21 mm Hg) under maximum-tolerated medical therapy had viscocanalostomy. Patients with active uveitis at the time of surgery, peripheral anterior synechias in the upper quadrant, previous ocular surgery, or sight in only 1 eye were excluded. Eleven eyes of 11 patients with a mean age of 52.2 years +/- 19.9 (SD) were operated on. The etiology of the uveitis was recorded. The ocular variables were IOP, best corrected visual acuity, number of antiglaucoma medications, and complications. Success was defined as an IOP between 6 mm Hg and 21 mm Hg (inclusive) without medication (complete success), or with 1 or more antiglaucoma medications and/or goniopuncture (qualified success). The mean follow-up was 45.9 +/- 11.6 months (range 23 to 56 months). RESULTS: Viscocanalostomy significantly reduced IOP from a mean baseline value of 35.1 +/- 7.0 mm Hg (range 23 to 48 mm Hg) to a mean final value of 18.1 +/- 4.9 mm Hg (range 12 to 30 mm Hg) (P<.0001). Complete success was achieved in 6 eyes (54.5%) and qualified success, in 10 eyes (90.9%). The mean number of preoperative and final antiglaucoma medications was 3.4 +/- 0.8 (range 2 to 4) and 0.7 +/- 1.2 (range 0 to 3), respectively (P =.0004). Complications were minor and included transient hyphema and postoperative IOP spike. CONCLUSION: This preliminary study suggests that viscocanalostomy is a safe, effective surgical alternative for treating glaucoma in patients with uveitis.

Are microarrays useful in the screening of ABCA4 mutations in Italian patients affected by macular degenerations?

BACKGROUND: Recessive Stargardt disease is due to mutation in the retina-specific ABC transporter gene. Established strategies for molecular characterization of this gene include direct detection by a microarray interrogating approximately 500 DNA variations and a scanning denaturing HPLC methodology. METHODS: Because 11 mutations were recorded to account for approximately 50% of molecular defects in the Italian population, we evaluated an alternative open microchip-based assay for a fast and simplified level 1 screening for these mutations. RESULTS: This approach allowed the characterization of both mutated alleles in 4% and one mutated allele in 43% of cases when applied to a cohort of 47 Stargardt patients. In the same patients, further investigation by denaturing HPLC for complete characterization identified both mutated allele in 51% and one mutated allele in 19% of cases, allowing the detection of 38 different mutations, five of which had never been described. Notably, new mutations account for a high proportion (13%) of molecular defects in our patient cohort. CONCLUSION: The findings raises the question about the choice of the optimal diagnostic strategy for complete genotyping of the ABCA4 gene, as new mutations could not be identified by any direct detection technology, irrespective of the total number of variations screened.

Moderate hyperhomocysteinemia and early-onset central retinal vein occlusion.

PURPOSE: To evaluate the prevalence of moderate fasting hyperhomocysteinemia (HHcy) and postmethionine load (PML) HHcy among patients with early-onset central retinal vein occlusion (CRVO). METHODS: The prevalence of fasting HHcy and that of PML HHcy were evaluated in a consecutive series of 58 patients with CRVO who were younger than 56 years of age (mean age, 40.3 years) and in 103 controls (mean age, 39.6 years). Plasma folate, vitamin B12, and pyridoxal-5'-phosphate (PLP) levels were measured in 42 patients and 67 controls. RESULTS: Mantel-Haenszel odds ratios for CRVO patients were 3.00 (95% confidence interval [CI], 0.83-10.8) for fasting HHcy, 3.50 (95% CI, 1.07-11.4) for PML HHcy, and 3.00 (1.18-7.6) for fasting HHcy and PML HHcy in subjects with normal fasting total homocysteine (tHcy) levels. Moderate HHcy was associated with reduced plasma levels of folate and PLP (P < or = 0.04). There was no significant dependence of fasting and PML tHcy levels on any traditional risk factor evaluated. CONCLUSIONS: Moderate HHcy is an independent risk factor for early-onset CRVO.

De novo deletion removes a conserved motif in the C-terminus of ABCA4 and results in cone-rod dystrophy.

BACKGROUND: Mutations in the retina-specific ABC transporter (ABCA4) gene are associated with different types of macular degeneration, including Stargardt disease, cone-rod dystrophy, Fundus flavimaculatus, Retinitis pigmentosa and probably age-related macular degeneration. METHODS: Screening for mutations in the ABCA4 gene was performed using denaturing high-performance liquid chromatography and direct sequencing. RESULTS: We describe the identification of a new de novo 44-bp deletion in an Italian patient affected by cone-rod dystrophy. The mutation, located in intron 48 of the ABCA4 gene, is predicted to cause exon 49 skipping, resulting in loss of the C-terminus of the ABCA4 protein. Interestingly, exon 49 also codes for a highly conserved VFVNFA motif, which has been demonstrated to be essential for the activity of ABCA1, another gene of the ABC transporter family. The presence of CT repeats at the breakpoints might have facilitated the generation of the deletion through a slippage mispairing mechanism. CONCLUSIONS: The new 6730-16del44 deletion is the first de novo mutation associated with cone-rod dystrophy and may contribute to a better understanding of the role of ABCA4 mutations in macular dystrophies.

OCT findings in patients with retinopathy after watching a solar eclipse.

PURPOSE: To evaluate the optical coherence tomography (OCT) findings in patients with solar retinopathy after watching a solar eclipse. METHODS: Complete ocular examinations and OCT were done in 4 patients presenting with acute solar retinopathy soon after observation of an eclipse. All 4 patients repeated the examinations about 1 month and 1 year after the first visit. RESULTS: The symptoms and fundus findings were similar in all patients; all eyes were emmetropic. However, the OCT images were different in all patients, and the alterations were at different levels. The most evident alterations shown by OCT were: a reduction in the intensity of reflectiveness of the retinal pigment epithelium in 3 cases; intraretinal nonreflective spaces between the inner retinal layers in 2 cases; increased reflectiveness of the inner retinal layers in 2 cases, and a round hyperreflective formation in the vitreous just in front of the fovea in 1 case. All these OCT alterations disappeared after 1 month. CONCLUSIONS: The retinal damage arising soon after exposure to sunlight showed many different aspects in the OCT images of the 4 cases examined. All retinal layers seemed to be altered, but these alterations disappeared after 1 month, and the OCT findings remained the same after 1 year.

Viscocanalostomy versus trabeculectomy in white adults affected by open-angle glaucoma: a 2-year randomized, controlled trial.

PURPOSE: To compare the effectiveness and safety of viscocanalostomy and trabeculectomy in adults with uncontrolled open-angle glaucoma. DESIGN: Single-masked, parallel-group, prospective, randomized 24-month trial, with 90% power to detect a clinically important difference between groups. PARTICIPANTS: Fifty consecutive patients (50 eyes) with primary open-angle or pseudoexfoliative glaucoma. INTERVENTION: Eyes were assigned randomly to either viscocanalostomy (group 1) or trabeculectomy (group 2) with no intraoperative antifibrotics in the study eye. In group 1, no further intervention was allowed, whereas trabeculectomy eyes could receive subconjunctival 5-fluorouracil (5-FU) injections or laser suture lysis after surgery. MAIN OUTCOME MEASURES: Success rate based on intraocular pressure (IOP), visual acuity, discomfort, and other complications. RESULTS: At the end of the 24-month follow-up, IOP of 21 mmHg or less and more than 6 mmHg was achieved in 76% in group 1 (n = 19) and in 80% in group 2 (n = 20; log-rank P = 0.60); an IOP between 6 and 16 mmHg was obtained in 56% in group 1 (n = 14) and in 72% in group 2 (n = 18; log-rank P = 0.17; Kaplan-Meier cumulative probability of success). Complications of viscocanalostomy included one intraoperative conversion into trabeculectomy; microruptures in Descemet's membrane in five eyes; three cases of iris incarceration in the Decemet's window, two of which caused early failure of the procedure requiring reoperation; and a 1-mm to 2-mm transient self-resolving hyphema in three cases. Complications of trabeculectomy included one case of postoperative bleb bleeding with early transient IOP spike; one early hyphema; five cases of postoperative hypotony, two of which had a positive Seidel test from the conjunctival suture; three cases of transient choroidal detachment, two of which had shallow anterior chamber. No patient required reoperation. Two eyes required argon laser suture lysis, and nine underwent one or more 5-FU injections, which caused punctate keratopathy in three eyes. CONCLUSIONS: Viscocanalostomy is an effective IOP-lowering procedure in white adults affected by open-angle glaucoma. Trabeculectomy with postoperative 5-FU can probably provides lower IOPs but, with more numerous complications, greater discomfort, and more intensive postoperative management.

Ocular and extracutaneous involvement in pyoderma gangrenosum.

PURPOSE: To report an unusual presentation of pyoderma gangrenosum with ocular and extracutaneous involvement. DESIGN: A single, interventional case report. METHODS: A 28-year-old female presented with nodular scleritis in the right eye and left orbital inflammation lasting 1 year. The patient initially responded to systemic steroids, but then ocular inflammation became more severe, associated with onset of fever, myalgias, and elevation of the erythrocyte sedimentation rate, accompanied by formation of multiple cutaneous abscesses. MAIN OUTCOME MEASURES: Ocular and systemic disease control. RESULTS: The diagnosis of pyoderma gangrenosum was made 1 year after the occurrence of ocular symptomatology, when the patient presented with ocular and skin lesions and abscesses in the spleen and liver. CONCLUSIONS: Pyoderma gangrenosum is a rare, necrotizing, noninfectious ulcerating skin disease. Ocular and extracutaneous involvement rarely occur, but the disease should be included in the differential diagnosis of scleritis and orbital inflammation.

Ultrasound biomicroscopy of residual vitreous base after vitreoretinal surgery.

Residual vitreous base after vitreoretinal surgery was evaluated by ultrasound biomicroscopy (UBM). Twenty aphakic and pseudoaphakic patients (20 eyes) undergoing surgery for different vitreoretinal diseases were evaluated by high-frequency (50 MHz), high-resolution (50 microm) UBM, performed the day before surgery, weekly up to 1 month after surgery and then monthly. One week after surgery, the vitreous remnants were 'hardly visible' in 3 cases, 'visible' in 6 cases and 'highly visible' in 11. At the end of the follow-up (2.2 months), the 'hardly visible' cases increased to 6 and the 'visible' cases to 12, while the 'highly visible' cases decreased to 2. UBM demonstrated that vitreous base remnants were present in spite of accurate surgery; a spontaneous volume reduction of vitreous was observed during the follow-up.

Outcome of choroidal neovascularization in angioid streaks after photodynamic therapy.

PURPOSE: To evaluate the visual and anatomic outcomes of photodynamic therapy for choroidal neovascularization (CNV) in patients with angioid streaks. METHODS: The authors retrospectively evaluated 40 consecutive patients (48 eyes) with visual acuity of 20/200 or greater who were treated at 6 referral centers for CNV associated with angioid streaks. Main outcome measures were visual acuity, greatest linear diameter of the lesion, and, in patients with nonsubfoveal CNV, distance from the foveola. RESULTS: Of 34 eyes with subfoveal CNV, 21 were followed up for at least 12 months (range, 5-33 months). Median visual acuity was 20/50 at baseline and 20/120 at the final examination. The 12-month estimate of the percentage of eyes with vision loss of fewer than 3 lines was 68% (95% confidence interval, 50%-85%) by using survival analysis, whereas eyes with no increase in the greatest linear diameter were 45% (95% confidence interval, 27%-62%). Fourteen eyes had extrafoveal (n = 11) or juxtafoveal (n = 3) CNV, 12 of which were followed up for at least 10 months (range, 4-36 months). Visual acuity was 20/40 or greater in all eyes with extrafoveal lesions at baseline and in 5 of 12 eyes at the last examination, when 3 cases of CNV had become subfoveal. At baseline, visual acuity was low in two eyes with juxtafoveal CNV and nearly normal in the third. It remained substantially stable at the end of follow-up (range, 10-36 months), when two lesions were subfoveal. CONCLUSIONS: Most of our patients had good baseline visual function and, thus, were at high risk for losing vision because of the poor prognosis of CNV in angioid streaks. Because most had no or limited vision loss after 1 year, the authors suggest that photodynamic therapy can be used to try to limit or delay visual damage caused by this aggressive disease.

Coenzyme q10 prevents apoptosis by inhibiting mitochondrial depolarization independently of its free radical scavenging property.

The permeability transition pore (PTP) is a mitochondrial channel whose opening causes the mitochondrial membrane potential (deltapsi) collapse that leads to apoptosis. Some ubiquinone analogues have been demonstrated previously to modulate the PTP open-closed transition in isolated mitochondria and thought to act through a common PTP-binding site rather than through oxidation-reduction reactions. We have demonstrated recently both in vitro and in vivo that the ubiquitous free radical scavenger and respiratory chain coenzyme Q10 (CoQ10) prevents keratocyte apoptosis induced by excimer laser irradiation more efficiently than other antioxidants. On this basis, we hypothesized that the antiapoptotic property of CoQ10 could be independent of its free radical scavenging ability and related to direct inhibition of PTP opening. In this study, we have verified this hypothesis by evaluating the antiapoptotic effects of CoQ10 in response to apoptotic stimuli, serum starvation, antimycin A, and ceramide, which do not generate free radicals, in comparison to control, free radical-generating UVC irradiation. As hypothesized, CoQ10 dramatically reduced apoptotic cell death, attenuated ATP decrease, and hindered DNA fragmentation elicited by all apoptotic stimuli. This was accompanied by inhibition of mitochondrial depolarization, cytochrome c release, and caspase 9 activation. Because these events are consequent to mitochondrial PTP opening, we suggest that the antiapoptotic activity of CoQ10 could be related to its ability to prevent this phenomenon.

Denaturing HPLC profiling of the ABCA4 gene for reliable detection of allelic variations.

BACKGROUND: Mutations in the retina-specific ABC transporter (ABCA4) gene have been associated with several forms of macular degenerations. Because the high complexity of the molecular genotype makes scanning of the ABCA4 gene cumbersome, we describe here the first use of denaturing HPLC (DHPLC) to screen for ABCA4 mutations. METHODS: Temperature conditions were designed for all 50 exons based on effective separation of 83 samples carrying 86 sequence variations and 19 mutagenized controls. For validation, samples from 23 previously characterized Stargardt patients were subjected to DHPLC profiling. Subsequently, samples from a cohort of 30 patients affected by various forms of macular degeneration were subjected to DHPLC scanning under the same conditions. RESULTS: DHPLC profiling not only identified all 132 sequence alterations previously detected by double-gradient denaturing gradient gel electrophoresis but also identified 5 sequence alterations that this approach had missed. Moreover, DHPLC scanning of an additional panel of 30 previously untested patients led to the identification of 26 different mutations and 29 polymorphisms, accounting for 203 sequence variations on 29 of the 30 patients screened. In total, the DHPLC approach allowed us to identify 16 mutations that had never been reported before. CONCLUSIONS: These results provide strong support for the use of DHPLC for molecular characterization of the ABCA4 gene.

Identification and characterization of C1orf36, a transcript highly expressed in photoreceptor cells, and mutation analysis in retinitis pigmentosa.

By means of computational methods, we identified an uncharacterized human transcript, Chromosome 1 open reading frame 36 (C1orf36), that is expressed in the retina and that maps to 1q32.3. The cDNA contains an open reading frame of 585bp that encodes a 195-aminoacid protein with a predicted mass of 22.7kDa. An alternatively spliced transcript in a retinoblastoma cell line, encoding for a truncated peptide, was also identified. PCR experiments performed using human cDNA from several sources indicate that C1orf36 has a preferential expression in the retina. Accordingly, in situ hybridization experiments, performed using as probe a murine C1orf36 cDNA fragment, detected a hybridization signal on mouse retinal adult sections. The C1orf36 protein shares homology with putative proteins in Mus musculus and Fugu rubripes, suggesting evolutionary conservation of its function. Additional sequence analysis of the C1orf36 gene product predicts its subcellular mitochondrial localization and the presence of both evolutionary conserved phosphorylation sites and regions adopting a coiled-coil conformation. We also defined the genomic structure of the gene. This enabled us to perform a mutational analysis of the C1orf36 coding region of about 300 patients affected by retinitis pigmentosa. No pathological mutations were detected in this analysis.